02859nas a2200181 4500008004100000245009200041210006900133260001200202300001400214490000700228520227800235100002002513700002502533700002402558700002102582700002002603856005402623 2024 eng d00aThe application and modification of WRF-Hydro/Glacier to a cold-based Antarctic glacier0 aapplication and modification of WRFHydroGlacier to a coldbased A c02/2024 a459 - 4780 v283 a

The McMurdo Dry Valleys (MDV) are home to a unique microbial ecosystem that is dependent on the availability of freshwater. This is a polar desert and freshwater originates almost entirely from surface and near-surface melt of the cold-based glaciers. Understanding the future evolution of these environments requires the simulation of the full chain of physical processes from net radiative forcing, surface energy balance, melt, runoff and transport of meltwater in stream channels from the glaciers to the terminal lakes where the microbial community resides. To establish a new framework to do this, we present the first application of WRF-Hydro/Glacier in the MDV, which as a fully distributed hydrological model has the capability to resolve the streams from the glaciers to the bare land that surround them. Given that meltwater generation in the MDV is almost entirely dependent on small changes in the energy balance of the glaciers, the aim of this study is to optimize the multi-layer snowpack scheme that is embedded in WRF-Hydro/Glacier to ensure that the feedbacks between albedo, snowfall and melt are fully resolved. To achieve this, WRF-Hydro/Glacier is implemented at a point scale using automatic weather station data on Commonwealth Glacier to physically model the onset, duration and end of melt over a 7-month period (1 August 2021 to 28 February 2022). To resolve the limited energetics controlling melt, it was necessary to (1) limit the percolation of meltwater through the ice layers in the multi-layer snowpack scheme and (2) optimize the parameters controlling the albedo of both snow and ice over the melt season based on observed spectral signatures of albedo. These modifications enabled the variability of broadband albedo over the melt season to be accurately simulated and ensured that modelled surface and near-surface temperatures, surface height change and runoff were fully resolved. By establishing a new framework that couples a detailed snowpack model to a fully distributed hydrological model, this work provides a stepping stone to model the spatial and temporal variability of melt and streamflow in the future, which will enable some of the unknown questions about the hydrological connectivity of the MDV to be answered.

1 aPletzer, Tamara1 aConway, Jonathan, P.1 aCullen, Nicolas, J.1 aEidhammer, Trude1 aKaturji, Marwan uhttps://hess.copernicus.org/articles/28/459/2024/02587nas a2200313 4500008004100000022001400041245012700055210006900182260001200251300001100263520145800274653001701732653001401749653000801763653001901771653001501790100002301805700001801828700001501846700002401861700002501885700003301910700002901943700001701972700002201989700002102011700002102032856022002053 2024 eng d a0954-102000aMcMurdo Dry Valley lake edge ‘moats’: The ecological intersection between terrestrial and aquatic polar desert habitat0 aMcMurdo Dry Valley lake edge moats The ecological intersection b c04/2024 a1 - 173 a

Aquatic ecosystems - lakes, ponds and streams - are hotspots of biodiversity in the cold and arid environment of Continental Antarctica. Environmental change is expected to increasingly alter Antarctic aquatic ecosystems and modify the physical characteristics and interactions within the habitats that they support. Here, we describe physical and biological features of the peripheral ‘moat’ of a closed-basin Antarctic lake. These moats mediate connectivity amongst streams, lake and soils. We highlight the cyclical moat transition from a frozen winter state to an active open-water summer system, through refreeze as winter returns. Summer melting begins at the lakebed, initially creating an ice-constrained lens of liquid water in November, which swiftly progresses upwards, creating open water in December. Conversely, freezing progresses slowly from the water surface downwards, with water at 1 m bottom depth remaining liquid until May. Moats support productive, diverse benthic communities that are taxonomically distinct from those under the adjacent permanent lake ice. We show how ion ratios suggest that summer exchange occurs amongst moats, streams, soils and sub-ice lake water, perhaps facilitated by within-moat density-driven convection. Moats occupy a small but dynamic area of lake habitat, are disproportionately affected by recent lake-level rises and may thus be particularly vulnerable to hydrological change.

10aconnectivity10aecosystem10aice10amicrobial mats10atransition1 aStone, Michael, S.1 aDevlin, Shawn1 aHawes, Ian1 aWelch, Kathleen, A.1 aGooseff, Michael, N.1 aTakacs-Vesbach, Cristina, D.1 aMorgan-Kiss, Rachael, M.1 aAdams, Byron1 aBarrett, John, E.1 aPriscu, John, C.1 aDoran, Peter, T. uhttps://www.cambridge.org/core/journals/antarctic-science/article/mcmurdo-dry-valley-lake-edge-moats-the-ecological-intersection-between-terrestrial-and-aquatic-polar-desert-habitats/31D94DD51E651603482A3AE6E8A52A5703255nas a2200277 4500008004100000022001300041245011100054210006900165260001200234300001100246520240400257653001502661653001302676653001102689653002902700653000902729653001702738100002102755700002402776700002002800700002102820700002502841700001702866700002202883856007202905 2024 eng d a2666017200aRemotely characterizing photosynthetic biocrust in snowpack-fed microhabitats of Taylor Valley, Antarctica0 aRemotely characterizing photosynthetic biocrust in snowpackfed m c02/2024 a1001203 a

Microbial communities are the primary drivers of carbon cycling in the McMurdo Dry Valleys of Antarctica. Dense microbial mats, consisting mainly of photosynthetic cyanobacteria, occupy aquatic areas associated with streams and lakes. Other microbial communities also occur at lower densities as patchy surface biological soil crusts (hereafter, biocrusts) across the terrestrial landscape. Multispectral satellite data have been used to model microbial mat abundance in high-density areas like stream and lake margins, but no previous studies have investigated the lower detection limits of biocrusts. Here, we describe remote sensing and field-based survey and sampling approaches to study the detectability and distribution of biocrusts in the McMurdo Dry Valleys. Using a combination of multi- and hyperspectral tools and spectral linear unmixing, we modeled the abundances of biocrust in eastern Taylor Valley. Our spectral approaches can detect low masses of biocrust material in laboratory microcosms down to biocrust concentrations of 1% by mass. These techniques also distinguish the spectra of biocrust from both surface rock and mineral signatures from orbit. We found that biocrusts are present throughout the soils of eastern Taylor Valley and are associated with diverse underlying soil communities. The densest biocrust communities identified in this study had total organic carbon 5x greater than the content of typical arid soils. The most productive biocrusts were located downslope of melting snowpacks in unique soil ecosystems that are distinct from the surrounding arid landscape. There are similarities between the snowpack and stream sediment communities (high diversity of soil invertebrates) as well as their ecosystem properties (e.g., persistence of liquid water, high transfer of available nutrients, lower salinity from flushing) compared to the typical arid terrestrial ecosystem of the dry valleys. Our approach extends the capability of orbital remote sensing of photosynthetic communities out of the aquatic margins and into the drier soils which comprise most of this landscape. This interdisciplinary work is critical for measuring and monitoring terrestrial carbon stocks and predicting future ecosystem dynamics in this currently water-limited but increasingly dynamic Antarctic landscape, which is particularly climate-sensitive and difficult to access.

10aAntarctica10abiocrust10acarbon10areflectance spectroscopy10asnow10asoil ecology1 aPower, Sarah, N.1 aSalvatore, Mark, R.1 aSokol, Eric, R.1 aStanish, Lee, F.1 aBorges, Schuyler, R.1 aAdams, Byron1 aBarrett, John, E. uhttps://www.sciencedirect.com/science/article/pii/S266601722400004X02559nas a2200301 4500008004100000245008000041210006900121260001200190300001200202490000700214520166000221653001501881653001601896653002901912653001801941653001201959100002901971700001802000700002202018700002002040700002202060700001202082700001602094700002602110700002102136700003302157856006702190 2024 eng d00aSentinel protist taxa of the McMurdo Dry Valley lakes, Antarctica: A review0 aSentinel protist taxa of the McMurdo Dry Valley lakes Antarctica c03/2024 a13234720 v123 a

High-latitude meromictic lakes such as those in the Antarctic McMurdo Dry Valleys (MDV) harbor aquatic ecosystems dominated by the microbial loop. Within this habitat, which is limited year-round by light and nutrients, protists, or single celled eukaryotes, play outsized roles in the food web as the dominant primary producers and the apex predators. Thus, the MDV lake ecosystem represents an ideal system to study the role of sentinel protist taxa in carbon and nutrient cycling. The perennially ice-covered lakes are part of the McMurdo Long Term Ecological Research (McM LTER; mcmlter.org) established in 1993. In this review we will highlight the diversity and trophic roles of the MDV lake protist community and compare environmental factors driving spatiotemporal patterns in key protist taxa in two lakes within the McM LTER, Lakes Bonney and Fryxell. We will then discuss lessons learned from manipulated experiments on the impact of current and future climate-driven environmental change on sensitive protist taxa. Last, we will integrate knowledge gained from 25 years of lab-controlled experiments on key photosynthetic protists to extend our understanding of the function of these extremophiles within the MDV aquatic food webs. Our research group has studied the distribution and function of the MDV microbial community for nearly two decades, training the next generation of scientists to tackle future problems of these globally significant microbes. This review article will also highlight early career scientists who have contributed to this body of work and represent the future of scientific understanding in the Anthropocene.

10aAntarctica10aDisturbance10aMcMurdo Dry Valley lakes10aphytoplankton10aprotist1 aMorgan-Kiss, Rachael, M.1 aPopson, Devon1 aPereira, Rochelle1 aDolhi-Binder, J1 aTeufel, Amber, G.1 aLi, Wei1 aKalra, Isha1 aSherwell, Shasten, S.1 aReynebeau, Emily1 aTakacs-Vesbach, Cristina, D. uhttps://www.frontiersin.org/articles/10.3389/fevo.2024.132347202567nas a2200337 4500008004100000245010300041210006900144260001200213300000900225490000700234520158600241653001601827653001201843653001401855653001901869653001801888100002401906700002201930700002401952700002001976700002101996700002102017700002502038700002102063700002102084700001902105700002102124700001702145700002102162856004602183 2023 eng d00aThe distribution of surface soil moisture over space and time in eastern Taylor Valley, Antarctica0 adistribution of surface soil moisture over space and time in eas c06/2023 a31700 v153 a

Available soil moisture is thought to be the limiting factor for most ecosystem processes in the cold polar desert of the McMurdo Dry Valleys (MDVs) of Antarctica. Previous studies have shown that microfauna throughout the MDVs are capable of biological activity when sufficient soil moisture is available (~2–10% gravimetric water content), but few studies have attempted to quantify the distribution, abundance, and frequency of soil moisture on scales beyond that of traditional field work or local field investigations. In this study, we present our work to quantify the soil moisture content of soils throughout the Fryxell basin using multispectral satellite remote sensing techniques. Our efforts demonstrate that ecologically relevant abundances of liquid water are common across the landscape throughout the austral summer. On average, the Fryxell basin of Taylor Valley is modeled as containing 1.5 ± 0.5% gravimetric water content (GWC) across its non-fluvial landscape with ~23% of the landscape experiencing an average GWC > 2% throughout the study period, which is the observed limit of soil nematode activity. These results indicate that liquid water in the soils of the MDVs may be more abundant than previously thought, and that the distribution and availability of liquid water is dependent on both soil properties and the distribution of water sources. These results can also help to identify ecological hotspots in the harsh polar Antarctic environment and serve as a baseline for detecting future changes in the soil hydrological regime.

10aDry valleys10aecology10ahydrology10aremote sensing10asoil moisture1 aSalvatore, Mark, R.1 aBarrett, John, E.1 aFackrell, Laura, E.1 aSokol, Eric, R.1 aLevy, Joseph, S.1 aKuentz, Lily, C.1 aGooseff, Michael, N.1 aAdams, Byron, J.1 aPower, Sarah, N.1 aKnightly, Paul1 aMatul, Haley, M.1 aSzutu, Brian1 aDoran, Peter, T. uhttps://www.mdpi.com/2072-4292/15/12/317002076nas a2200313 4500008004100000245008700041210006900128260001200197300001100209490000800220520114900228653002801377653002701405653002401432653002401456653001301480653000901493100001301502700002501515700001601540700002201556700001701578700001801595700001601613700002401629700002001653700001701673856007201690 2023 eng d00aEcological stoichiometry drives the evolution of soil nematode life history traits0 aEcological stoichiometry drives the evolution of soil nematode l c02/2023 a1088910 v1773 a

Ecological stoichiometry is a useful theoretical framework for understanding the sources and controls on nutrient availability that structure the composition and diversity of biotic communities. One such relationship is that organismal development rate is positively linked to cellular Phosphorus (P). We hypothesized that P availability, relative to other nutrients, e.g., nitrogen and carbon, would drive the evolution of traits associated with organismal growth and development. We examined the effects of P availability both in situ and in vitro, on free-living soil nematodes. We found that P-deficient environments produce predictable changes in the ecology and evolution of important life history traits. Our results identify altered rRNA gene copy number and subsequent changes in gene expression and protein synthesis as mechanisms by which P-deficiency influences these traits. These findings have important implications for explaining soil ecological and evolutionary patterns across multiple levels of organization, including the structure and functioning of organisms, populations, communities, and ecosystems.

10aelemental stoichiometry10agrowth rate hypothesis10alife history theory10amolecular evolution10anematoda10arRNA1 aXue, Xia1 aAdhikari, Bishwo, N.1 aBall, Becky1 aBarrett, John, E.1 aMiao, Jinxin1 aPerkes, Ammon1 aMartin, Mac1 aSimmons, Breana, L.1 aWall, Diana, H.1 aAdams, Byron uhttps://www.sciencedirect.com/science/article/pii/S003807172200348002063nas a2200277 4500008004100000245013600041210006900177260001200246300001300258490000600271520117000277100002601447700002601473700002601499700001601525700002101541700002701562700001901589700001901608700002501627700001501652700002101667700002201688700002001710856005501730 2023 eng d00aPostglacial adaptations enabled colonization and quasi-clonal dispersal of ammonia-oxidizing archaea in modern European large lakes0 aPostglacial adaptations enabled colonization and quasiclonal dis c02/2023 aeadc93920 v93 a

Ammonia-oxidizing archaea (AOA) play a key role in the aquatic nitrogen cycle. Their genetic diversity is viewed as the outcome of evolutionary processes that shaped ancestral transition from terrestrial to marine habitats. However, current genome-wide insights into AOA evolution rarely consider brackish and freshwater representatives or provide their divergence timeline in lacustrine systems. An unbiased global assessment of lacustrine AOA diversity is critical for understanding their origins, dispersal mechanisms, and ecosystem roles. Here, we leveraged continental-scale metagenomics to document that AOA species diversity in freshwater systems is remarkably low compared to marine environments. We show that the uncultured freshwater AOA, “Candidatus Nitrosopumilus limneticus,” is ubiquitous and genotypically static in various large European lakes where it evolved 13 million years ago. We find that extensive proteome remodeling was a key innovation for freshwater colonization of AOA. These findings reveal the genetic diversity and adaptive mechanisms of a keystone species that has survived clonally in lakes for millennia.

1 aNgugi, David, Kamanda1 aSalcher, Michaela, M.1 aAndrei, Adrian-Stefan1 aGhai, Rohit1 aKlotz, Franziska1 aChiriac, Maria-Cecilia1 aIonescu, Danny1 aBüsing, Petra1 aGrossart, Hans-Peter1 aXing, Peng1 aPriscu, John, C.1 aAlymkulov, Salmor1 aPester, Michael uhttps://www.science.org/doi/10.1126/sciadv.adc939201387nas a2200157 4500008004100000022001400041245006900055210006900124260001200193300001600205490000700221520088600228100002701114700002101141856006701162 2023 eng d a0024-359000aSediment oxygen consumption in Antarctic subglacial environments0 aSediment oxygen consumption in Antarctic subglacial environments c07/2023 a1557 - 15660 v683 a

Oxygen consumption in aquatic sediments is an indicator of overall biological activity of the ecosystem. As such, rates of sedimentary oxygen utilization are well documented for much of the open oceans and freshwater lakes. However, there are few direct measurements of sedimentary oxygen consumption from Antarctic subglacial aquatic sediments. We report the first microsensor oxygen profiles and derived sedimentary oxygen consumption rates from beneath the Ross Ice Shelf and a subglacial lake beneath the West Antarctic Ice Sheet. Rates of oxygen consumption in these two environments are relatively low, but comparable to those reported from ice-free polar oceans and oligotrophic Arctic lakes. Our study demonstrates the presence of oxygen within Antarctic subglacial aquatic sediments and its importance for oxygen-consuming microorganisms living in these ecosystems.

1 aMichaud, Alexander, B.1 aPriscu, John, C. uhttps://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lno.1236602039nas a2200169 4500008004100000245013000041210007100171260001200242520142300254100002601677700001601703700001201719700002401731700002101755700002901776856006401805 2022 eng d00aAntarctic lake phytoplankton and bacteria from near‐surface waters exhibit high sensitivity to climate‐driven disturbance0 aAntarctic lake phytoplankton and bacteria from near‐surface wate c07/20223 a

The McMurdo Dry Valleys (MDVs), Antarctica, represent a cold, desert ecosystem poised on the threshold of melting and freezing water. The MDVs have experienced dramatic signs of climatic change, most notably a warm austral summer in 2001–2002 that caused widespread flooding, partial ice cover loss and lake level rise. To understand the impact of these climatic disturbances on lake microbial communities, we simulated lake level rise and ice-cover loss by transplanting dialysis-bagged communities from selected depths to other locations in the water column or to an open water perimeter moat. Bacteria and eukaryote communities residing in the surface waters (5 m) exhibited shifts in community composition when exposed to either disturbance, while microbial communities from below the surface were largely unaffected by the transplant. We also observed an accumulation of labile dissolved organic carbon in the transplanted surface communities. In addition, there were taxa-specific sensitivities: cryptophytes and Actinobacteria were highly sensitive particularly to the moat transplant, while chlorophytes and several bacterial taxa increased in relative abundance or were unaffected. Our results reveal that future climate-driven disturbances will likely undermine the stability and productivity of MDV lake phytoplankton and bacterial communities in the surface waters of this extreme environment.

1 aSherwell, Shasten, S.1 aKalra, Isha1 aLi, Wei1 aMcKnight, Diane, M.1 aPriscu, John, C.1 aMorgan-Kiss, Rachael, M. uhttps://onlinelibrary.wiley.com/doi/10.1111/1462-2920.1611301629nas a2200217 4500008004100000022001400041245007400055210006900129260001200198300001200210490000600222520097000228100002101198700002201219700002401241700001901265700002101284700002101305700001701326856006801343 2022 eng d a2378-224200aBarotropic seiches in a perennially ice-covered lake, East Antarctica0 aBarotropic seiches in a perennially icecovered lake East Antarct c02/2022 a26 - 330 v73 a

Water movement in ice-covered lakes is known to be driven by wind, sediment heat flux, solar radiation, saline density flows, and advective stream discharge. In large ice-covered lakes, wind-induced oscillations have been found to play a major role in horizontal flows. Here, we report recurrent, wind-driven, barotropic seiches in a small lake with a thick (4 m) permanent ice-cover. Between 2010 and 2016, we recorded 10.5- to 13-min oscillations of the hydrostatic water level in Lake Hoare, McMurdo Dry Valleys, East Antarctica, using pressure transducers moored to the lake bottom and suspended from the ice cover. Theoretical calculations showed a barotropic seiche should have a period of 12.6 min. Barotropic seiches were most frequent during high wind events (> 5 m s-1) in winter months (February–November). The period increased during summer months (December–January) when fast ice thinned and melted along the shoreline.

1 aCastendyk, Devin1 aDugan, Hilary, A.1 aGallagher, Hugh, A.1 aPujara, Nimish1 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry uhttps://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lol2.1022602136nas a2200205 4500008004100000245007300041210007100114260001200185520148400197653001901681653001901700653002301719653001701742653002601759653002301785653002001808100002701828700001701855856005801872 2022 eng d00aCommunity assembly in the wake of glacial retreat: A meta‐analysis0 aCommunity assembly in the wake of glacial retreat A meta‐analysi c09/20223 a

Antarctic biodiversity faces an unknown future with a changing climate. Most terrestrial biota is restricted to limited patches of ice-free land in a sea of ice, where they are adapted to the continent's extreme cold and wind and exploit microhabitats of suitable conditions. As temperatures rise, ice-free areas are predicted to expand, more rapidly in some areas than others. There is high uncertainty as to how species' distributions, physiology, abundance, and survivorship will be affected as their habitats transform. Here we use current knowledge to propose hypotheses that ice-free area expansion (i) will increase habitat availability, though the quality of habitat will vary; (ii) will increase structural connectivity, although not necessarily increase opportunities for species establishment; (iii) combined with milder climates will increase likelihood of non-native species establishment, but may also lengthen activity windows for all species; and (iv) will benefit some species and not others, possibly resulting in increased homogeneity of biodiversity. We anticipate considerable spatial, temporal, and taxonomic variation in species responses, and a heightened need for interdisciplinary research to understand the factors associated with ecosystem resilience under future scenarios. Such research will help identify at-risk species or vulnerable localities and is crucial for informing environmental management and policymaking into the future.

10achronosequence10aclimate change10acommunity assembly10adeglaciation10aecological succession10aglacial forefields10asoil ecosystems1 aPothula, Satyendra, K.1 aAdams, Byron uhttps://onlinelibrary.wiley.com/doi/10.1111/gcb.1642702219nas a2200349 4500008004100000022001400041245012300055210006900178260001200247520113200259653000901391653001901400653001601419653001201435653000901447653001301456100002001469700002501489700001601514700002501530700002101555700001701576700002501593700002501618700002101643700002501664700002601689700002201715700002301737700001801760856009101778 2022 eng d a0006-356800aCross-site comparisons of dryland ecosystem response to climate change in the US Long-Term Ecological Research Network0 aCrosssite comparisons of dryland ecosystem response to climate c c08/20223 a

Long-term observations and experiments in diverse drylands reveal how ecosystems and services are responding to climate change. To develop generalities about climate change impacts at dryland sites, we compared broadscale patterns in climate and synthesized primary production responses among the eight terrestrial, nonforested sites of the United States Long-Term Ecological Research (US LTER) Network located in temperate (Southwest and Midwest) and polar (Arctic and Antarctic) regions. All sites experienced warming in recent decades, whereas drought varied regionally with multidecadal phases. Multiple years of wet or dry conditions had larger effects than single years on primary production. Droughts, floods, and wildfires altered resource availability and restructured plant communities, with greater impacts on primary production than warming alone. During severe regional droughts, air pollution from wildfire and dust events peaked. Studies at US LTER drylands over more than 40 years demonstrate reciprocal links and feedbacks among dryland ecosystems, climate-driven disturbance events, and climate change.

10aANPP10aclimate change10aDisturbance10adrought10aLTER10awildfire1 aHudson, Amy, R.1 aPeters, Debra, P. C.1 aBlair, J.M.1 aChilders, Daniel, L.1 aDoran, Peter, T.1 aGeil, Kerrie1 aGooseff, Michael, N.1 aGross, Katherine, L.1 aHaddad, Nick, M.1 aPastore, Melissa, A.1 aRudgers, Jennifer, A.1 aSala, Osvaldo, E.1 aSeabloom, Eric, W.1 aShaver, Gaius uhttps://academic.oup.com/bioscience/advance-article/doi/10.1093/biosci/biab134/665484002454nas a2200277 4500008004100000245020000041210006900241260001200310300001400322490000800336520152000344653001501864653001401879653002501893653001801918653001701936653000801953100002401961700001601985700002102001700001902022700001802041700002302059700002902082856006502111 2022 eng d00aCyclic electron flow (CEF) and ascorbate pathway activity provide constitutive photoprotection for the photopsychrophile, Chlamydomonas sp. UWO 241 (renamed Chlamydomonas priscuii)0 aCyclic electron flow CEF and ascorbate pathway activity provide  c03/2022 a235 - 2500 v1513 a

Under environmental stress, plants and algae employ a variety of strategies to protect the photosynthetic apparatus and maintain photostasis. To date, most studies on stress acclimation have focused on model organisms which possess limited to no tolerance to stressful extremes. We studied the ability of the Antarctic alga Chlamydomonas sp. UWO 241 (UWO 241) to acclimate to low temperature, high salinity or high light. UWO 241 maintained robust growth and photosynthetic activity at levels of temperature (2 °C) and salinity (700 mM NaCl) which were nonpermissive for a mesophilic sister species, Chlamydomonas raudensis SAG 49.72 (SAG 49.72). Acclimation in the mesophile involved classic mechanisms, including downregulation of light harvesting and shifts in excitation energy between photosystem I and II. In contrast, UWO 241 exhibited high rates of PSI-driven cyclic electron flow (CEF) and a larger capacity for nonphotochemical quenching (NPQ). Furthermore, UWO 241 exhibited constitutively high activity of two key ascorbate cycle enzymes, ascorbate peroxidase and glutathione reductase and maintained a large ascorbate pool. These results matched the ability of the psychrophile to maintain low ROS under short-term photoinhibition conditions. We conclude that tight control over photostasis and ROS levels are essential for photosynthetic life to flourish in a native habitat of permanent photooxidative stress. We propose to rename this organism Chlamydomonas priscuii.

10aAntarctica10aascorbate10aCyclic electron flow10aPhotosystem I10aPsychrophile10aROS1 aStahl-Rommel, Sarah1 aKalra, Isha1 aD'Silva, Susanna1 aHahn, Mark, M.1 aPopson, Devon1 aCvetkovska, Marina1 aMorgan-Kiss, Rachael, M. uhttps://link.springer.com/article/10.1007/s11120-021-00877-502431nas a2200277 4500008004100000022001300041245008500054210006900139260001200208300001100220490000800231520163400239653001501873653001301888653001401901653001901915653001901934653001901953100001401972700001201986700002501998700002102023700001702044700001602061856007602077 2022 eng d a0048969700aOrganic matter distribution in the icy environments of Taylor Valley, Antarctica0 aOrganic matter distribution in the icy environments of Taylor Va c10/2022 a1566390 v8413 a

Glaciers can accumulate and release organic matter affecting the structure and function of associated terrestrial and aquatic ecosystems. We analyzed 18 ice cores collected from six locations in Taylor Valley (McMurdo Dry Valleys), Antarctica to determine the spatial abundance and quality of organic matter, and the spatial distribution of bacterial density and community structure from the terminus of the Taylor Glacier to the coast (McMurdo Sound). Our results showed that dissolved and particulate organic carbon (DOC and POC) concentrations in the ice core samples increased from the Taylor Glacier to McMurdo Sound, a pattern also shown by bacterial cell density. Fluorescence Excitation Emission Matrices Spectroscopy (EEMs) and multivariate parallel factor (PARAFAC) modeling identified one humic-like (C1) and one protein-like (C2) component in ice cores whose fluorescent intensities all increased from the Polar Plateau to the coast. The fluorescence index showed that the bioavailability of dissolved organic matter (DOM) also decreased from the Polar Plateau to the coast. Partial least squares path modeling analysis revealed that bacterial abundance was the main positive biotic factor influencing both the quantity and quality of organic matter. Marine aerosol influenced the spatial distribution of DOC more than katabatic winds in the ice cores. Certain bacterial taxa showed significant correlations with DOC and POC concentrations. Collectively, our results show the tight connectivity among organic matter spatial distribution, bacterial abundance and meteorology in the McMurdo Dry Valley ecosystem.

10aAntarctica10abacteria10aice cores10akatabatic wind10amarine aerosol10aorganic matter1 aGuo, Bixi1 aLi, Wei1 aSantibáñez, Pamela1 aPriscu, John, C.1 aLiu, Yongqin1 aLiu, Keshao uhttps://www.sciencedirect.com/science/article/abs/pii/S004896972203736602569nas a2200373 4500008004100000245008100041210006900122260004300191520135400234100001701588700001801605700002201623700002101645700002001666700003001686700002101716700002401737700002301761700001801784700002101802700002301823700002201846700002001868700002301888700002401911700001601935700002301951700002401974700002101998700001902019700001802038700002002056856011902076 2022 eng d00aTen scientific messages on risks and opportunities for life in the Antarctic0 aTen scientific messages on risks and opportunities for life in t bAntarctic Environments Portalc02/20223 a

Initiated by the SCAR scientific research programme “Antarctic Thresholds – Ecosystem Resilience and Adaptation” (AnT-ERA, 2013-2021), 26 experts synthesized knowledge on impacts and risks of climate-change on biological processes and ecosystem functions in the Antarctic. The ten main scientific messages that emerged addressed (1) accelerating marine and terrestrial biogeochemical cycles, (2) response to ocean acidification, (3) ecological changes in climate change hot spots, (4) unexpected dynamism of marine seafloor communities, (5) biodiversity shifts, (6) low temperature limitation of protein synthesis, (7) life intrinsically linked to changing sea ice conditions, (8) pollution, (9) genetically distinct terrestrial populations under threat, and (10) newly discovered habitats. Two-thirds of the literature included in this synthesis was published between 2010 and 2020 and only one-third was published earlier. The fast mounting, recent decadal evidence indicates various Antarctic biological communities now experience climate stress, or will experience such stress in the coming decades. The responses of organisms, ecosystem functions and services to environmental changes are complex and varied. Key knowledge gaps remain and need addressing to adequately assess future prospects for life in the Antarctic.

1 aGutt, Julian1 aIsla, Enrique1 aXavier, José, C.1 aAdams, Byron, J.1 aAhn, In‐Young1 aCheng, C.‐H., Christina1 aColesie, Claudia1 aCummings, Vonda, J.1 aGriffiths, Huw, J.1 aHogg, Ian, D.1 aMcIntyre, Trevor1 aMeiners, Klaus, M.1 aPearce, David, A.1 aPeck, Lloyd, S.1 aPiepenburg, Dieter1 aReisinger, Ryan, R.1 aSaba, Grace1 aSchloss, Irene, R.1 aSignori, Camila, N.1 aSmith, Craig, R.1 aVacchi, Marino1 aVerde, Cinzia1 aWall, Diana, H. uhttps://environments.aq/publications/ten-scientific-messages-on-risks-and-opportunities-for-life-in-the-antarctic/02273nas a2200205 4500008004100000022001400041245012200055210006900177260001200246490000800258520159800266653001401864653001901878653002201897653001901919100002001938700002701958700002101985856006102006 2022 eng d a2169-900300aWintertime brine discharge at the surface of a cold polar glacier and the unexpected absence of associated seismicity0 aWintertime brine discharge at the surface of a cold polar glacie c03/20220 v1273 a

A subglacial groundwater system beneath Taylor Glacier, Antarctica, discharges hypersaline, iron-rich brine episodically at the glacier surface to create Blood Falls. However, the triggering mechanism for these brine release events is not yet understood. Identifying which fracture processes are observed seismically can help us better characterize the hydrological system at Taylor Glacier, and more generally, provide us with a broader understanding of englacial hydrologic activity in cold glaciers. We document wintertime brine discharge using time-lapse photography. Subfreezing air temperatures during the brine discharge indicate that surface melt-induced hydrofracture is an unlikely trigger for brine release. Further, we analyze local seismic data to test a hypothesis that fracturing generates elevated surface wave energy preceding and/or coinciding with brine release events. Our results show no discernible elevated Rayleigh wave activity prior to or during Blood Falls brine release. Instead, we find a pattern of seismic events dominated by a seasonal signal, with more Rayleigh events occurring in the summer than the winter from the Blood Falls source area. We calculate that the volumetric opening of cracks that would generate Rayleigh waves at our detection limits are of similar size to myriad cracks in glacier ice, lake ice, and frozen sediment in the terminus area. We therefore propose that any fracturing coincident with brine release activity likely consists of a series of smaller opening events that are masked by other seismicity in the local environment.

10acrevasses10acryoseismology10aglacier hydrology10aRayleigh waves1 aCarr, Chris, G.1 aCarmichael, Joshua, D.1 aPettit, Erin, C. uhttps://onlinelibrary.wiley.com/doi/10.1029/2021JF00632503115nas a2200517 4500008004100000245008300041210006900124260001200193520161800205653001501823653002101838653002601859653001901885653001301904653001701917653002401934653002301958653001701981653001201998100001702010700001802027700002202045700002102067700002002088700003002108700002102138700002402159700002102183700002302204700001502227700001802242700002102260700002302281700002202304700002002326700002302346700002402369700001602393700002302409700002402432700002102456700001902477700001802496700002002514856006302534 2021 eng d00aAntarctic ecosystems in transition – life between stresses and opportunities0 aAntarctic ecosystems in transition life between stresses and opp c06/20213 a

Important findings from the second decade of the 21st century on the impact of environmental change on biological processes in the Antarctic were synthesised by 26 international experts. Ten key messages emerged that have stakeholder‐relevance and/or a high impact for the scientific community. They address (i) altered biogeochemical cycles, (ii) ocean acidification, (iii) climate change hotspots, (iv) unexpected dynamism in seabed‐dwelling populations, (v) spatial range shifts, (vi) adaptation and thermal resilience, (vii) sea ice related biological fluctuations, (viii) pollution, (ix) endangered terrestrial endemism and (x) the discovery of unknown habitats. Most Antarctic biotas are exposed to multiple stresses and considered vulnerable to environmental change due to narrow tolerance ranges, rapid change, projected circumpolar impacts, low potential for timely genetic adaptation, and migration barriers. Important ecosystem functions, such as primary production and energy transfer between trophic levels, have already changed, and biodiversity patterns have shifted. A confidence assessment of the degree of ‘scientific understanding’ revealed an intermediate level for most of the more detailed sub‐messages, indicating that process‐oriented research has been successful in the past decade. Additional efforts are necessary, however, to achieve the level of robustness in scientific knowledge that is required to inform protection measures of the unique Antarctic terrestrial and marine ecosystems, and their contributions to global biodiversity and ecosystem services.

