<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Xue, Xia</style></author><author><style face="normal" font="default" size="100%">Bishwo N. Adhikari</style></author><author><style face="normal" font="default" size="100%">Ball, Becky</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Miao, Jinxin</style></author><author><style face="normal" font="default" size="100%">Perkes, Ammon</style></author><author><style face="normal" font="default" size="100%">Martin, Mac</style></author><author><style face="normal" font="default" size="100%">Breana L. Simmons</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Ecological stoichiometry drives the evolution of soil nematode life history traits</style></title><secondary-title><style face="normal" font="default" size="100%">Soil Biology and Biochemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">elemental stoichiometry</style></keyword><keyword><style  face="normal" font="default" size="100%">growth rate hypothesis</style></keyword><keyword><style  face="normal" font="default" size="100%">life history theory</style></keyword><keyword><style  face="normal" font="default" size="100%">molecular evolution</style></keyword><keyword><style  face="normal" font="default" size="100%">nematoda</style></keyword><keyword><style  face="normal" font="default" size="100%">rRNA</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2023</style></year><pub-dates><date><style  face="normal" font="default" size="100%">02/2023</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.sciencedirect.com/science/article/pii/S0038071722003480</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">177</style></volume><pages><style face="normal" font="default" size="100%">108891</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;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 &lt;i&gt;in situ&lt;/i&gt; and &lt;i&gt;in vitro&lt;/i&gt;, 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.&lt;/p&gt;</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Power, Sarah N.</style></author><author><style face="normal" font="default" size="100%">Salvatore, Mark R.</style></author><author><style face="normal" font="default" size="100%">Eric R. Sokol</style></author><author><style face="normal" font="default" size="100%">Lee F. Stanish</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Estimating microbial mat biomass in the McMurdo Dry Valleys, Antarctica using satellite imagery and ground surveys</style></title><secondary-title><style face="normal" font="default" size="100%">Polar Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Antarctica</style></keyword><keyword><style  face="normal" font="default" size="100%">microbial mat</style></keyword><keyword><style  face="normal" font="default" size="100%">multispectral imagery</style></keyword><keyword><style  face="normal" font="default" size="100%">NDVI</style></keyword><keyword><style  face="normal" font="default" size="100%">Nostocales</style></keyword><keyword><style  face="normal" font="default" size="100%">remote sensing</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2020</style></year><pub-dates><date><style  face="normal" font="default" size="100%">09/2020</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://link.springer.com/article/10.1007%2Fs00300-020-02742-y</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;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 m&lt;sup&gt;2&lt;/sup&gt; 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 (R&lt;sup&gt;2&lt;/sup&gt;&amp;thinsp;=&amp;thinsp;0.84), biomass (R&lt;sup&gt;2&lt;/sup&gt;&amp;thinsp;=&amp;thinsp;0.74), chlorophyll-a content (R&lt;sup&gt;2&lt;/sup&gt;&amp;thinsp;=&amp;thinsp;0.65), and scytonemin content (R&lt;sup&gt;2&lt;/sup&gt;&amp;thinsp;=&amp;thinsp;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&amp;mdash;biomass correlation we developed, we estimate carbon (C) stocks of 21,715 kg (14.7 g C m&lt;sup&gt;&amp;minus;2&lt;/sup&gt;) in the Canada Glacier Antarctic Specially Protected Area, with an upper and lower limit of 74,871 and 6312 kg of C, respectively.&lt;/p&gt;</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Eric R. Sokol</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Tyler J. Kohler</style></author><author><style face="normal" font="default" size="100%">Diane M. McKnight</style></author><author><style face="normal" font="default" size="100%">Salvatore, Mark R.</style></author><author><style face="normal" font="default" size="100%">Lee F. Stanish</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Evaluating alternative metacommunity hypotheses for diatoms in the McMurdo Dry Valleys using simulations and remote sensing data</style></title><secondary-title><style face="normal" font="default" size="100%">Frontiers in Ecology and Evolution</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Antarctica</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacillariophyceae</style></keyword><keyword><style  face="normal" font="default" size="100%">dispersal</style></keyword><keyword><style  face="normal" font="default" size="100%">Nostoc</style></keyword><keyword><style  face="normal" font="default" size="100%">stream ecology</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2020</style></year><pub-dates><date><style  face="normal" font="default" size="100%">09/2020</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.frontiersin.org/article/10.3389/fevo.2020.521668/full</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">8</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Diatoms are diverse and widespread freshwater Eukaryotes that make excellent microbial subjects for addressing questions in metacommunity ecology. In the McMurdo Dry Valleys of Antarctica, the simple trophic structure of glacier-fed streams provides an ideal outdoor laboratory where well-described diatom assemblages are found within two cyanobacterial mat types, which occupy different habitats and vary in