<?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%">Charles K. Lee</style></author><author><style face="normal" font="default" size="100%">Laughlin, Daniel C.</style></author><author><style face="normal" font="default" size="100%">Bottos, Eric M.</style></author><author><style face="normal" font="default" size="100%">Caruso, Tancredi</style></author><author><style face="normal" font="default" size="100%">Joy, Kurt</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Brabyn, Lars</style></author><author><style face="normal" font="default" size="100%">Uffe N. Nielsen</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author><author><style face="normal" font="default" size="100%">D. W. Hopkins</style></author><author><style face="normal" font="default" size="100%">Pointing, Steve B.</style></author><author><style face="normal" font="default" size="100%">McDonald, Ian R.</style></author><author><style face="normal" font="default" size="100%">Cowan, Don A.</style></author><author><style face="normal" font="default" size="100%">Banks, Jonathan C.</style></author><author><style face="normal" font="default" size="100%">Stichbury, Glen A.</style></author><author><style face="normal" font="default" size="100%">Jones, Irfon</style></author><author><style face="normal" font="default" size="100%">Zawar-Reza, Peyman</style></author><author><style face="normal" font="default" size="100%">Katurji, Marwan</style></author><author><style face="normal" font="default" size="100%">Hogg, Ian D.</style></author><author><style face="normal" font="default" size="100%">Sparrow, Ashley D.</style></author><author><style face="normal" font="default" size="100%">Storey, Bryan C.</style></author><author><style face="normal" font="default" size="100%">Allan Green, T. G.</style></author><author><style face="normal" font="default" size="100%">Craig S Cary</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Biotic interactions are an unexpected yet critical control on the complexity of an abiotically driven polar ecosystem</style></title><secondary-title><style face="normal" font="default" size="100%">Communications Biology</style></secondary-title><short-title><style face="normal" font="default" size="100%">Commun Biol</style></short-title></titles><dates><year><style  face="normal" font="default" size="100%">2019</style></year><pub-dates><date><style  face="normal" font="default" size="100%">02/2019</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.nature.com/articles/s42003-018-0274-5</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">2</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;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 km&lt;sup&gt;2&lt;/sup&gt;. 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.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">1</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%">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%">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%">Bacterial community composition of divergent soil habitats from a polar desert.</style></title><secondary-title><style face="normal" font="default" size="100%">FEMS Microbiology Ecology</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2014</style></year><pub-dates><date><style  face="normal" font="default" size="100%">08/2014</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">89</style></volume><pages><style face="normal" font="default" size="100%">490-494</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Edaphic factors such as pH, organic matter, and salinity are often the most significant drivers of diversity patterns in soil bacterial communities. Desert ecosystems in particular are model locations for examining such relationships as food web complexity is low and the soil environment is biogeochemically heterogeneous. Here, we present the findings from a 16S rRNA gene sequencing approach used to observe the differences in diversity and community composition among three divergent soil habitats of the McMurdo Dry Valleys, Antarctica. Results show that alpha diversity is significantly lowered in high pH soils, which contain higher proportions of the phyla Acidobacteria and Actinobacteria, while mesic soils with higher soil organic carbon (and ammonium) content contain high proportions of Nitrospira, a nitrite-oxidizing bacteria. Taxonomic community resolution also had a significant impact on our conclusions, as pH was the primary predictor of phylum-level diversity, while moisture was the most significant predictor of diversity at the genus level. Predictive power also increased with increasing taxonomic resolution, suggesting a potential increase in nic</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><work-type><style face="normal" font="default" size="100%">Short Communication</style></work-type><section><style face="normal" font="default" size="100%">490</style></section></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%">Lydia H. Zeglin</style></author><author><style face="normal" font="default" size="100%">Clifford N. Dahm</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Michael N. Gooseff</style></author><author><style face="normal" font="default" size="100%">Shannon K. Fitpatrick</style></author><author><style face="normal" font="default" size="100%">Cristina D. Takacs-Vesbach</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Bacterial Community Structure Along Moisture Gradients in the Parafluvial Sediments of Two Ephemeral Desert Streams</style></title><secondary-title><style face="normal" font="default" size="100%">Microbial Ecology</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">4/2011</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/content/r83j53334v5n505w/</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">61</style></volume><pages><style face="normal" font="default" size="100%">543 - 556</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">3</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%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Ross A. Virginia</style></author><author><style face="normal" font="default" size="100%">W. Berry Lyons</style></author><author><style face="normal" font="default" size="100%">Diane M. McKnight</style></author><author><style face="normal" font="default" size="100%">John C. Priscu</style></author><author><style face="normal" font="default" size="100%">Andrew G Fountain</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author><author><style face="normal" font="default" size="100%">Daryl L. Moorhead</style></author><author><style face="normal" font="default" size="100%">Peter T. Doran</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Biogeochemical stoichiometry of Antarctic Dry Valley ecosystems</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Geophysical Research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Biggie</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">02/2007</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">112</style></volume><pages><style face="normal" font="default" size="100%">G01010+12</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: 'Open Sans', Arial, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 16px; line-height: 24px; background-color: rgb(249, 249, 249);&quot;&gt;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&amp;ndash;10&lt;/span&gt;&lt;span style=&quot;line-height: 0; top: -0.5em; padding-right: 1px; padding-left: 1px; outline: 0px; font-size: 0.688em; position: relative; color: rgb(51, 51, 51); font-family: 'Open Sans', Arial, Helvetica, 'Lucida Sans Unicode', sans-serif; background: 0px 0px rgb(249, 249, 249);&quot;&gt;6&lt;/span&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: 'Open Sans', Arial, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 16px; line-height: 24px; background-color: rgb(249, 249, 249);&quot;&gt;&amp;nbsp;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.&lt;/span&gt;&lt;/p&gt;</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>5</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Ross A. Virginia</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">B. Riffenburgh</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Biogeochemistry, terrestrial</style></title><secondary-title><style face="normal" font="default" size="100%">Encyclopedia of the Antarctic  Vol 1</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><publisher><style face="normal" font="default" size="100%">Routledge Press</style></publisher><pub-location><style face="normal" font="default" size="100%">New York</style></pub-location><volume><style face="normal" font="default" size="100%">1</style></volume><pages><style face="normal" font="default" size="100%">154-155</style></pages><language><style face="normal" font="default" size="100%">eng</style></language></record></records></xml>