10aadaptation10abenthic dynamism10abiogeochemical cycles10aclimate change10ainvasion10anew habitats10aocean acidification10aPrimary production10arange shifts10asea ice1 aGutt, Julian1 aIsla, Enrique1 aXavier, José, C.1 aAdams, Byron, J.1 aAhn, In‐Young1 aCheng, C.‐H., Christina1 aColesie, Claudia1 aCummings, Vonda, J.1 adi Prisco, Guido1 aGriffiths, Huw, J.1 aHawes, Ian1 aHogg, Ian, D.1 aMcIntyre, Trevor1 aMeiners, Klaus, M.1 aPearce, David, A.1 aPeck, Lloyd, S.1 aPiepenburg, Dieter1 aReisinger, Ryan, R.1 aSaba, Grace1 aSchloss, Irene, R.1 aSignori, Camila, N.1 aSmith, Craig, R.1 aVacchi, Marino1 aVerde, Cinzia1 aWall, Diana, H. uhttps://onlinelibrary.wiley.com/doi/full/10.1111/brv.1267904166nas a2200565 4500008004100000022001400041245007900055210006900134260001200203300001100215490000700226520245300233653001802686653002702704653001902731653001902750653001202769653001202781653001502793653008902808653002002897100002302917700002502940700002602965700002702991700002103018700002503039700001703064700002203081700002903103700002603132700002403158700002603182700002403208700002103232700001603253700002703269700002403296700002303320700002203343700002403365700002303389700001503412700002203427700002103449700002203470700002603492700002403518856005803542 2021 eng d a2150-892500aConnectivity: Insights from the U.S. Long Term Ecological Research Network0 aConnectivity Insights from the US Long Term Ecological Research  c05/2021 ae034320 v123 a

Ecosystems across the United States are changing in complex and surprising ways. Ongoing demand for critical ecosystem services requires an understanding of the populations and communities in these ecosystems in the future. This paper represents a synthesis effort of the U.S. National Science Foundation-funded Long-Term Ecological Research (LTER) network addressing the core research area of “populations and communities.” The objective of this effort was to show the importance of long-term data collection and experiments for addressing the hardest questions in scientific ecology that have significant implications for environmental policy and management. Each LTER site developed at least one compelling case study about what their site could look like in 50–100 yr as human and environmental drivers influencing specific ecosystems change. As the case studies were prepared, five themes emerged, and the studies were grouped into papers in this LTER Futures Special Feature addressing state change, connectivity, resilience, time lags, and cascading effects. This paper addresses the “connectivity” theme and has examples from the Phoenix (urban), Niwot Ridge (alpine tundra), McMurdo Dry Valleys (polar desert), Plum Island (coastal), Santa Barbara Coastal (coastal), and Jornada (arid grassland and shrubland) sites. Connectivity has multiple dimensions, ranging from multi-scalar interactions in space to complex interactions over time that govern the transport of materials and the distribution and movement of organisms. The case studies presented here range widely, showing how land-use legacies interact with climate to alter the structure and function of arid ecosystems and flows of resources and organisms in Antarctic polar desert, alpine, urban, and coastal marine ecosystems. Long-term ecological research demonstrates that connectivity can, in some circumstances, sustain valuable ecosystem functions, such as the persistence of foundation species and their associated biodiversity or, it can be an agent of state change, as when it increases wind and water erosion. Increased connectivity due to warming can also lead to species range expansions or contractions and the introduction of undesirable species. Continued long-term studies are essential for addressing the complexities of connectivity. The diversity of ecosystems within the LTER network is a strong platform for these studies.

10aalpine tundra10aAntarctic polar desert10aarid grassland10aarid shrubland10acoastal10aestuary10asalt marsh10aSpecial Feature: Forecasting Earth’s Ecosystems with Long-Term Ecological Research10aurban ecosystem1 aIwaniec, David, M.1 aGooseff, Michael, N.1 aSuding, Katharine, N.1 aJohnson, David, Samuel1 aReed, Daniel, C.1 aPeters, Debra, P. C.1 aAdams, Byron1 aBarrett, John, E.1 aBestelmeyer, Brandon, T.1 aCastorani, Max, C. N.1 aCook, Elizabeth, M.1 aDavidson, Melissa, J.1 aGroffman, Peter, M.1 aHanan, Niall, P.1 aHuenneke, L1 aJohnson, Pieter, T. J.1 aMcKnight, Diane, M.1 aMiller, Robert, J.1 aOkin, Gregory, S.1 aPreston, Daniel, L.1 aRassweiler, Andrew1 aRay, Chris1 aSala, Osvaldo, E.1 aSchooley, Robert1 aSeastedt, Timothy1 aSpasojevic, Marko, J.1 aVivoni, Enrique, R. uhttps://onlinelibrary.wiley.com/doi/10.1002/ecs2.343202111nas a2200205 4500008004100000245010700041210006900148260001200217300001600229490000700245520142400252100002401676700002201700700002501722700002101747700002101768700002001789700002501809856007101834 2021 eng d00aCounting carbon: Quantifying biomass in the McMurdo Dry Valleys through orbital and field observations0 aCounting carbon Quantifying biomass in the McMurdo Dry Valleys t c10/2021 a8597 - 86230 v423 a

We use correlative field studies and high-resolution multispectral remote sensing data from the WorldView-2 instrument to estimate the abundance of photosynthetically active biomass (photoautotrophs consisting primarily of microbial mats and mosses) in Canada Stream in Taylor Valley, McMurdo Dry Valleys (MDV), Antarctica. In situ field investigations were performed to (1) acquire ground validation targets for atmospherically correcting satellite imagery, (2) derive spectra of “pure” geologic and biological endmembers, (3) estimate photoautotroph cover from remote sensing data, and (4) convert these coverage estimates to biomass using data collected in the field. Our results suggest that, on the morning of 12 December 2018, the Canada Stream system contained more than 3,800 kg of photosynthetically active carbon. Extrapolating our unmixing results to the entirety of the Fryxell basin of Taylor Valley, Antarctica, we model the presence of more than 750,000 kg of photosynthetically active carbon across the landscape and carbon fixation rates roughly equivalent to five hectares of tropical rainforest. The ability to spatially and temporally quantify the amount of photosynthetically active biomass using remote sensing data in the MDV of Antarctica is a revolutionary development that will help elucidate the ecological drivers and environmental responses in this cold desert landscape.

1 aSalvatore, Mark, R.1 aBarrett, John, E.1 aBorges, Schuyler, R.1 aPower, Sarah, N.1 aStanish, Lee, F.1 aSokol, Eric, R.1 aGooseff, Michael, N. uhttps://www.tandfonline.com/doi/full/10.1080/01431161.2021.198155902080nas a2200361 4500008004100000245006800041210006800109260001200177300000900189490000700198520108000205653001501285653001701300653001201317653001301329653001501342653000901357100001901366700002401385700001801409700002101427700002501448700002501473700002201498700002001520700001901540700001701559700002601576700001601602700001801618710002301636856005901659 2021 eng d00aDiatoms define a novel freshwater biogeography of the Antarctic0 aDiatoms define a novel freshwater biogeography of the Antarctic c01/2021 a1-130 v443 a

Terrestrial biota in the Antarctic are more globally distinct and highly structured biogeographically than previously believed, but information on biogeographic patterns and endemism in freshwater communities is largely lacking. We studied biogeographic patterns of Antarctic freshwater diatoms based on the analysis of species occurrences in a dataset of 439 lakes spread across the Antarctic realm. Highly distinct diatom floras, both in terms of composition and richness, characterize Continental Antarctica, Maritime Antarctica and the sub-Antarctic islands, with marked biogeographic provincialism in each region. A total of 44% of all species is estimated to be endemic to the Antarctic, and most of them are confined to a single biogeographic region. The level of endemism significantly increases with increasing latitude and geographic isolation. Our results have implications for conservation planning, and suggest that successful dispersal of freshwater diatoms to and within the Antarctic is limited, fostering the evolution of highly endemic diatom floras.

10aAntarctica10abiogeography10adiatoms10aendemism10afreshwater10alake1 aVerleyen, Elie1 aVan de Vijver, Bart1 aTytgat, Bjorn1 aPinseel, Eveline1 aHodgson, Dominic, A.1 aKopalová, Kateřina1 aChown, Steven, L.1 aVan Ranst, Eric1 aImura, Satoshi1 aKudoh, Sakae1 aVan Nieuwenhuyze, Wim1 aSabbe, Koen1 aVyverman, Wim1 aANTDIAT consortium uhttps://onlinelibrary.wiley.com/doi/10.1111/ecog.0537402579nas a2200397 4500008004100000022001300041245012700054210006900181260001200250300001100262490000600273520134500279653003401624653002501658653003101683653002701714653001801741653001401759100002201773700002401795700002201819700002301841700002301864700001401887700001901901700001601920700002101936700002701957700002601984700001602010700002402026700001602050700002102066700002202087856007202109 2021 eng d a2666900500aPatterns and trends of organic matter processing and transport: Insights from the US Long-term Ecological Research Network0 aPatterns and trends of organic matter processing and transport I c12/2021 a1000250 v23 a

Organic matter (OM) dynamics determine how much carbon is stored in ecosystems, a service that modulates climate. We synthesized research from across the US Long-Term Ecological Research (LTER) Network to assemble a conceptual model of OM dynamics that is consistent with inter-disciplinary perspectives and emphasizes vulnerability of OM pools to disturbance. Guided by this conceptual model, we identified unanticipated patterns and long-term trends in processing and transport of OM emerging from terrestrial, freshwater, wetland, and marine ecosystems. Cross-ecosystem synthesis combined with a survey of researchers revealed several themes: 1) strong effects of climate change on OM dynamics, 2) surprising patterns in OM storage and dynamics resulting from coupling with nutrients, 3) characteristic and often complex legacies of land use and disturbance, 4) a significant role of OM transport that is often overlooked in terrestrial ecosystems, and 5) prospects for reducing uncertainty in forecasting OM dynamics by incorporating the chemical composition of OM. Cross-fertilization of perspectives and approaches across LTER sites and other research networks can stimulate the comprehensive understanding required to support large-scale characterizations of OM budgets and the role of ecosystems in regulating global climate.

10acoupled biogeochemical cycles10across-site synthesis10aorganic matter composition10aorganic matter storage10astabilization10atransport1 aHarms, Tamara, K.1 aGroffman, Peter, M.1 aAluwihare, Lihini1 aCraft, Christopher1 aWieder, William, R1 aHobbie, S1 aBaer, Sara, G.1 aBlair, J.M.1 aFrey, Serita, D.1 aRemucal, Christina, K.1 aRudgers, Jennifer, A.1 aCollins, SL1 aKominoski, John, S.1 aBall, Becky1 aPriscu, John, C.1 aBarrett, John, E. uhttps://www.sciencedirect.com/science/article/pii/S266690052100025302753nas a2200325 4500008004100000022001400041245011500055210007300170260001200243300001800255490000800273520178400281653001002065653001402075653001602089653000802105653001002113653001002123653001402133653001102147100002802158700002102186700003302207700002202240700002202262700002402284700002902308700002102337856006902358 2021 eng d a2169-895300aYear‐round and long‐term phytoplankton dynamics in Lake Bonney, a permanently ice‐covered Antarctic lake0 aYear‐round and long‐term phytoplankton dynamics in Lake Bonney a c04/2021 ae2020JG0059250 v1263 a

Lake Bonney (McMurdo Dry Valleys, east Antarctica) represents a year‐round refugium for life adapted to permanent extreme conditions. Despite intensive research since the 1960s, due to the logistical constraints posed by 4‐months of 24‐h darkness, knowledge of how the resident photosynthetic microorganisms respond to the polar winter is limited. In addition, the lake level has risen by more than 3 m since 2004: impacts of rapid lake level rise on phytoplankton community structure is also poorly understood. From 2004 to 2015 an in situ submersible spectrofluorometer (bbe FluoroProbe) was deployed in Lake Bonney during the austral summer to quantify the vertical structure of four functional algal groups (green algae, mixed algae, and cryptophytes, cyanobacteria). During the 2013–2014 field season the Fluoroprobe was mounted on autonomous cable‐crawling profilers deployed in both the east and west lobes of Lake Bonney, obtaining the first daily phytoplankton profiles through the polar night. Our findings showed that phytoplankton communities were differentially impacted by physical and chemical factors over long‐term versus seasonal time scales. Following a summer of rapid lake level rise (2010–2011), an increase in depth integrated chlorophyll a (chl‐a) occurred in Lake Bonney caused by stimulation of photoautotrophic green algae. Conversely, peaks in chl‐a during the polar night were associated with an increase in mixotrophic haptophytes and cryptophytes. Collectively our data reveal that phytoplankton groups possessing variable trophic abilities are differentially competitive during seasonal and long‐term time scales owing to periods of higher nutrients (photoautotrophs) versus light/energy limitation (mixotrophs).

10aalgae10aAntarctic10afluorometry10aice10alakes10alight10aprofiling10awinter1 aPatriarche, Jeffrey, D.1 aPriscu, John, C.1 aTakacs-Vesbach, Cristina, D.1 aWinslow, Luke, A.1 aMyers, Krista, F.1 aBuelow, Heather, N.1 aMorgan-Kiss, Rachael, M.1 aDoran, Peter, T. uhttps://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JG00592502509nas a2200205 4500008004100000245012600041210006900167260005300236490000900289520180200298653002502100653001502125653001702140653002402157653002002181653002302201100002502224700001702249856003702266 2020 eng d00aAnalysis of acid-leachable barium, copper, iron, lead, & zinc concentrations in Taylor Valley, Antarctic stream sediments0 aAnalysis of acidleachable barium copper iron lead zinc concentra aColumbus, OHbThe Ohio State Universityc05/20200 vB.S.3 a

The purpose of this study is to assess the concentrations of Barium (Ba), Copper (Cu), Iron (Fe), Lead (Pb), and Zinc (Zn) in sediment samples obtained from the Wales and Commonwealth streams located in Taylor Valley, Antarctica. These samples were collected at seven sample sites (three in Wales Glacier and four in Commonwealth Glacier) in 0 to 2 cm, 2 to 4 cm, 4 to 6 cm, and 6 to 8 cm depth increments which resulted in 28 total samples. After the collection process, these samples underwent a volumetric 1:5 sediment: 10% HCl leach for 48 hours, filtration through 4-µm pore-size, cellulose acetate membrane filters, and inductively coupled plasma mass spectrometry (ICP-MS) analyses in the Trace Element Research Laboratory at The Ohio State University. Upon completion of the analyses, results showed that the Wales samples had a higher average concentration of every metal element overall and at each depth increment when compared to the Commonwealth samples. In addition to the weak-acid leachate metal analyses, a second aliquot of one sediment profile from each stream was analyzed at Villanova University for the 210Pb activity via gamma spectroscopy. This was done to estimate the sedimentation rates at each of these sites. From the sedimentation rates, sedimentation fluxes were calculated for each element for each sediment profile at each of these sites. The data demonstrated that Fe is the most abundant element while Pb is the least abundant. Lastly, upon examination of results, it was found that the concentrations of these metals are often higher in samples collected closer to the surface. These findings suggest these streams, and their sources, have had little, if any, impact by anthropogenic input of metals, and that metal fluxes to the sediments are low.

10aacid-leachable metal10aAntarctica10ageochemistry10aMcMurdo Dry Valleys10apolar sediments10asedimentation rate1 aPiergallini, Brianna1 aLyons, Berry uhttp://hdl.handle.net/1811/9177204249nas a2200253 4500008004100000245009000041210006900131260001200200490000600212520350100218653002003719653002003739653001303759100001903772700002003791700002203811700002403833700002503857700001903882700001203901700001703913700002103930856004403951 2020 eng d00aChange in Pictures: Creating best practices in archiving ecological imagery for reuse0 aChange in Pictures Creating best practices in archiving ecologic c09/20200 v43 a

The research data repository of the Environmental Data Initiative (EDI) is building on over 30 years of data curation research and experience in the National Science Foundation-funded US Long-Term Ecological Research (LTER) Network. It provides mature functionalities, well established workflows, and now publishes all ‘long-tail’ environmental data. High quality scientific metadata are enforced through automatic checks against community developed rules and the Ecological Metadata Language (EML) standard. Although the EDI repository is far along in making its data findable, accessible, interoperable, and reusable (FAIR), representatives from EDI and the LTER are developing best practices for the edge cases in environmental data publishing. One of these is the vast amount of imagery taken in the context of ecological research, ranging from wildlife camera traps to plankton imaging systems to aerial photography. Many images are used in biodiversity research for community analyses (e.g., individual counts, species cover, biovolume, productivity), while others are taken to study animal behavior and landscape-level change.

Some examples from the LTER Network include: using photos of a heron colony to measure provisioning rates for chicks (Clarkson and Erwin 2018) or identifying changes in plant cover and functional type through time (Peters et al. 2020). Multi-spectral images are employed to identify prairie species. Underwater photo quads are used to monitor changes in benthic biodiversity (Edmunds 2015). Sosik et al. (2020) used a continuous Imaging FlowCytobot to identify and measure phyto- and microzooplankton. Cameras at McMurdo Dry Valleys assess snow and ice cover on Antarctic lakes allowing estimation of primary production (Myers 2019).

It has been standard practice to publish numerical data extracted from images in EDI; however, the supporting imagery generally has not been made publicly available. Our goal in developing best practices for documenting and archiving these images is for them to be discovered and re-used. Our examples demonstrate several issues. The research questions, and hence, the image subjects are variable. Images frequently come in logical sets of time series. The size of such sets can be large and only some images may be contributed to a dedicated specialized repository. Finally, these images are taken in a larger monitoring context where many other environmental data are collected at the same time and location.

Currently, a typical approach to publishing image data in EDI are packages containing compressed (ZIP or tar) files with the images, a directory manifest with additional image-specific metadata, and a package-level EML metadata file. Images in the compressed archive may be organized within directories with filenames corresponding to treatments, locations, time periods, individuals, or other grouping attributes. Additionally, the directory manifest table has columns for each attribute. Package-level metadata include standard coverage elements (e.g., date, time, location) and sampling methods. This approach of archiving logical ‘sets’ of images reduces the effort of providing metadata for each image when most information would be repeated, but at the expense of not making every image individually searchable. The latter may be overcome if the provided manifest contains standard metadata that would allow searching and automatic integration with other images.

10adata repository10aecological data10ametadata1 aGries, Corinna1 aBeaulieu, Stace1 aBrown, Renée, F.1 aGastil-Buhl, Gastil1 aElmendorf, Sarah, C.1 aHsieh, Hsun-Yi1 aKui, Li1 aMaurer, Greg1 aPorter, John, H. uhttps://biss.pensoft.net/article/59082/02447nas a2200181 4500008004100000245007900041210006900120260001200189490000700201520187300208100002002081700002602101700002002127700002402147700001902171700002102190856005402211 2020 eng d00aA digital archive of human activity in the McMurdo Dry Valleys, Antarctica0 adigital archive of human activity in the McMurdo Dry Valleys Ant c05/20200 v123 a

Over the last half century, the McMurdo Dry Valleys (MDV) of East Antarctica have become a globally important site for scientific research and environmental monitoring. Historical data can make important contributions to current research activities and environmental management in Antarctica but tend to be widely scattered and difficult to access. We address this need in the MDV by compiling over 5000 historical photographs, sketches, maps, oral interviews, publications, and other archival resources into an online digital archive. The data have been digitized and georeferenced using a standardized metadata structure, which enables intuitive searches and data discovery via an online interface. The ultimate aim of the archive is to create as comprehensive as possible a record of human activity in the MDV to support ongoing research, management, and conservation efforts. This is a valuable tool for scientists seeking to understand the dynamics of change in lakes, glaciers, and other physical systems, as well as humanistic inquiry into the history of the Southern Continent. In addition to providing benchmarks for understanding change over time, the data can help target field sampling for studies working under the assumption of a pristine landscape by enabling researchers to identify the date and extent of past human activities. The full database is accessible via a web browser-based interface hosted by the McMurdo Long Term Ecological Research site: http://mcmurdohistory.lternet.edu/ (last access: 5 May 2020). The complete metadata data for all resources in the database are also available at the Environmental Data Initiative: https://doi.org/10.6073/pasta/6744cb28a544fda827805db123d36557 (Howkins et al., 2019).

1 aHowkins, Adrian1 aChignell, Stephen, M.1 aGullett, Poppie1 aFountain, Andrew, G1 aBrett, Melissa1 aPreciado, Evelin uhttps://www.earth-syst-sci-data.net/12/1117/2020/02597nas a2200229 4500008004100000245011900041210006900160260001200229520184900241653001502090653001802105653002602123653000902149653001502158653001902173100002102192700002402213700002002237700002102257700002202278856006702300 2020 eng d00aEstimating microbial mat biomass in the McMurdo Dry Valleys, Antarctica using satellite imagery and ground surveys0 aEstimating microbial mat biomass in the McMurdo Dry Valleys Anta c09/20203 a

Cyanobacterial mat communities are the main drivers of primary productivity in the McMurdo Dry Valleys, Antarctica. These microbial communities form laminar mats on desert pavement surfaces adjacent to glacial meltwater streams, ponds, and lakes. The low-density nature of these communities and their patchy distribution make assessments of distribution, biomass, and productivity challenging. We used satellite imagery coupled with in situ surveying, imaging, and sampling to systematically estimate microbial mat biomass in selected wetland regions in Taylor Valley, Antarctica. On January 19th, 2018, the WorldView-2 multispectral satellite acquired an image of our study areas, where we surveyed and sampled seven 100 m2 plots of microbial mats for percent ground cover, ash-free dry mass (AFDM), and pigment content (chlorophyll-a, carotenoids, and scytonemin). Multispectral analyses revealed spectral signatures consistent with photosynthetic activity (relatively strong reflection at near-infrared wavelengths and relatively strong absorption at visible wavelengths), with average normalized difference vegetation index (NDVI) values of 0.09 to 0.28. Strong correlations of microbial mat ground cover (R2 = 0.84), biomass (R2 = 0.74), chlorophyll-a content (R2 = 0.65), and scytonemin content (R2 = 0.98) with logit transformed NDVI values demonstrate that satellite imagery can detect both the presence of microbial mats and their key biological properties. Using the NDVI—biomass correlation we developed, we estimate carbon (C) stocks of 21,715 kg (14.7 g C m−2) in the Canada Glacier Antarctic Specially Protected Area, with an upper and lower limit of 74,871 and 6312 kg of C, respectively.

10aAntarctica10amicrobial mat10amultispectral imagery10aNDVI10aNostocales10aremote sensing1 aPower, Sarah, N.1 aSalvatore, Mark, R.1 aSokol, Eric, R.1 aStanish, Lee, F.1 aBarrett, John, E. uhttps://link.springer.com/article/10.1007%2Fs00300-020-02742-y03683nas a2200997 4500008004100000245008200041210006900123260001200192490000600204520084100210100002601051700001901077700002001096700001401116700002501130700002501155700001701180700001701197700001901214700002601233700002301259700002701282700002301309700002101332700003101353700001801384700002101402700002001423700003001443700001501473700002001488700001901508700002501527700002301552700001901575700002101594700001701615700002201632700002101654700002601675700002301701700001101724700001701735700002201752700002101774700003101795700002401826700002201850700001501872700002201887700001801909700001701927700002501944700002201969700001901991700002702010700001602037700001802053700002202071700003202093700002302125700002302148700002002171700002202191700002002213700002702233700001802260700002102278700001902299700002302318700001502341700002302356700002202379700002402401700002102425700002302446700002102469700001802490700001802508700001902526700001402545700002802559700001702587700002702604856005402631 2020 eng d00aA global database of soil nematode abundance and functional group composition0 aglobal database of soil nematode abundance and functional group  c03/20200 v73 a

As the most abundant animals on earth, nematodes are a dominant component of the soil community. they play critical roles in regulating biogeochemical cycles and vegetation dynamics within and across landscapes and are an indicator of soil biological activity. Here, we present a comprehensive global dataset of soil nematode abundance and functional group composition. This dataset includes 6,825 georeferenced soil samples from all continents and biomes. For geospatial mapping purposes these samples are aggregated into 1,933 unique 1-km pixels, each of which is linked to 73 global environmental covariate data layers. Altogether, this dataset can help to gain insight into the spatial distribution patterns of soil nematode abundance and community composition, and the environmental drivers shaping these patterns.

1 avan den Hoogen, Johan1 aGeisen, Stefan1 aWall, Diana, H.1 aWardle, D1 aTraunspurger, Walter1 ade Goede, Ron, G. M.1 aAdams, Byron1 aAhmad, Wasim1 aFerris, Howard1 aBardgett, Richard, D.1 aBonkowski, Michael1 aCampos-Herrera, Raquel1 aCares, Juvenil, E.1 aCaruso, Tancredi1 aCaixeta, Larissa, de Brito1 aChen, Xiaoyun1 aCosta, Sofia, R.1 aCreamer, Rachel1 aCastro, José, da Cunha e1 aDam, Marie1 aDjigal, Djibril1 aEscuer, Miguel1 aGriffiths, Bryan, S.1 aGutiérrez, Carmen1 aHohberg, Karin1 aKalinkina, Daria1 aKardol, Paul1 aKergunteuil, Alan1 aKorthals, Gerard1 aKrashevska, Valentyna1 aKudrin, Alexey, A.1 aLi, Qi1 aLiang, Wenju1 aMagilton, Matthew1 aMarais, Mariette1 aMartín, José, Antonio Ro1 aMatveeva, Elizaveta1 aMayad, El, Hassan1 aMzough, E.1 aMulder, Christian1 aMullin, Peter1 aNeilson, Roy1 aNguyen, T., A. Duong1 aNielsen, Uffe, N.1 aOkada, Hiroaki1 aRius, Juan, Emilio Pal1 aPan, Kaiwen1 aPeneva, Vlada1 aPellissier, Loïc1 ada Silva, Julio, Carlos Per1 aPitteloud, Camille1 aPowers, Thomas, O.1 aPowers, Kirsten1 aQuist, Casper, W.1 aRasmann, Sergio1 aMoreno, Sara, Sánchez1 aScheu, Stefan1 aSetälä, Heikki1 aSushchuk, Anna1 aTiunov, Alexei, V.1 aTrap, Jean1 aVestergård, Mette1 aVillenave, Cecile1 aWaeyenberge, Lieven1 aWilschut, Rutger1 aWright, Daniel, G.1 aKeith, Aidan, M.1 aYang, Jiue-in1 aSchmidt, Olaf1 aBouharroud, R.1 aFerji, Z.1 avan der Putten, Wim, H.1 aRouth, Devin1 aCrowther, Thomas, Ward uhttps://www.nature.com/articles/s41597-020-0437-302262nas a2200145 4500008004100000245013600041210006900177260001200246520154000258100002001798700002301818700002101841700002001862856023401882 2020 eng d00aThe influence of environmental microseismicity on detection and interpretation of small-magnitude events in a polar glacier setting0 ainfluence of environmental microseismicity on detection and inte c07/20203 a

Glacial environments exhibit temporally variable microseismicity. To investigate how microseismicity influences event detection, we implement two noise-adaptive digital power detectors to process seismic data from Taylor Glacier, Antarctica. We add scaled icequake waveforms to the original data stream, run detectors on the hybrid data stream to estimate reliable detection magnitudes and compare analytical magnitudes predicted from an ice crack source model. We find that detection capability is influenced by environmental microseismicity for seismic events with source size comparable to thermal penetration depths. When event counts and minimum detectable event sizes change in the same direction (i.e. increase in event counts and minimum detectable event size), we interpret measured seismicity changes as ‘true’ seismicity changes rather than as changes in detection. Generally, one detector (two degree of freedom (2dof)) outperforms the other: it identifies more events, a more prominent summertime diurnal signal and maintains a higher detection capability. We conclude that real physical processes are responsible for the summertime diurnal inter-detector difference. One detector (3dof) identifies this process as environmental microseismicity; the other detector (2dof) identifies it as elevated waveform activity. Our analysis provides an example for minimizing detection biases and estimating source sizes when interpreting temporal seismicity patterns to better infer glacial seismogenic processes.

1 aCarr, Chris, G.1 aCarmichael, J., D.1 aPettit, Erin, C.1 aTruffer, Martin uhttps://www.cambridge.org/core/journals/journal-of-glaciology/article/influence-of-environmental-microseismicity-on-detection-and-interpretation-of-smallmagnitude-events-in-a-polar-glacier-setting/E1A441425341F677117509351F3C676302448nas a2200217 4500008004100000245010000041210006900141260001200210490000700222520174400229100001201973700001901985700002702004700002102031700001602052700001702068700002902085700002302114700002102137856007202158 2020 eng d00aMethane production in the oxygenated water column of a perennially ice‐covered Antarctic lake0 aMethane production in the oxygenated water column of a perennial c01/20200 v653 a

Aerobic methane production in aquatic ecosystems impacts the global atmospheric budget of methane, but the extent, mechanism, and taxa responsible for producing this greenhouse gas are not fully understood. Lake Bonney (LB), a perennially ice‐covered Antarctic lake, has cold hypersaline waters underlying an oxygenated freshwater layer. We present temporal methane concentration profiles in LB indicating methane production in the oxygenated (> 200% air saturation) water. Experiments amended with methylphosphonate (MPn) yielded methane generation, suggesting in situ methanogenesis via the carbon‐phosphorus (C‐P) lyase pathway. Enrichment cultures from the lake were used to isolate five bacterial strains capable of generating methane when supplied with MPn as the sole P source. Based on 16S rRNA gene sequencing, the isolates belong to the Proteobacteria (closely related to Marinomonas, Hoeflea, and Marinobacter genera) and Bacteroidetes (Algoriphagus genus). 16S rRNA metagenomic sequencing confirms the presence of these taxa in LB. None of the isolated species were reported to be capable to produce methane. In addition, orthologs of the phosphoenolpyruvate mutase gene (PepM) and methylphosphonate synthase (MPnS), enzymes involved in phosphonate and MPn biosynthesis, were widely spread in the LB shotgun metagenomic libraries; genes related to C‐P lyase pathways (phn gene clusters) were also abundant. 16S rRNA and mcrA genes of anaerobic methanogens were absent in both 16S rRNA and metagenomics libraries. These data reveal that in situ aerobic biological methane production is likely a significant source of methane in LB.

1 aLi, Wei1 aDore, John, E.1 aSteigmeyer, August, J.1 aCho, Yong‐Joon1 aKim, Ok-Sun1 aLiu, Yongqin1 aMorgan-Kiss, Rachael, M.1 aSkidmore, Mark, L.1 aPriscu, John, C. uhttps://aslopubs.onlinelibrary.wiley.com/doi/full/10.1002/lno.1125702051nas a2200253 4500008004100000245010800041210006900149260001200218520110900230653001201339653001401351653002401365653001701389653001901406653001701425100002401442700002501466700002201491700002001513700002101533700002101554700001601575856020601591 2020 eng d00aRemote characterization of photosynthetic communities in the Fryxell basin of Taylor Valley, Antarctica0 aRemote characterization of photosynthetic communities in the Fry c03/20203 a

We investigate the spatial distribution, spectral properties and temporal variability of primary producers (e.g. communities of microbial mats and mosses) throughout the Fryxell basin of Taylor Valley, Antarctica, using high-resolution multispectral remote-sensing data. Our results suggest that photosynthetic communities can be readily detected throughout the Fryxell basin based on their unique near-infrared spectral signatures. Observed intra- and inter-annual variability in spectral signatures are consistent with short-term variations in mat distribution, hydration and photosynthetic activity. Spectral unmixing is also implemented in order to estimate mat abundance, with the most densely vegetated regions observed from orbit correlating spatially with some of the most productive regions of the Fryxell basin. Our work establishes remote sensing as a valuable tool in the study of these ecological communities in the McMurdo Dry Valleys and demonstrates how future scientific investigations and the management of specially protected areas could benefit from these tools and techniques.

10aecology10ahydrology10aMcMurdo Dry Valleys10amicrobiology10aremote sensing10aspectroscopy1 aSalvatore, Mark, R.1 aBorges, Schuyler, R.1 aBarrett, John, E.1 aSokol, Eric, R.1 aStanish, Lee, F.1 aPower, Sarah, N.1 aMorin, Paul uhttps://www.cambridge.org/core/journals/antarctic-science/article/remote-characterization-of-photosynthetic-communities-in-the-fryxell-basin-of-taylor-valley-antarctica/8576F6BB1BCFDCA8409F5EA96CA00C6F01789nas a2200205 4500008004100000245008500041210006900126260001200195520112400207653001601331653001801347653001001365653001501375653001601390100001901406700002101425700002201446700002101468856009401489 2020 eng d00aSubglacial brine flow and wind-induced internal waves in Lake Bonney, Antarctica0 aSubglacial brine flow and windinduced internal waves in Lake Bon c02/20203 a

Brine beneath Taylor Glacier has been proposed to enter the proglacial west lobe of Lake Bonney (WLB) as well as from Blood Falls, a surface discharge point at the Taylor Glacier terminus. The brine strongly influences the geochemistry of the water column of WLB. Year-round measurements from this study are the first to definitively identify brine intrusions from a subglacial entry point into WLB. Furthermore, we excluded input from Blood Falls by focusing on winter dynamics when the absence of an open water moat prevents surface brine entry. Due to the extremely high salinities below the chemocline in WLB, density stratification is dominated by salinity, and temperature can be used as a passive tracer. Cold brine intrusions enter WLB at the glacier face and intrude into the water column at the depth of neutral buoyancy, where they can be identified by anomalously cold temperatures at that depth. High-resolution measurements also reveal under-ice internal waves associated with katabatic wind events, a novel finding that challenges long-held assumptions about the stability of the WLB water column.

