@article {4833, title = {Ecological stoichiometry drives the evolution of soil nematode life history traits}, journal = {Soil Biology and Biochemistry}, volume = {177}, year = {2023}, month = {02/2023}, pages = {108891}, abstract = {

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.

}, keywords = {LTER-MCM, elemental stoichiometry, growth rate hypothesis, life history theory, molecular evolution, nematoda, rRNA}, doi = {10.1016/j.soilbio.2022.108891}, url = {https://www.sciencedirect.com/science/article/pii/S0038071722003480}, author = {Xue, Xia and Bishwo N. Adhikari and Ball, Becky and John E. Barrett and Miao, Jinxin and Perkes, Ammon and Martin, Mac and Breana L. Simmons and Diana H. Wall and Byron Adams} } @article {4107, title = {Spatial and temporal patterns of microbial mats and associated invertebrates along an Antarctic stream}, journal = {Polar Biology}, volume = {41}, year = {2018}, month = {10/2018}, pages = {1911{\textendash}1921}, abstract = {

Microbial biofilms are biological hotspots in many alpine and polar ecosystems, but the controls on and functional significance of their fauna are little known. We studied cyanobacterial mats and the underlying sediment in a glacial meltwater stream in the McMurdo Dry Valleys, Antarctica. We investigated mat biomass (total and phototrophic), diatoms, and micro-meiofauna (nematodes, rotifers, and tardigrades) at nine sites along a 1670 m stream reach in a cold, low-flow growing season, and in a warmer growing season in which peak flows (above 100 L s\−1) scoured the mats. Diatom and invertebrate communities were not related, but mat biomass in the low-flow year was negatively related to nematode abundance, including that of the omnivore\ Eudorylaimus. In the high-flow year that followed, invertebrate abundance was reduced in the mats, diatom community structure was altered, and mat biomass was higher. The difference in invertebrate abundance between years was greater in mats in upstream reaches, where the greatest increases in flow velocity may have occurred, and was negligible in mats in downstream reaches as well as in the sediment beneath the mats. Integrating our results with previous findings, we generate two predictive hypotheses to be tested in glacial meltwater streams: (1) under peak flows invertebrates decline in the microbial mats, while (2) the sediment beneath the mats is a refuge from the flow disturbance. Our results also suggest that, under stable flow conditions, microinvertebrate grazers could exert top-down control on microbial mat biomass.

}, keywords = {LTER-MCM, diatoms, Disturbance, Dry valleys, Epilithon, Microfauna, Stream flow}, doi = {10.1007/s00300-018-2331-4}, url = {http://link.springer.com/10.1007/s00300-018-2331-4}, author = {Andriuzzi, Walter S. and Lee F. Stanish and Breana L. Simmons and Chris Jaros and Byron Adams and Diana H. Wall and Diane M. McKnight} } @article {1116, title = {Extreme streams: flow intermittency as a control on diatom communities in meltwater streams in the McMurdo Dry Valleys, Antarctica}, journal = {Canadian Journal of Fisheries and Aquatic Sciences}, volume = {69}, year = {2012}, month = {08/2012}, pages = {1405 - 1419}, keywords = {LTER-MCM}, doi = {10.1139/f2012-022}, url = {http://www.nrcresearchpress.com/doi/abs/10.1139/f2012-022$\#$.UH2NlWcnq9g}, author = {Lee F. Stanish and Tyler J. Kohler and Rhea M.M. Esposito and Breana L. Simmons and Uffe N. Nielsen and Diana H. Wall and Diana R. Nemergut and Diane M. McKnight} } @article {1147, title = {Experimentally increased snow accumulation alters soil moisture and animal community structure in a polar desert}, journal = {Polar Biology}, volume = {33}, year = {2010}, month = {7/2010}, pages = {897 - 907}, keywords = {LTER-MCM}, doi = {10.1007/s00300-010-0766-3}, author = {Edward Ayres and Johnson N. Nkem and Diana H. Wall and Byron Adams and John E. Barrett and Breana L. Simmons and Ross A. Virginia and Andrew G Fountain} } @article {1190, title = {Long-term experimental warming reduces soil nematode populations in the McMurdo Dry Valleys, Antarctica}, journal = {Soil Biology \& Biochemistry}, volume = {41}, year = {2009}, pages = {2052-2060}, keywords = {LTER-MCM}, doi = {10.1016/j.soilbio.2009.07.009}, author = {Breana L. Simmons and Diana H. Wall and Byron Adams and Edward Ayres and John E. Barrett and Ross A. Virginia} } @article {1195, title = {Terrestrial mesofauna in above- and below-ground habitats: Taylor Valley, Antarctica}, journal = {Polar Biology}, volume = {32}, year = {2009}, pages = {1549-1558}, keywords = {LTER-MCM}, doi = {LTER}, author = {Breana L. Simmons and Diana H. Wall and Byron Adams and Edward Ayres and John E. Barrett and Ross A. Virginia} } @article {1211, title = {Effects of Human Trampling on Populations of Soil Fauna in the McMurdo Dry Valleys, Antarctica.}, journal = {Conservation Biology}, volume = {22}, year = {2008}, month = {12/2008}, pages = {1544-1551}, abstract = {

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.

}, keywords = {LTER-MCM}, doi = {10.1111/j.1523-1739.2008.01034.x}, author = {Edward Ayres and Johnson N. Nkem and Diana H. Wall and Byron Adams and John E. Barrett and Broos, E and Andrew N. Parsons and Powers, Laura E. and Breana L. Simmons and Ross A. Virginia} }