Soil Biodiversity and Community Structure in the Mcmurdo Dry Valleys, Antarctica

  1. John C. Priscu
  1. Diana Wall Freckman1 and
  2. Ross A. Virginia2

Published Online: 16 MAR 2013

DOI: 10.1029/AR072p0323

Ecosystem Dynamics in a Polar Desert: the Mcmurdo Dry Valleys, Antarctica

Ecosystem Dynamics in a Polar Desert: the Mcmurdo Dry Valleys, Antarctica

How to Cite

Freckman, D. W. and Virginia, R. A. (1998) Soil Biodiversity and Community Structure in the Mcmurdo Dry Valleys, Antarctica, in Ecosystem Dynamics in a Polar Desert: the Mcmurdo Dry Valleys, Antarctica (ed J. C. Priscu), American Geophysical Union, Washington, D. C.. doi: 10.1029/AR072p0323

Author Information

  1. 1

    Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, Colorado

  2. 2

    Environmental Studies Program, Dartmouth College, Hanover, New Hampshire

Publication History

  1. Published Online: 16 MAR 2013
  2. Published Print: 28 JAN 1998

ISBN Information

Print ISBN: 9780875908991

Online ISBN: 9781118668313

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Keywords:

  • Desert ecology—Antarctica—McMurdo Dry Valleys

Summary

A conceptual model is proposed that defines the soil and environmental conditions determining suitable and unsuitable habitats for soil biota in the McMurdo Dry Valley ecosystem of Antarctica. We hypothesized that if dispersal of soil fauna among the dry valleys was equal, then diverse and abundant communities of soil organisms would develop in all suitable habitats. The majority of soils sampled across the valleys (65%) support up to three soil invertebrate taxa (tardigrades, rotifers, nematodes). The rest of the soils are presumed to be unsuitable habitats as none of the target organisms were found, but there appears to be no single soil property that defines a suitable or unsuitable habitat. Most soils contain only one invertebrate taxa (nematodes); two and three taxa communities are rare. There are no other soil systems known where nematodes represent the top of the food chain and where food webs appear so simple in structure. Nematodes are more abundant and more widely distributed than either tardigrades or rotifers. The species diversity of nematodes is very low (n = 3), with only Scottnema lindsayae, a microbial feeder, occurring throughout the dry valleys. In many locations, soil conditions may be outside the tolerances of dispersing organisms preventing community establishment, thus creating the patchy distribution of soil biota that uniquely defines the dry valley landscape. The unusually low diversity and low functional redundancy of the dry valley soils suggest that these systems will be highly disrupted by the loss or decline of even a single species that is sensitive to environmental change. We suggest that nematodes may be a useful indicator organism for detecting environmental change in the dry valley system. As more people enter the dry valleys, human-induced impacts will directly affect soil habitats and the associated biota and the ecosystem functions they perform.