10aDry valleys10ahypersalinity10alakes10aproglacial10atemperature1 aLawrence, Jade1 aDoran, Peter, T.1 aWinslow, Luke, A.1 aPriscu, John, C. uhttps://www.cambridge.org/core/services/aop-cambridge-core/content/view/S095410202000003602357nas a2200205 4500008004100000245012200041210006900163260001200232490000700244520163100251100002501882700002701907700001801934700002501952700002501977700002902002700002502031700002302056856007202079 2020 eng d00aVertical stratification and stability of biogeochemical processes in the deep saline waters of Lake Vanda, Antarctica0 aVertical stratification and stability of biogeochemical processe c03/20200 v653 a

Lake Vanda is a permanently ice-covered lake in the McMurdo Dry Valleys of Antarctica. Its bottom waters remain stratified year-round because of a strong salinity-driven density gradient. We have assessed spatial patterns in and relationships between major biogeochemical processes in the water column of Lake Vanda. Samples were collected in the austral summers of 2008 and 2011 to measure concentrations of metabolites associated with a suite of biogeochemical processes across the deep salinity gradient. The shapes of the resulting geochemical profiles were consistent between 2008 and 2011. Metabolite production and consumption rates were estimated using a reactive transport model based on the assumption that vertical diffusion was the only activephysical transport process. We validated this model for nitrification by using stable isotope incubations to show that this process was only active at depths predicted by the model. No nitrification activity was observed at 68 m depth in spite of overlapping oxygen and ammonium gradients. We attribute this lack of activity to the competitive inhibition of ammonia monooxygenase by methane. Net nitrous oxide and nitrate consumption were observed in the oxic water column, providing evidence of aerobic denitrification. The depth of maximum net oxygen production did not coincide with the deep chlorophyll maxima (at 59.3, 63, and 68.2 m) measured in the same profile. Finally, the integrated sulfide oxidation rate was high compared with other oxidation processes, indicating that sulfide was an important electron donor for the water column microbial community.

1 aSchutte, Charles, A.1 aSamarkin, Vladimir, A.1 aPeters, Brian1 aMadigan, Michael, T.1 aBowles, Marshall, W.1 aMorgan-Kiss, Rachael, M.1 aCasciotti, Karen, L.1 aJoye, Samantha, B. uhttps://aslopubs.onlinelibrary.wiley.com/doi/full/10.1002/lno.1132702684nas a2200265 4500008004100000022001400041245014900055210006900204260001200273490000600285520185300291653001502144653002502159653000902184653001802193653001702211100001502228700001802243700001602261700001202277700001402289700002102303700002902324856006502353 2019 eng d a0166-859500aThe Antarctic psychrophiles Chlamydomonas spp. UWO241 and ICE-MDV exhibit differential restructuring of photosystem I in response to iron0 aAntarctic psychrophiles iChlamydomonasi spp UWO241 and ICEMDV ex c02/20190 v93 a

Chlamydomonas sp. UWO241 is a psychrophilic alga isolated from the deep photic zone of a perennially ice-covered Antarctic lake (east lobe Lake Bonney, ELB). Past studies have shown that C. sp. UWO241 exhibits constitutive downregulation of photosystem I (PSI) and high rates of PSI-associated cyclic electron flow (CEF). Iron levels in ELB are in the nanomolar range leading us to hypothesize that the unusual PSI phenotype of C. sp. UWO241 could be a response to chronic Fe-deficiency. We studied the impact of Fe availability in C. sp. UWO241, a mesophile, C. reinhardtii SAG11-32c, as well as a psychrophile isolated from the shallow photic zone of ELB, Chlamydomonas sp. ICE-MDV. Under Fe-deficiency, PsaA abundance and levels of photooxidizable P700 (ΔA820/A820) were reduced in both psychrophiles relative to the mesophile. Upon increasing Fe, C. sp. ICE-MDV and C. reinhardtii exhibited restoration of PSI function, while C. sp. UWO241 exhibited only moderate changes in PSI activity and lacked almost all LHCI proteins. Relative to Fe-excess conditions (200 μM Fe2+), C. sp. UWO241 grown in 18 μM Fe2+ exhibited downregulation of light harvesting and photosystem core proteins, as well as upregulation of a bestrophin-like anion channel protein and two CEF-associated proteins (NdsS, PGL1). Key enzymes of starch synthesis and shikimate biosynthesis were also upregulated. We conclude that in response to variable Fe availability, the psychrophile C. sp. UWO241 exhibits physiological plasticity which includes restructuring of the photo-chemical apparatus, increased PSI-associated CEF, and shifts in downstream carbon metabolism toward storage carbon and secondary stress metabolites.

10aAntarctica10aCyclic electron flow10aIron10aPhotosystem I10aPsychrophile1 aCook, Greg1 aTeufel, Amber1 aKalra, Isha1 aLi, Wei1 aWang, Xin1 aPriscu, John, C.1 aMorgan-Kiss, Rachael, M. uhttps://link.springer.com/article/10.1007/s11120-019-00621-002353nas a2200397 4500008004100000245012200041210006900163260001200232490000600244520115100250100002101401700002501422700002101447700002101468700001401489700002201503700001701525700002201542700001701564700002001581700002001601700002401621700002201645700001901667700002401686700002401710700001701734700002301751700002001774700001801794700002401812700002201836700002401858700001901882856005401901 2019 eng d00aBiotic interactions are an unexpected yet critical control on the complexity of an abiotically driven polar ecosystem0 aBiotic interactions are an unexpected yet critical control on th c02/20190 v23 a

Abiotic and biotic factors control ecosystem biodiversity, but their relative contributions remain unclear. The ultraoligotrophic ecosystem of the Antarctic Dry Valleys, a simple yet highly heterogeneous ecosystem, is a natural laboratory well-suited for resolving the abiotic and biotic controls of community structure. We undertook a multidisciplinary investigation to capture ecologically relevant biotic and abiotic attributes of more than 500 sites in the Dry Valleys, encompassing observed landscape heterogeneities across more than 200 km2. Using richness of autotrophic and heterotrophic taxa as a proxy for functional complexity, we linked measured variables in a parsimonious yet comprehensive structural equation model that explained significant variations in biological complexity and identified landscape-scale and fine-scale abiotic factors as the primary drivers of diversity. However, the inclusion of linkages among functional groups was essential for constructing the best-fitting model. Our findings support the notion that biotic interactions make crucial contributions even in an extremely simple ecosystem.

1 aLee, Charles, K.1 aLaughlin, Daniel, C.1 aBottos, Eric, M.1 aCaruso, Tancredi1 aJoy, Kurt1 aBarrett, John, E.1 aBrabyn, Lars1 aNielsen, Uffe, N.1 aAdams, Byron1 aWall, Diana, H.1 aHopkins, D., W.1 aPointing, Steve, B.1 aMcDonald, Ian, R.1 aCowan, Don, A.1 aBanks, Jonathan, C.1 aStichbury, Glen, A.1 aJones, Irfon1 aZawar-Reza, Peyman1 aKaturji, Marwan1 aHogg, Ian, D.1 aSparrow, Ashley, D.1 aStorey, Bryan, C.1 aGreen, T., G. Allan1 aCary, Craig, S uhttps://www.nature.com/articles/s42003-018-0274-502367nas a2200205 4500008004100000245011400041210006900155260001200224300001400236490000800250520166200258100002501920700002701945700002801972700002602000700002002026700002002046700002102066856007402087 2019 eng d00aDifferential incorporation of bacteria, organic matter, and inorganic ions into lake ice during ice formation0 aDifferential incorporation of bacteria organic matter and inorga c02/2019 a585 - 6000 v1243 a

The segregation of bacteria, inorganic solutes, and total organic carbon between liquid water and ice during winter ice formation on lakes can significantly influence the concentration and survival of microorganisms in icy systems, and their roles in biogeochemical processes. Our study quantifies the distributions of bacteria and solutes between liquid and solid water phases during progressive freezing. We simulated lake ice formation in mesocosm experiments using water from perennially (Antarctica) and seasonally (Alaska and Montana, USA) ice covered lakes. We then computed concentration factors and effective segregation coefficients, which are parameters describing the incorporation of bacteria and solutes into ice. Experimental results revealed that, contrary to major ions, bacteria were readily incorporated into ice and did not concentrate in the liquid phase. The organic matter incorporated into the ice was labile, amino acid-like material, differing from the humic-like compounds that remained in the liquid phase. Results from a control mesocosm experiment (dead bacterial cells) indicated that viability of bacterial cells did not influence the incorporation of free bacterial cells into ice, but did have a role in the formation and incorporation of bacterial aggregates. Together, these findings demonstrate that bacteria, unlike other solutes, were preferentially incorporated into lake-ice during our freezing experiments, a process controlled mainly by the initial solute concentration of the liquid water source, regardless of cell viability.

1 aSantibáñez, Pamela1 aMichaud, Alexander, B.1 aVick-Majors, Trista, J.1 aD’Andrilli, Juliana1 aChiuchiolo, Amy1 aHand, Kevin, P.1 aPriscu, John, C. uhttps://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JG00482502504nas a2200229 4500008004100000245007200041210006700113260001200180490000800192520178600200100001701986700002202003700002202025700002402047700001502071700002902086700002502115700002102140700002002161700002002181856007302201 2019 eng d00aThe Geochemistry of Englacial Brine From Taylor Glacier, Antarctica0 aGeochemistry of Englacial Brine From Taylor Glacier Antarctica c03/20190 v1243 a

Blood Falls is a hypersaline, iron‐rich discharge at the terminus of the Taylor Glacier in the McMurdo Dry Valleys, Antarctica. In November 2014, brine in a conduit within the glacier was penetrated and sampled using clean‐entry techniques and a thermoelectric melting probe called the IceMole. We analyzed the englacial brine sample for filterable iron (fFe), total Fe, major cations and anions, nutrients, organic carbon, and perchlorate. In addition, aliquots were analyzed for minor and trace elements and isotopes including δD and δ18O of water, δ34S and δ18O of sulfate, 234U, 238U, δ11B, 87Sr/86Sr, and δ81Br. These measurements were made in order to (1) determine the source and geochemical evolution of the brine and (2) compare the chemistry of the brine to that of nearby hypersaline lake waters and previous supraglacially sampled collections of Blood Falls outflow that were interpreted as end‐member brines. The englacial brine had higher Cl− concentrations than the Blood Falls end‐member outflow; however, other constituents were similar. The isotope data indicate that the water in the brine is derived from glacier melt. The H4SiO4 concentrations and U and Sr isotope suggest a high degree of chemical weathering products. The brine has a low N:P ratio of ~7.2 with most of the dissolved inorganic nitrogen in the form of NH4+. Dissolved organic carbon concentrations are similar to end‐member outflow values. Our results provide strong evidence that the original source of solutes in the brine was ancient seawater, which has been modified with the addition of chemical weathering products.

1 aLyons, Berry1 aMikucki, Jill, A.1 aGerman, Laura, A.1 aWelch, Kathleen, A.1 aWelch, Sue1 aGardner, Christopher, B.1 aTulaczyk, Slawek, M.1 aPettit, Erin, C.1 aKowalski, Julia1 aDachwald, Bernd uhttps://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JG00441102147nas a2200193 4500008004100000022001400041245007800055210006900133260001200202490000700214520142200221653002201643653001801665653002001683653002501703100002801728700002101756856017601777 2019 eng d a0954-102000aInorganic carbon fixation in ice-covered lakes of the McMurdo Dry Valleys0 aInorganic carbon fixation in icecovered lakes of the McMurdo Dry c04/20190 v723 a

Inorganic carbon fixation, usually mediated by photosynthetic microorganisms, is considered to form the base of the food chain in aquatic ecosystems. In high-latitude lakes, lack of sunlight owing to seasonal solar radiation limits the activity of photosynthetic plankton during the polar winter, causing respiration-driven demand for carbon to exceed supply. Here, we show that inorganic carbon fixation in the dark, driven by organisms that gain energy from chemical reactions rather than sunlight (chemolithoautotrophs), provides a significant influx of fixed carbon to two permanently ice-covered lakes (Fryxell and East Bonney). Fryxell, which has higher biomass per unit volume of water, had higher rates of inorganic dark carbon fixation by chemolithoautotrophs than East Bonney (trophogenic zone average 1.0 µg C l−1 d−1 vs 0.08 µg C l−1 d−1, respectively). This contribution from dark carbon fixation was partly due to the activity of ammonia oxidizers, which are present in both lakes. Despite the potential importance of new carbon input by chemolithoautotrophic activity, both lakes remain net heterotrophic, with respiratory demand for carbon exceeding supply. Dark carbon fixation increased the ratio of new carbon supply to respiratory demand from 0.16 to 0.47 in Fryxell, and from 0.14 to 0.22 in East Bonney.

10aammonia oxidation10acarbon budget10achemoautotrophy10achemolithoautotrophy1 aVick-Majors, Trista, J.1 aPriscu, John, C. uhttps://www.cambridge.org/core/journals/antarctic-science/article/inorganic-carbon-fixation-in-icecovered-lakes-of-the-mcmurdo-dry-valleys/4B5CA9E91C85B307EFDA69F8D7B5BFD901888nas a2200301 4500008004100000245004500041210004100086260001200127300001300139490000600152520103800158100001501196700002301211700002801234700002401262700002201286700002501308700001401333700002301347700002401370700002201394700002001416700002601436700001601462700002301478700001601501856006901517 2019 eng d00aThe polar regions in a 2°C warmer world0 apolar regions in a 2°C warmer world c12/2019 aeaaw98830 v53 a

Over the past decade, the Arctic has warmed by 0.75°C, far outpacing the global average, while Antarctic tem- peratures have remained comparatively stable. As Earth approaches 2°C warming, the Arctic and Antarctic may reach 4°C and 2°C mean annual warming, and 7°C and 3°C winter warming, respectively. Expected consequences of increased Arctic warming include ongoing loss of land and sea ice, threats to wildlife and traditional human livelihoods, increased methane emissions, and extreme weather at lower latitudes. With low biodiversity, Antarctic ecosystems may be vulnerable to state shifts and species invasions. Land ice loss in both regions will contribute substantially to global sea level rise, with up to 3 m rise possible if certain thresholds are crossed. Mitigation efforts can slow or reduce warming, but without them northern high latitude warming may accelerate in the next two to four decades. International cooperation will be crucial to foreseeing and adapting to expected changes.

1 aPost, Eric1 aAlley, Richard, B.1 aChristensen, Torben, R.1 aMacias-Fauria, Marc1 aForbes, Bruce, C.1 aGooseff, Michael, N.1 aIler, Amy1 aKerby, Jeffrey, T.1 aLaidre, Kristin, L.1 aMann, Michael, E.1 aOlofsson, Johan1 aStroeve, Julienne, C.1 aUlmer, Fran1 aVirginia, Ross, A.1 aWang, Muyin uhttp://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aaw988301525nas a2200145 4500008004100000245008300041210006900124260001200193490000800205520102800213100002201241700002101263700002101284856007401305 2019 eng d00aPrediction of ice-free conditions for a perennially ice-covered Antarctic lake0 aPrediction of icefree conditions for a perennially icecovered An c02/20190 v1243 a

Although perennially ice-covered Antarctic lakes have experienced variable ice thicknesses over the past several decades, future ice thickness trends and associated aquatic biological responses under projected global warming remain unknown. Heat stored in the water column in chemically stratified Antarctic lakes that have mid-depth temperature maxima, can significantly influence the ice thickness trends via upward heat flux to the ice/water interface. We modeled ice thickness of the west of lobe of Lake Bonney, Antarctica based on possible future climate scenarios utilizing a 1D thermodynamic model that accounts for surface radiative fluxes as well as the heat flux associated with the temperature evolution of the water column. Model results predict that the ice cover of Lake Bonney will shift from perennial to seasonal within one to four decades, a change that will drastically influence ecosystem processes within the lake.

1 aObryk, Maciek, K.1 aDoran, Peter, T.1 aPriscu, John, C. uhttps://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JF00475601897nas a2200133 4500008004100000245008000041210006900121260001200190520131700202100002501519700002301544700001701567856017901584 2019 eng d00aProvisional checklist of terrestrial heterotrophic protists from Antarctica0 aProvisional checklist of terrestrial heterotrophic protists from c11/20193 a

Heterotrophic soil protists encompass lineages that are both evolutionarily ancient and highly diverse, providing an untapped wealth of scientific insight. Yet the diversity of free-living heterotrophic terrestrial protists is still largely unknown. To contribute to our understanding of this diversity, we present a checklist of heterotrophic protists currently reported from terrestrial Antarctica, for which no comprehensive evaluation currently exists. As a polar continent, Antarctica is especially susceptible to rising temperatures caused by anthropogenic climate change. Establishing a baseline for future conservation efforts of Antarctic protists is therefore important. We performed a literature search and found 236 taxa identified to species and an additional 303 taxa identified to higher taxonomic levels in 54 studies spanning over 100 years of research. Isolated by distance, climate and the circumpolar vortex, Antarctica is the most extreme continent on Earth: it is not unreasonable to think that it may host physiologically and evolutionarily unique species of protists, yet currently most species discovered in Antarctica are considered cosmopolitan. Additional sampling of the more extreme intra-continental zones will probably result in the discovery of more novel and unique taxa.

1 aThompson, Andrew, R.1 aPowell, Gareth, S.1 aAdams, Byron uhttps://www.cambridge.org/core/journals/antarctic-science/article/provisional-checklist-of-terrestrial-heterotrophic-protists-from-antarctica/DC08D89ABDC5AF2CC83E38B1C6F1F78C03892nas a2200949 4500008004100000245007900041210006900120260001200189490000800201520116600209100002601375700001901401700001701420700001901437700002501456700001401481700002501495700001701520700001701537700002601554700002601580700002301606700002701629700002301656700002101679700003101700700001801731700002101749700002001770700003001790700001501820700002001835700001901855700002501874700002301899700001901922700002101941700001701962700002201979700002102001700002602022700002302048700001102071700001702082700002202099700002102121700003102142700002402173700002202197700002202219700001802241700001702259700002502276700002202301700001902323700002702342700001602369700001802385700002202403700003202425700002302457700002302480700002002503700002202523700002002545700002702565700001802592700002102610700001902631700002302650700001502673700002202688700002302710700002202733700002402755700002002779700002102799700002302820700001802843700002702861856005402888 2019 eng d00aSoil nematode abundance and functional group composition at a global scale0 aSoil nematode abundance and functional group composition at a gl c08/20190 v5723 a

Soil organisms are a crucial part of the terrestrial biosphere. Despite their importance for ecosystem functioning, few quantitative, spatially explicit models of the active belowground community currently exist. In particular, nematodes are the most abundant animals on Earth, filling all trophic levels in the soil food web. Here we use 6,759 georeferenced samples to generate a mechanistic understanding of the patterns of the global abundance of nematodes in the soil and the composition of their functional groups. The resulting maps show that 4.4 ± 0.64 × 1020 nematodes (with a total biomass of approximately 0.3 gigatonnes) inhabit surface soils across the world, with higher abundances in sub-Arctic regions (38% of total) than in temperate (24%) or tropical (21%) regions. Regional variations in these global trends also provide insights into local patterns of soil fertility and functioning. These high-resolution models provide the first steps towards representing soil ecological processes in global biogeochemical models and will enable the prediction of elemental cycling under current and future climate scenarios.

1 avan den Hoogen, Johan1 aGeisen, Stefan1 aRouth, Devin1 aFerris, Howard1 aTraunspurger, Walter1 aWardle, D1 ade Goede, Ron, G. M.1 aAdams, Byron1 aAhmad, Wasim1 aAndriuzzi, Walter, S.1 aBardgett, Richard, D.1 aBonkowski, Michael1 aCampos-Herrera, Raquel1 aCares, Juvenil, E.1 aCaruso, Tancredi1 aCaixeta, Larissa, de Brito1 aChen, Xiaoyun1 aCosta, Sofia, R.1 aCreamer, Rachel1 aCastro, José, Mauro da C1 aDam, Marie1 aDjigal, Djibril1 aEscuer, Miguel1 aGriffiths, Bryan, S.1 aGutiérrez, Carmen1 aHohberg, Karin1 aKalinkina, Daria1 aKardol, Paul1 aKergunteuil, Alan1 aKorthals, Gerard1 aKrashevska, Valentyna1 aKudrin, Alexey, A.1 aLi, Qi1 aLiang, Wenju1 aMagilton, Matthew1 aMarais, Mariette1 aMartín, José, Antonio Ro1 aMatveeva, Elizaveta1 aMayad, El, Hassan1 aMulder, Christian1 aMullin, Peter1 aNeilson, Roy1 aNguyen, T., A. Duong1 aNielsen, Uffe, N.1 aOkada, Hiroaki1 aRius, Juan, Emilio Pal1 aPan, Kaiwen1 aPeneva, Vlada1 aPellissier, Loïc1 ada Silva, Julio, Carlos Per1 aPitteloud, Camille1 aPowers, Thomas, O.1 aPowers, Kirsten1 aQuist, Casper, W.1 aRasmann, Sergio1 aMoreno, Sara, Sánchez1 aScheu, Stefan1 aSetälä, Heikki1 aSushchuk, Anna1 aTiunov, Alexei, V.1 aTrap, Jean1 avan der Putten, W1 aVestergård, Mette1 aVillenave, Cecile1 aWaeyenberge, Lieven1 aWall, Diana, H.1 aWilschut, Rutger1 aWright, Daniel, G.1 aYang, Jiue-in1 aCrowther, Thomas, Ward uhttps://www.nature.com/articles/s41586-019-1418-610050nas a2202965 4500008004100000245007300041210006900114260001200183300001200195490000700207520154900214653001701763653001101780653001201791653002101803653001301824653001301837100002001850700002201870700001601892700002201908700002301930700001701953700002801970700002001998700002502018700001802043700002402061700001602085700002202101700002002123700002702143700002002170700002202190700002302212700003102235700002002266700002302286700002702309700002202336700002702358700002702385700001602412700001902428700002302447700002102470700002202491700001802513700002302531700002802554700002502582700002302607700002002630700002902650700002502679700002002704700002602724700002602750700001702776700002402793700002502817700002302842700002202865700001902887700002002906700002102926700002202947700002102969700001802990700001703008700002203025700001703047700002503064700001903089700002603108700002203134700001903156700002103175700001903196700002703215700003003242700002403272700002403296700001703320700002303337700003203360700002103392700002403413700002203437700002903459700001403488700003103502700002303533700001903556700002303575700002603598700001803624700002103642700001603663700001803679700002403697700002103721700002003742700001903762700001703781700001903798700002103817700002003838700002603858700002003884700002003904700002003924700002503944700002003969700002703989700002404016700003304040700001804073700001504091700002304106700002204129700002004151700001704171700002404188700001804212700002404230700002104254700002204275700002104297700002004318700002004338700002804358700002604386700001704412700002104429700001904450700002304469700003104492700002604523700002004549700002704569700002204596700002104618700002204639700002004661700002804681700001804709700002204727700002604749700002004775700001904795700002404814700001804838700002404856700002604880700001804906700002304924700002504947700002804972700002205000700002505022700001505047700001705062700001505079700003105094700001905125700001805144700002605162700002405188700001905212700001805231700002205249700002605271700002405297700002005321700002405341700002105365700002905386700002105415700002205436700002005458700001905478700002405497700002505521700002105546700002805567700001905595700002205614700001505636700002605651700002105677700002105698700002505719700002205744700001905766700002805785700002305813700002605836700002105862700002105883700002705904700002805931700002105959700001905980700001905999700003006018700002106048700002406069700003206093700003606125700001806161700001606179700002206195700002306217700001906240700001806259700001506277700002106292700002606313700003306339700001706372700002006389700002106409700002406430700002106454700002206475700001906497700002306516700002106539700001806560700002806578700003406606700002406640700002106664700001806685700002006703700003206723700002606755700002706781700002906808700003106837700002106868700002306889700002506912700002106937700002306958700002506981700001607006856006207022 2018 eng d00aBioTIME: A database of biodiversity time series for the Anthropocene0 aBioTIME A database of biodiversity time series for the Anthropoc c07/2018 a760-7860 v273 a

Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.

Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record.

Spatial location and grain: BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km2 (158 cm2) to 100 km2 (1,000,000,000,000 cm2). Time period and grain BioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year.

Major taxa and level of measurement: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.

Software format: .csv and .SQL.

10abiodiversity10aglobal10aspatial10aspecies richness10atemporal10aturnover1 aDornelas, Maria1 aAntão, Laura, H.1 aMoyes, Faye1 aBates, Amanda, E.1 aMagurran, Anne, E.1 aAdam, Dušan1 aAkhmetzhanova, Asem, A.1 aAppeltans, Ward1 aArcos, José, Manuel1 aArnold, Haley1 aAyyappan, Narayanan1 aBadihi, Gal1 aBaird, Andrew, H.1 aBarbosa, Miguel1 aBarreto, Tiago, Egydio1 aBässler, Claus1 aBellgrove, Alecia1 aBelmaker, Jonathan1 aBenedetti-Cecchi, Lisandro1 aBett, Brian, J.1 aBjorkman, Anne, D.1 aBłażewicz, Magdalena1 aBlowes, Shane, A.1 aBloch, Christopher, P.1 aBonebrake, Timothy, C.1 aBoyd, Susan1 aBradford, Matt1 aBrooks, Andrew, J.1 aBrown, James, H.1 aBruelheide, Helge1 aBudy, Phaedra1 aCarvalho, Fernando1 aCastañeda-Moya, Edward1 aChen, Chaolun, Allen1 aChamblee, John, F.1 aChase, Tory, J.1 aCollier, Laura, Siegwart1 aCollinge, Sharon, K.1 aCondit, Richard1 aCooper, Elisabeth, J.1 aCornelissen, Hans, C.1 aCotano, Unai1 aCrow, Shannan, Kyle1 aDamasceno, Gabriella1 aDavies, Claire, H.1 aDavis, Robert, A.1 aDay, Frank, P.1 aDegraer, Steven1 aDoherty, Tim, S.1 aDunn, Timothy, E.1 aDurigan, Giselda1 aDuffy, Emmett1 aEdelist, Dor1 aEdgar, Graham, J.1 aElahi, Robin1 aElmendorf, Sarah, C.1 aEnemar, Anders1 aErnest, S., K. Morgan1 aEscribano, Rubén1 aEstiarte, Marc1 aEvans, Brian, S.1 aFan, Tung-Yung1 aFarah, Fabiano, Turini1 aFernandes, Luiz, Loureiro1 aFarneda, Fábio, Z.1 aFidelis, Alessandra1 aFitt, Robert1 aFosaa, Anna, Maria1 aFranco, Geraldo, Antonio Da1 aFrank, Grace, E.1 aFraser, William, R.1 aGarcía, Hernando1 aGatti, Roberto, Cazzolla1 aGivan, Or1 aGorgone-Barbosa, Elizabeth1 aGould, William, A.1 aGries, Corinna1 aGrossman, Gary, D.1 aGutierréz, Julio, R.1 aHale, Stephen1 aHarmon, Mark, E.1 aHarte, John1 aHaskins, Gary1 aHenshaw, Donald, L.1 aHermanutz, Luise1 aHidalgo, Pamela1 aHiguchi, Pedro1 aHoey, Andrew1 aVan Hoey, Gert1 aHofgaard, Annika1 aHoleck, Kristen1 aHollister, Robert, D.1 aHolmes, Richard1 aHoogenboom, Mia1 aHsieh, Chih-hao1 aHubbell, Stephen, P.1 aHuettmann, Falk1 aHuffard, Christine, L.1 aHurlbert, Allen, H.1 aIvanauskas, Natália, Macedo1 aJaník, David1 aJandt, Ute1 aJażdżewska, Anna1 aJohannessen, Tore1 aJohnstone, Jill1 aJones, Julia1 aJones, Faith, A. M.1 aKang, Jungwon1 aKartawijaya, Tasrif1 aKeeley, Erin, C.1 aKelt, Douglas, A.1 aKinnear, Rebecca1 aKlanderud, Kari1 aKnutsen, Halvor1 aKoenig, Christopher, C.1 aKortz, Alessandra, R.1 aKrál, Kamil1 aKuhnz, Linda, A.1 aKuo, Chao-Yang1 aKushner, David, J.1 aLaguionie-Marchais, Claire1 aLancaster, Lesley, T.1 aLee, Cheol, Min1 aLefcheck, Jonathan, S.1 aLévesque, Esther1 aLightfoot, David1 aLloret, Francisco1 aLloyd, John, D.1 aLópez-Baucells, Adrià1 aLouzao, Maite1 aMadin, Joshua, S.1 aMagnússon, Borgþór1 aMalamud, Shahar1 aMatthews, Iain1 aMcFarland, Kent, P.1 aMcGill, Brian1 aMcKnight, Diane, M.1 aMcLarney, William, O.1 aMeador, Jason1 aMeserve, Peter, L.1 aMetcalfe, Daniel, J.1 aMeyer, Christoph, F. J.1 aMichelsen, Anders1 aMilchakova, Nataliya1 aMoens, Tom1 aMoland, Even1 aMoore, Jon1 aMoreira, Carolina, Mathias1 aMüller, Jörg1 aMurphy, Grace1 aMyers-Smith, Isla, H.1 aMyster, Randall, W.1 aNaumov, Andrew1 aNeat, Francis1 aNelson, James, A.1 aNelson, Michael, Paul1 aNewton, Stephen, F.1 aNorden, Natalia1 aOliver, Jeffrey, C.1 aOlsen, Esben, M.1 aOnipchenko, Vladimir, G.1 aPabis, Krzysztof1 aPabst, Robert, J.1 aPaquette, Alain1 aPardede, Sinta1 aPaterson, David, M.1 aPélissier, Raphaël1 aPeñuelas, Josep1 aPérez-Matus, Alejandro1 aPizarro, Oscar1 aPomati, Francesco1 aPost, Eric1 aPrins, Herbert, H. T.1 aPriscu, John, C.1 aProvoost, Pieter1 aPrudic, Kathleen, L.1 aPulliainen, Erkki1 aRamesh, B., R.1 aRamos, Olivia, Mendivil1 aRassweiler, Andrew1 aRebelo, Jose, Eduardo1 aReed, Daniel, C.1 aReich, Peter, B.1 aRemillard, Suzanne, M.1 aRichardson, Anthony, J.1 aRichardson, Paul1 avan Rijn, Itai1 aRocha, Ricardo1 aRivera-Monroy, Victor, H.1 aRixen, Christian1 aRobinson, Kevin, P.1 aRodrigues, Ricardo, Ribeiro1 aRossa-Feres, Denise, de Cerquei1 aRudstam, Lars1 aRuhl, Henry1 aRuz, Catalina, S.1 aSampaio, Erica, M.1 aRybicki, Nancy1 aRypel, Andrew1 aSal, Sofia1 aSalgado, Beatriz1 aSantos, Flavio, A. M.1 aSavassi-Coutinho, Ana, Paula1 aScanga, Sara1 aSchmidt, Jochen1 aSchooley, Robert1 aSetiawan, Fakhrizal1 aShao, Kwang-Tsao1 aShaver, Gaius, R.1 aSherman, Sally1 aSherry, Thomas, W.1 aSiciński, Jacek1 aSievers, Caya1 ada Silva, Ana, Carolina1 ada Silva, Fernando, Rodrigues1 aSilveira, Fabio, L.1 aSlingsby, Jasper1 aSmart, Tracey1 aSnell, Sara, J.1 aSoudzilovskaia, Nadejda, A.1 aSouza, Gabriel, B. G.1 aSouza, Flaviana, Maluf1 aSouza, Vinícius, Castro1 aStallings, Christopher, D.1 aStanforth, Rowan1 aStanley, Emily, H.1 aSterza, José, Mauro1 aStevens, Maarten1 aStuart-Smith, Rick1 aSuarez, Yzel, Rondon1 aSupp, Sarah uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/geb.1272902508nas a2200181 4500008004100000245017000041210006900211260001200280300001600292490000700308520183400315100002302149700002102172700002202193700002302215700002102238856006702259 2018 eng d00aThe physical limnology of a permanently ice-covered and chemically stratified Antarctic lake using high resolution spatial data from an autonomous underwater vehicle0 aphysical limnology of a permanently icecovered and chemically st c05/2018 a1234 - 12520 v633 a

We used an Environmentally Non-Disturbing Under-ice Robotic ANtarctic Explorer to make measurements of conductivity and temperature in Lake Bonney, a chemically stratified, permanently ice-covered Antarctic lake that abuts Taylor Glacier, an outlet glacier from the Polar Plateau. The lake is divided into two lobes – East Lobe Bonney (ELB) and West Lobe Bonney (WLB), each with unique temperature and salinity profiles. Most of our data were collected in November 2009 from WLB to examine the influence of the Taylor Glacier on the structure of the water column. Temperatures adjacent to the glacier face between 20 m and 22 m were 38C colder than in the rest of WLB, due to latent heat transfer associated with melting of the submerged glacier face and inflow of cold brines that originate beneath the glacier. Melting of the glacier face into the salinity gradient below the chemocline generates a series of nearly horizontal intrusions into WLB that were previously documented in profiles measured with 3 cm vertical resolution in 1990–1991. WLB and ELB are connected by a narrow channel through which water can be exchanged over a shallow sill that controls the position of the chemocline in WLB. A complex exchange flow appears to exist through the narrows, driven by horizontal density gradients and melting at the glacier face. Superimposed on the exchange is a net west- to-east flow generated by the higher volume of meltwater inflows to WLB. Both of these processes can be expected to be enhanced in the future as more meltwater is produced. 

1 aSpigel, Robert, H.1 aPriscu, John, C.1 aObryk, Maciek, K.1 aStone, William, C.1 aDoran, Peter, T. uhttp://onlinelibrary.wiley.com/wol1/doi/10.1002/lno.10768/full02880nas a2200625 4500008004100000245007400041210006900115260001200184490000800196520106500204100002301269700002101292700002101313700001601334700001801350700002301368700002201391700002301413700002201436700002001458700002701478700002001505700002301525700002801548700002301576700002201599700002101621700002401642700002001666700002401686700001601710700001501726700001801741700002201759700002701781700001901808700002401827700002201851700002101873700002801894700002201922700002201944700001701966700002101983700001902004700002202023700001802045700002702063700002302090700002302113700002202136700001602158700003202174856004802206 2017 eng d00aA communal catalogue reveals Earth’s multiscale microbial diversity0 acommunal catalogue reveals Earth s multiscale microbial diversit c11/20170 v5513 a

Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity.

