Distribution and diversity of soil microfauna from East Antarctica: assessing the link between biotic and abiotic factors.
Terrestrial life in Antarctica has been described as some of the simplest on the planet, and mainly confined to soil microfaunal communities. Studies have suggested that the lack of diversity is due to extreme environmental conditions and thought to be driven by abiotic factors. In this study we investigated soil microfauna composition, abundance, and distribution in East Antarctica, and assessed correlations with soil geochemistry and environmental variables. We examined 109 soil samples from a wide range of ice-free habitats, spanning 2000 km from Framnes Mountains to Bailey Peninsula. Microfauna across all samples were patchily distributed, from complete absence of invertebrates to over 1600 specimens/gram of dry weight of soil (gdw), with highest microfauna abundance observed in samples with visible vegetation. Bdelloid rotifers were on average the most widespread found in 87% of sampled sites and the most abundant (44 specimens/gdw). Tardigrades occurred in 57% of the sampled sites with an abundance of 12 specimens/gdw. Nematodes occurred in 71% of samples with a total abundance of 3 specimens/gdw. Ciliates and mites were rarely found in soil samples, with an average abundance of 1.3 and 0.04 specimens/gdw, respectively. We found that microfaunal composition and abundance were mostly correlated with the soil geochemical parameters; phosphorus, NO3 (-) and salinity, and likely to be the result of soil properties and historic landscape formation and alteration, rather than the geographic region they were sampled from. Studies focusing on Antarctic biodiversity must take into account soil geochemical and environmental factors that influence population and species heterogeneity.
Australian Centre for Evolutionary Biology and Biodiversity, School of Earth and Environmental Sciences, The University of Adelaide, Adelaide, South Australia, Australia.
Alejandro
A
Velasco-Castrillón
Department of Genetics, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia.
Mark B
MB
Schultz
Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, New South Wales, Australia.
Federica
F
Colombo
Institute of Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia.
John A E
JA
Gibson
Australian Centre for Evolutionary Biology and Biodiversity, School of Agriculture Food and Wine, The University of Adelaide, Urrbrae, Adelaide, South Australia, Australia.
Kerrie A
KA
Davies
Australian Centre for Evolutionary Biology and Biodiversity, School of Earth and Environmental Sciences, The University of Adelaide, Adelaide, South Australia, Australia.
Andrew D
AD
Austin
South Australian Museum, Adelaide, South Australia, Australia ; School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia.
Mark I
MI
Stevens
D000818:Animals; D000864:Antarctic Regions; D058448:Biota / Q000502:physiology*; D060146:Ecotype; D012987:Soil
D012987:Soil