Variation in biogeochemistry and soil biodiversity across spatial scales in a polar desert

TitleVariation in biogeochemistry and soil biodiversity across spatial scales in a polar desert
Publication TypeJournal Article
Year of Publication2004
AuthorsBarrett, JE, Virginia, RA, Wall, DH, Parsons, AN, Powers, LE, Burkins, MB

Desert ecosystems are characterized by distinct spatial patterning in soilbiogeochemistry and biodiversity. In the Antarctic Dry Valleys, soil polygons are prominentfeatures of the landscape and may be key units for scaling local ecological information tothe greater region. We examined polygon soils in each of the three basins of Taylor Valley,Antarctica. Our objectives were to characterize variability in soil biogeochemistry andbiodiversity at local to regional scales, and to test the influence of soil properties uponinvertebrate communities. We found that soil biogeochemical properties and biodiversityvary over multiple spatial scales from fine (,10 m) to broad (.10 km) scales. Differencesin biogeochemistry were most pronounced at broad scales among the major lake basins ofTaylor Valley corresponding to differences in geology and microclimate, while variationin invertebrate biodiversity and abundance occurred at landscape scales of 10–500 m, andwithin individual soil polygons. Variation in biogeochemistry and invertebrate communitiesacross these scales reflects the influence of physical processes and landscape developmentover ecosystem structure in the dry valleys. The development of soil polygons influencesthe spatial patterning of soil properties such as soil organic matter, salinity, moisture, andinvertebrate habitat suitability. Nematode abundance and life history data indicate thatpolygon interiors are more suitable habitats than soils in the troughs at the edges of polygons.These data suggest that physical processes (i.e., polygon development) and biogeochemistryare important influences on the spatial variability of biotic communities in dry valley soilecosystems.