1 aThompson, Luke, R.1 aSanders, Jon, G.1 aMcDonald, Daniel1 aAmir, Amnon1 aLadau, Joshua1 aLocey, Kenneth, J.1 aPrill, Robert, J.1 aTripathi, Anupriya1 aGibbons, Sean, M.1 aAckermann, Gail1 aNavas-Molina, Jose, A.1 aJanssen, Stefan1 aKopylova, Evguenia1 aVázquez-Baeza, Yoshiki1 aGonzález, Antonio1 aMorton, James, T.1 aMirarab, Siavash1 aXu, Zhenjiang, Zech1 aJiang, Lingjing1 aHaroon, Mohamed, F.1 aKanbar, Jad1 aZhu, Qiyun1 aSong, Se, Jin1 aKosciolek, Tomasz1 aBokulich, Nicholas, A.1 aLefler, Joshua1 aBrislawn, Colin, J.1 aHumphrey, Gregory1 aOwens, Sarah, M.1 aHampton-Marcell, Jarrad1 aBerg-Lyons, Donna1 aMcKenzie, Valerie1 aFierer, Noah1 aFuhrman, Jed, A.1 aClauset, Aaron1 aStevens, Rick, L.1 aShade, Ashley1 aPollard, Katherine, S.1 aGoodwin, Kelly, D.1 aJansson, Janet, K.1 aGilbert, Jack, A.1 aKnight, Rob1 aConsortium, The, Earth Micr uhttps://www.nature.com/articles/nature2462100851nas a2200265 4500008004100000245009100041210006900132260001200201300001400213490000600227100002500233700002200258700001700280700002100297700002400318700001700342700002400359700002100383700002000404700003300424700003100457700002300488700002000511856005400531 2017 eng d00aDecadal ecosystem response to an anomalous melt season in a polar desert in Antarctica0 aDecadal ecosystem response to an anomalous melt season in a pola c09/2017 a1334-13380 v11 aGooseff, Michael, N.1 aBarrett, John, E.1 aAdams, Byron1 aDoran, Peter, T.1 aFountain, Andrew, G1 aLyons, Berry1 aMcKnight, Diane, M.1 aPriscu, John, C.1 aSokol, Eric, R.1 aTakacs-Vesbach, Cristina, D.1 aVandegehuchte, Martijn, L.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://www.nature.com/articles/s41559-017-0253-001933nas a2200181 4500008004100000245012100041210006900162260001200231490000600243520129900249100002001548700001901568700002101587700002001608700002501628700002501653856007301678 2017 eng d00aDiversity and Distribution of Freshwater Aerobic Anoxygenic Phototrophic Bacteria across a Wide Latitudinal Gradient0 aDiversity and Distribution of Freshwater Aerobic Anoxygenic Phot c02/20170 v83 a

Aerobic anoxygenic phototrophs (AAPs) have been shown to exist in numerous marine and brackish environments where they are hypothesized to play important ecological roles. Despite their potential significance, the study of freshwater AAPs is in its infancy and limited to local investigations. Here, we explore the occurrence, diversity and distribution of AAPs in lakes covering a wide latitudinal gradient: Mongolian and German lakes located in temperate regions of Eurasia, tropical Great East African lakes, and polar permanently ice-covered Antarctic lakes. Our results show a widespread distribution of AAPs in lakes with contrasting environmental conditions and confirm that this group is composed of different members of the Alpha- and Betaproteobacteria. While latitude does not seem to strongly influence AAP abundance, clear patterns of community structure and composition along geographic regions were observed as indicated by a strong macro-geographical signal in the taxonomical composition of AAPs. Overall, our results suggest that the distribution patterns of freshwater AAPs are likely driven by a combination of small-scale environmental conditions (specific of each lake and region) and large-scale geographic factors (climatic regions across a latitudinal gradient).

1 aFerrera, Isabel1 aSarmento, Hugo1 aPriscu, John, C.1 aChiuchiolo, Amy1 aGonzález, José, M.1 aGrossart, Hans-Peter uhttp://journal.frontiersin.org/article/10.3389/fmicb.2017.00175/full02077nas a2200181 4500008004100000245016100041210006900202260001200271490000600283520140000289100002601689700002601715700003301741700002001774700002101794700002501815856005501840 2017 eng d00aEarly diverging lineages within Cryptomycota and Chytridiomycota dominate the fungal communities in ice-covered lakes of the McMurdo Dry Valleys, Antarctica0 aEarly diverging lineages within Cryptomycota and Chytridiomycota c11/20170 v73 a

Antarctic ice-covered lakes are exceptional sites for studying the ecology of aquatic fungi under conditions of minimal human disturbance. In this study, we explored the diversity and community composition of fungi in five permanently covered lake basins located in the Taylor and Miers Valleys of Antarctica. Based on analysis of the 18S rRNA sequences, we showed that fungal taxa represented between 0.93% and 60.32% of the eukaryotic sequences. Cryptomycota and Chytridiomycota dominated the fungal communities in all lakes; however, members of Ascomycota, Basidiomycota, Zygomycota, and Blastocladiomycota were also present. Of the 1313 fungal OTUs identified, the two most abundant, belonging to LKM11 and Chytridiaceae, comprised 74% of the sequences. Significant differences in the community structure were determined among lakes, water depths, habitat features (i.e., brackish vs. freshwaters), and nucleic acids (DNA vs. RNA), suggesting niche differentiation. Network analysis suggested the existence of strong relationships among specific fungal phylotypes as well as between fungi and other eukaryotes. This study sheds light on the biology and ecology of basal fungi in aquatic systems. To our knowledge, this is the first report showing the predominance of early diverging lineages of fungi in pristine limnetic ecosystems, particularly of the enigmatic phylum Cryptomycota.

1 aRojas-Jimenez, Keilor1 aWurzbacher, Christian1 aBourne, Elizabeth, Charlotte1 aChiuchiolo, Amy1 aPriscu, John, C.1 aGrossart, Hans-Peter uhttps://www.nature.com/articles/s41598-017-15598-w02800nas a2200133 4500008004100000245009000041210006900131260004800200490000900248520230200257100002802559700002102587856005802608 2017 eng d00aLong-term and over winter phytoplankton community dynamics in Lake Bonney, Antarctica0 aLongterm and over winter phytoplankton community dynamics in Lak aBozeman, MTbMontana State Universityc20170 vM.S.3 a

Lake Bonney is a hypersaline permanently ice-covered lake in the Taylor Valley, Antarctica that hosts simplified microbial food-webs. Studied since the 1960s, there are many aspects which are poorly understood. Logistical constraints have prevented sampling during the austral winter, a 4-month period of 24-hour darkness. Our knowledge of how the resident photosynthetic microorganisms respond during this period is limited. With inputs from ephemeral glacial-melt streams the lake level (stage) of Bonney has risen more than 3 m since 2004. With no outflow streams, the only known water loss is via ablation of the permanent ice-cover. A study of the spatial and temporal changes in the phytoplankton community structure during this period of rapid lake level rise is lacking. During the summers (November-January) from 2004-05 to 2014-15 an in situ submersible spectrofluorometer was deployed in Lake Bonney to quantify the chlorophyll-a concentrations (microgram L -1) of four functional groups of microalgae (green algae, brown/mixed algae, cryptophytes, cyanobacteria) using known excitation/emission spectra. During the 2013-14 field season this same instrument was mounted on autonomous cable-crawling profilers deployed in both east and west lobes of Lake Bonney, obtaining the first ever daily profiles of chlorophyll-a concentration at an annual scale. Following a summer of rapid lake level rise (2010-11), an increasing trend in depth integrated chlorophyll-a concentration was observed in Lake Bonney. During the same period, the nutrient poor surface water has become increasingly dominated by green algae. Dramatic shifts were also observed in the phytoplankton communities during the polar night. The highest concentrations of mean chlorophyll-a were measured during the 24-hour darkness. Algal spectral groups containing species capable of a mixotrophic metabolism (brown/mixed and cryptophytes) increased in concentration and relative abundance when photosynthetically active radiation was unavailable. This work provides valuable contributions to our knowledge of long-term and year-round phytoplankton community dynamics in Lake Bonney, and improves our understanding of the metabolic strategies employed by organisms in this high latitude permanently ice-covered lake.

1 aPatriarche, Jeffrey, D.1 aPriscu, John, C. uhttps://scholarworks.montana.edu/xmlui/handle/1/1280302127nas a2200217 4500008004100000245010900041210006900150260001200219300001600231490000700247520142800254100001501682700001801697700003301715700001601748700002001764700002001784700002101804700001601825856006801841 2017 eng d00aNiche specialization of bacteria in permanently ice-covered lakes of the McMurdo Dry Valleys, Antarctica0 aNiche specialization of bacteria in permanently icecovered lakes c06/2017 a2258 - 22710 v193 a

Perennially ice‐covered lakes in the McMurdo Dry Valleys, Antarctica, are chemically stratified with depth and have distinct biological gradients. Despite long‐term research on these unique environments, data on the structure of the microbial communities in the water columns of these lakes are scarce. Here, we examined bacterial diversity in five ice‐covered Antarctic lakes by 16S rRNA gene‐based pyrosequencing. Distinct communities were present in each lake, reflecting the unique biogeochemical characteristics of these environments. Further, certain bacterial lineages were confined exclusively to specific depths within each lake. For example, candidate division WM88 occurred solely at a depth of 15 m in Lake Fryxell, whereas unknown lineages of Chlorobi were found only at a depth of 18 m in Lake Miers, and two distinct classes of Firmicutes inhabited East and West Lobe Bonney at depths of 30 m. Redundancy analysis revealed that community variation of bacterioplankton could be explained by the distinct conditions of each lake and depth; in particular, assemblages from layers beneath the chemocline had biogeochemical associations that differed from those in the upper layers. These patterns of community composition may represent bacterial adaptations to the extreme and unique biogeochemical gradients of ice‐covered lakes in the McMurdo Dry Valleys.

1 aKwon, Miye1 aKim, Mincheol1 aTakacs-Vesbach, Cristina, D.1 aLee, Jaejin1 aHong, Soon, Gyu1 aKim, Sang, Jong1 aPriscu, John, C.1 aKim, Ok-Sun uhttps://onlinelibrary.wiley.com/doi/pdf/10.1111/1462-2920.1372101407nas a2200445 4500008004100000245007700041210006900118260001200187490005900199100002200258700002400280700001900304700002100323700002100344700001900365700002400384700002000408700001700428700002400445700001700469700002300486700001900509700002100528700002000549700002100569700002200590700002300612700002500635700001800660700002200678700002300700700002300723700002500746700001800771700002000789700002400809700002600833700002500859856007700884 2016 eng d00aAerobiology Over Antarctica – A New Initiative for Atmospheric Ecology0 aAerobiology Over Antarctica A New Initiative for Atmospheric Eco c02/20160 v7767961946103149272350113651344451428464791101239365741 aPearce, David, A.1 aAlekhina, Irina, A.1 aTerauds, Aleks1 aWilmotte, Annick1 aQuesada, Antonio1 aEdwards, Arwyn1 aDommergue, Aurelien1 aSattler, Birgit1 aAdams, Byron1 aMagalhaes, Catarina1 aChu, Wan-Loy1 aLau, Maggie, C. Y.1 aCary, Craig, S1 aSmith, David, J.1 aWall, Diana, H.1 aEguren, Gabriela1 aMatcher, Gwynneth1 aBradley, James, A.1 ade Vera, Jean-Pierre1 aElster, Josef1 aHughes, Kevin, A.1 aCuthbertson, Lewis1 aBenning, Liane, G.1 aGunde-Cimerman, Nina1 aConvey, Peter1 aHong, Soon, Gyu1 aPointing, Steve, B.1 aPellizari, Vivian, H.1 aVincent, Warwick, F. uhttp://journal.frontiersin.org/Article/10.3389/fmicb.2016.00016/abstract01022nas a2200289 4500008004100000245010700041210006900148260001200217300001400229490000700243100002800250700002200278700002500300700001900325700002000344700002700364700002500391700002600416700002300442700001700465700001900482700002000501700002100521700001800542700002100560856015100581 2016 eng d00aBiogeochemistry and microbial diversity in the marine cavity beneath the McMurdo Ice Shelf, Antarctica0 aBiogeochemistry and microbial diversity in the marine cavity ben c11/2015 a572 - 5860 v611 aVick-Majors, Trista, J.1 aAchberger, Amanda1 aSantibáñez, Pamela1 aDore, John, E.1 aHodson, Timothy1 aMichaud, Alexander, B.1 aChristner, Brent, C.1 aAi, Jill., Mikucki Ji1 aSkidmore, Mark, L.1 aPowell, Ross1 aAdkins, Peyton1 aBarbante, Carlo1 aMitchell, Andrew1 aScherer, Reed1 aPriscu, John, C. uhttp://doi.wiley.com/10.1002/lno.v61.2http://doi.wiley.com/10.1002/lno.10234http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Flno.1023400639nas a2200205 4500008004100000245007600041210006900117260001200186300001300198490000700211100001700218700002500235700001700260700002400277700001700301700002500318700002100343700001700364856005200381 2016 eng d00aHydrological Controls on Ecosystem Dynamics in Lake Fryxell, Antarctica0 aHydrological Controls on Ecosystem Dynamics in Lake Fryxell Anta c07/2016 ae01590380 v111 aHerbei, Radu1 aRytel, Alexander, L.1 aLyons, Berry1 aMcKnight, Diane, M.1 aJaros, Chris1 aGooseff, Michael, N.1 aPriscu, John, C.1 aHewitt, Judi uhttp://dx.plos.org/10.1371/journal.pone.015903801797nas a2200253 4500008004100000022001400041245007900055210006900134260001200203300001400215490000700229520101000236100002401246700001601270700001701286700002101303700002001324700002501344700002201369700002101391700002801412700002301440856008001463 2016 eng d a0006-356800aThe Impact of a Large-Scale Climate Event on Antarctic Ecosystem Processes0 aImpact of a LargeScale Climate Event on Antarctic Ecosystem Proc c10/2016 a848 - 8630 v663 a

Extreme climate and weather events, such as a drought, hurricanes, or ice storms, can strongly imprint ecosystem processing and may alter ecosystem structure. Ecosystems in extreme environments are particularly vulnerable because of their adaptation to severe limitations in energy, water, or nutrients. The vulnerability can be expressed as a relatively long-lasting ecosystem response to a small or brief change in environmental conditions. Such an event occurred in Antarctica and affected two vastly different ecosystems: a marine-dominated coastal system and a terrestrial polar desert. Both sites experienced winds that warmed air temperatures above the 0°C threshold, resulting in extensive snow and ice melt and triggering a series of cascading effects through the ecosystems that are continuing to play out more than a decade later. This highlights the sensitivity of Antarctic ecosystems to warming events, which should occur more frequently in the future with global climate warming.

1 aFountain, Andrew, G1 aSaba, Grace1 aAdams, Byron1 aDoran, Peter, T.1 aFraser, William1 aGooseff, Michael, N.1 aObryk, Maciek, K.1 aPriscu, John, C.1 aStammerjohn, Sharon, E.1 aVirginia, Ross, A. uhttp://academic.oup.com/bioscience/article-pdf/66/10/848/7510601/biw110.pdf00845nas a2200193 4500008004100000022001400041245014300055210006900198260001600267300001400283490000700297100002100304700002800325700002900353700003300382700002200415700002100437856019300458 2016 eng d a0006-356800aMicrobial Community Dynamics in Two Polar Extremes: The Lakes of the McMurdo Dry Valleys and the West Antarctic Peninsula Marine Ecosystem0 aMicrobial Community Dynamics in Two Polar Extremes The Lakes of  cJan-10-2016 a829 - 8470 v661 aBowman, Jeff, S.1 aVick-Majors, Trista, J.1 aMorgan-Kiss, Rachael, M.1 aTakacs-Vesbach, Cristina, D.1 aDucklow, Hugh, W.1 aPriscu, John, C. uhttps://academic.oup.com/bioscience/article-lookup/doi/10.1093/biosci/biw103https://academic.oup.com/bioscience/article/66/10/829/2236137/Microbial-Community-Dynamics-in-Two-Polar-Extremes00604nas a2200169 4500008004100000245007900041210006900120260001600189490000600205100002200211700002500233700002700258700002100285700002300306700002800329856007700357 2016 eng d00aMicrobial Community Structure of Subglacial Lake Whillans, West Antarctica0 aMicrobial Community Structure of Subglacial Lake Whillans West A cOct-09-20170 v71 aAchberger, Amanda1 aChristner, Brent, C.1 aMichaud, Alexander, B.1 aPriscu, John, C.1 aSkidmore, Mark, L.1 aVick-Majors, Trista, J. uhttp://journal.frontiersin.org/Article/10.3389/fmicb.2016.01457/abstract02725nas a2200133 4500008004100000245007400041210006900115260004200184490001000226520224900236100002702485700002102512856005802533 2016 eng d00aMicrobially mediated biogeochemical cycles in polar ice covered lakes0 aMicrobially mediated biogeochemical cycles in polar ice covered  aBozeman, MTbMontana State University0 vPh.D.3 a

Lakes are important sites for globally-relevant biogeochemical cycles mediated by microorganisms. In the Arctic, seasonally ice covered thermokarst lakes are a large component in Earth's carbon cycle due to their methane emissions from organic carbon degradation. In the Antarctic, over 400 unexplored lakes exist beneath the Antarctic ice sheet with unknown biogeochemical contributions to the Earth system. This dissertation seeks to investigate the biogeochemical role of microorganisms in the lake habitat and how they interact with the seasonal and permanent ice covers of lakes in polar environments. Microbiologically clean hot water drilling was used to access a subglacial lake beneath Antarctica's ice to collect, for the first time, intact sediment and water samples. Laboratory experiments on Arctic and Antarctic, seasonally and perennially, respectively, ice covered lakes were used to investigate the impact of lake ice freezing regimes on microorganisms. My results show that subglacial lake sediments beneath the West Antarctic Ice Sheet contain solute ratios that suggest relict marine sediments were deposited during previous interglacial periods. Microbial activity overprints the marine geochemical signature to produce fluxes of ions into the Subglacial Lake Whillans water column, which ultimately drains to the Southern Ocean. Microbial activity in Subglacial Lake Whillans is partially fueled by biologically-formed methane diffusing from below our deepest collected (~38 cm) subglacial sediment samples. The ice above Subglacial Lake Whillans appears to be an important source of molecular oxygen for microorganisms to drive oxidative physiologies. My experimental evidence shows microorganisms incorporate into lake ice cover to, potentially, avoid increasing stressors from progressive lake ice freezing. Taken together, the results from this dissertation reinforce the hypothesis that subglacial environments beneath the Antarctic ice sheet are habitats for life. Further, the microorganisms in subglacial lakes participate in globally-relevant biogeochemical cycles. Here, I extend the extent of the biosphere and show sediments at the base of ice sheets are an active component of the Earth system.

1 aMichaud, Alexander, B.1 aPriscu, John, C. uhttps://scholarworks.montana.edu/xmlui/handle/1/1379302208nas a2200181 4500008004100000022001400041245010400055210006900159260001200228300001100240520160100251100002201852700002101874700001801895700002701913700002101940856006501961 2016 eng d a0022-143000aModeling the thickness of perennial ice covers on stratified lakes of the Taylor Valley, Antarctica0 aModeling the thickness of perennial ice covers on stratified lak c06/2016 a1 - 103 a
A 1-D ice cover model was developed to predict and constrain drivers of long-term ice thickness trends in chemically stratified lakes of Taylor Valley, Antarctica. The model is driven by surface radiative heat fluxes and heat fluxes from the underlying water column. The model successfully reproduced 16 a (between 1996 and 2012) of ice thickness changes for the west lobe of Lake Bonney (average ice thickness = 3.53 m) and Lake Fryxell (average ice thickness = 4.22 m). Long-term ice thickness trends require coupling with the thermal structure of the water column. The heat stored within the temperature maximum of lakes exceeding a liquid water column depth of 20 m can either impede or facilitate ice thickness change depending on the predominant climatic trend (cooling or warming). As such, shallow (<20 m deep water columns) perennially ice-covered lakes without deep temperature maxima are more sensitive indicators of climate change. The long-term ice thickness trends are a result of surface energy flux and heat flux from the deep temperature maximum in the water column, the latter of which results from absorbed solar radiation.

 

1 aObryk, Maciek, K.1 aDoran, Peter, T.1 aHicks, J., A.1 aMcKay, Christopher, P.1 aPriscu, John, C. uhttp://www.journals.cambridge.org/abstract_S002214301600069104082nas a2200157 4500008004100000245010000041210006900141260001200210490000700222520353000229100002903759700002503788700001803813700002103831856007203852 2016 eng d00aPhotoadaptation to the polar night by phytoplankton in a permanently ice-covered Antarctic lake0 aPhotoadaptation to the polar night by phytoplankton in a permane c05/20150 v613 a

Photosynthetic microorganisms are a primary source of new organic carbon production in polar ecosystems. Despite their importance, relatively little is known about how they adapt to the bimodal solar cycles that exist at high latitudes. To understand how phytoplankton adapt to the extreme seasonal change in photoperiod, we transplanted cultures of a well-studied laboratory model for photosynthetic cold adaptation, Chlamydomonas raudensis UWO241, back to the water column of Lake Bonney (McMurdo Dry Valleys, Antarctica) at the depth from which it was originally cultured. The organism was suspended at this depth in dialysis tubing to allow the microalga to respond to the in situ light, temperature and dissolved ions. We then integrated in situ biological and chemical measurements with environmental molecular analyses and compared the responses of transplanted C. raudensis cultures with the natural phytoplankton community over the 6-week transition from Antarctic summer (24-h daylight) to polar night (24-h darkness). As solar radiation declined, natural communities exhibited a cessation of inorganic carbon fixation which was accompanied by a downregulation of expression of genes encoding for essential carbon fixation and photochemistry proteins. Transplanted C. raudensis cultures matched natural community trends in the regulation of photochemistry and carbon fixation gene expression, and shifted photochemical function to a shade adapted state in response to the polar night transition. We present a conceptual model for seasonal shifts in microbial community energy and carbon acquisition which integrates past cultivation-based studies in this model photopsychrophile with a body of recent work on adaptation of natural populations to polar night.

1 aMorgan-Kiss, Rachael, M.1 aLizotte, Michael, P.1 aKong, Weidong1 aPriscu, John, C. uhttps://aslopubs.onlinelibrary.wiley.com/doi/full/10.1002/lno.1010702602nas a2200133 4500008004100000245008200041210006900123260004200192490000900234520212000243100002702363700002102390856005702411 2016 eng d00aPhysiological characteristics of fungi associated with Antarctic environments0 aPhysiological characteristics of fungi associated with Antarctic aBozeman, MTbMontana State University0 vM.S.3 a

The permanent ice covers on the lakes of Antarctica's McMurdo Dry Valleys region harbor a diverse group of phototrophic and heterotrophic microorganisms that metabolize during the short summer months when solar radiation produces melt inclusions within the ice and provides energy to drive photosynthesis. Laboratory cultures of fungi were obtained from ice cores taken from Lakes Bonney (east lobe) and Chad, and sediments collected from Subglacial Lake Whillans (West Antarctica). Using molecular techniques, the internal transcribed spacer (ITS) region of the ribosomal DNA (rDNA) was sequenced to identify fungal types and to determine whether they may be unique to this region. Four axenic fungal cultures, Tetracladium ellipsoideum, Lecythophora hoffmannii, Mucor sp., and an unidentified Ascomycota were successfully isolated. These isolates are closely related to organisms that have been previously reported in Antarctica and other cold habitats. The isolates were tested for growth characteristics under various temperature and nutrient regimes. Temperature response experiments revealed that all the isolated fungi were psychrotolerant and growth rates were greatest at 25°C. Of major significance in evaluating the potential of Antarctic fungi as a bioresource is their ability to produce bioactive compounds. Two out of four isolated organisms exhibited antimicrobial activity against several plant pathogens. The metabolic potential and preferred substrate utilization was examined by exposing fungal isolates to a variety of substrates in a 96 well "Biolog" plate. A strong correlation was found among substrate utilization, isolates, temperature and the different carbon substrates. This experiment revealed that the isolated fungi have preferences for different labile carbon substrates at 4°C and 24°C which may imply different physiologies at different times of year in the lake ice-covers. Results from my studies will help understand the role of fungi in lake ice and subglacial lake sediment ecosystems, and the physiology of fungi living in cold environments.

1 aKudalkar, Priyanka, S.1 aPriscu, John, C. uhttps://scholarworks.montana.edu/xmlui/handle/1/983500836nas a2200229 4500008004100000245007200041210006900113260001600182490000600198100002800204700002100232700002200253700002500275700001900300700002700319700002200346700002400368700002300392700002100415710002900436856014100465 2016 eng d00aPhysiological Ecology of Microorganisms in Subglacial Lake Whillans0 aPhysiological Ecology of Microorganisms in Subglacial Lake Whill cMar-10-20180 v71 aVick-Majors, Trista, J.1 aMitchell, Andrew1 aAchberger, Amanda1 aChristner, Brent, C.1 aDore, John, E.1 aMichaud, Alexander, B.1 aMikucki, Jill, A.1 aPurcell, Alicia, M.1 aSkidmore, Mark, L.1 aPriscu, John, C.1 aThe WISSARD Science Team uhttp://journal.frontiersin.org/article/10.3389/fmicb.2016.01705/fullhttp://journal.frontiersin.org/article/10.3389/fmicb.2016.01705/full00943nas a2200253 4500008004100000022001400041245008700055210006900142260001600211300001400227490000700241100002200248700002100270700002600291700002500317700001200342700002900354700002100383700002100404700002800425700002700453700002200480856018700502 2016 eng d a0006-356800aResponses of Antarctic Marine and Freshwater Ecosystems to Changing Ice Conditions0 aResponses of Antarctic Marine and Freshwater Ecosystems to Chang cJan-10-2016 a864 - 8790 v661 aObryk, Maciek, K.1 aDoran, Peter, T.1 aFriedlaender, Ari, S.1 aGooseff, Michael, N.1 aLi, Wei1 aMorgan-Kiss, Rachael, M.1 aPriscu, John, C.1 aSchofield, Oscar1 aStammerjohn, Sharon, E.1 aSteinberg, Deborah, K.1 aDucklow, Hugh, W. uhttps://academic.oup.com/bioscience/article-lookup/doi/10.1093/biosci/biw109https://academic.oup.com/bioscience/article/66/10/864/2415532/Responses-of-Antarctic-Marine-and-Freshwater04687nas a2200181 4500008004100000022001400041245015900055210006900214260001200283300001600295490000700311520405500318100001204373700001804385700002904403700001804432856005504450 2016 eng d a0099-224000aUltrastructural and Single-Cell-Level Characterization Reveals Metabolic Versatility in a Microbial Eukaryote Community from an Ice-Covered Antarctic Lake0 aUltrastructural and SingleCellLevel Characterization Reveals Met c06/2016 a3659 - 36700 v823 a

The McMurdo Dry Valleys (MCM) of southern Victoria Land, Antarctica, harbor numerous ice-covered bodies of water that provide year-round liquid water oases for isolated food webs dominated by the microbial loop. Single-cell microbial eukaryotes (protists) occupy major trophic positions within this truncated food web, ranging from primary producers (e.g., chlorophytes, haptophytes, and cryptophytes) to tertiary predators (e.g., ciliates, dinoflagellates, and choanoflagellates). To advance the understanding of MCM protist ecology and the roles of MCM protists in nutrient and energy cycling, we investigated potential metabolic strategies and microbial interactions of key MCM protists isolated from a well-described lake (Lake Bonney). Fluorescence-activated cell sorting (FACS) of enrichment cultures, combined with single amplified genome/amplicon sequencing and fluorescence microscopy, revealed that MCM protists possess diverse potential metabolic capabilities and interactions. Two metabolically distinct bacterial clades (Flavobacteria and Methylobacteriaceae) were independently associated with two key MCM lake microalgae (Isochrysis and Chlamydomonas, respectively). We also report on the discovery of two heterotrophic nanoflagellates belonging to the Stramenopila supergroup, one of which lives as a parasite ofChlamydomonas, a dominate primary producer in the shallow, nutrient-poor layers of the lake.

IMPORTANCE Single-cell eukaryotes called protists play critical roles in the cycling of organic matter in aquatic environments. In the ice-covered lakes of Antarctica, protists play key roles in the aquatic food web, providing the majority of organic carbon to the rest of the food web (photosynthetic protists) and acting as the major consumers at the top of the food web (predatory protists). In this study, we utilized a combination of techniques (microscopy, cell sorting, and genomic analysis) to describe the trophic abilities of Antarctic lake protists and their potential interactions with other microbes. Our work reveals that Antarctic lake protists rely on metabolic versatility for their energy and nutrient requirements in this unique and isolated environment.

1 aLi, Wei1 aPodar, Mircea1 aMorgan-Kiss, Rachael, M.1 aKelly, R., M. uhttp://aem.asm.org/lookup/doi/10.1128/AEM.00478-1600496nas a2200133 4500008004100000022001400041245011800055210006900173260001200242300001400254490000700268100002100275856006600296 2016 eng d a0006-356800aUnraveling ecosystem responses to climate change on the Antarctic continent through Long-Term Ecological Research0 aUnraveling ecosystem responses to climate change on the Antarcti c10/2016 a799 - 8000 v661 aPriscu, John, C. uhttps://academic.oup.com/bioscience/article/66/10/799/223616602358nas a2200229 4500008004100000022001400041245011300055210006900168260001200237490000600249520163400255100002801889700001901917700001901936700002401955700001601979700001701995700001902012700002002031700002102051856005602072 2015 eng d a2150-892500aFostering ecological data sharing: collaborations in the International Long Term Ecological Research Network0 aFostering ecological data sharing collaborations in the Internat c10/20150 v63 a

The International Long Term Ecological Research (ILTER) Network was established in 1993 and is now composed of thirty-eight national networks representing a diversity of ecosystems around the globe. Data generated by the ILTER Network are valuable for scientists addressing broad spatial and temporal scale research questions, but only if these data can be easily discovered, accessed, and understood. Challenges to publishing ILTER data have included unequal distribution among networks of information management expertise, user-friendly tools, and resources. Language and translation have also been issues. Despite these significant obstacles, ILTER information managers have formed grassroots partnerships and collaborated to provide information management training, adopt a common metadata standard, develop information management tools useful throughout the network, and organize scientist/information manager workshops that encourage scientists to share and integrate data. Throughout this article, we share lessons learned from the successes of these grassroots international partnerships to inform others who wish to collaborate internationally on projects that depend on data sharing entailing similar management challenges.
 

