@article {4374, title = {The polar regions in a 2{\textdegree}C warmer world}, journal = {Science Advances}, volume = {5}, year = {2019}, month = {12/2019}, pages = {eaaw9883}, abstract = {

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.

}, keywords = {LTER-MCM}, doi = {10.1126/sciadv.aaw9883}, url = {http://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aaw9883}, author = {Post, Eric and Alley, Richard B. and Christensen, Torben R. and Macias-Fauria, Marc and Forbes, Bruce C. and Michael N. Gooseff and Iler, Amy and Kerby, Jeffrey T. and Laidre, Kristin L. and Mann, Michael E. and Olofsson, Johan and Stroeve, Julienne C. and Ulmer, Fran and Ross A. Virginia and Wang, Muyin} } @article {4021, title = {Primary productivity as a control over soil microbial diversity along environmental gradients in a polar desert ecosystem}, journal = {PeerJ}, volume = {5}, year = {2017}, month = {07/2017}, pages = {e3377}, abstract = {

Primary production is the fundamental source of energy to foodwebs and ecosystems, and is thus an important constraint on soil communities. This coupling is particularly evident in polar terrestrial ecosystems where biological diversity and activity is tightly constrained by edaphic gradients of productivity (e.g., soil moisture, organic carbon availability) and geochemical severity (e.g., pH, electrical conductivity). In the McMurdo Dry Valleys of Antarctica, environmental gradients determine numerous properties of soil communities and yet relatively few estimates of gross or net primary productivity (GPP, NPP) exist for this region. Here we describe a survey utilizing pulse amplitude modulation (PAM) fluorometry to estimate rates of GPP across a broad environmental gradient along with belowground microbial diversity and decomposition. PAM estimates of GPP ranged from an average of 0.27 mmol O2/m2/s in the most arid soils to an average of 6.97 mmol O2/m2/s in the most productive soils, the latter equivalent to 217 g C/m2/y in annual NPP assuming a 60 day growing season. A diversity index of four carbon-acquiring enzyme activities also increased with soil productivity, suggesting that the diversity of organic substrates in mesic environments may be an additional driver of microbial diversity. Overall, soil productivity was a stronger predictor of microbial diversity and enzymatic activity than any estimate of geochemical severity. These results highlight the fundamental role of environmental gradients to control community diversity and the dynamics of ecosystem-scale carbon pools in arid systems.\ 

}, keywords = {LTER-MCM}, doi = {10.7717/peerj.3377}, url = {https://peerj.com/articles/3377/}, author = {Kevin M. Geyer and Cristina D. Takacs-Vesbach and Michael N. Gooseff and John E. Barrett} } @article {3718, title = {Patterns of hydrologic connectivity in the McMurdo dry valleys, Antarctica: a synthesis of 20 years of hydrologic data}, journal = {Hydrological Processes}, volume = {30}, year = {2016}, month = {04/2016}, pages = {2958-2975}, chapter = {2958}, abstract = {

Streams in the McMurdo Dry Valleys (MDVs) of Antarctica moderate an important hydrologic and biogeochemical connection between upland alpine glaciers, valley-bottom soils, and lowland closed-basin lakes. Moreover, MDV streams are simple but dynamic systems ideal for studying interacting hydrologic and ecological dynamics. This work synthesizes 20\ years of hydrologic data, collected as part of the MDVs Long-Term Ecological Research project, to assess spatial and temporal dynamics of hydrologic connectivity between glaciers, streams, and lakes. Long-term records of stream discharge (Q), specific electrical conductance (EC), and water temperature (T) from 18 streams were analysed in order to quantify the magnitude, duration, and frequency of hydrologic connections over daily, annual, and inter-annual timescales. At a daily timescale, we observe predictable diurnal variations in Q, EC, and T. At an annual timescale, we observe longer streams to be more intermittent, warmer, and have higher median EC values, compared to shorter streams. Longer streams also behave chemostatically with respect to EC, whereas shorter streams are more strongly characterized by dilution. Inter-annually, we observe significant variability in annual runoff volumes, likely because of climatic variability over the 20 record years considered. Hydrologic connections at all timescales are vital to stream ecosystem structure and function. This synthesis of hydrologic connectivity in the MDVs provides a useful end-member template for assessing hydrologic connectivity in more structurally complex temperate watersheds.\ 

}, keywords = {LTER-MCM}, doi = {10.1002/hyp.10818}, url = {http://onlinelibrary.wiley.com/doi/10.1002/hyp.10818}, author = {Wlostowski, Adam and Michael N. Gooseff and Diane M. McKnight and Chris Jaros and W. Berry Lyons} } @article {3712, title = {Potential for real-time understanding of coupled hydrologic and biogeochemical processes in stream ecosystems: Future integration of telemetered data with process models for glacial meltwater streams}, journal = {Water Resources Research}, volume = {51}, year = {2015}, month = {08/2015}, pages = {6725 - 6738}, keywords = {LTER-MCM}, doi = {10.1002/2015WR017618}, url = {http://doi.wiley.com/10.1002/2015WR017618http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002\%2F2015WR017618}, author = {Diane M. McKnight and Cozzetto, K and Cullis, James D.S. and Michael N. Gooseff and Chris Jaros and Koch, J. and W. Berry Lyons and Neupauer, R. M. and Wlostowski, Adam} }