<?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%">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%">Diana H. Wall</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%">Melody B. Burkins</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Variation in biogeochemistry and soil biodiversity across spatial scales in a polar desert</style></title><secondary-title><style face="normal" font="default" size="100%">Ecology</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><volume><style face="normal" font="default" size="100%">85</style></volume><pages><style face="normal" font="default" size="100%">3105-3118</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;div&gt;Desert ecosystems are characterized by distinct spatial patterning in soil&lt;/div&gt;&lt;div&gt;biogeochemistry and biodiversity. In the Antarctic Dry Valleys, soil polygons are prominent&lt;/div&gt;&lt;div&gt;features of the landscape and may be key units for scaling local ecological information to&lt;/div&gt;&lt;div&gt;the greater region. We examined polygon soils in each of the three basins of Taylor Valley,&lt;/div&gt;&lt;div&gt;Antarctica. Our objectives were to characterize variability in soil biogeochemistry and&lt;/div&gt;&lt;div&gt;biodiversity at local to regional scales, and to test the influence of soil properties upon&lt;/div&gt;&lt;div&gt;invertebrate communities. We found that soil biogeochemical properties and biodiversity&lt;/div&gt;&lt;div&gt;vary over multiple spatial scales from fine (,10 m) to broad (.10 km) scales. Differences&lt;/div&gt;&lt;div&gt;in biogeochemistry were most pronounced at broad scales among the major lake basins of&lt;/div&gt;&lt;div&gt;Taylor Valley corresponding to differences in geology and microclimate, while variation&lt;/div&gt;&lt;div&gt;in invertebrate biodiversity and abundance occurred at landscape scales of 10&amp;ndash;500 m, and&lt;/div&gt;&lt;div&gt;within individual soil polygons. Variation in biogeochemistry and invertebrate communities&lt;/div&gt;&lt;div&gt;across these scales reflects the influence of physical processes and landscape development&lt;/div&gt;&lt;div&gt;over ecosystem structure in the dry valleys. The development of soil polygons influences&lt;/div&gt;&lt;div&gt;the spatial patterning of soil properties such as soil organic matter, salinity, moisture, and&lt;/div&gt;&lt;div&gt;invertebrate habitat suitability. Nematode abundance and life history data indicate that&lt;/div&gt;&lt;div&gt;polygon interiors are more suitable habitats than soils in the troughs at the edges of polygons.&lt;/div&gt;&lt;div&gt;These data suggest that physical processes (i.e., polygon development) and biogeochemistry&lt;/div&gt;&lt;div&gt;are important influences on the spatial variability of biotic communities in dry valley soil&lt;/div&gt;&lt;div&gt;ecosystems.&lt;/div&gt;</style></abstract><issue><style face="normal" font="default" size="100%">11</style></issue></record></records></xml>