1 aVanderbilt, Kristin, L.1 aLin, Chau-Chin1 aLu, Sheng-Shan1 aKassim, Abd, Rahman1 aHe, Honglin1 aGuo, Xuebing1 aSan Gil, Inigo1 aBlankman, David1 aPorter, John, H. uhttp://www.esajournals.org/doi/10.1890/ES14-00281.100801nas a2200253 4500008004100000022001400041245008400055210006900139260001200208300000800220490000700228100003400235700002400269700002200293700002600315700002500341700002400366700001700390700002200407700002300429700002600452700002200478856004700500 2015 eng d a1445-522600aMitochondrial DNA analyses reveal widespread tardigrade diversity in Antarctica0 aMitochondrial DNA analyses reveal widespread tardigrade diversit c12/2015 a5780 v291 aVelasco-Castrillon, Alejandro1 aMcInnes, Sandra, J.1 aSchultz, Mark, B.1 aArroniz-Crespo, Maria1 aD'Haese, Cyrille, A.1 aGibson, John, A. E.1 aAdams, Byron1 aPage, Timothy, J.1 aAustin, Andrew, D.1 aCooper, Steven, J. B.1 aStevens, Mark, I. uhttp://www.publish.csiro.au/?paper=IS1401904591nas a2201033 4500008004100000022001400041245009100055210006900146260001600215300001100231490000700242520199300249100002002242700002202262700001802284700001602302700002002318700001502338700001802353700001502371700001802386700001702404700001602421700001402437700001402451700001702465700001802482700002102500700001602521700001102537700001502548700002002563700001902583700001602602700001802618700001602636700001402652700001602666700001502682700001602697700001602713700001602729700001802745700001602763700001602779700001302795700001802808700001202826700001402838700001402852700001402866700001602880700001402896700001402910700002002924700001102944700001702955700001502972700002502987700001603012700001703028700001703045700001503062700001703077700001403094700001403108700001703122700001803139700001603157700002403173700002303197700001603220700001503236700001603251700001803267700001803285700001803303700001803321700001503339700001803354700002003372700001603392700001503408700001803423700001703441700001303458700002103471856006503492 2015 eng d a0954-102000aA roadmap for Antarctic and Southern Ocean science for the next two decades and beyond0 aroadmap for Antarctic and Southern Ocean science for the next tw cJan-02-2015 a3 - 180 v273 a

Antarctic and Southern Ocean science is vital to understanding natural variability, the processes that govern global change and the role of humans in the Earth and climate system. The potential for new knowledge to be gained from future Antarctic science is substantial. Therefore, the international Antarctic community came together to ‘scan the horizon’ to identify the highest priority scientific questions that researchers should aspire to answer in the next two decades and beyond. Wide consultation was a fundamental principle for the development of a collective, international view of the most important future directions in Antarctic science. From the many possibilities, the horizon scan identified 80 key scientific questions through structured debate, discussion, revision and voting. Questions were clustered into seven topics: i) Antarctic atmosphere and global connections, ii) Southern Ocean and sea ice in a warming world, iii) ice sheet and sea level, iv) the dynamic Earth, v) life on the precipice, vi) near-Earth space and beyond, and vii) human presence in Antarctica. Answering the questions identified by the horizon scan will require innovative experimental designs, novel applications of technology, invention of next-generation field and laboratory approaches, and expanded observing systems and networks. Unbiased, non-contaminating procedures will be required to retrieve the requisite air, biota, sediment, rock, ice and water samples. Sustained year-round access to Antarctica and the Southern Ocean will be essential to increase winter-time measurements. Improved models are needed that represent Antarctica and the Southern Ocean in the Earth System, and provide predictions at spatial and temporal resolutions useful for decision making. A co-ordinated portfolio of cross-disciplinary science, based on new models of international collaboration, will be essential as no scientist, programme or nation can realize these aspirations alone

1 aKennicutt, M.C.1 aChown, Steven, L.1 aCassano, J.J.1 aLiggett, D.1 aPeck, Lloyd, S.1 aMassom, R.1 aRintoul, S.R.1 aStorey, J.1 aVaughan, D.G.1 aWilson, T.J.1 aAllison, I.1 aAyton, J.1 aBadhe, R.1 aBaeseman, J.1 aBarrett, P.J.1 aBell, Elanor, R.1 aBertler, N.1 aBo, S.1 aBrandt, A.1 aBromwich, David1 aCary, Craig, S1 aClark, M.S.1 aConvey, Peter1 aCosta, E.S.1 aCowan, D.1 aDeconto, R.1 aDunbar, R.1 aElfring, C.1 aEscutia, C.1 aFrancis, J.1 aFricker, H.A.1 aFukuchi, M.1 aGilbert, N.1 aGutt, J.1 aHavermans, C.1 aHik, D.1 aHosie, G.1 aJones, C.1 aKim, Y.D.1 aLe Maho, Y.1 aLee, S.H.1 aLeppe, M.1 aLeitchenkov, G.1 aLi, X.1 aLipenkov, V.1 aLochte, K.1 aLópez-Martínez, J.1 aüdecke, C.1 aLyons, Berry1 aMarenssi, S.1 aMiller, H.1 aMorozova, P.1 aNaish, T.1 aNayak, S.1 aRavindra, R.1 aRetamales, J.1 aRicci, C.A.1 aRogan-Finnemore, M.1 aRopert-Coudert, Y.1 aSamah, A.A.1 aSanson, L.1 aScambos, T.1 aSchloss, I.R.1 aShiraishi, K.1 aSiegert, M.J.1 aSimões, J.C.1 aStorey, B.1 aSparrow, M.D.1 aWall, Diana, H.1 aWalsh, J.C.1 aWilson, G.1 aWinther, J.G.1 aXavier, J.C.1 aYang, H.1 aSutherland, W.J. uhttp://www.journals.cambridge.org/abstract_S095410201400067402177nas a2200217 4500008004100000022001300041245014200054210006900196260001600265300001100281490000700292520131900299100002201618700002201640700002401662700002101686700002101707700003301728700002101761856017701782 2014 eng d a0025332400aAutonomous Year-Round Sampling and Sensing to Explore the Physical and Biological Habitability of Permanently Ice-Covered Antarctic Lakes0 aAutonomous YearRound Sampling and Sensing to Explore the Physica cJan-09-2014 a8 - 170 v483 a

The lakes of the McMurdo Dry Valleys, Antarctica, are some of the only systems on our planet that are perennially ice-covered and support year-round metabolism. As such, these ecosystems can provide important information on conditions and life in polar regions on Earth and on other icy worlds in our solar system. Working in these extreme environments of the Dry Valleys poses many challenges, particularly with respect to data collection during dark winter months when logistical constraints make fieldwork difficult. In this paper, we describe the motivation, design, and challenges for this recently deployed instrumentation in Lake Bonney, a lake that has been the subject of summer research efforts for more than 40 years. The instrumentation deployed includes autonomous water, phytoplankton, and sediment samplers as well as cable-mounted profiling platforms with dissolved gas and fluorometry sensors. Data obtained from these instruments will allow us, for the first time, to define the habitability of this environment during the polar night. We include lessons learned during deployment and recommendations for effective instrument operation in these extreme conditions.

1 aWinslow, Luke, A.1 aDugan, Hilary, A.1 aBuelow, Heather, N.1 aCronin, Kyle, D.1 aPriscu, John, C.1 aTakacs-Vesbach, Cristina, D.1 aDoran, Peter, T. uhttp://openurl.ingenta.com/content/xref?genre=article&issn=0025-3324&volume=48&issue=5&spage=8http://www.ingentaconnect.com/content/mts/mtsj/2014/00000048/00000005/art0000202282nas a2200181 4500008004100000245010600041210006900147260001200216300001200228490000800240520160500248100001301853700002801866700002901894700002101923700003001944856012601974 2014 eng d00aCiliate diversity, community structure and novel taxa in lakes of the McMurdo Dry Valleys, Antarctica0 aCiliate diversity community structure and novel taxa in lakes of c10/2014 a175-1900 v2273 aWe report an in-depth survey of next-generation DNA sequencing of ciliate diversity and community structure in two permanently ice-covered McMurdo Dry Valley lakes during the austral summer and autumn (November 2007 and March 2008). We tested hypotheses on the relationship between species richness and environmental conditions including environmental extremes, nutrient status, and day length. On the basis of the unique environment that exists in these high-latitude lakes, we expected that novel taxa would be present. Alpha diversity analyses showed that extreme conditions-that is, high salinity, low oxygen, and extreme changes in day length-did not impact ciliate richness; however, ciliate richness was 30% higher in samples with higher dissolved organic matter. Beta diversity analyses revealed that ciliate communities clustered by dissolved oxygen, depth, and salinity, but not by season (i.e., day length). The permutational analysis of variance test indicated that depth, dissolved oxygen, and salinity had significant influences on the ciliate community for the abundance matrices of resampled data, while lake and season were not significant. This result suggests that the vertical trends in dissolved oxygen concentration and salinity may play a critical role in structuring ciliate communities. A PCR-based strategy capitalizing on divergent eukaryotic V9 hypervariable region ribosomal RNA gene targets unveiled two new genera in these lakes. A novel taxon belonging to an unknown class most closely related to Cryptocaryon irritans was also inferred from separate gene phylogenies.1 aYuan, Xu1 aVick-Majors, Trista, J.1 aMorgan-Kiss, Rachael, M.1 aPriscu, John, C.1 aAmaral-Zettler, Linda, A. uhttps://mcm.lternet.edu/content/ciliate-diversity-community-structure-and-novel-taxa-lakes-mcmurdo-dry-valleys-antarctica02515nas a2200169 4500008004100000022001400041245016900055210006900224260001600293300001400309490000700323520188900330100002102219700002302240700001702263856006502280 2014 eng d a0954-102000aThe effects of high meltwater on the limnology of Lake Fryxell and Lake Hoare, Taylor Valley, Antarctica, as shown by dissolved gas, tritium and chlorofluorocarbons0 aeffects of high meltwater on the limnology of Lake Fryxell and L cJan-08-2014 a331 - 3400 v263 a

Small changes in the availability of liquid water can have profound effects on the water levels, aqueous chemistry and biogeochemical dynamics of the closed-basin, perennially ice-covered lakes of the McMurdo Dry Valleys, Antarctica. We have compiled the published and unpublished data on dissolved gas, tritium and chlorofluorocarbons (CFCs) for Lake Fryxell and Lake Hoare to determine the effects of a high meltwater year (2001–02 summer) on the lakes. The dissolved gas, tritium and CFC data indicate that the pulse of freshwater that flowed onto the surfaces of the lakes did not mix extensively with the upper water column. At the bottom of Lake Hoare, the measurable CFC and lower dissolved gas values suggest that the recent meltwater may have mixed with bottom waters. The probable mechanism for this transportation is weak density currents with c. 0.1–1.5% surface water being transported downwards in Lake Hoare. This deep water input, while not constant, may have a significant effect on the chemistry of the bottom waters in Lake Hoare over time. In Lake Fryxell, the tritium and CFC data indicate that the recent meltwater did not significantly affect the bottom water chemistry; therefore, weak density currents may not be present in Lake Fryxell.

1 aDowling, Carolyn1 aPoreda, Robert, J.1 aLyons, Berry uhttp://www.journals.cambridge.org/abstract_S095410201300062X00531nas a2200121 4500008004100000245013000041210006900171260001200240100002800252700002100280700003000301856007800331 2014 eng d00aModular community structure suggests metabolic plasticity during the transition to polar night in ice-covered Antarctic lakes0 aModular community structure suggests metabolic plasticity during c10/20131 aVick-Majors, Trista, J.1 aPriscu, John, C.1 aAmaral-Zettler, Linda, A. uhttp://www.nature.com/ismej/journal/vaop/ncurrent/full/ismej2013190a.html03712nas a2200157 4500008004100000245021300041210006900254260001200323300001600335490000800351520308500359100002203444700002103466700002103487856004603508 2014 eng d00aThe permanent ice cover of Lake Bonney, Antarctica: The influence of thickness and sediment distribution on photosynthetically available radiation and chlorophyll-a distribution in the underlying water column0 apermanent ice cover of Lake Bonney Antarctica The influence of t c09/2014 a1879 - 18910 v1193 a

The thick permanent ice cover on the lakes of the McMurdo Dry Valleys, Antarctica, inhibits spatial lake sampling due to logistical constraints of penetrating the ice cover. To date most sampling of these lakes has been made at only a few sites with the assumption that there is a spatial homogeneity of the physical and biogeochemical properties of the ice cover and the water column at any given depth. To test this underlying assumption, an autonomous underwater vehicle (AUV) was deployed in Lake Bonney, Taylor Valley. Measurements were obtained over the course of 2 years in a 100 × 100 m horizontal sampling grid (at a 0.2 m vertical resolution). Additionally, the AUV measured the ice thickness (in water equivalent) and collected images looking up through the ice, which were used to quantify sediment distribution on the surface and within the ice. Satellite imagery was used to map sediment distribution on the surface of the ice. We present results of the spatial investigation of the sediment distribution on the ice cover and its effects on biological processes, with particular emphasis on photosynthetically active radiation (PAR). The surface sediment is a secondary controller of the ice cover thickness, which in turn controls the depth-integrated PAR in the water column. Our data revealed that depth-integrated PAR was negatively correlated with depth-integrated chlorophyll-a (r = 0.88, p < 0.001, n = 83), which appears to be related to short-term photoadaptation of phytoplanktonic communities to spatial and temporal variation in PAR within the water column.

1 aObryk, Maciek, K.1 aDoran, Peter, T.1 aPriscu, John, C. uhttp://doi.wiley.com/10.1002/2014JG00267200468nas a2200145 4500008004100000245005400041210005400095260001200149300001400161490000700175100002100182700002800203700001900231856007200250 2014 eng d00aPolar and alpine microbiology in a changing world0 aPolar and alpine microbiology in a changing world c08/2014 a209 - 2100 v891 aPriscu, John, C.1 aLaybourn-Parry, Johanna1 aHäggblom, Max uhttp://onlinelibrary.wiley.com/doi/10.1111/1574-6941.12371/abstract02909nas a2200193 4500008004100000245012700041210006900168260001200237300001600249490000700265520221300272100002502485700002002510700002302530700002502553700002402578700002202602856009102624 2014 eng d00aSoil animal responses to moisture availability are largely scale, not ecosystem dependent: insight from a cross-site study0 aSoil animal responses to moisture availability are largely scale c08/2014 a2631 - 26430 v203 a

Climate change will result in reduced soil water availability in much of the world either due to changes in precipitation or increased temperature and evapotranspiration. How communities of mites and nematodes may respond to changes in moisture availability is not well known, yet these organisms play important roles in decomposition and nutrient cycling processes. We determined how communities of these organisms respond to changes in moisture availability and whether common patterns occur along fine-scale gradients of soil moisture within four individual ecosystem types (mesic, xeric and arid grasslands and a polar desert) located in the western United States and Antarctica, as well as across a cross-ecosystem moisture gradient (CEMG) of all four ecosystems considered together. An elevation transect of three sampling plots was monitored within each ecosystem and soil samples were collected from these plots and from existing experimental precipitation manipulations within each ecosystem once in fall of 2009 and three times each in 2010 and 2011. Mites and nematodes were sorted to trophic groups and analyzed to determine community responses to changes in soil moisture availability. We found that while both mites and nematodes increased with available soil moisture across the CEMG, within individual ecosystems, increases in soil moisture resulted in decreases to nematode communities at all but the arid grassland ecosystem; mites showed no responses at any ecosystem. In addition, we found changes in proportional abundances of mite and nematode trophic groups as soil moisture increased within individual ecosystems, which may result in shifts within soil food webs with important consequences for ecosystem functioning. We suggest that communities of soil animals at local scales may respond predictably to changes in moisture availability regardless of ecosystem type but that additional factors, such as climate variability, vegetation composition, and soil properties may influence this relationship over larger scales.

1 aSylvain, Zachary, A.1 aWall, Diana, H.1 aCherwin, Karie, L.1 aPeters, Debra, P. C.1 aReichmann, Lara, G.1 aSala, Osvaldo, E. uhttp://doi.wiley.com/10.1111/gcb.2014.20.issue-8http://doi.wiley.com/10.1111/gcb.1252203560nas a2200397 4500008004100000022001400041245005200055210004800107260001200155300001400167490000700181520243500188100001802623700002202641700001902663700002502682700001902707700002002726700002202746700002102768700002402789700002102813700002302834700002702857700002302884700002802907700001702935700001902952700002202971700002002993700002103013700002503034700002603059700002003085856005703105 2014 eng d a0012-961500aThe spatial structure of Antarctic biodiversity0 aspatial structure of Antarctic biodiversity c05/2014 a203 - 2440 v843 a

Patterns of environmental spatial structure lie at the heart of the most fundamental and familiar patterns of diversity on Earth. Antarctica contains some of the strongest environmental gradients on the planet and therefore provides an ideal study ground to test hypotheses on the relevance of environmental variability for biodiversity. To answer the pivotal question, “How does spatial variation in physical and biological environmental properties across the Antarctic drive biodiversity?” we have synthesized current knowledge on environmental variability across terrestrial, freshwater, and marine Antarctic biomes and related this to the observed biotic patterns. The most important physical driver of Antarctic terrestrial communities is the availability of liquid water, itself driven by solar irradiance intensity. Patterns of biota distribution are further strongly influenced by the historical development of any given location or region, and by geographical barriers. In freshwater ecosystems, free water is also crucial, with further important influences from salinity, nutrient availability, oxygenation, and characteristics of ice cover and extent. In the marine biome there does not appear to be one major driving force, with the exception of the oceanographic boundary of the Polar Front. At smaller spatial scales, ice cover, ice scour, and salinity gradients are clearly important determinants of diversity at habitat and community level. Stochastic and extreme events remain an important driving force in all environments, particularly in the context of local extinction and colonization or recolonization, as well as that of temporal environmental variability. Our synthesis demonstrates that the Antarctic continent and surrounding oceans provide an ideal study ground to develop new biogeographical models, including life history and physiological traits, and to address questions regarding biological responses to environmental variability and change.

 

1 aConvey, Peter1 aChown, Steven, L.1 aClarke, Andrew1 aBarnes, David, K. A.1 aBokhorst, Stef1 aCummings, Vonda1 aDucklow, Hugh, W.1 aFrati, Francesco1 aGreen, T., G. Allan1 aGordon, Shulamit1 aGriffiths, Huw, J.1 aHoward-Williams, Clive1 aHuiskes, Ad, H. L.1 aLaybourn-Parry, Johanna1 aLyons, Berry1 aMcMinn, Andrew1 aMorley, Simon, A.1 aPeck, Lloyd, S.1 aQuesada, Antonio1 aRobinson, Sharon, A.1 aSchiaparelli, Stefano1 aWall, Diana, H. uhttp://www.esajournals.org/doi/abs/10.1890/12-2216.102237nas a2200337 4500008004100000024003300041245010300074210006900177260001200246300001300258490000700271520126700278100001301545700001701558700001901575700001401594700002001608700001801628700001801646700001301664700001701677700001401694700002001708700001801728700001401746700002101760700001801781700002001799700001701819856006301836 2013 eng d ahdl: 10013 / epic.42531.d00100aAntarctic Thresholds - Ecosystem Resilience and Adaptation (AnT-ERA), a new SCAR-biology programme0 aAntarctic Thresholds Ecosystem Resilience and Adaptation AnTERA  c10/2013 a147-150.0 v823 a

Stresses on Antarctic ecosystems result from environmental change, including extreme events, and from (other) human impacts. Consequently, Antarctic habitats are changing, some at a rapid pace while others are relatively stable. A cascade of responses from molecular through organismic to the community level are expected. The differences in biological complexity and evolutionary histories between both polar regions and the rest of the planet suggest that stresses on polar ecosystem function may have fundamentally different outcomes from those at lower latitudes. Polar ecosystem processes are therefore key to informing wider ecological debate about the nature of stability and potential changes across the biosphere. The main goal of AnT-ERA is to facilitate the science required to examine changes in biological processes in Antarctic and sub-Antarctic marine-, freshwater and terrestrial ecosystems. Tolerance limits, as well as thresholds, resistance and resilience to environmental change will be determined. AnT-ERA is classified into three overlapping themes, which represent three levels of biological organisation: (1) molecular and physiological performance, (2) population processes and species traits, (3) ecosystem function and services.

1 aGutt, J.1 aAdams, Byron1 aBracegirdle, T1 aCowan, D.1 aCummings, Vonda1 adi Prisco, G.1 aGradinger, R.1 aIsla, E.1 aMcIntyre, T.1 aMurphy, E1 aPeck, Lloyd, S.1 aSchloss, I.R.1 aSmith, C.1 aSuckling, C., C.1 aTakahashi, A.1 aWall, Diana, H.1 aXavier, J.C. uhttp://epic.awi.de/34238/1/Polarforschung_82-2_147-150.pdf00646nas a2200193 4500008004100000245007700041210006900118260001100187300001400198490001200212100002100224700002100245700002400266700002400290700002000314700002300334700002400357856007100381 2012 eng d00aAeolian flux of biotic and abiotic material in Taylor Valley, Antarctica0 aAeolian flux of biotic and abiotic material in Taylor Valley Ant c6/2012 a102 - 1110 v155-1561 aŠabacká, Marie1 aPriscu, John, C.1 aBasagic, Hassan, J.1 aFountain, Andrew, G1 aWall, Diana, H.1 aVirginia, Ross, A.1 aGreenwood, Mark, C. uhttp://www.sciencedirect.com/science/article/pii/S0169555X1100622203100nas a2200157 4500008004100000022001400041245011100055210006900166260001200235300001200247490000700259520257200266100002802838700002102866856005502887 2012 eng d a0948-305500aBacterioplankton productivity in lakes of the Taylor Valley, Antarctica, during the polar night transition0 aBacterioplankton productivity in lakes of the Taylor Valley Anta c12/2013 a77 - 900 v683 a

Research on the lakes of the McMurdo Dry Valleys, Antarctica, is typically conducted during the period of 24 h sunlight (October to January) when logistical support is readily available. As part of the International Polar Year initiative, we obtained logistical support to study microbial dynamics in the permanently ice-covered lakes of the Taylor Valley during the transition from 24 h of sunlight to the complete darkness of the polar night (mid-April). Our study focused on the perennially ice-covered lakes Fryxell (FRX), East Lobe Bonney (ELB), and West Lobe Bonney (WLB), all of which are chemically stratified and have food webs dominated by microorganisms. Depth-integrated bacterioplankton productivity (BP; leucine incorporation [Leu] and thymidine incorporation [TdR]) in the lakes ranged from 1.2 to 3.4 mg C m−2 d−1. Overall, summer was characterized by relatively high rates of BP and photoautotrophic primary productivity. Rapid decreases in photosynthetically active radiation marked a subsequent transition period, which was characterized by variable cell counts and decreasing Leu:TdR ratios (ratios >1 signify a physiological shift from growth to maintenance mode). Finally, cell counts decreased and Leu:TdR increased by as much as 280% during the fall, revealing a distinct change in the physiological state of the bacterioplankton as light-mediated primary productivity ceased. Our data reveal that the shift in physiological state may result from a switch from contemporary phytoplankton-excreted carbon to other sources of dissolved organic carbon, which can support the bacterioplankton populations through the winter.

1 aVick-Majors, Trista, J.1 aPriscu, John, C. uhttp://www.int-res.com/abstracts/ame/v68/n1/p77-9004191nas a2200445 4500008004100000022001400041245005900055210005900114260001600173300001400189490000800203520302300211100002203234700001603256700001903272700001503291700001803306700002003324700001503344700001903359700001603378700001303394700001503407700001803422700001303440700002203453700001503475700001503490700002303505700001303528700001903541700001703560700001503577700001703592700001803609700002003627700001603647700002003663856006203683 2012 eng d a0036-807500aChallenges to the Future Conservation of the Antarctic0 aChallenges to the Future Conservation of the Antarctic cJan-07-2013 a158 - 1590 v3373 a

The Antarctic Treaty System, acknowledged as a successful model of cooperative regulation of one of the globe's largest commons (1), is under substantial pressure. Concerns have been raised about increased stress on Antarctic systems from global environmental change and growing interest in the region's resources (23). Although policy-makers may recognize these challenges, failure to respond in a timely way can have substantial negative consequences. We provide a horizon scan, a systematic means for identifying emerging trends and assisting decision-makers in identifying policies that address future challenges (23). Previous analyses of conservation threats in the Antarctic have been restricted to matters for which available evidence is compelling (4). We reconsider these concerns because they might escalate quickly, judging from recent rapid environmental change in parts of Antarctica and increasing human interest in the region (see the map). We then focus on a more distant time horizon.

1 aChown, Steven, L.1 aLee, J., E.1 aHughes, K., A.1 aBarnes, J.1 aBarrett, P.J.1 aBergstrom, D.M.1 aConvey, P.1 aCowan, Don, A.1 aCrosbie, K.1 aDyer, G.1 aFrenot, Y.1 aGrant, S., M.1 aHerr, D.1 aKennicutt, M., C.1 aLamers, M.1 aMurray, A.1 aPossingham, H., P.1 aReid, K.1 aRiddle, M., J.1 aRyan, P., G.1 aSanson, L.1 aShaw, J., D.1 aSparrow, M.D.1 aSummerhayes, C.1 aTerauds, A.1 aWall, Diana, H. uhttp://www.sciencemag.org/cgi/doi/10.1126/science.122282100624nas a2200169 4500008004100000245011500041210006900156260001200225300001600237490000700253100002500260700002100285700002100306700002200327700002500349856008000374 2012 eng d00aChemical analysis of ice vein microenvironments: II. Analysis of glacial samples from Greenland and Antarctica0 aChemical analysis of ice vein microenvironments II Analysis of g c12/2012 a1109 - 11180 v581 aBarletta, Robert, E.1 aPriscu, John, C.1 aMader, Heidy, M.1 aJones, Warren, L.1 aRoe, Christopher, H. uhttp://www.montana.edu/priscu/DOCS/Publications/BarlettaEtAl2012IceVein.pdf00532nas a2200145 4500008004100000245009700041210006900138260001200207300001400219490000700233100002700240700002100267700002100288856007700309 2012 eng d00aCyanobacterial diversity across landscape units in a polar desert: Taylor Valley, Antarctica0 aCyanobacterial diversity across landscape units in a polar deser c11/2012 a268 - 2780 v821 aMichaud, Alexander, B.1 aŠabacká, Marie1 aPriscu, John, C. uhttp://onlinelibrary.wiley.com/doi/10.1111/j.1574-6941.2012.01297.x/full00561nas a2200157 4500008004100000245012400041210006900165260001200234300001400246490000700260100001800267700002000285700002100305700002900326856004800355 2012 eng d00aDiversity and Expression of RubisCO Genes in a Perennially Ice-Covered Antarctic Lake during the Polar Night Transition0 aDiversity and Expression of RubisCO Genes in a Perennially IceCo c04/2012 a4358-43660 v781 aKong, Weidong1 aReam, David, C.1 aPriscu, John, C.1 aMorgan-Kiss, Rachael, M. uhttp://aem.asm.org/content/78/12/4358.short00583nas a2200169 4500008004100000245008400041210006900125260001200194300001400206490000700220100001800227700002100245700002000266700002100286700002900307856007700336 2012 eng d00aEvidence of form II RubisCO ( cbbM) in a perennially ice-covered Antarctic lake0 aEvidence of form II RubisCO cbbM in a perennially icecovered Ant c11/2012 a491 - 5000 v821 aKong, Weidong1 aDolhi, Jenna, M.1 aChiuchiolo, Amy1 aPriscu, John, C.1 aMorgan-Kiss, Rachael, M. uhttp://onlinelibrary.wiley.com/doi/10.1111/j.1574-6941.2012.01431.x/full00684nas a2200193 4500008004100000245011200041210006900153260001200222300001400234490000700248100001800255700002200273700002100295700002100316700002800337700002000365700002800385856007700413 2012 eng d00aMicrobial dynamics and flagellate grazing during transition to winter in Lakes Hoare and Bonney, Antarctica0 aMicrobial dynamics and flagellate grazing during transition to w c11/2012 a449 - 4580 v821 aThurman, Jill1 aParry, Jacqueline1 aHill, Philip, J.1 aPriscu, John, C.1 aVick-Majors, Trista, J.1 aChiuchiolo, Amy1 aLaybourn-Parry, Johanna uhttp://onlinelibrary.wiley.com/doi/10.1111/j.1574-6941.2012.01423.x/full01017nas a2200337 4500008004100000022001400041245007500055210006900130260001200199300001800211490000800229100001900237700001800256700002700274700002700301700002300328700002000351700001900371700002400390700002500414700001700439700001800456700002100474700002700495700002400522700001800546700001900564700001900583700002100602856005600623 2012 eng d a0027-842400aMicrobial life at -13  C in the brine of an ice-sealed Antarctic lake0 aMicrobial life at 13 C in the brine of an icesealed Antarctic la c12/2012 a20626 - 206310 v1091 aMurray, A., E.1 aKenig, Fabien1 aFritsen, Christian, H.1 aMcKay, Christopher, P.1 aCawley, Kaelin, M.1 aEdwards, R., L.1 aKuhn, Emanuele1 aMcKnight, Diane, M.1 aOstrom, Nathaniel, E1 aPeng, Vivian1 aPonce, Adrian1 aPriscu, John, C.1 aSamarkin, Vladimir, A.1 aTownsend, Ashley, T1 aWagh, Protima1 aYoung, Seth, A1 aYung, Pung, To1 aDoran, Peter, T. uhttp://www.pnas.org/cgi/doi/10.1073/pnas.120860710900621nas a2200181 4500008004100000245010500041210006900146260001200215300001200227490000700239100002000246700002400266700001900290700001700309700002100326700002100347856007100368 2012 eng d00aPerchlorate and chlorate biogeochemistry in ice-covered lakes of the McMurdo Dry Valleys, Antarctica0 aPerchlorate and chlorate biogeochemistry in icecovered lakes of  c12/2012 a19 - 300 v981 aJackson, Andrew1 aDavila, Alfonso, F.1 aEstrada, Nubia1 aLyons, Berry1 aCoates, John, D.1 aPriscu, John, C. uhttp://www.sciencedirect.com/science/article/pii/S001670371200511X01724nam a2200385 4500008004100000020002200041245011900063210006900182260005100251300001400302490000900316520052100325100002500846700002200871700001900893700002500912700002700937700002000964700002300984700002101007700002101028700001801049700001901067700001901086700001901105700002201124700001401146700002001160700002101180700002101201700002001222700001901242700001901261856005801280 2012 eng d a978-3-642-33179-400aPoisson Reconstruction of Extreme Submersed Environments: The ENDURANCE Exploration of an Under-Ice Antarctic Lake0 aPoisson Reconstruction of Extreme Submersed Environments The END aBerlin, HeidelbergbSpringer Berlin Heidelberg a394 - 4030 v74313 a

We evaluate the use of Poisson reconstruction to generate a 3D bathymetric model of West Lake Bonney, Antarctica. The source sonar dataset has been collected by the ENDURANCE autonomous ve- hicle in the course of two Antarctic summer missions. The reconstruction workflow involved processing 200 million datapoints to generate a high resolution model of the lake bottom, Narrows region and underwater glacier face. A novel and flexible toolset has been developed to automate the processing of the Bonney data.

1 aFebretti, Alessandro1 aRichmond, Kristof1 aGulati, Shilpa1 aFlesher, Christopher1 aHogan, Bartholomew, P.1 aJohnson, Andrew1 aStone, William, C.1 aPriscu, John, C.1 aDoran, Peter, T.1 aBebis, George1 aBoyle, Richard1 aParvin, Bahram1 aKoracin, Darko1 aFowlkes, Charless1 aWang, Sen1 aChoi, Min-Hyung1 aMantler, Stephan1 aSchulze, Jürgen1 aAcevedo, Daniel1 aMueller, Klaus1 aPapka, Michael uhttp://www.springerlink.com/content/hg97w43588229087/02772nas a2200169 4500008004100000245009200041210006900133260001200202490000800214520222300222100002302445700001502468700001502483700002402498700001502522856006502537 2012 eng d00aSeismic multiplet response triggered by melt at Blood Falls, Taylor Glacier, Antarctica0 aSeismic multiplet response triggered by melt at Blood Falls Tayl c07/20120 v1173 a

Meltwater input often triggers a seismic response from glaciers and ice sheets. It is difficult, however, to measure melt production on glaciers directly, while subglacial water storage is not directly observable. Therefore, we document temporal changes in seismicity from a dry-based polar glacier (Taylor Glacier, Antarctica) during a melt season using a synthesis of seismic observation and melt modeling. We record icequakes using a dense six-receiver network of three-component geophones and compare this with melt input generated from a calibrated surface energy balance model. In the absence of modeled surface melt, we find that seismicity is well-described by a diurnal signal composed of microseismic events in lake and glacial ice. During melt events, the diurnal signal is suppressed and seismicity is instead characterized by large glacial icequakes. We perform network-based correlation and clustering analyses of seismic record sections and determine that 18% of melt-season icequakes are repetitive (multiplets). The epicentral locations for these multiplets suggest that they are triggered by meltwater produced near a brine seep known as Blood Falls. Our observations of the correspondingp-wave first motions are consistent with volumetric source mechanisms. We suggest that surface melt enables a persistent pathway through this cold ice to an englacial fracture system that is responsible for brine release episodes from the Blood Falls seep. The scalar moments for these events suggest that the volumetric increase at the source region can be explained by melt input.

1 aCarmichael, J., D.1 aPettit, E.1 aHoffman, M1 aFountain, Andrew, G1 aHallet, B. uhttp://onlinelibrary.wiley.com/doi/10.1029/2011JF002221/full02476nas a2200145 4500008004100000245007200041210006900113260004800182300000800230490001000238520198300248100002102231700002102252856005702273 2012 eng d00aWind as an ecological factor in the McMurdo Dry Valleys, Antarctica0 aWind as an ecological factor in the McMurdo Dry Valleys Antarcti aBozeman, MTbMontana State Universityc2012 a2010 vPh.D.3 a

The aim of this work was to investigate the role of wind on the ecology of the McMurdo Dry Valleys in Antarctica (MDV), one of the coldest and driest deserts on Earth. The MDV landscape consists of a mosaic of permanently ice-covered lakes, ephemeral streams, exposed soils, and glaciers, all of which contain habitats dominated by microorganisms. Data on wind-driven flux of sediments and associated organic matter were collected using passive aeolian traps and dynamic mass erosion particle counters to investigate the timing, direction and magnitude of aeolian sediment transport. Combination of genomic techniques and phenotypical fingerprinting (pigment analysis) was used to examine microbial diversity over a wide variety of wind-eroded habitats across the MDV landscape to elucidate the role of wind dispersal on the contemporary distribution of microorganisms across the MDVs. Sediment entrainment occurs predominantly within 20 cm of the ground surface and has character of saltation bursts that occupy <3% of the total time within a year. The high-energy winter föhn winds uplift sediments in the upper parts of the MDVs and transport them down-valley where they are deposited onto the surface of perennially ice-covered lakes and surrounding soils. The sediment that enters the water column of the lakes does not provide a significant source of organic carbon for bacterioplankton communities compared to the in situ production by phytoplankton but can be a source of new microbial propagules. The aeolian material is low in organic matter (<1% dw) but is composed of a relatively large numbers of cyanobacterial taxa (~20 OTUs) that can be found in all other MDV habitats. In conclusion, wind distributes microorganisms across the MDV landscape but local environment selects for specific taxa. Predicted climate warming will increase the importance of wind transport, which will affect nutrient cycling and connectivity among MDV ecosystem components.