coverage within and among streams. Specifically, black mats of &lt;em&gt;Nostoc&lt;/em&gt; spp. occur in marginal wetted habitats, and orange mats (&lt;em&gt;Oscillatoria&lt;/em&gt; spp. and &lt;em&gt;Phormidium&lt;/em&gt; spp.) occur in areas of consistent stream flow. Despite their importance as bioindicators for changing environmental conditions, the role of dispersal in structuring dry valley diatom metacommunities remains unclear. Here, we use MCSim, a spatially explicit metacommunity simulation package for R, to test alternative hypotheses about the roles of dispersal and species sorting in maintaining the biodiversity of diatom assemblages residing in black and orange mats. The spatial distribution and patchiness of cyanobacterial mat habitats was characterized by remote imagery of the Lake Fryxell sub-catchment in Taylor Valley. The available species pool for diatom metacommunity simulation scenarios was informed by the Antarctic Freshwater Diatoms Database, maintained by the McMurdo Dry Valleys Long Term Ecological Research program. We used simulation outcomes to test the plausibility of alternative community assembly hypotheses to explain empirically observed patterns of freshwater diatom biodiversity in the long-term record. The most plausible simulation scenarios suggest species sorting by environmental filters, alone, was not sufficient to maintain biodiversity in the Fryxell Basin diatom metacommunity. The most plausible scenarios included either (1) neutral models with different immigration rates for diatoms in orange and black mats or (2) species sorting by a relatively weak environmental filter, such that dispersal dynamics also influenced diatom community assembly, but there was not such a strong disparity&amp;nbsp;in immigration rates between mat types. The results point to the importance of dispersal for understanding current and future biodiversity patterns for diatoms in this ecosystem, and more generally, provide further evidence that metacommunity theory is a useful framework for testing hypotheses about microbial community assembly.&lt;/p&gt;</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sakaeva, A.</style></author><author><style face="normal" font="default" size="100%">Eric R. Sokol</style></author><author><style face="normal" font="default" size="100%">Tyler J. Kohler</style></author><author><style face="normal" font="default" size="100%">Lee F. Stanish</style></author><author><style face="normal" font="default" size="100%">Sarah A. Spaulding</style></author><author><style face="normal" font="default" size="100%">Howkins, Adrian</style></author><author><style face="normal" font="default" size="100%">Kathleen A. Welch</style></author><author><style face="normal" font="default" size="100%">W. Berry Lyons</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Diane M. McKnight</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Evidence for dispersal and habitat controls on pond diatom communities from the McMurdo Sound Region of Antarctica</style></title><secondary-title><style face="normal" font="default" size="100%">Polar Biology</style></secondary-title><short-title><style face="normal" font="default" size="100%">Polar Biol</style></short-title></titles><dates><year><style  face="normal" font="default" size="100%">2016</style></year><pub-dates><date><style  face="normal" font="default" size="100%">02/2016</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://link.springer.com/10.1007/s00300-016-1901-6http://link.springer.com/content/pdf/10.1007/s00300-016-1901-6http://link.springer.com/content/pdf/10.1007/s00300-016-1901-6.pdfhttp://link.springer.com/article/10.1007/s00300-016-1901-6/fulltext.html</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>32</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Kevin M. Geyer</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">John E. Barrett</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Environmental Controls Over the Distribution and Function of Antarctic Soil Bacterial Communities</style></title><secondary-title><style face="normal" font="default" size="100%">Biological Sciences</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">biogeochemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">biogeography</style></keyword><keyword><style  face="normal" font="default" size="100%">McMurdo Dry Valleys</style></keyword><keyword><style  face="normal" font="default" size="100%">microbial ecology</style></keyword><keyword><style  face="normal" font="default" size="100%">productivity/diversity theory</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://hdl.handle.net/10919/64417</style></url></web-urls></urls><publisher><style face="normal" font="default" size="100%">Virginia Tech</style></publisher><pub-location><style face="normal" font="default" size="100%">Blacksburg, VA</style></pub-location><volume><style face="normal" font="default" size="100%">Ph.D.</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;div title=&quot;Page 2&quot;&gt;&lt;div&gt;&lt;div&gt;&lt;p&gt;Microbial community composition plays a vital role in soil biogeochemical cycling. Information that explains the biogeography of microorganisms is consequently necessary for predicting the timing and magnitude of important ecosystem services mediated by soil biota, such as decomposition and nutrient cycling. Theory developed to explain patterns in plant and animal distributions such as the prevalent relationship between ecosystem productivity and diversity may be successfully extended to microbial systems and accelerate an emerging ecological understanding of the &amp;quot;unseen majority.