Antarctic Science


Special Issue: The Latitudinal Gradient Project (LGP)

Co-variation in soil biodiversity and biogeochemistry in northern and southern Victoria Land, Antarctica


J.E. Barrett a1c1, R.A. Virginia a1, D.H. Wall a2, S.C. Cary a3a5, B.J. Adams a4, A.L. Hacker a5 and J.M. Aislabie a6
a1 Environmental Studies Program, Dartmouth College, Hanover, NH 03755, USA
a2 Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523, USA
a3 College of Marine Studies, University of Delaware, Lewes, DE 19958, USA
a4 Microbiology and Molecular Biology and Evolutionary Ecology Laboratories, Brigham Young University, Provo, UT 84602, USA
a5 University of Waikato, Private Bag 3105, Hamilton, New Zealand
a6 Landcare Research, Private Bag 3127, Hamilton, New Zealand

Article author query
barrett je   [PubMed][Google Scholar] 
virginia ra   [PubMed][Google Scholar] 
wall dh   [PubMed][Google Scholar] 
cary sc   [PubMed][Google Scholar] 
adams bj   [PubMed][Google Scholar] 
hacker al   [PubMed][Google Scholar] 
aislabie jm   [PubMed][Google Scholar] 

Abstract

Data from six sites in Victoria Land (72–77°S) investigating co-variation in soil communities (microbial and invertebrate) with biogeochemical properties showthe influence of soil properties on habitat suitability varied among local landscapes as well as across climate gradients. Species richness of metazoan invertebrates (Nematoda, Tardigrada and Rotifera) was similar to previous descriptions in this region, though identification of three cryptic nematode species of Eudorylaimus through DNA analysis contributed to the understanding of controls over habitat preferences for individual species. Denaturing Gradient Gel Electrophoresis profiles revealed unexpectedly high diversity of bacteria. Distribution of distinct bacterial communities was associated with specific sites in northern and southern Victoria Land, as was the distribution of nematode and tardigrade species. Variation in soil metazoan communities was related to differences in soil organic matter, while bacterial diversity and community structure were not strongly correlated with any single soil property. There were no apparent correlations between metazoan and bacterial diversity, suggesting that controls over distribution and habitat suitability are different for bacterial and metazoan communities. Our results imply that top-down controls over bacterial diversity mediated by their metazoan consumers are not significant determinants of bacterial community structure and biomass in these ecosystems.

(Published Online November 14 2006)
(Received May 24 2006)
(Accepted August 16 2006)


Key Words: habitat suitability; invertebrate diversity; Latitudinal Gradient Project; microbial diversity; nematodes.

Correspondence:
c1 Corresponding author: John.E.Barrett@Dartmouth.edu


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