1 aŠabacká, Marie1 aPriscu, John, C. uhttps://scholarworks.montana.edu/xmlui/handle/1/217100484nam a2200121 4500008004100000020001800041245006800059210006700127260003300194100001800227700002100245856009600266 2011 eng d a0-309-21087-900aFrontiers in Understanding Climate Change and Polar Ecosystems0 aFrontiers in Understanding Climate Change and Polar Ecosystems bThe National Academies Press1 aGrebmeier, J.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/frontiers-understanding-climate-change-and-polar-ecosystems00627nam a2200145 4500008004100000245012700041210006900168260002200237300001400259100002500273700001700298700001800315700002000333856012800353 2011 eng d00aMolecular and physiological basis of nematode survival: Molecular analyses of desiccation survival in Antarctic nematodes.0 aMolecular and physiological basis of nematode survival Molecular aWallingfordbCABI a205 - 2321 aAdhikari, Bishwo, N.1 aAdams, Byron1 aPerry, R., N.1 aWharton, D., A. uhttps://mcm.lternet.edu/content/molecular-and-physiological-basis-nematode-survival-molecular-analyses-desiccation-survival00623nas a2200181 4500008004100000245010000041210006900141260001100210300001600221490000600237100002100243700002100264700001800285700002000303700002100323700002900344856006800373 2011 eng d00aProtist diversity in a permanently ice-covered Antarctic Lake during the polar night transition0 aProtist diversity in a permanently icecovered Antarctic Lake dur c9/2011 a1559 - 15640 v51 aBielewicz, Scott1 aBell, Elanor, R.1 aKong, Weidong1 aFriedberg, Iddo1 aPriscu, John, C.1 aMorgan-Kiss, Rachael, M. uhttp://www.nature.com/ismej/journal/v5/n9/abs/ismej201123a.html00655nas a2200193 4500008004100000245008400041210006900125260001100194300001400205490000600219100002700225700002500252700002500277700002500302700002100327700002700348700002300375856006300398 2010 eng d00aAbiotic nitrous oxide emission from the hypersaline Don Juan Pond in Antarctica0 aAbiotic nitrous oxide emission from the hypersaline Don Juan Pon c5/2010 a341 - 3440 v31 aSamarkin, Vladimir, A.1 aMadigan, Michael, T.1 aBowles, Marshall, W.1 aCasciotti, Karen, L.1 aPriscu, John, C.1 aMcKay, Christopher, P.1 aJoye, Samantha, B. uhttp://www.nature.com/ngeo/journal/v3/n5/full/ngeo847.html02548nas a2200145 4500008004100000245011900041210006900160260004800229300000700277490000900284520200300293100002802296700002102324856005702345 2010 eng d00aBacterioplakton dynamics in stratified lakes of the Taylor Valley, Antarctica during the transition to polar night0 aBacterioplakton dynamics in stratified lakes of the Taylor Valle aBozeman, MTbMontana State Universityc2010 a830 vM.S.3 a

Limnological research on the lakes of the McMurdo Dry Valleys (MCM), Antarctica, is typically carried out during the austral spring-summer (October January) when logistical support is readily available; the current study marks the first sampling effort during the summer-fall transition (January-April). Sampling during the darkness of winter is logistically difficult and expensive, and my study is an important step towards understanding the year-round ecology of the dry valley lakes. Bacterial productivity, measured as protein synthesis and DNA replication, and bacterial cell numbers were measured 10-12 times between October 2007 and April 2008 in Lakes Fryxell (FRX) and the east and west lobes of Lake Bonney (ELB and WLB). Lake Fryxell was the most productive (bacterial) lake on average by an order of magnitude (average = 1.24 mg C m -²d -¹; range = 0.00 to 3.29 mg C m -²d -¹), and also contained the greatest bacterial biomass (~10 ⁶ cells ml -¹) by 1 to 3 orders of magnitude. If bacterial production were directly linked to organic carbon supplied by photosynthetic primary production, a decrease in bacterial production would be expected during the sunset; however, no statistically significant change in bacterial production (a=0.05) was observed during the summer-fall transition. A distinct decoupling of bacterial protein production and DNA replication was detected in FRX and ELB of the lakes as the season progressed, and was present in WLB throughout the season, indicating either a shift towards a lower growth-rate in response to decreasing light or nutrient supply, or a mechanism for dealing with the perennially low temperatures, low light, and nutrient poor conditions in the lakes. Overall, it appears that bacterial communities remain active during the darkness of winter, when the lakes enter a period of "net heterotrophy", which cannot be sustained unless the carbon balance of the TV lakes is reset by climatic events.

1 aVick-Majors, Trista, J.1 aPriscu, John, C. uhttps://scholarworks.montana.edu/xmlui/handle/1/247700620nas a2200205 4500008004100000245005400041210005300095260000900148490000700157100001900164700002000183700001600203700001900219700002100238700001700259700001400276700001300290700002600303856008500329 2010 eng d00aBiogeochemical weathering under ice: Size matters0 aBiogeochemical weathering under ice Size matters c20100 v241 aWadham, J., L.1 aTranter, Martyn1 aSkidmore, M1 aHodson, A., J.1 aPriscu, John, C.1 aLyons, Berry1 aSharp, M.1 aWynn, P.1 aJackson, Margaret, S. uhttps://mcm.lternet.edu/content/biogeochemical-weathering-under-ice-size-matters00861nas a2200253 4500008004100000245013000041210006900171260001200240300001400252490000800266100001300274700002600287700001500313700001400328700002200342700001500364700001500379700001500394700001400409700001600423700002100439700002100460856012600481 2010 eng d00aDesign and deployment of a four-degrees-of-freedom hovering autonomous underwater vehicle for sub-ice exploration and mapping0 aDesign and deployment of a fourdegreesoffreedom hovering autonom c11/2010 a341 - 3610 v2241 aStone, W1 aHogan, Bartholomew, P1 aFlesher, C1 aGulati, S1 aRichmond, Kristof1 aMurarka, A1 aKuhlman, G1 aIdharan, M1 aSiegel, V1 aPrice, R, M1 aDoran, Peter, T.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/design-and-deployment-four-degrees-freedom-hovering-autonomous-underwater-vehicle-sub-ice00641nas a2200181 4500008004100000020001800041245006900059210006900128260003100197300001200228490000600240100003300246700002200279700002500301700002200326700002100348856009000369 2010 eng d a978052188919300aFactors promoting microbial diversity in the McMurdo Dry Valleys0 aFactors promoting microbial diversity in the McMurdo Dry Valleys bCambridge University Press a221-2570 v51 aTakacs-Vesbach, Cristina, D.1 aZeglin, Lydia, H.1 aGooseff, Michael, N.1 aBarrett, John, E.1 aPriscu, John, C. uhttp://ebooks.cambridge.org/chapter.jsf?bid=CBO9780511712258&cid=CBO9780511712258A01500667nas a2200169 4500008004100000020001800041245012500059210006900184260004200253300001300295490000600308100002200314700001300336700002500349700003300374856009000407 2010 eng d a978052188919300aThe legacy of aqueous environments on soils of the McMurdo Dry Valleys: contexts for future exploration of martian soils0 alegacy of aqueous environments on soils of the McMurdo Dry Valle aCambridgebCambridge University Press a78 - 1090 v51 aBarrett, John, E.1 aPoage, M1 aGooseff, Michael, N.1 aTakacs-Vesbach, Cristina, D. uhttp://ebooks.cambridge.org/chapter.jsf?bid=CBO9780511712258&cid=CBO9780511712258A01000627nas a2200145 4500008004100000245010900041210006900150100001700219700001700236700002800253700002900281700002100310700002400331856012600355 2010 eng d00aPhysiochemical properties influencing biomass abundance and primary production in Lake Hoare, Antarctica0 aPhysiochemical properties influencing biomass abundance and prim1 aHerbei, Radu1 aLyons, Berry1 aLaybourn-Parry, Johanna1 aGardner, Christopher, B.1 aPriscu, John, C.1 aMcKnight, Diane, M. uhttps://mcm.lternet.edu/content/physiochemical-properties-influencing-biomass-abundance-and-primary-production-lake-hoare00461nas a2200133 4500008004100000245005900041210005900100300001000159490000700169100002300176700002200199700002100221856008500242 2010 eng d00aSediment Melt Dynamics in Permanent Antarctic Lake Ice0 aSediment Melt Dynamics in Permanent Antarctic Lake Ice a57-660 v421 aJepsen, Steven, M.1 aAdams, Edward, E.1 aPriscu, John, C. uhttp://mcmlter.lternet.edu/reports/lakes/JepsenEtAl2010SedimentMeltMigration.pdf00685nas a2200193 4500008004100000245010500041210006900146260001200215300001400227490000700241100002400248700001700272700001900289700002900308700002500337700002400362700002100386856008400407 2010 eng d00aSpatial variations in the geochemistry of glacial meltwater streams in the Taylor Valley, Antarctica0 aSpatial variations in the geochemistry of glacial meltwater stre c12/2010 a662 - 6720 v221 aWelch, Kathleen, A.1 aLyons, Berry1 aWhisner, Carla1 aGardner, Christopher, B.1 aGooseff, Michael, N.1 aMcKnight, Diane, M.1 aPriscu, John, C. uhttp://www.montana.edu/lkbonney/DOCS/Publications/WelchEtAl2010Geochemistry.pdf01928nas a2200169 4500008004100000245010300041210006900144260001200213300001400225490000700239520131500246100001901561700002001580700002101600700002701621856011001648 2010 eng d00aViable microbes in ice: application of molecular assays to McMurdo Dry Valley lake ice communities0 aViable microbes in ice application of molecular assays to McMurd c10/2010 a470 - 4760 v223 a

The permanent ice covers of the McMurdo Dry Valley lakes, Antarctica, are colonized by a diverse microbial assemblage. We collected ice cores from Lakes Fryxell, Hoare and Bonney. Propidium monoazide (PMA) was used in combination with quantitative PCR (qPCR) and denaturing gradient gel electrophoresis (DGGE) to examine membrane integrity of prokaryotes in these extreme environments. PMA selectively penetrates cells with compromised membranes and modifies their DNA resulting in the suppression of PCR amplification. Our results based on analysis of 16S rRNA genes demonstrate that despite the hostile conditions of the Dry Valleys, the permanent ice covers of the lakes support a ‘potentially viable’ microbial community. The level of membrane integrity, as well as diversity, was higher in samples where sediment was entrapped in the ice cover. Pronounced differences in the fraction of cells with intact and compromised cell membranes were found for Lake Fryxell and east lobe of Lake Bonney, both expressed in differences in DGGE banding patterns and qPCR signal reductions. Limitations in the ability to distinguish between intact or compromised cells occurred in samples from Lake Hoare and west lobe of Lake Bonney due to low DNA template concentrations recovered from the samples.

1 aDieser, Markus1 aNocker, Andreas1 aPriscu, John, C.1 aForeman, Christine, M. uhttp://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=7909836&fileId=S095410201000040400918nas a2200325 4500008004100000245006400041210006300105300001200168490000700180100001700187700001600204700001400220700001600234700001500250700001400265700002500279700001500304700001300319700002000332700002600352700001600378700001700394700001900411700001300430700001500443700001200458700001500470700001500485856009200500 2009 eng d00aAccelerate Synthesis in Ecology and Environmental Sciences.0 aAccelerate Synthesis in Ecology and Environmental Sciences a699-7010 v591 aCarpenter, S1 aLundberg, P1 aMangel, M1 aMerchant, N1 aMurdoch, W1 aPalmer, M1 aPeters, Debra, P. C.1 aPickett, S1 aSmith, K1 aWall, Diana, H.1 aZimmerman, Maggie, K.1 aArmbrust, E1 aArzberger, E1 aChapin, F., S.1 aElser, J1 aHackett, E1 aIves, A1 aKareiva, P1 aLeibold, M uhttps://mcm.lternet.edu/content/accelerate-synthesis-ecology-and-environmental-sciences00627nas a2200157 4500008004100000245011700041210006900158300001400227490000700241100001500248700001800263700002100281700002100302700002400323856012200347 2009 eng d00aComposition and Biodegradation of a Synthetic Oil Spilled on the Perennial Ice Cover of Lake Fryxell, Antarctica0 aComposition and Biodegradation of a Synthetic Oil Spilled on the a2708-27130 v431 aJaraula, C1 aKenig, Fabien1 aDoran, Peter, T.1 aPriscu, John, C.1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/composition-and-biodegradation-synthetic-oil-spilled-perennial-ice-cover-lake-fryxell01755nas a2200241 4500008004100000245006900041210006500110260001200175300001200187490000800199520109500207653001101302100002201313700001501335700001601350700001501366700001601381700001401397700001301411700002101424700001101445856005701456 2009 eng d00aA Contemporary Microbially Maintained Subglacial Ferrous "Ocean"0 aContemporary Microbially Maintained Subglacial Ferrous Ocean c04/2009 a397-4000 v3243 a

An active microbial assemblage cycles sulfur in a sulfate-rich, ancient marine brine beneath Taylor Glacier, an outlet glacier of the East Antarctic Ice Sheet, with Fe(III) serving as the terminal electron acceptor. Isotopic measurements of sulfate, water, carbonate, and ferrous iron and functional gene analyses of adenosine 5′-phosphosulfate reductase imply that a microbial consortium facilitates a catalytic sulfur cycle. These metabolic pathways result from a limited organic carbon supply because of the absence of contemporary photosynthesis, yielding a subglacial ferrous brine that is anoxic but not sulfidic. Coupled biogeochemical processes below the glacier enable subglacial microbes to grow in extended isolation, demonstrating how analogous organic-starved systems, such as Neoproterozoic oceans, accumulated Fe(II) despite the presence of an active sulfur cycle.

10aBiggie1 aMikucki, Jill, A.1 aPearson, A1 aJohnston, D1 aTurchyn, A1 aFarquhar, J1 aSchrag, D1 aAnbar, A1 aPriscu, John, C.1 aLee, P uhttp://www.sciencemag.org/content/324/5925/397.short00622nas a2200157 4500008004100000245010300041210006900144300001400213490000700227100001600234700002300250700002200273700002400295700002000319856012500339 2009 eng d00aInteractions between physical and biotic factors influence CO_2 flux in Antarctic dry valley soils0 aInteractions between physical and biotic factors influence CO2 f a1510-15170 v411 aBall, Becky1 aVirginia, Ross, A.1 aBarrett, John, E.1 aParsons, Andrew, N.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/interactions-between-physical-and-biotic-factors-influence-co2-flux-antarctic-dry-valley01451nas a2200481 4500008004100000245006900041210006900110260001200179300001600191490001400207100002200221700002200243700002200265700002500287700002400312700002600336700001800362700001800380700002100398700002200419700002800441700001700469700001800486700002200504700002000526700002300546700002400569700002100593700001900614700002200633700001800655700002500673700001800698700002600716700002500742700002100767700002000788700002300808700002700831700002700858700002600885856005800911 2009 eng d00aLakes and reservoirs as regulators of carbon cycling and climate0 aLakes and reservoirs as regulators of carbon cycling and climate c11/2009 a2298–23140 v54 part 21 aTranvik, Lars, J.1 aDowning, John, A.1 aCotner, James, B.1 aLoiselle, Steven, A.1 aStriegl, Robert, G.1 aBallatore, Thomas, J.1 aDillon, Peter1 aFinlay, Kerri1 aFortino, Kenneth1 aKnoll, Lesley, B.1 aKortelainen, Pirkko, L.1 aKutser, Tiit1 aLarsen, Soren1 aLaurion, Isabelle1 aLeech, Dina, M.1 aMcCallister, Leigh1 aMcKnight, Diane, M.1 aMelack, John, M.1 aOverholt, Erin1 aPorter, Jason, A.1 aPrairie, Yves1 aRenwick, William, H.1 aRoland, Fabio1 aSherman, Bradford, S.1 aSchindler, David, W.1 aSobek, Sebastian1 aTremblay, Alain1 aVanni, Michael, J.1 aVerschoor, Antonie, M.1 avon Wachenfeldt, Eddie1 aWeyhenmeyer, Gesa, A. uhttp://aslo.org/lo/toc/vol_54/issue_6_part_2/2298.pdf00380nas a2200133 4500008004100000245002400041210002400065260002700089300001200116100002100128700002700149700001700176856005300193 2009 eng d00aLakes of Antarctica0 aLakes of Antarctica aOxfordbElsevier Press a555-5661 aPriscu, John, C.1 aForeman, Christine, M.1 aLikens, G.E. uhttps://mcm.lternet.edu/content/lakes-antarctica00718nas a2200241 4500008004100000245007300041210006900114300001200183490000600195100001500201700001300216700001800229700002000247700001600267700001300283700001200296700001400308700001500322700001500337700001300352700001300365856009800378 2009 eng d00aManaging for ocean biodiversity to sustain marine ecosystem services0 aManaging for ocean biodiversity to sustain marine ecosystem serv a204-2110 v71 aPalumbi, S1 aNorse, E1 aStachowicz, J1 aWall, Diana, H.1 aSandifer, P1 aAllan, J1 aBeck, M1 aFautin, D1 aFogerty, M1 aHalpern, B1 aIncze, L1 aLeong, J uhttps://mcm.lternet.edu/content/managing-ocean-biodiversity-sustain-marine-ecosystem-services00440nas a2200145 4500008004100000245004600041210004400087260001200131300001400143490000800157100002300165700002000188700001700208856006900225 2009 eng d00aWhere's the ecology in molecular ecology?0 aWheres the ecology in molecular ecology c05/2009 a1601-16090 v1181 aJohnson, Jerry, B.1 aPeat, Scott, M.1 aAdams, Byron uhttps://mcm.lternet.edu/content/wheres-ecology-molecular-ecology00572nas a2200157 4500008004100000245006300041210006000104260003600164100002100200700001600221700001700237700001600254700002500270700002700295856009200322 2008 eng d00aAntarctic subglacial water: origin, evolution, and ecology0 aAntarctic subglacial water origin evolution and ecology aOxfordbOxford University Press1 aPriscu, John, C.1 aTulaczyk, S1 aStudinger, M1 aKenicutt, M1 aChristner, Brent, C.1 aForeman, Christine, M. uhttps://mcm.lternet.edu/content/antarctic-subglacial-water-origin-evolution-and-ecology00526nas a2200169 4500008004100000245004000041210004000081260003000121300001000151100002500161700001600186700002100202700002000223700002700243700001700270856006900287 2008 eng d00aBacteria in Subglacial Environments0 aBacteria in Subglacial Environments aNew YorkbSpringer Verlag a51-711 aChristner, Brent, C.1 aSkidmore, M1 aPriscu, John, C.1 aTranter, Martyn1 aForeman, Christine, M.1 aMargesin, R. uhttps://mcm.lternet.edu/content/bacteria-subglacial-environments00464nas a2200157 4500008004100000245004100041210004100082300001200123490000700135100001600142700002000158700002600178700002100204700002800225856005300253 2008 eng d00aBacteriophage in polar inland waters0 aBacteriophage in polar inland waters a167-1750 v121 aSawstrom, C1 aLisle, John, T.1 aAnesio, Alexandre, M.1 aPriscu, John, C.1 aLaybourn-Parry, Johanna u/reports/lakes/SawstromEtAl2008Bacteriophage.pdf02709nas a2200241 4500008004100000245010000041210006900141260001200210300001400222490000700236520190500243100001802148700002202166700002002188700001702208700002202225700001302247700002402260700002202284700002402306700002302330856011402353 2008 eng d00aEffects of Human Trampling on Populations of Soil Fauna in the McMurdo Dry Valleys, Antarctica.0 aEffects of Human Trampling on Populations of Soil Fauna in the M c12/2008 a1544-15510 v223 a

Antarctic ecosystems are often considered nearly pristine because levels of anthropogenic disturbance are extremely low there. Nevertheless, over recent decades there has been a rapid increase in the number of people, researchers and tourists, visiting Antarctica. We evaluated, over 10 years, the direct impact of foot traffic on the abundance of soil animals and soil properties in Taylor Valley within the McMurdo Dry Valleys region of Antarctica. We compared soils from minimally disturbed areas with soils from nearby paths that received intermediate and high levels of human foot traffic (i.e., up to approximately 80 passes per year). The nematodes Scottnema lindsayae and Eudorylaimus sp. were the most commonly found animal species, whereas rotifers and tardigrades were found only occasionally. On the highly trampled footpaths, abundance of S. lindsayae and Eudorylaimus sp. was up to 52 and 76% lower, respectively, than in untrampled areas. Moreover, reduction in S. lindsayae abundance was more pronounced after 10 years than 2 years and in the surface soil than in the deeper soil, presumably because of the longer period of disturbance and the greater level of physical disturbance experienced by the surface soil. The ratio of living to dead Eudorylaimus sp. also declined with increased trampling intensity, which is indicative of increased mortality or reduced fecundity. At one site there was evidence that high levels of trampling reduced soil CO2 fluxes, which is related to total biological activity in the soil. Our results show that even low levels of human traffic can significantly affect soil biota in this ecosystem and may alter ecosystem processes, such as carbon cycling. Consequently, management and conservation plans for Antarctic soils should consider the high sensitivity of soil fauna to physical disturbance as human presence in this ecosystem increases.

1 aAyres, Edward1 aNkem, Johnson, N.1 aWall, Diana, H.1 aAdams, Byron1 aBarrett, John, E.1 aBroos, E1 aParsons, Andrew, N.1 aPowers, Laura, E.1 aSimmons, Breana, L.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/effects-human-trampling-populations-soil-fauna-mcmurdo-dry-valleys-antarctica02787nas a2200241 4500008004100000245002300041210002300064250000600087300001000093490000700103520220500110653001102315653001702326100001402343700002602357700002002383700002402403700001402427700002102441700002802462700001502490856004002505 2008 eng d00aGlacial ecosystems0 aGlacial ecosystems a1 a41-670 v783 a
There is now compelling evidence that microbially mediated reactions impart a significant effect upon the dynamics, composition, and abundance of nutrients in glacial melt water. Consequently, we must now consider ice masses as ecosystem habitats in their own right and address their diversity, functional potential, and activity as part of alpine and polar environments. Although such research is already underway, its fragmentary nature provides little basis for developing modern concepts of glacier ecology. This paper therefore provides a much-needed framework for development by reviewing the physical, biogeochemical, and microbiological characteristics of microbial habitats that have been identified within glaciers and ice sheets. Two key glacial ecosystems emerge, one inhabiting the glacier surface (the supraglacial ecosystem) and one at the ice-bed interface (the subglacial ecosystem). The supraglacial ecosystem is characterized by a diverse consortium of microbes (usually bacteria, algae, phytoflagellates, fungi, viruses and occasional rotifers, tardigrades, and diatoms) within the snowpack, supraglacial streams, and melt pools (cryoconite holes). The subglacial system is dominated by aerobic/anaerobic bacteria and most probably viruses in basal ice/till mixtures and subglacial lakes. A third, so-called englacial ecosystem is also described, but it is demonstrated that conditions within glacier ice are sufficient to make metabolic activity and its impact upon nutrient dynamics negligible at the glacier scale.
 
Consideration of the surface and internal heat balances of the glacier show that all glacial ecosystems are sensitive to climate change, although at different timescales. Thus, while rapid, melt-driven habitat changes lead to melt-out, resuscitation, and redistribution of microorganisms in many supraglacial ecosystems, much slower climatic and glacial mass-balance processes effect such changes in the subglacial ecosystem. Paradoxically, it is shown that these forces have brought about net refreezing and the onset of cryostasis in the subglacial ecosystems of many Arctic glaciers subject to thinning in recent decades.
10aBiggie10asnow ecology1 aHodson, A1 aAnesio, Alexandre, M.1 aTranter, Martyn1 aFountain, Andrew, G1 aOsborn, M1 aPriscu, John, C.1 aLaybourn-Parry, Johanna1 aSattler, B uhttp://dx.doi.org/10.1890/07-0187.101642nas a2200541 4500008004100000245010100041210006900142260001200211300001400223490000700237100002000244700002300264700002100287700002300308700002900331700002300360700002200383700002400405700001700429700002000446700002100466700002600487700002000513700002200533700002400555700002400579700001900603700002200622700002200644700002100666700001700687700002200704700002300726700001500749700001900764700002100783700002100804700002400825700002200849700002300871700002600894700002300920700001900943700002900962700001500991700001701006856007701023 2008 eng d00aGlobal decomposition experiment shows soil animal impacts on decomposition are climate dependent0 aGlobal decomposition experiment shows soil animal impacts on dec c11/2008 a2661-26770 v141 aWall, Diana, H.1 aBradford, Mark, A.1 aStJohn, Mark, G.1 aTrofymow, John, A.1 aBehan-Pelletier, Valerie1 aBignell, David, E.1 aDangerfield, Mark1 aParton, William, J.1 aRusek, Josef1 aVoigt, Winfried1 aWolters, Volkmar1 aGardel, Holley, Zadeh1 aAyuke, Fred, O.1 aBashford, Richard1 aBeljakova, Olga, I.1 aBohlen, Patrick, J.1 aBrauman, Alain1 aFlemming, Stephen1 aHenschel, Joh, R.1 aJohnson, Dan, L.1 aJones, Hefin1 aKovarova, Marcela1 aKranabetter, Marty1 aKutny, Les1 aLin, Kuo-Chuan1 aMaryati, Mohamed1 aMasse, Dominique1 aPokarzhevsk, Andrei1 aRahman, Homathevi1 aSabara, Millor, G.1 aSalamon, Joerg-Alfred1 aSwift, Michael, J.1 aVarela, Amanda1 aVasconcelos, Heraldo, L.1 aWhite, Don1 aZou, Xiaming uhttp://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2008.01672.x/full00521nas a2200157 4500008004100000245003800041210003600079260003600115100002400151700002500175700002500200700001600225700002500241700002800266856006900294 2008 eng d00aHigh-latitude rivers and streams.0 aHighlatitude rivers and streams aOxfordbOxford University Press1 aMcKnight, Diane, M.1 aGooseff, Michael, N.1 aVincent, Warwick, F.1 aPeterson, B1 aVincent, Warwick, F.1 aLaybourn-Parry, Johanna uhttps://mcm.lternet.edu/content/high-latitude-rivers-and-streams00591nas a2200157 4500008004100000245009700041210006900138260001200207300001200219490000700231100001300238700002200251700002300273700002000296856011700316 2008 eng d00aThe influence of soil geochemistry on nematode distribution, McMurdo Dry Valleys, Antarctica0 ainfluence of soil geochemistry on nematode distribution McMurdo  c02/2008 a119-1280 v401 aPoage, M1 aBarrett, John, E.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/influence-soil-geochemistry-nematode-distribution-mcmurdo-dry-valleys-antarctica00528nas a2200145 4500008004100000245005900041210005900100260003600159100001500195700002100210700001700231700002500248700002800273856008100301 2008 eng d00aOrigin and geomorphology of lakes in the polar regions0 aOrigin and geomorphology of lakes in the polar regions aOxfordbOxford University Press1 aPienitz, R1 aDoran, Peter, T.1 aLamoureuz, S1 aVincent, Warwick, F.1 aLaybourn-Parry, Johanna uhttps://mcm.lternet.edu/content/origin-and-geomorphology-lakes-polar-regions00475nas a2200097 4500008004100000245012300041210006900164490000600233100002100239856011700260 2008 eng d00aPlankton Dynamics in the McMurdo Dry Valley Lakes During the Transition to Polar Night - A Project Contributing to EBA0 aPlankton Dynamics in the McMurdo Dry Valley Lakes During the Tra0 v21 aPriscu, John, C. uhttps://mcm.lternet.edu/content/plankton-dynamics-mcmurdo-dry-valley-lakes-during-transition-polar-night-project00685nas a2200205 4500008004100000245010300041210006900144260000900213490000700222100002300229700002300252700002900275700001500304700002300319700002100342700001500363700001500378700002500393856006100418 2008 eng d00aReply to comment by K. Gajewski on “Abrupt environmental change in Canada's northernmost lake”0 aReply to comment by K Gajewski on Abrupt environmental change in c20080 v351 aAntoniades, Dermot1 aCrawley, Catherine1 aDouglas, Marianne, S. V.1 aPienitz, R1 aAndersen, Dale, T.1 aDoran, Peter, T.1 aHawes, Ian1 aPollard, W1 aVincent, Warwick, F. uhttp://www.agu.org/pubs/crossref/2008/2007GL032889.shtml00475nas a2200145 4500008004100000245005700041210005700098300001000155490000800165100001500173700002200188700001300210700002300223856008300246 2008 eng d00aSoil phosphorus cycling in an Antarctic polar desert0 aSoil phosphorus cycling in an Antarctic polar desert a21-320 v1441 aBate, Brad1 aBarrett, John, E.1 aPoage, M1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/soil-phosphorus-cycling-antarctic-polar-desert00645nas a2200157 4500008004100000245012900041210006900170300001200239490000800251100001500259700001800274700002100292700002100313700002400334856012900358 2008 eng d00aSPME-GCMS study of the natural attenuation of aviation diesel spilled on the perennial ice cover of Lake Fryxell, Antarctica0 aSPMEGCMS study of the natural attenuation of aviation diesel spi a250-2620 v4071 aJaraula, C1 aKenig, Fabien1 aDoran, Peter, T.1 aPriscu, John, C.1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/spme-gcms-study-natural-attenuation-aviation-diesel-spilled-perennial-ice-cover-lake-fryxell00949nas a2200349 4500008004100000245005900041210005800100300001400158490000700172100001800179700001300197700001500210700001400225700001500239700001400254700001400268700001600282700003300298700001500331700001900346700001400365700001100379700002200390700001700412700001300429700001500442700001600457700001600473700001400489700001200503856008400515 2008 eng d00aStoichiometry of soil enzyme activity at global scale.0 aStoichiometry of soil enzyme activity at global scale a1252-12640 v111 aSinsabaugh, R1 aGallo, M1 aGartner, T1 aHobbie, S1 aHolland, K1 aKeeler, B1 aPowers, J1 aStursova, M1 aTakacs-Vesbach, Cristina, D.1 aWaldrop, M1 aWallenstein, M1 aLauber, M1 aZak, D1 aZeglin, Lydia, H.1 aWeintraub, M1 aAhmed, B1 aAllison, S1 aCrenshaw, C1 aContosta, A1 aCusack, D1 aFrey, S uhttps://mcm.lternet.edu/content/stoichiometry-soil-enzyme-activity-global-scale00658nas a2200181 4500008004100000245013600041210006900177300001400246490000700260100002100267700002500288700001900313700002400332700002000356700002500376700001700401856005800418 2008 eng d00aSupersaturated N2O in a perennially ice-covered Antarctic lake: Molecular and stable isotopic evidence for a biogeochemical relict.0 aSupersaturated N2O in a perennially icecovered Antarctic lake Mo a2439-24500 v531 aPriscu, John, C.1 aChristner, Brent, C.1 aDore, John, E.1 aWestley, Marian, B.1 aPopp, Brian, N.1 aCasciotti, Karen, L.1 aLyons, Berry uhttp://brent.xner.net/pdf/Priscu_etal2008_ELB-N2O.pdf00530nas a2200121 4500008004100000245011000041210006900151300001400220490000700234100002200241700002100263856012400284 2007 eng d00aBacterial diversity associated with Blood Falls, A subglacial outflow from the Taylor Glacier, Antarctica0 aBacterial diversity associated with Blood Falls A subglacial out a4029-40390 v731 aMikucki, Jill, A.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/bacterial-diversity-associated-blood-falls-subglacial-outflow-taylor-glacier-antarctica03147nas a2200241 4500008004100000245006800041210006800109260001200177300001400189490000800203520239000211653001102601100002202612700002302634700001702657700002402674700002102698700002402719700002002743700002402763700002102787856009702808 2007 eng d00aBiogeochemical stoichiometry of Antarctic Dry Valley ecosystems0 aBiogeochemical stoichiometry of Antarctic Dry Valley ecosystems c02/2007 aG01010+120 v1123 a

Among aquatic and terrestrial landscapes of the McMurdo Dry Valleys, Antarctica, ecosystem stoichiometry ranges from values near the Redfield ratios for C:N:P to nutrient concentrations in proportions far above or below ratios necessary to support balanced microbial growth. This polar desert provides an opportunity to evaluate stoichiometric approaches to understand nutrient cycling in an ecosystem where biological diversity and activity are low, and controls over the movement and mass balances of nutrients operate over 10–106 years. The simple organisms (microbial and metazoan) comprising dry valley foodwebs adhere to strict biochemical requirements in the composition of their biomass, and when activated by availability of liquid water, they influence the chemical composition of their environment according to these ratios. Nitrogen and phosphorus varied significantly in terrestrial and aquatic ecosystems occurring on landscape surfaces across a wide range of exposure ages, indicating strong influences of landscape development and geochemistry on nutrient availability. Biota control the elemental ratio of stream waters, while geochemical stoichiometry (e.g., weathering, atmospheric deposition) evidently limits the distribution of soil invertebrates. We present a conceptual model describing transformations across dry valley landscapes facilitated by exchanges of liquid water and biotic processing of dissolved nutrients. We conclude that contemporary ecosystem stoichiometry of Antarctic Dry Valley soils, glaciers, streams, and lakes results from a combination of extant biological processes superimposed on a legacy of landscape processes and previous climates.

10aBiggie1 aBarrett, John, E.1 aVirginia, Ross, A.1 aLyons, Berry1 aMcKnight, Diane, M.1 aPriscu, John, C.1 aFountain, Andrew, G1 aWall, Diana, H.1 aMoorhead, Daryl, L.1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/biogeochemical-stoichiometry-antarctic-dry-valley-ecosystems00558nas a2200145 4500008004100000245008500041210006900126490000800195100002700203700001500230700002200245700001800267700002100285856010600306 2007 eng d00aMetabolic activity and diversity of cryoconites in the Taylor Valley, Antarctica0 aMetabolic activity and diversity of cryoconites in the Taylor Va0 v1121 aForeman, Christine, M.1 aSattler, B1 aMikucki, Jill, A.1 aPorazinska, D1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/metabolic-activity-and-diversity-cryoconites-taylor-valley-antarctica00476nas a2200121 4500008004100000245007900041210006900120260002900189490000900218100001300227700002100240856009300261 2007 eng d00aMicrobial Processes in the Moats of Lakes in the Taylor Valley, Antarctica0 aMicrobial Processes in the Moats of Lakes in the Taylor Valley A bMontana State University0 vM.S.1 aMoore, J1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/microbial-processes-moats-lakes-taylor-valley-antarctica02534nas a2200193 4500008004100000245009700041210006900138260001200207300001200219490000700231520185500238653001102093100002902104700002102133700001402154700002502168700002402193856012302217 2006 eng d00aAdaptation and acclimation of photosynthetic microorganisms to permanently cold environments0 aAdaptation and acclimation of photosynthetic microorganisms to p c03/2006 a222-2520 v703 a

Persistently cold environments constitute one of our world's largest ecosystems, and microorganisms dominate the biomass and metabolic activity in these extreme environments. The stress of low temperatures on life is exacerbated in organisms that rely on photoautrophic production of organic carbon and energy sources. Phototrophic organisms must coordinate temperature-independent reactions of light absorption and photochemistry with temperature-dependent processes of electron transport and utilization of energy sources through growth and metabolism. Despite this conundrum, phototrophic microorganisms thrive in all cold ecosystems described and (together with chemoautrophs) provide the base of autotrophic production in low-temperature food webs. Psychrophilic (organisms with a requirement for low growth temperatures) and psychrotolerant (organisms tolerant of low growth temperatures) photoautotrophs rely on low-temperature acclimative and adaptive strategies that have been described for other low-temperature-adapted heterotrophic organisms, such as cold-active proteins and maintenance of membrane fluidity. In addition, photoautrophic organisms possess other strategies to balance the absorption of light and the transduction of light energy to stored chemical energy products (NADPH and ATP) with downstream consumption of photosynthetically derived energy products at low temperatures. Lastly, differential adaptive and acclimative mechanisms exist in phototrophic microorganisms residing in low-temperature environments that are exposed to constant low-light environments versus high-light- and high-UV-exposed phototrophic assemblages.