&amp;quot; These considerations suggest a need to define the important mechanisms which affect microbial biogeography as well as the sensitivity of community structure/function to changing climatic or environmental conditions. To this end, my dissertation covers three data chapters in which I have 1) examined patterns in bacterial biogeography using gradients of environmental severity and productivity to identify changes in community diversity (e.g. taxonomic richness) and structure (e.g. similarity); 2) detected potential bacterial ecotypes associated with distinct soil habitats such as those of high alkalinity or electrical conductivity and; 3) measured environmental controls over the function (e.g. primary production, exoenzyme activity) of soil organisms in an environment of severe environmental limitations. Sampling was performed in the polar desert of Antarctica&amp;#39;s McMurdo Dry Valleys, a model ecosystem which hosts microbially-dominated soil foodwebs and displays heterogeneously distributed soil properties across the landscape. Results for Chapter 2 indicate differential effects of resource availability and geochemical severity on bacterial communities,&amp;nbsp;&lt;span style=&quot;font-size: 0.923em;&quot;&gt;with a significant productivity-diversity relationship that plateaus near the highest observed concentrations of the limiting resource organic carbon (0.30mg C/g soil). Geochemical severity (e.g. pH, electrical conductivity) primarily affected bacterial community similarity and successfully explained the divergent structure of a subset of samples. 16S rRNA amplicon pyrosequencing further revealed in Chapter 3 the identity of specific phyla that preferentially exist within certain habitats (i.e.&amp;nbsp;Acidobacteria&amp;nbsp;in alkaline soils,&amp;nbsp;Nitrospira&amp;nbsp;in mesic soils) suggesting the presence of niche specialists and spatial heterogeneity of taxa-specific functions (i.e. nitrite oxidation). Additionally, environmental parameters had different explanatory power towards predicting bacterial richness at varying taxonomic scales, from 57% of phylum-level richness with pH to 91% of order- and genus-level richness with moisture. Finally, Chapter 4 details a simultaneous sampling of soil communities and their associated ecosystem functions (primary productivity, enzymatic decomposition) and indicates that the overall organic substrate diversity may be greater in mesic soils where bacterial diversity is also highest, thus a potentially unforeseen driver of community dynamics. I also quantified annual rates of soil production which range between 0.7 - 18.1g C/m2/yr from the more arid to productive soils, respectively. In conclusion, the extension of biogeographical theory for macroorganisms has proven successful and both environmental severity and resource availability have obvious (although different) effects on the diversity and composition of soil microbial communities.&lt;/span&gt;&lt;/p&gt;&lt;/div&gt;&lt;/div&gt;&lt;/div&gt;&lt;p&gt;&amp;nbsp;&lt;/p&gt;</style></abstract><work-type><style face="normal" font="default" size="100%">doctoral</style></work-type></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Kevin M. Geyer</style></author><author><style face="normal" font="default" size="100%">Adam E. Altrichter</style></author><author><style face="normal" font="default" size="100%">David J. Van Horn</style></author><author><style face="normal" font="default" size="100%">Cristina D. Takacs-Vesbach</style></author><author><style face="normal" font="default" size="100%">Michael N. Gooseff</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Environmental controls over bacterial communities in polar desert soils</style></title><secondary-title><style face="normal" font="default" size="100%">Ecosphere</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2013</style></year><pub-dates><date><style  face="normal" font="default" size="100%">10/2013</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">4</style></volume><pages><style face="normal" font="default" size="100%">art127</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">10</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Edward Ayres</style></author><author><style face="normal" font="default" size="100%">Johnson N. Nkem</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Breana L. Simmons</style></author><author><style face="normal" font="default" size="100%">Ross A. Virginia</style></author><author><style face="normal" font="default" size="100%">Andrew G Fountain</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Experimentally increased snow accumulation alters soil moisture and animal community structure in a polar desert</style></title><secondary-title><style face="normal" font="default" size="100%">Polar Biology</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">7/2010</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">33</style></volume><pages><style face="normal" font="default" size="100%">897 - 907</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">7</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Edward Ayres</style></author><author><style face="normal" font="default" size="100%">Johnson N. Nkem</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Broos, E</style></author><author><style face="normal" font="default" size="100%">Andrew N. Parsons</style></author><author><style face="normal" font="default" size="100%">Powers, Laura E.</style></author><author><style face="normal" font="default" size="100%">Breana L. Simmons</style></author><author><style face="normal" font="default" size="100%">Ross A. Virginia</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effects of Human Trampling on Populations of Soil Fauna in the McMurdo Dry Valleys, Antarctica.</style></title><secondary-title><style face="normal" font="default" size="100%">Conservation Biology</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">12/2008</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">22</style></volume><pages><style face="normal" font="default" size="100%">1544-1551</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;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.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">6</style></issue></record></records></xml>