10aBiggie1 aMorgan-Kiss, Rachael, M.1 aPriscu, John, C.1 aPocock, T1 aGudynaite-Savitch, L1 aHuner, Norman, P.A. uhttps://mcm.lternet.edu/content/adaptation-and-acclimation-photosynthetic-microorganisms-permanently-cold-environments00563nas a2200169 4500008004100000245004600041210004600087260003400133100001700167700002800184700002400212700002100236700002000257700001800277700002000295856007800315 2006 eng d00aAntarctic lake systems and climate change0 aAntarctic lake systems and climate change aDordrecht, The NetherlandsbS1 aLyons, Berry1 aLaybourn-Parry, Johanna1 aWelch, Kathleen, A.1 aPriscu, John, C.1 aBergstrom, D.M.1 aConvey, Peter1 aHuiskes, A.H.L. uhttps://mcm.lternet.edu/content/antarctic-lake-systems-and-climate-change00439nas a2200133 4500008004100000245005000041210005000091300001200141490000700153100002300160700002200183700002100205856007900226 2006 eng d00aFuel movement between grain boundaries in ice0 aFuel movement between grain boundaries in ice a158-1650 v451 aJepsen, Steven, M.1 aAdams, Edward, E.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/fuel-movement-between-grain-boundaries-ice00655nas a2200181 4500008004100000245011400041210006900155300000800224490000800232100001400240700001400254700002100268700001800289700001400307700001400321700001300335856012500348 2006 eng d00aGlacial and postglacial sedimentation in the Fryxell basin, Taylor Valley, Southern Victoria Land, Antarctica0 aGlacial and postglacial sedimentation in the Fryxell basin Taylo a3200 v3411 aWagner, B1 aMelles, M1 aDoran, Peter, T.1 aKenig, Fabien1 aForman, S1 aPierau, R1 aAllan, P uhttps://mcm.lternet.edu/content/glacial-and-postglacial-sedimentation-fryxell-basin-taylor-valley-southern-victoria-land00592nas a2200145 4500008004100000245010200041210006900143490000700212100002700219700001600246700001700262700002300279700002100302856012300323 2006 eng d00aMeasuring ecosystem response in a rapidly changing environment: the Latitudinal Gradient Project0 aMeasuring ecosystem response in a rapidly changing environment t0 v101 aHoward-Williams, Clive1 aPeterson, D1 aLyons, Berry1 aCattaneo-Vietti, R1 aGordon, Shulamit uhttps://mcm.lternet.edu/content/measuring-ecosystem-response-rapidly-changing-environment-latitudinal-gradient-project00531nas a2200145 4500008004100000245007100041210006900112300001400181490000700195100002200202700002300224700002400247700002000271856009400291 2006 eng d00aSoil carbon turnover model for the McMurdo Dry Valleys, Antarctica0 aSoil carbon turnover model for the McMurdo Dry Valleys Antarctic a3065-30820 v381 aBarrett, John, E.1 aVirginia, Ross, A.1 aParsons, Andrew, N.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/soil-carbon-turnover-model-mcmurdo-dry-valleys-antarctica02560nas a2200205 4500008004100000245008000041210006900121300001200190490000700202520193000209653001102139100002202150700002002172700002302192700002202215700001302237700001802250700001702268856006902285 2006 eng d00aWind dispersal of soil invertebrates in the McMurdo Dry Valleys, Antarctica0 aWind dispersal of soil invertebrates in the McMurdo Dry Valleys  a346-3520 v293 a

Dispersal of soil organisms is crucial for their spatial distribution and adaptation to the prevailing conditions of the Antarctic Dry Valleys. This study investigated the possibility of wind dispersal of soil invertebrates within the dry valleys. Soil invertebrates were evaluated in (1) pockets of transported sediments to lake ice and glacier surfaces, (2) wind-transported dust particles in collection pans (Bundt pans) 100 cm above the soil surface, and (3) sediments transported closer to the surface (<50 cm) and collected in open top chambers (OTCs). Invertebrates were extracted and identified. Nematodes were identified to species and classified according to life stage and sex. Three species of nematodes were recovered and Scottnema lindsayae was the most dominant. There were more juveniles (∼71%) in the transported sediments than adults (29%). Tardigrades and rotifers were more abundant in sediments on lake and glacier surfaces while nematodes were more abundant in the dry sediment collections of Bundt pans and OTCs. The abundance of immobile (dead) nematodes in the Bundt pans and OTCs was three times greater than active (live) nematodes. Anhydrobiosis constitutes a survival mechanism that allows wind dispersal of nematodes in the McMurdo Dry Valleys. Our results show that soil invertebrates are dispersed by wind in the Dry Valleys and are viable in ice communities on lake surfaces and glaciers.

10aBiggie1 aNkem, Johnson, N.1 aWall, Diana, H.1 aVirginia, Ross, A.1 aBarrett, John, E.1 aBroos, E1 aPorazinska, D1 aAdams, Byron uhttp://link.springer.com/content/pdf/10.1007%2Fs00300-005-0061-x00884nas a2200265 4500008004100000245007800041210007000119300001100189490000700200653002500207100002100232700001900253700002700272700002700299700002400326700002100350700001700371700001300388700002400401700002400425700002400449700002300473700002000496856010200516 2005 eng d00aComment on ``El Niño suppresses Antarctic warming'' by N. Bertler et al.0 aComment on El Niño suppresses Antarctic warming by N Bertler et  aL077060 v3210aTropical meteorology1 aDoran, Peter, T.1 aClow, Gary, D.1 aFritsen, Christian, H.1 aMcKay, Christopher, P.1 aParsons, Andrew, N.1 aPriscu, John, C.1 aLyons, Berry1 aWalsh, J1 aFountain, Andrew, G1 aMcKnight, Diane, M.1 aMoorhead, Daryl, L.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/comment-el-ni%C3%B1o-suppresses-antarctic-warming-n-bertler-et-al00618nas a2200181 4500008004100000245006900041210006800110300000900178490000700187100001700194700002100211700002400232700001400256700002300270700002100293700002400314856009800338 2005 eng d00aDating water and solute additions to ice-covered Antarctic lakes0 aDating water and solute additions to icecovered Antarctic lakes aA7200 v691 aLyons, Berry1 aDowling, Carolyn1 aWelch, Kathleen, A.1 aSnyder, G1 aPoreda, Robert, J.1 aDoran, Peter, T.1 aFountain, Andrew, G uhttps://mcm.lternet.edu/content/dating-water-and-solute-additions-ice-covered-antarctic-lakes00612nas a2200169 4500008004100000245007600041210006900117260003100186300000900217100002000226700001500246700001700261700002600278700001800304700002000322856010000342 2005 eng d00aDeveloping new perspectives from advances in soil biodiversity research0 aDeveloping new perspectives from advances in soil biodiversity r bCambridge University Press a3-301 aWall, Diana, H.1 aFritter, A1 aPaul, E., A.1 aBardgett, Richard, D.1 aUsher, M., B.1 aHopkins, D., W. uhttps://mcm.lternet.edu/content/developing-new-perspectives-advances-soil-biodiversity-research00340nas a2200109 4500008004100000245003300041210003000074300001200104490000700116100002100123856008600144 2005 eng d00aAn Ecosystem of Superlatives0 aEcosystem of Superlatives a804-8060 v551 aPriscu, John, C. uhttp://www.jstor.org/stable/10.1641/0006-3568%282005%29055%5B0804:AEOS%5D2.0.CO;200549nas a2200157 4500008004100000245009600041210006900137300001200206490000800218100002500226700002200251700002700273700001400300700002100314856005600335 2005 eng d00aGlacial ice cores: a model system for developing extraterrestrial decontamination protocols0 aGlacial ice cores a model system for developing extraterrestrial a572-5840 v1741 aChristner, Brent, C.1 aMikucki, Jill, A.1 aForeman, Christine, M.1 aDenson, J1 aPriscu, John, C. u/reports/lakes/ChristnerEtAl2005Decontamination.pdf00681nas a2200181 4500008004100000245012100041210006900162300001200231490000700243100001700250700002400267700001400291700001400305700001400319700001900333700002300352856012400375 2005 eng d00aHalogen geochemistry of the McMurdo Dry Valleys Lakes, Antarctica: clues to the origin of solutes and lake evolution0 aHalogen geochemistry of the McMurdo Dry Valleys Lakes Antarctica a305-3230 v691 aLyons, Berry1 aWelch, Kathleen, A.1 aSnyder, G1 aOlesik, J1 aGraham, E1 aMarion, G., M.1 aPoreda, Robert, J. uhttps://mcm.lternet.edu/content/halogen-geochemistry-mcmurdo-dry-valleys-lakes-antarctica-clues-origin-solutes-and-lake00454nas a2200121 4500008004100000245006100041210006100102260002900163490001000192100002200202700002100224856008700245 2005 eng d00aMicrobial Ecology of an Antarctic Subglacial Environment0 aMicrobial Ecology of an Antarctic Subglacial Environment bMontana State University0 vPh.D.1 aMikucki, Jill, A.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/microbial-ecology-antarctic-subglacial-environment00755nas a2200217 4500008004100000245008700041210006900128260003100197300001000228100002100238700002200259700002000281700002700301700001900328700002000347700002000367700002200387700001900409700001700428856009200445 2005 eng d00aPerennial Antarctic lake ice: A refuge for cyanobacteria in an extreme environment0 aPerennial Antarctic lake ice A refuge for cyanobacteria in an ex bPrinceton University Press a22-491 aPriscu, John, C.1 aAdams, Edward, E.1 aPaerl, Hans, W.1 aFritsen, Christian, H.1 aDore, John, E.1 aLisle, John, T.1 aWolf, Craig, F.1 aMikucki, Jill, A.1 aRogers, S., O.1 aCastello, J. uhttp://www.montana.edu/lkbonney/DOCS/Publications/PriscuEtAl2005CyanobacteriaRefuge.pdf00677nas a2200181 4500008004100000245009700041210006900138300001000207490000600217100002000223700002400243700002700267700001700294700002100311700001600332700002400348856012300372 2005 eng d00aPerturbation of hydrochemical conditions in natural microcosms entombed within Antarctic ice0 aPerturbation of hydrochemical conditions in natural microcosms e a22-230 v61 aTranter, Martyn1 aFountain, Andrew, G1 aFritsen, Christian, H.1 aLyons, Berry1 aPriscu, John, C.1 aStratham, P1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/perturbation-hydrochemical-conditions-natural-microcosms-entombed-within-antarctic-ice00662nas a2200193 4500008004100000245008500041210006900126260004000195300001200235100002700247700002300274700001500297700001600312700002100328700002700349700002100376700002000397856005100417 2005 eng d00aPolar lakes, streams, and springs as analogs for the hydrological cycle on Mars.0 aPolar lakes streams and springs as analogs for the hydrological  aBerlin, HeidelbergbSpringer Verlag a219-2331 aMcKay, Christopher, P.1 aAndersen, Dale, T.1 aPollard, W1 aHeldmann, J1 aDoran, Peter, T.1 aFritsen, Christian, H.1 aPriscu, John, C.1 aTokano, Tetsuya u/reports/lakes/McKayEtAl2005StreamsSprings.pdf02635nas a2200181 4500008004100000245007200041210006900113260001200182300001200194490000700206520208100213653001102294100002202305700002302327700002402350700002002374856005902394 2005 eng d00aPotential soil organic matter turnover in Taylor Valley, Antarctica0 aPotential soil organic matter turnover in Taylor Valley Antarcti c02/2005 a108-1170 v373 a

Antarctic Dry Valley ecosystems are among the most inhospitable soil ecosystems on earth with simple food webs and nearly undetectable fluxes of carbon (C) and nitrogen (N). Due to the lack of vascular plants, soil organic matter concentrations are extremely low, and it is unclear how much of the contemporary soil C budget is actively cycling or a legacy of paleolake production and sedimentation. While recent work indicates multiple sources of organic matter for dry valley soils, the composition and kinetics of organic pools remain poorly characterized. We examined soil organic matter pools and potential C and N turnover in soils from within six sites located across three hydrological basins of Taylor Valley, Antarctica that differed in surface age, microclimate and proximity to legacy (paleolake) sources of organic matter. We estimated potential C and N mineralization, and rate kinetics using gas exchange and repeated leaching techniques during 90-d incubations of surface soils collected from valley basin and valley slope positions in three basins of Taylor Valley. Soil organic C content was negatively correlated with the ages of underlying tills, supporting previous descriptions of legacy organic matter. Carbon and N mineralization generally followed 1st order kinetics and were well described by exponential models. Labile pools of C (90 d) were 10% of the total organic C in the upper 5 cm of the soil profile. Labile N was 50% of the total N in surface soils of Taylor Valley. These results show that a large proportion of soil C and particularly N are mineralizable under suitable conditions and suggest that a kinetically defined labile pool of organic matter is potentially active in the field during brief intervals of favorable microclimate. Climate variation changing the duration of these conditions may have potentially large effects on the small pools of C and N in these soils.

10aBiggie1 aBarrett, John, E.1 aVirginia, Ross, A.1 aParsons, Andrew, N.1 aWall, Diana, H. uhttp://instaar.metapress.com/content/e653225425230175/00468nas a2200157 4500008004100000245002900041210002900070260003100099100001500130700002400145700002100169700001500190700002900205700001500234856006100249 2004 eng d00aAntarctic Paleolimnology0 aAntarctic Paleolimnology bKluwer Academic Publishers1 aHodgson, D1 aGibson, John, A. E.1 aDoran, Peter, T.1 aPienitz, R1 aDouglas, Marianne, S. V.1 aSmol, J.P. uhttps://mcm.lternet.edu/content/antarctic-paleolimnology00655nas a2200169 4500008004100000245010600041210006900147300001000216490000700226100001800233700002400251700002200275700002000297700002300317700002000340856012500360 2004 eng d00aThe Biodiversity and Biogeochemistry of Cryoconite Holes from McMurdo Dry Valley Glaciers, Antarctica0 aBiodiversity and Biogeochemistry of Cryoconite Holes from McMurd a84-910 v361 aPorazinska, D1 aFountain, Andrew, G1 aNylen, Thomas, H.1 aTranter, Martyn1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/biodiversity-and-biogeochemistry-cryoconite-holes-mcmurdo-dry-valley-glaciers-antarctica00642nas a2200145 4500008004100000245014700041210006900188490000700257100001900264700001700283700002100300700002500321700002400346856012600370 2004 eng d00aThe Carbon Isotopic Composition of Dissolved Inorganic Carbon in Perennially Ice-Covered Antarctica Lakes: Searching for a Biogenic Signature.0 aCarbon Isotopic Composition of Dissolved Inorganic Carbon in Per0 v391 aNeumann, Klaus1 aLyons, Berry1 aPriscu, John, C.1 aDesMarais, David, J.1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/carbon-isotopic-composition-dissolved-inorganic-carbon-perennially-ice-covered-antarctica00811nas a2200301 4500008004100000245004900041210004700090300001200137490000600149100001300155700001300168700001900181700001700200700001200217700001200229700001200241700002300253700002000276700001400296700002300310700002500333700001200358700001500370700001500385700001400400700001600414856007900430 2004 eng d00aDetritus, trophic dynamics and biodiversity.0 aDetritus trophic dynamics and biodiversity a584-6000 v71 aMoore, J1 aMorin, P1 aNadelhoffer, K1 aRosemound, A1 aPost, D1 aSabo, J1 aScow, K1 aVanni, Michael, J.1 aWall, Diana, H.1 aBerlow, E1 aColeman, David, C.1 aDe Ruiter, Peter, C.1 aDong, Q1 aHasting, A1 aJohnson, N1 aMcCann, K1 aMelville, K uhttps://mcm.lternet.edu/content/detritus-trophic-dynamics-and-biodiversity00670nas a2200157 4500008004100000245014600041210006900187300001200256490000700268100002300275700002100298700002000319700001700339700002800356856012800384 2004 eng d00aThe distribution of microplankton in the McMurdo dry valley lakes, Antarctica: Response to ecosystem legacy or present-day climate controls?0 adistribution of microplankton in the McMurdo dry valley lakes An a238-2490 v271 aRoberts, Emily, C.1 aPriscu, John, C.1 aWolf, Craig, F.1 aLyons, Berry1 aLaybourn-Parry, Johanna uhttps://mcm.lternet.edu/content/distribution-microplankton-mcmurdo-dry-valley-lakes-antarctica-response-ecosystem-legacy-or00394nas a2200121 4500008004100000245002600041210002500067260003800092100002100130700002500151700001900176856007700195 2004 eng d00aEarth's Icy Biosphere0 aEarths Icy Biosphere bAmerican Society for Microbiology1 aPriscu, John, C.1 aChristner, Brent, C.1 aBull, Alan, T. uhttp://mcm.lternet.edu/reports/lakes/PriscuChristner2004IcyBiosphere.pdf00627nas a2200169 4500008004100000245010400041210006900145300001400214490000700228100001100235700002100246700001900267700001500286700001500301700001400316856012700330 2004 eng d00aElevated levels of dimethylated-sulfur compounds in Lake Bonney, a poorly ventilated Antarctic lake0 aElevated levels of dimethylatedsulfur compounds in Lake Bonney a a1044-10550 v491 aLee, P1 aPriscu, John, C.1 aDiTullio, G, R1 aRiseman, S1 aTursich, N1 aDeMora, S uhttps://mcm.lternet.edu/content/elevated-levels-dimethylated-sulfur-compounds-lake-bonney-poorly-ventilated-antarctic-lake00667nas a2200181 4500008004100000245009000041210006900131300001200200490000700212100002000219700002400239700002700263700001700290700002100307700001500328700002400343856011800367 2004 eng d00aExtreme hydrochemical conditions in natural microcosms entombed within Antarctic ice.0 aExtreme hydrochemical conditions in natural microcosms entombed  a379-3870 v181 aTranter, Martyn1 aFountain, Andrew, G1 aFritsen, Christian, H.1 aLyons, Berry1 aPriscu, John, C.1 aStathan, P1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/extreme-hydrochemical-conditions-natural-microcosms-entombed-within-antarctic-ice00594nas a2200193 4500008004100000245005000041210005000091260003100141100001200172700001400184700001300198700001400211700002100225700001600246700001500262700002900277700001500306856007900321 2004 eng d00aGeochronology of high latitude lake sediments0 aGeochronology of high latitude lake sediments bKluwer Academic Publishers1 aWolf, A1 aMiller, G1 aOlsen, C1 aForman, S1 aDoran, Peter, T.1 aHolmgren, S1 aPienitz, R1 aDouglas, Marianne, S. V.1 aSmol, J.P. uhttps://mcm.lternet.edu/content/geochronology-high-latitude-lake-sediments00629nas a2200157 4500008004100000245011500041210006900156300001200225490000700237100002200244700002700266700001500293700001700308700002100325856012500346 2004 eng d00aGeomicrobiology of Blood Fall: An iron-rich saline discharge at the terminus of the Taylor Glacier, Antarctica0 aGeomicrobiology of Blood Fall An ironrich saline discharge at th a199-2000 v101 aMikucki, Jill, A.1 aForeman, Christine, M.1 aSattler, B1 aLyons, Berry1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/geomicrobiology-blood-fall-iron-rich-saline-discharge-terminus-taylor-glacier-antarctica00455nas a2200121 4500008004100000245007100041210006900112300001000181490000700191100002300198700001500221856009700236 2004 eng d00aGradient analysis of cryoconite ecosystems from two Polar glaciers0 aGradient analysis of cryoconite ecosystems from two Polar glacie a66-740 v271 aMueller, Derek, R.1 aPollard, W uhttps://mcm.lternet.edu/content/gradient-analysis-cryoconite-ecosystems-two-polar-glaciers-000667nas a2200169 4500008004100000245013500041210006900176300001400245490000700259100001400266700001600280700001700296700002100313700001100334700002400345856012800369 2004 eng d00aIdentification of a psychrophilic green alga from Lake Bonney, Antarctica: Chlamydomonas raudensis ETTL. (UWO 241) (Chlorophyceae)0 aIdentification of a psychrophilic green alga from Lake Bonney An a1138-11480 v401 aPocock, T1 aLachance, M1 aProschold, T1 aPriscu, John, C.1 aKim, S1 aHuner, Norman, P.A. uhttps://mcm.lternet.edu/content/identification-psychrophilic-green-alga-lake-bonney-antarctica-chlamydomonas-raudensis-ettl00616nas a2200169 4500008004100000245014100041210006900182260001200251300001200263490000700275653002100282653001800303100002700321700001200348700002100360856006500381 2004 eng d00aImpact of episodic warming events on the physical, chemical and biological relationships of lakes in the McMurdo Dry Valleys, Antarctica0 aImpact of episodic warming events on the physical chemical and b c09/2004 a239-2680 v1010aClimate Response10astoichiometry1 aForeman, Christine, M.1 aWolf, C1 aPriscu, John, C. uhttp://link.springer.com/article/10.1007%2Fs10498-004-2261-300526nas a2200133 4500008004100000245008200041210006900123300001200192490000700204100002300211700002100234700002800255856010900283 2004 eng d00aMicroplankton dynamics in a perennially ice-covered Antarctic lake-Lake Hoare0 aMicroplankton dynamics in a perennially icecovered Antarctic lak a238-2490 v271 aRoberts, Emily, C.1 aPriscu, John, C.1 aLaybourn-Parry, Johanna uhttps://mcm.lternet.edu/content/microplankton-dynamics-perennially-ice-covered-antarctic-lake-lake-hoare00538nas a2200121 4500008004100000245011800041210006900159300001200228490000700240100002000247700002100267856012800288 2004 eng d00aThe Occurrence of Lysogenic Bacteria and Microbial Aggregates in the Lakes of the McMurdo Dry Valleys, Antarctica0 aOccurrence of Lysogenic Bacteria and Microbial Aggregates in the a427-4390 v471 aLisle, John, T.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/occurrence-lysogenic-bacteria-and-microbial-aggregates-lakes-mcmurdo-dry-valleys-antarctica00791nas a2200217 4500008004100000020002200041245008200063210006900145260005900214300001200273100002100285700002100306700001700327700001400344700002300358700002300381700001500404700002900419700001500448856011000463 2004 eng d a978-1-4020-2125-100aPaleolimnology of extreme cold terrestrial and extraterrestrial environments.0 aPaleolimnology of extreme cold terrestrial and extraterrestrial  aDordrecht, The NetherlandsbKluwer Academic Publishers a475-5071 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry1 aPowell, R1 aPoreda, Robert, J.1 aAndersen, Dale, T.1 aPienitz, R1 aDouglas, Marianne, S. V.1 aSmol, J.P. uhttps://mcm.lternet.edu/content/paleolimnology-extreme-cold-terrestrial-and-extraterrestrial-environments00602nas a2200193 4500008004100000245004700041210004600088260003100134300001200165100002100177700002100198700001700219700001400236700002300250700001500273700002900288700001500317856007600332 2004 eng d00aPaleolimnology of Ice-covered Environments0 aPaleolimnology of Icecovered Environments bKluwer Academic Publishers a475-5071 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry1 aPowell, R1 aPoreda, Robert, J.1 aPienitz, R1 aDouglas, Marianne, S. V.1 aSmol, John uhttps://mcm.lternet.edu/content/paleolimnology-ice-covered-environments00504nas a2200145 4500008004100000245006100041210006100102300001200163490000600175100002400181700002200205700002000227700002300247856008800270 2004 eng d00aSoil carbon dioxide flux from Antarctic Dry Valley soils0 aSoil carbon dioxide flux from Antarctic Dry Valley soils a286-2950 v71 aParsons, Andrew, N.1 aBarrett, John, E.1 aWall, Diana, H.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/soil-carbon-dioxide-flux-antarctic-dry-valley-soils00661nas a2200157 4500008004100000245015000041210006900191300001200260490000700272100001400279700002100293700001800314700002500332700002100357856012500378 2004 eng d00aStable carbon and nitrogen isotopic compositions of benthic and pelagic organic matter in four polar lakes of the McMurdo Dry Valleys, Antarctica0 aStable carbon and nitrogen isotopic compositions of benthic and  a269-3010 v101 aLawson, J1 aDoran, Peter, T.1 aKenig, Fabien1 aDesMarais, David, J.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/stable-carbon-and-nitrogen-isotopic-compositions-benthic-and-pelagic-organic-matter-four00726nas a2200205 4500008004100000245011200041210006900153300000900222490000700231100001100238700002200249700002700271700002100298700001900319700001500338700001400353700002000367700001400387856011900401 2004 eng d00aThermodynamic constraints on microbially mediated processes in lakes of the McMurdo Dry Valleys, Antarctica0 aThermodynamic constraints on microbially mediated processes in l a1-170 v211 aLee, P1 aMikucki, Jill, A.1 aForeman, Christine, M.1 aPriscu, John, C.1 aDiTullio, G, R1 aRiseman, S1 aDeMora, S1 aWolf, Craig, F.1 aKester, L uhttps://mcm.lternet.edu/content/thermodynamic-constraints-microbially-mediated-processes-lakes-mcmurdo-dry-valleys00681nas a2200205 4500008004100000245009300041210006900134300001200203490000600215100001600221700001700237700001500254700001500269700001300284700001200297700001400309700001300323700002000336856011900356 2004 eng d00aTrophic interactions in a changing world: modelling aboveground-belowground interactions0 aTrophic interactions in a changing world modelling abovegroundbe a515-5280 v51 aSchroter, D1 aBrussaard, L1 aDe Deyn, G1 aProveda, K1 aBrown, V1 aBerg, M1 aWardle, D1 aMoore, J1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/trophic-interactions-changing-world-modelling-aboveground-belowground-interactions02593nas a2200181 4500008004100000245009500041210006900136300001400205490000700219520193100226100002202157700002302179700002002202700002402222700002202246700002402268856011902292 2004 eng d00aVariation in biogeochemistry and soil biodiversity across spatial scales in a polar desert0 aVariation in biogeochemistry and soil biodiversity across spatia a3105-31180 v853 a
Desert ecosystems are characterized by distinct spatial patterning in soil
biogeochemistry and biodiversity. In the Antarctic Dry Valleys, soil polygons are prominent
features of the landscape and may be key units for scaling local ecological information to
the greater region. We examined polygon soils in each of the three basins of Taylor Valley,
Antarctica. Our objectives were to characterize variability in soil biogeochemistry and
biodiversity at local to regional scales, and to test the influence of soil properties upon
invertebrate communities. We found that soil biogeochemical properties and biodiversity
vary over multiple spatial scales from fine (,10 m) to broad (.10 km) scales. Differences
in biogeochemistry were most pronounced at broad scales among the major lake basins of
Taylor Valley corresponding to differences in geology and microclimate, while variation
in invertebrate biodiversity and abundance occurred at landscape scales of 10–500 m, and
within individual soil polygons. Variation in biogeochemistry and invertebrate communities
across these scales reflects the influence of physical processes and landscape development
over ecosystem structure in the dry valleys. The development of soil polygons influences
the spatial patterning of soil properties such as soil organic matter, salinity, moisture, and
invertebrate habitat suitability. Nematode abundance and life history data indicate that
polygon interiors are more suitable habitats than soils in the troughs at the edges of polygons.
These data suggest that physical processes (i.e., polygon development) and biogeochemistry
are important influences on the spatial variability of biotic communities in dry valley soil
ecosystems.
1 aBarrett, John, E.1 aVirginia, Ross, A.1 aWall, Diana, H.1 aParsons, Andrew, N.1 aPowers, Laura, E.1 aBurkins, Melody, B. uhttps://mcm.lternet.edu/content/variation-biogeochemistry-and-soil-biodiversity-across-spatial-scales-polar-desert00957nas a2200301 4500008004100000020001800041245008800059210006900147260001700216300001200233100001400245700001600259700002900275700001400304700001700318700002600335700001800361700001500379700001500394700002200409700002100431700001700452700001800469700001700487700002000504700002000524856011100544 2004 eng d a1-55963-760-900aVulnerability to global change of ecosystem goods and services driven by soil biota0 aVulnerability to global change of ecosystem goods and services d bIsland Press a101-1361 aWardle, D1 aBrown, V.K.1 aBehan-Pelletier, Valerie1 aJohn, St.1 aWojtowicz, T1 aBardgett, Richard, D.1 aBrown, G., G.1 aIneson, P.1 aLavelle, P1 avan der Putten, W1 aAnderson, J., M.1 aBrussaard, L1 aHunt, William1 aPaul, E., A.1 aWall, Diana, H.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/vulnerability-global-change-ecosystem-goods-and-services-driven-soil-biota00536nas a2200157 4500008004100000245006700041210006600108300001200174490000600186100001200192700002400204700001700228700002100245700002400266856008800290 2003 eng d00aBiochemistry of Si in the McMurdo Dry Valley lakes, Antarctica0 aBiochemistry of Si in the McMurdo Dry Valley lakes Antarctica a737-7490 v11 aPugh, H1 aWelch, Kathleen, A.1 aLyons, Berry1 aPriscu, John, C.1 aMcKnight, Diane, M. uhttps://mcm.lternet.edu/content/biochemistry-si-mcmurdo-dry-valley-lakes-antarctica00567nas a2200169 4500008004100000245009200041210006900133260001200202300001000214490000800224100002100232700002700253700002700280700002100307700002200328856004700350 2003 eng d00aFormation and character of an ancient 19 m ice cover and underlying trapped brine in an0 aFormation and character of an ancient 19 m ice cover and underly c01/2003 a26-310 v1001 aDoran, Peter, T.1 aFritsen, Christian, H.1 aMcKay, Christopher, P.1 aPriscu, John, C.1 aAdams, Edward, E. uhttp://www.pnas.org/content/100/1/26.short00584nas a2200181 4500008004100000245006300041210006000104300001000164100001500174700001600189700002000205700001300225700001600238700001800254700002500272700001400297856009100311 2003 eng d00aLong-term perspectives on biodiversity-ecosystem function.0 aLongterm perspectives on biodiversityecosystem function a89-981 aSymstad, A1 aIII, Chapin1 aWall, Diana, H.1 aGross, K1 aHuenneke, L1 aMittelbach, G1 aPeters, Debra, P. C.1 aTilman, D uhttps://mcm.lternet.edu/content/long-term-perspectives-biodiversity-ecosystem-function00585nas a2200157 4500008004100000245008200041210006900123300001400192490000700206100002400213700002200237700002300259700002000282700001800302856010700320 2003 eng d00aOrganic matter and soil biota of upland wetlands in Taylor Valley, Antarctica0 aOrganic matter and soil biota of upland wetlands in Taylor Valle a1009-10190 v261 aMoorhead, Daryl, L.1 aBarrett, John, E.1 aVirginia, Ross, A.1 aWall, Diana, H.1 aPorazinska, D uhttps://mcm.lternet.edu/content/organic-matter-and-soil-biota-upland-wetlands-taylor-valley-antarctica00491nas a2200121 4500008004100000245008000041210006900121260002900190490000900219100001400228700002100242856010600263 2003 eng d00aSpatial and temporal variations of phytoplankton populations in Lake Bonney0 aSpatial and temporal variations of phytoplankton populations in  bMontana State University0 vM.S.1 aTurish, N1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/spatial-and-temporal-variations-phytoplankton-populations-lake-bonney00890nas a2200277 4500008004100000245006500041210006500106260001200171300001200183490000800195653002100203100002100224700002100245700001700266700002000283700002400303700002400327700002400351700002300375700002000398700001900418700002700437700002700464700002400491856009700515 2002 eng d00aAntarctic climate cooling and terrestrial ecosystem response0 aAntarctic climate cooling and terrestrial ecosystem response c01/2002 a517-5200 v41510aClimate Response1 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry1 aWalsh, John, E.1 aFountain, Andrew, G1 aMcKnight, Diane, M.1 aMoorhead, Daryl, L.1 aVirginia, Ross, A.1 aWall, Diana, H.1 aClow, Gary, D.1 aFritsen, Christian, H.1 aMcKay, Christopher, P.1 aParsons, Andrew, N. uhttps://mcm.lternet.edu/content/antarctic-climate-cooling-and-terrestrial-ecosystem-response00431nas a2200121 4500008004100000245006200041210005800103260003000161490000900191100001200200700001700212856008000229 2002 eng d00aThe biogeochemistry of Si in the McMurdo Dry Valley Lakes0 abiogeochemistry of Si in the McMurdo Dry Valley Lakes bThe Ohio State University0 vB.S.1 aPugh, H1 aLyons, Berry uhttps://mcm.lternet.edu/content/biogeochemistry-si-mcmurdo-dry-valley-lakes00625nas a2200145 4500008004100000245013200041210006900173300001200242490000700254100002400261700002000285700002300305700002400328856012700352 2002 eng d00aDistribution and life cycle of Scottnema lindsayae (Nematoda) in Antarctic soils: A modeling analysis of tempaerature responses0 aDistribution and life cycle of Scottnema lindsayae Nematoda in A a118-1250 v251 aMoorhead, Daryl, L.1 aWall, Diana, H.1 aVirginia, Ross, A.1 aParsons, Andrew, N. uhttps://mcm.lternet.edu/content/distribution-and-life-cycle-scottnema-lindsayae-nematoda-antarctic-soils-modeling-analysis00548nas a2200169 4500008004100000245005100041210005000092260004700142300001200189100001500201700001300216700002100229700001700250700001400267700001500281856008200296 2002 eng d00aExtremophiles: ice ecosystems and biodiversity0 aExtremophiles ice ecosystems and biodiversity aOxfordbUNESCO Publishing-Eolss Publishers a573-5981 aPsenner, R1 aFelip, M1 aPriscu, John, C.1 aWagenbach, D1 aWillie, A1 aSattler, B uhttps://mcm.lternet.edu/content/extremophiles-ice-ecosystems-and-biodiversity00481nas a2200133 4500008004100000245006800041210006600109300001200175490000700187100001800194700002000212700002300232856009200255 2002 eng d00aInvertebrates in ornithogenic soils at Ross Island, Antarctica.0 aInvertebrates in ornithogenic soils at Ross Island Antarctica a569-5740 v251 aPorazinska, D1 aWall, Diana, H.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/invertebrates-ornithogenic-soils-ross-island-antarctica00543nas a2200121 4500008004100000245011700041210006900158260002900227490000900256100001400265700002100279856012100300 2002 eng d00aLinkages between soils and lake ice sediments biogeochemistry: Taylor Valley, southern Victoria Land, Antarctica0 aLinkages between soils and lake ice sediments biogeochemistry Ta bMontana State University0 vM.S.1 aKonley, S1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/linkages-between-soils-and-lake-ice-sediments-biogeochemistry-taylor-valley-southern00578nas a2200133 4500008004100000245012500041210006900166300001200235490000700247100001800254700002000272700002300292856012900315 2002 eng d00aPopulation age structure of nematodes in the Antarctic Dry Valleys: perspectives on time, space, and habitat suitability0 aPopulation age structure of nematodes in the Antarctic Dry Valle a159-1680 v341 aPorazinska, D1 aWall, Diana, H.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/population-age-structure-nematodes-antarctic-dry-valleys-perspectives-time-space-and-habitat00772nas a2200253 4500008004100000245004700041210004700088300001200135490000800147100002000155700001900175700002700194700002700221700002400248700002100272700002100293700001700314700002400331700002400355700002400379700002300403700002000426856007200446 2002 eng d00aRecent Temperature Trends in the Antarctic0 aRecent Temperature Trends in the Antarctic a291-2920 v4181 aWalsh, John, E.1 aClow, Gary, D.1 aFritsen, Christian, H.1 aMcKay, Christopher, P.1 aParsons, Andrew, N.1 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry1 aFountain, Andrew, G1 aMcKnight, Diane, M.1 aMoorhead, Daryl, L.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/recent-temperature-trends-antarctic00760nas a2200229 4500008004100000245012700041210006900168260001200237300001000249490000700259653001100266100002500277700002200302700002100324700002400345700001700369700002400386700001800410700002300428700002000451856005900471 2002 eng d00aSnow patch influence on soil biogeochemical processes and invertebrate distribution in the McMurdo Dry Valleys, Antarctica0 aSnow patch influence on soil biogeochemical processes and invert c02/2003 a91-990 v3510aBiggie1 aGooseff, Michael, N.1 aBarrett, John, E.1 aDoran, Peter, T.1 aFountain, Andrew, G1 aLyons, Berry1 aParsons, Andrew, N.1 aPorazinska, D1 aVirginia, Ross, A.1 aWall, Diana, H. uhttp://instaar.metapress.com/content/r086455ju7213711/00506nas a2200157 4500008004100000245007600041210006900117260001200186300001400198490000700212653001100219100003300230700002100263700002400284856004000308 2001 eng d00aBacterial dissolved organic carbon demand in antarctic dry valley lakes0 aBacterial dissolved organic carbon demand in antarctic dry valle c07/2001 a1189-11940 v4610aBiggie1 aTakacs-Vesbach, Cristina, D.1 aPriscu, John, C.1 aMcKnight, Diane, M. uhttp://www.jstor.org/stable/267103100607nas a2200133 4500008004100000245015900041210006900200300001200269490000600281100002000287700001700307700002200324856012700346 2001 eng d00aBiodiversity in critical transition zones between terrestrial freshwater and marine soils and sediments: processes, linkages, and management implications.0 aBiodiversity in critical transition zones between terrestrial fr a418-4200 v41 aWall, Diana, H.1 aPalmer, M.A.1 aSnelgrove, P.V.R. uhttps://mcm.lternet.edu/content/biodiversity-critical-transition-zones-between-terrestrial-freshwater-and-marine-soils-and00540nas a2200145 4500008004100000245008500041210006900126300001000195490000700205100001900212700001700231700002100248700001500269856011000284 2001 eng d00aCO2 concentrations in perennially ice-covered lakes of Taylor Valley, Antarctica0 aCO2 concentrations in perennially icecovered lakes of Taylor Val a27-500 v561 aNeumann, Klaus1 aLyons, Berry1 aPriscu, John, C.1 aDonahoe, R uhttps://mcm.lternet.edu/content/co2-concentrations-perennially-ice-covered-lakes-taylor-valley-antarctica00572nas a2200145 4500008004100000245009000041210006900131300001200200490000800212100002300220700002500243700001500268700002700283856011600310 2001 eng d00aGlacial cryoconite ecosystems: a bipolar comparison of algal communities and habitats0 aGlacial cryoconite ecosystems a bipolar comparison of algal comm a173-1970 v1231 aMueller, Derek, R.1 aVincent, Warwick, F.1 aPollard, W1 aFritsen, Christian, H. uhttps://mcm.lternet.edu/content/glacial-cryoconite-ecosystems-bipolar-comparison-algal-communities-and-habitats00774nas a2200193 4500008004100000245014400041210006900185300001200254490000700266100001700273700002400290700002100314700002800335700002400363700002400387700002100411700002000432856012800452 2001 eng d00aThe McMurdo Dry Valleys Long-Term Ecological Research Program: new understanding of the biogeochemistry of the Dry Valley lakes: a review.0 aMcMurdo Dry Valleys LongTerm Ecological Research Program new und a202-2170 v251 aLyons, Berry1 aWelch, Kathleen, A.1 aPriscu, John, C.1 aLaybourn-Parry, Johanna1 aMoorhead, Daryl, L.1 aMcKnight, Diane, M.1 aDoran, Peter, T.1 aTranter, Martyn uhttps://mcm.lternet.edu/content/mcmurdo-dry-valleys-long-term-ecological-research-program-new-understanding-biogeochemistry00561nas a2200133 4500008004100000245011900041210006900160260001200229300001400241490000700255100001900262700002100281856012500302 2001 eng d00aPhytoplankton phosphorus deficiency and alkaline phosphatase activity in the McMurdo Dry Valley lakes, Antarctica.0 aPhytoplankton phosphorus deficiency and alkaline phosphatase act c09/2001 a1331-13460 v461 aDore, John, E.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/phytoplankton-phosphorus-deficiency-and-alkaline-phosphatase-activity-mcmurdo-dry-valley00477nas a2200169 4500008004100000245002200041210002200063260003000085300001000115100002000125700002000145700002400165700001900189700002200208700002300230856005400253 2001 eng d00aSoil Biodiversity0 aSoil Biodiversity aNew YorkbSpringer Verlag a47-821 aWall, Diana, H.1 aAdams, Gina, A.1 aParsons, Andrew, N.1 aChapin, F., S.1 aSala, Osvaldo, E.1 aHuber-Sannwald, E. uhttps://mcm.lternet.edu/content/soil-biodiversity00578nas a2200133 4500008004100000245011300041210006900154300001200223490000700235100002400242700002100266700002800287856012900315 2000 eng d00aDistribution and phylogeny of bacterial communities associated with mineral particles in Antarctic lake ice.0 aDistribution and phylogeny of bacterial communities associated w a197-2020 v391 aGordon, Douglas, A.1 aPriscu, John, C.1 aGiovannoni, Stephen, J. uhttps://mcm.lternet.edu/content/distribution-and-phylogeny-bacterial-communities-associated-mineral-particles-antarctic-lake00550nas a2200133 4500008004100000245010500041210006900146300001200215490000700227100002700234700001200261700002100273856012200294 2000 eng d00aDistribution of organic carbon and nitrogen in surface soils in the McMurdo Dry Valleys, Antarctica.0 aDistribution of organic carbon and nitrogen in surface soils in  a121-1280 v231 aFritsen, Christian, H.1 aGrue, A1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/distribution-organic-carbon-and-nitrogen-surface-soils-mcmurdo-dry-valleys-antarctica00870nas a2200325 4500008004100000245005200041210005200093300001400145490000800159100002200167700001400189700001500203700001300218700001400231700001800245700001200263700001300275700001400288700001500302700002000317700001900337700001500356700001400371700001800385700001300403700002100416700001600437700001500453856007600468 2000 eng d00aGlobal biodiversity scenarios for the year 21000 aGlobal biodiversity scenarios for the year 2100 a1770-17740 v2871 aSala, Osvaldo, E.1 aKinzig, A1 aLeemans, R1 aLodge, D1 aMooney, H1 aOesterheld, M1 aPoff, N1 aSykes, M1 aWalker, B1 aWalkder, M1 aWall, Diana, H.1 aChapin, F., S.1 aArmesto, J1 aBerlow, E1 aBloomfield, J1 aDirzo, R1 aHuber-Sanwald, E1 aHuenneke, L1 aJackson, R uhttps://mcm.lternet.edu/content/global-biodiversity-scenarios-year-210000667nas a2200169 4500008004100000245011600041210006900157300001200226490000700238100001700245700002400262700002100286700002100307700001900328700002400347856012600371 2000 eng d00aThe importance of landscape position and legacy: The evolution of the Taylor Valley Lake District, Antarctica.0 aimportance of landscape position and legacy The evolution of the a355-3670 v431 aLyons, Berry1 aFountain, Andrew, G1 aDoran, Peter, T.1 aPriscu, John, C.1 aNeumann, Klaus1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/importance-landscape-position-and-legacy-evolution-taylor-valley-lake-district-antarctica00388nas a2200133 4500008004100000245003300041210002900074260003100103300000800134100002000142700002400162700001400186856005400200 2000 eng d00aThe Lions of the Dry Valleys0 aLions of the Dry Valleys bLonely Planet Publications a3131 aWall, Diana, H.1 aParsons, Andrew, N.1 aRubin, J. uhttps://mcm.lternet.edu/content/lions-dry-valleys00374nas a2200145 4500008004100000245002200041210002200063260001900085300001200104490000600116100001800122700002000140700001400160856005400174 2000 eng d00aSoil Conservation0 aSoil Conservation bAcademic Press a315-3260 v51 aPorazinska, D1 aWall, Diana, H.1 aLevin, S. uhttps://mcm.lternet.edu/content/soil-conservation00607nas a2200157 4500008004100000245007100041210006900112100002100181700002000202700003300222700002700255700002800282700002300310700001800333856009800351 1999 eng d00aCarbon transformations in a perennially ice-covered Antarctic lake0 aCarbon transformations in a perennially icecovered Antarctic lak1 aPriscu, John, C.1 aWolf, Craig, F.1 aTakacs-Vesbach, Cristina, D.1 aFritsen, Christian, H.1 aLaybourn-Parry, Johanna1 aRoberts, Emily, C.1 aSattl, Birgit uhttps://mcm.lternet.edu/content/carbon-transformations-perennially-ice-covered-antarctic-lake00574nas a2200133 4500008004100000245012300041210006900164300001200233490000800245100002100253700002100274700001900295856012600314 1999 eng d00aThe distribution and relative abundance of ammonium-oxidizing bacteria in lakes of the McMurdo Dry Valleys, Antarctica0 adistribution and relative abundance of ammoniumoxidizing bacteri a113-1300 v4011 aVoytek, Mary, A.1 aPriscu, John, C.1 aWard, Bess, B. uhttps://mcm.lternet.edu/content/distribution-and-relative-abundance-ammonium-oxidizing-bacteria-lakes-mcmurdo-dry-valleys00781nas a2200241 4500008004100000245006000041210005900101300001400160490000800174100002100182700002200203700001700225700002100242700002000263700002200283700002700305700003300332700002400365700002000389700002500409700001600434856008900450 1999 eng d00aGeomicrobiology of sub-glacial ice above Vostok Station0 aGeomicrobiology of subglacial ice above Vostok Station a2141-21440 v2861 aPriscu, John, C.1 aAdams, Edward, E.1 aLyons, Berry1 aVoytek, Mary, A.1 aMogk, David, W.1 aBrown, Robert, L.1 aMcKay, Christopher, P.1 aTakacs-Vesbach, Cristina, D.1 aWelch, Kathleen, A.1 aWolf, Craig, F.1 aKirshtein, Julie, D.1 aAvci, Recep uhttps://mcm.lternet.edu/content/geomicrobiology-sub-glacial-ice-above-vostok-station00544nas a2200157 4500008004100000245006500041210006500106100001500171700001500186700001400201700002700215700002100242700001300263700001600276856009400292 1999 eng d00aLake ice microbial communities in alpine and Antarctic lakes0 aLake ice microbial communities in alpine and Antarctic lakes1 aPsenner, R1 aSattler, B1 aWillie, A1 aFritsen, Christian, H.1 aPriscu, John, C.1 aFelip, M1 aCatalan, J. uhttps://mcm.lternet.edu/content/lake-ice-microbial-communities-alpine-and-antarctic-lakes00338nas a2200121 4500008004100000245003500041210003500076260001200111300001200123490000700135100002100142856005300163 1999 eng d00aLife in the valley of the dead0 aLife in the valley of the dead c12/1999 a959-9600 v491 aPriscu, John, C. uhttps://mcm.lternet.edu/content/life-valley-dead00878nas a2200277 4500008004100000245006500041210006400106260001200170300001200182490000700194653002300201100002400224700001700248700002400265700002000289700002100309700002100330700002400351700002400375700002400399700002100423700002000444700002400464700002300488856008900511 1999 eng d00aPhysical controls on the Taylor Valley Ecosystem, Antarctica0 aPhysical controls on the Taylor Valley Ecosystem Antarctica c12/1999 a961-9720 v4910aWater availability1 aFountain, Andrew, G1 aLyons, Berry1 aBurkins, Melody, B.1 aDana, Gayle, L.1 aDoran, Peter, T.1 aLewis, Karen, J.1 aMcKnight, Diane, M.1 aMoorhead, Daryl, L.1 aParsons, Andrew, N.1 aPriscu, John, C.1 aWall, Diana, H.1 aWharton, Robert, A.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/physical-controls-taylor-valley-ecosystem-antarctica00589nas a2200121 4500008004100000245016300041210006900204300001200273490000700285100002700292700002100319856012700340 1999 eng d00aSeasonal change in the optical properties of the permanent ice cover on Lake Bonney, Antarctica: Consequences for lake productivity and phytoplankton dynamics0 aSeasonal change in the optical properties of the permanent ice c a447-4540 v441 aFritsen, Christian, H.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/seasonal-change-optical-properties-permanent-ice-cover-lake-bonney-antarctica-consequences00670nas a2200133 4500008004100000245021900041210006900260300001200329490000700341100002100348700001900369700002100388856012700409 1998 eng d00aThe Abundance of Ammonium-Oxidizing Bacteria in Lake Bonney, Antarctica Determined by Immunofluorescence, PCR and In Situ Hybridization, in Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica0 aAbundance of AmmoniumOxidizing Bacteria in Lake Bonney Antarctic a217-2280 v721 aVoytek, Mary, A.1 aWard, Bess, B.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/abundance-ammonium-oxidizing-bacteria-lake-bonney-antarctica-determined-immunofluorescence00505nas a2200121 4500008004100000245008900041210006900130300001200199490000700211100002100218700002700239856011700266 1998 eng d00aAntarctic lake-ice microbial consortia: Origin, distribution, and growth physiology0 aAntarctic lakeice microbial consortia Origin distribution and gr a223-2240 v311 aPriscu, John, C.1 aFritsen, Christian, H. uhttps://mcm.lternet.edu/content/antarctic-lake-ice-microbial-consortia-origin-distribution-and-growth-physiology00553nas a2200121 4500008004100000245012200041210006900163300001200232490000700244100003300251700002100284856012600305 1998 eng d00aBacterioplankton dynamics in the McMurdo Dry Valley lakes, Antarctica: Production and biomass loss over four seasons0 aBacterioplankton dynamics in the McMurdo Dry Valley lakes Antarc a239-2500 v361 aTakacs-Vesbach, Cristina, D.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/bacterioplankton-dynamics-mcmurdo-dry-valley-lakes-antarctica-production-and-biomass-loss00670nas a2200133 4500008004100000245021400041210006900255300001100324490000700335100002600342700001800368700002400386856012600410 1998 eng d00aThe Composite Glacial Erosional Landscape of the Northern McMurdo Dry Valleys: Implications for Antarctic Tertiary Glacial History, in Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica0 aComposite Glacial Erosional Landscape of the Northern McMurdo Dr aJan-380 v721 aPrentice, Michael, L.1 aKleman, Johan1 aStroeven, Arjen, P. uhttps://mcm.lternet.edu/content/composite-glacial-erosional-landscape-northern-mcmurdo-dry-valleys-implications-antarctic00574nas a2200121 4500008004100000245014600041210006900187300001200256490000700268100002700275700002100302856012900323 1998 eng d00aCyanobacterial assemblages in permanent ice covers on Antarctic lakes: distribution, growth rate, and temperature response of photosynthesis0 aCyanobacterial assemblages in permanent ice covers on Antarctic  a587-5970 v341 aFritsen, Christian, H.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/cyanobacterial-assemblages-permanent-ice-covers-antarctic-lakes-distribution-growth-rate-and00568nas a2200145 4500008004100000245008700041210006900128300001200197490000700209100002400216700002200240700002800262700002100290856011100311 1998 eng d00aCyanobacterial communities associated with mineral particles in antarctic lake ice0 aCyanobacterial communities associated with mineral particles in  a224-2250 v311 aGordon, Douglas, A.1 aLanoil, Brian, D.1 aGiovannoni, Stephen, J.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/cyanobacterial-communities-associated-mineral-particles-antarctic-lake-ice00610nas a2200145 4500008004100000245012600041210006900167300001200236490000700248100002200255700001600277700002400293700002300317856012400340 1998 eng d00aDistribution, Community Structure, and Microhabitats of Soil Invertebrates along an Elevational Gradient in Taylor Valley0 aDistribution Community Structure and Microhabitats of Soil Inver a133-1410 v301 aPowers, Laura, E.1 aHo, Mengchi1 aFreckman, Diana, W.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/distribution-community-structure-and-microhabitats-soil-invertebrates-along-elevational00522nas a2200097 4500008004100000245014600041210006900187100002100256700002100277856012600298 1998 eng d00aEcosystem dynamics in a polar desert: the McMurdo Dry Valleys, Antarctica (American Geophysical Union Antarctic Research Series. 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4500008004100000245012400041210006900165300001200234490000700246100001900253700002100272856012300293 1998 eng d00aMcMurdo Dry Valleys LTER: Phosphorus deficiency and alkaline phosphatase activity in lakes of Taylor Valley, Antarctica0 aMcMurdo Dry Valleys LTER Phosphorus deficiency and alkaline phos a206-2080 v311 aDore, John, E.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/mcmurdo-dry-valleys-lter-phosphorus-deficiency-and-alkaline-phosphatase-activity-lakes00567nas a2200121 4500008004100000245015200041210006900193300001200262490000700274100002000281700002100301856012300322 1998 eng d00aMicrobial phototrophic, heterotrophic, and diazotrophic activities associated with aggregates in the permanent ice cover of Lake Bonney, Antarctica0 aMicrobial phototrophic heterotrophic and diazotrophic activities a221-2300 v361 aPaerl, Hans, W.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/microbial-phototrophic-heterotrophic-and-diazotrophic-activities-associated-aggregates00549nas 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4500008004100000245007100041210006900112260001200181300001400193490000800207653001100215100002100226700002700247700002200274700002800296700002000324700002700344700002100371700002400392700002200416700002400438856005800462 1998 eng d00aPerennial Antarctic Lake Ice: An Oasis for Life in a Polar Desert0 aPerennial Antarctic Lake Ice An Oasis for Life in a Polar Desert c06/1998 a2095-20980 v28010aBiggie1 aPriscu, John, C.1 aFritsen, Christian, H.1 aAdams, Edward, E.1 aGiovannoni, Stephen, J.1 aPaerl, Hans, W.1 aMcKay, Christopher, P.1 aDoran, Peter, T.1 aGordon, Douglas, A.1 aLanoil, Brian, D.1 aPinckney, James, L. uhttp://www.sciencemag.org/content/280/5372/2095.short00632nas a2200157 4500008004100000245010400041210006900145300001200214490000700226100002200233700002100255700002700276700001900303700002500322856012700347 1998 eng d00aPermanent Ice Covers of the McMurdo Dry Valley Lakes, Antarctica: Bubble Formation and Metamorphism0 aPermanent Ice Covers of the McMurdo Dry Valley Lakes 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Ventilated  a1544-15510 v411 aPriscu, John, C.1 aDownes, Malcolm, T.1 aMcKay, Christopher, P. uhttps://mcm.lternet.edu/content/extreme-supersaturation-nitrous-oxide-poorly-ventilated-antarctic-lake00603nas a2200133 4500008004100000245015200041210006900193300001200262490000700274100002500281700002200306700002100328856012000349 1996 eng d00aPhytoplankton Dynamics in the Stratified Water Column of Lake Bonney, Antarctica. 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uhttps://mcm.lternet.edu/content/soil-chemistry-along-glacial-chronosequence-andrews-ridge-taylor-valley00490nas a2200133 4500008004100000245007400041210006900115300001200184490000700196100002200203700002100225700001800246856009200264 1995 eng d00aSome metamorphic processes in the lake ice of the McMurdo Dry Valleys0 aSome metamorphic processes in the lake ice of the McMurdo Dry Va a307-3090 v301 aAdams, Edward, E.1 aPriscu, John, C.1 aSato, Atsushi uhttps://mcm.lternet.edu/content/some-metamorphic-processes-lake-ice-mcmurdo-dry-valleys00503nas a2200133 4500008004100000245007400041210006900115300001200184490000700196100002200203700002400225700002300249856009700272 1995 eng d00aSpatial Distribution of Nematodes in Polar Desert Soils of Antarctica0 aSpatial Distribution of Nematodes in Polar Desert Soils of Antar a325-3330 v151 aPowers, Laura, E.1 aFreckman, Diana, W.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/spatial-distribution-nematodes-polar-desert-soils-antarctica00497nas a2200133 4500008004100000245007000041210006900111300001200180490000700192100002200199700002400221700002300245856009500268 1994 eng d00aDepth distribution of soil nematodes in Taylor Valley, Antarctica0 aDepth distribution of soil nematodes in Taylor Valley Antarctica a175-1760 v291 aPowers, Laura, E.1 aFreckman, Diana, W.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/depth-distribution-soil-nematodes-taylor-valley-antarctica00688nas a2200181 4500008004100000245010100041210006900142300001200211490000700223100002400230700001700254700002100271700002000292700002400312700002200336700002400358856012400382 1994 eng d00aMcMurdo LTER: Inorganic geochemical studies with special reference to calcium carbonate dynamics0 aMcMurdo LTER Inorganic geochemical studies with special referenc a237-2390 v291 aWelch, Kathleen, A.1 aLyons, Berry1 aPriscu, John, C.1 aEdwards, R., L.1 aMcKnight, Diane, M.1 aHouse, Harold, R.1 aWharton, Robert, A. uhttps://mcm.lternet.edu/content/mcmurdo-lter-inorganic-geochemical-studies-special-reference-calcium-carbonate-dynamics00468nas a2200109 4500008004100000245009400041210006900135300001200204490000700216100002100223856011400244 1994 eng d00aMcMurdo LTER: Phytoplankton nutrient deficiency in lakes of the Taylor Valley, Antarctica0 aMcMurdo LTER Phytoplankton nutrient deficiency in lakes of the T a239-2410 v291 aPriscu, John, C. uhttps://mcm.lternet.edu/content/mcmurdo-lter-phytoplankton-nutrient-deficiency-lakes-taylor-valley-antarctica00587nas a2200145 4500008004100000245010700041210006900148300001200217490000700229100002200236700002400258700001600282700002300298856012000321 1994 eng d00aMcMurdo LTER:Soil and nematode distribution along an elevational gradient in Taylor Valley, Antarctica0 aMcMurdo LTERSoil and nematode distribution along an elevational  a228-2290 v291 aPowers, Laura, E.1 aFreckman, Diana, W.1 aHo, Mengchi1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/mcmurdo-ltersoil-and-nematode-distribution-along-elevational-gradient-taylor-valley00545nas a2200121 4500008004100000245011800041210006900159300001400228490000700242100002500249700002100274856012800295 1994 eng d00aNatural Fluorescence and Quantum Yields in Vertically Stationary Phytoplankton from Perennially Ice-Covered Lakes0 aNatural Fluorescence and Quantum Yields in Vertically Stationary a1399-14100 v391 aLizotte, Michael, P.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/natural-fluorescence-and-quantum-yields-vertically-stationary-phytoplankton-perennially-ice00544nas a2200145 4500008004100000245008200041210006900123300000800192490000700200653001100207100002200218700002400240700002300264856011100287 1994 eng d00aNematode biodiversity and community structure in Antarctic Polar Desert Soils0 aNematode biodiversity and community structure in Antarctic Polar a1860 v7510aBiggie1 aPowers, Laura, E.1 aFreckman, Diana, W.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/nematode-biodiversity-and-community-structure-antarctic-polar-desert-soils00486nas a2200121 4500008004100000245006900041210006900110260001800179100002400197700002300221700002200244856009800266 1994 eng d00aNematode biodiversity and survival in Antarctic Dry Valley soils0 aNematode biodiversity and survival in Antarctic Dry Valley soils aVenice, Italy1 aFreckman, Diana, W.1 aVirginia, Ross, A.1 aPowers, Laura, E. uhttps://mcm.lternet.edu/content/nematode-biodiversity-and-survival-antarctic-dry-valley-soils00456nas a2200109 4500008004100000245006900041210006900110100002200179700002400201700002300225856009800248 1994 eng d00aSurvival of Scottnema lindsayae under extreme osmotic conditions0 aSurvival of Scottnema lindsayae under extreme osmotic conditions1 aPowers, Laura, E.1 aFreckman, Diana, W.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/survival-scottnema-lindsayae-under-extreme-osmotic-conditions00438nas a2200109 4500008004100000245007400041210006900115300001400184490000700198100002100205856010200226 1993 eng d00aBook Review: Physical and biogeochemical processes in Antarctic lakes0 aBook Review Physical and biogeochemical processes in Antarctic l a1499-15000 v391 aPriscu, John, C. uhttps://mcm.lternet.edu/content/book-review-physical-and-biogeochemical-processes-antarctic-lakes00582nas a2200133 4500008004100000245012100041210006900162300001200231490000700243100002600250700002100276700003000297856012100327 1993 eng d00aInfluence of high salinity levels on ambient inorganic nitrogen and nitrogen-15 extraction efficiency in Lake Bonney0 aInfluence of high salinity levels on ambient inorganic nitrogen  a245-2460 v281 aBartlett, Richard, D.1 aPriscu, John, C.1 aWoolston, Christopher, D. uhttps://mcm.lternet.edu/content/influence-high-salinity-levels-ambient-inorganic-nitrogen-and-nitrogen-15-extraction00549nas a2200121 4500008004100000245013900041210006900180300001200249490000700261100001900268700002100287856011900308 1993 eng d00aMicrobial communities in the permanent ice cap of Lake Bonney, Antarctica: Relationships among chlorophyll-a , gravel, and nutrients.0 aMicrobial communities in the permanent ice cap of Lake Bonney An a247-2490 v281 aWing, Kate, T.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/microbial-communities-permanent-ice-cap-lake-bonney-antarctica-relationships-among00508nas a2200121 4500008004100000245009400041210006900135300001200204490000700216100002100223700002100244856012100265 1993 eng d00aMicrobial respiration potential in Lake Bonney using a novel tetrazolium-reduction method0 aMicrobial respiration potential in Lake Bonney using a novel tet a244-2450 v281 aSmith, James, J.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/microbial-respiration-potential-lake-bonney-using-novel-tetrazolium-reduction-method00451nas a2200133 4500008004100000245005600041210005600097300001200153490000700165100001900172700002000191700002100211856008500232 1993 eng d00aNitrifying and denitrifying bacteria in Lake Bonney0 aNitrifying and denitrifying bacteria in Lake Bonney a239-2410 v281 aWard, Bess, B.1 aCockcroft, A.R.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/nitrifying-and-denitrifying-bacteria-lake-bonney00517nas a2200121 4500008004100000245009700041210006900138300001200207490000700219100003000226700002100256856011800277 1993 eng d00aPhytoplankton utilization of ammonium and nitrate in Lake Bonney: A preliminary assessment.0 aPhytoplankton utilization of ammonium and nitrate in Lake Bonney a241-2430 v281 aWoolston, Christopher, D.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/phytoplankton-utilization-ammonium-and-nitrate-lake-bonney-preliminary-assessment00554nas a2200133 4500008004100000245010200041210006900143300001200212490000700224100002100231700001900252700002400271856012500295 1993 eng d00aWater column transformations of nitrogen in Lake Bonney, a perennially ice-covered antarctic lake0 aWater column transformations of nitrogen in Lake Bonney a perenn a237-2390 v281 aPriscu, John, C.1 aWard, Bess, B.1 aDownes, Malcolm, T. uhttps://mcm.lternet.edu/content/water-column-transformations-nitrogen-lake-bonney-perennially-ice-covered-antarctic-lake00579nas a2200121 4500008004100000245016100041210006900202300001200271490000700283100002500290700002100315856012100336 1992 eng d00aPhotosynthesis-Irradiance Relationships in Phytoplankton From the Physically Stable Water Column of a Perennially Ice-Covered Lake (Lake Bonney, Antarctica)0 aPhotosynthesisIrradiance Relationships in Phytoplankton From the a179-1850 v281 aLizotte, Michael, P.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/photosynthesis-irradiance-relationships-phytoplankton-physically-stable-water-column00550nas a2200121 4500008004100000245013100041210006900172300000900241490000700250100002500257700002100282856012500303 1992 eng d00aSpectral Irradiance and Bio-Optical Properties in Perennially Ice-Covered Lakes of the Dry Valleys (McMurdo Sound, Antarctica)0 aSpectral Irradiance and BioOptical Properties in Perennially Ice a1-140 v571 aLizotte, Michael, P.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/spectral-irradiance-and-bio-optical-properties-perennially-ice-covered-lakes-dry-valleys00513nas a2200121 4500008004100000245010000041210006900141300001000210490000800220100002200228700002100250856012000271 1990 eng d00aDevelopment and Application of a Technique for Estimating Nutrient Deficiency in Soft Sediments0 aDevelopment and Application of a Technique for Estimating Nutrie a93-970 v2031 aDodds, Walter, K.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/development-and-application-technique-estimating-nutrient-deficiency-soft-sediments00573nas a2200133 4500008004100000245011000041210006900151300001200220490000700232100002100239700002500260700002700285856012700312 1989 eng d00aInorganic Nitrogen Uptake and Regeneration in Perennially Ice-Covered Lakes Fryxell and Vanda, Antarctica0 aInorganic Nitrogen Uptake and Regeneration in Perennially IceCov a335-3510 v111 aPriscu, John, C.1 aVincent, Warwick, F.1 aHoward-Williams, Clive uhttps://mcm.lternet.edu/content/inorganic-nitrogen-uptake-and-regeneration-perennially-ice-covered-lakes-fryxell-and-vanda00496nas a2200109 4500008004100000245011400041210006900155300001200224490000800236100002100244856012100265 1989 eng d00aPhoton Dependence of Inorganic Nitrogen Transport by Phytoplankton in Perennially Ice-Covered Antarctic Lakes0 aPhoton Dependence of Inorganic Nitrogen Transport by Phytoplankt a173-1820 v1721 aPriscu, John, C. uhttps://mcm.lternet.edu/content/photon-dependence-inorganic-nitrogen-transport-phytoplankton-perennially-ice-covered00594nas a2200145 4500008004100000245010500041210006900146300001200215490000600227100002100233700002400254700002200278700002800300856012000328 1989 eng d00aTemperature Dependence of Inorganic Nitrogen Uptake and Assimilation in Antarctic Sea-Ice Microalgae0 aTemperature Dependence of Inorganic Nitrogen Uptake and Assimila a443-4460 v91 aPriscu, John, C.1 aPalmisano, Anna, C.1 aPriscu, Linda, R.1 aSullivan, Cornelius, W. uhttps://mcm.lternet.edu/content/temperature-dependence-inorganic-nitrogen-uptake-and-assimilation-antarctic-sea-ice00629nas a2200145 4500008004100000245013400041210006900175300001200244490000700256100002100263700002200284700002700306700002500333856012500358 1988 eng d00aDiel Patterns of Photosynthate Biosynthesis by Phytoplankton in Permanently Ice-Covered Antarctic Lakes Under Continuous Sunlight0 aDiel Patterns of Photosynthate Biosynthesis by Phytoplankton in  a333-3400 v101 aPriscu, John, C.1 aPriscu, Linda, R.1 aHoward-Williams, Clive1 aVincent, Warwick, F. uhttps://mcm.lternet.edu/content/diel-patterns-photosynthate-biosynthesis-phytoplankton-permanently-ice-covered-antarctic00592nas a2200145 4500008004100000245009800041210006900139300001200208490000700220100002100227700002200248700002500270700002700295856012400322 1987 eng d00aPhotosynthate Distribution by Microplankton in Permanently Ice-Covered Antarctic Desert Lakes0 aPhotosynthate Distribution by Microplankton in Permanently IceCo a260-2700 v321 aPriscu, John, C.1 aPriscu, Linda, R.1 aVincent, Warwick, F.1 aHoward-Williams, Clive uhttps://mcm.lternet.edu/content/photosynthate-distribution-microplankton-permanently-ice-covered-antarctic-desert-lakes