Thawing permafrost alters nematode populations and soil habi

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TitleThawing permafrost alters nematode populations and soil habitat characteristics in an Antarctic polar desert ecosystemAbstractSpatial distribution of soil nematode populations in Antarctic terrestrial ecosystems is tightly controlled by environmental factors and thus highly sensitive to changes in soil properties. Increases in the magnitude and frequency of episodic warming events as well as eventual warming trends are likely to result in increased water availability due to glacial melting and permafrost thaw, and may also incite changes in soil physical and chemical characteristics that determine nematode habitat suitability. We hypothesized that climate warming would result in new suitable soil habitats leading to heightened diversity and activity in nematode communities. In order to test this hypothesis, we compared nematode populations in patches of soil wetted by naturally enhanced permafrost thaw versus adjacent soils unaffected by thaw. We found that thaw sites had significantly lower nematode abundances and living to dead ratios, contradicting our hypothesis. We also observed significantly altered soil texture (finer particle size), lower pH and higher salinity in permafrost seeps. These observations suggest that current and future changes in climate may alter soil properties and result in significant changes in nematode population structure, distribution and function. Copyright 2011 Elsevier GmbH.AcknowledgementsFunding and logistical support for this research was provided by the NSF-funded McMurdo Dry Valleys Long-Term Ecological Research program (OPP-0423595) to DHW, RAV and BJA, and by the New Zealand Foundation for Research, Science and Technology (FRST), the University of Waikato, and Antarctica New Zealand to IH and TS. TS also received a New Zealand Terrestrial Antarctic Bio- complexity Survey (NZTABS) Research Fellowship in support of this research. Additional logistical support was provided by PHI, and Raytheon Polar Services Corporation. We thank Bishwo Adhikari, Nick Demetras, Eddie Molina, Karen Seaver, Breana Simmons, Kathy Welch, Colin Pinney and Dan Reuss for field and lab support, as well as Rich Conant and Alan Knapp for their insightful reviews of this manuscript.

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1st AuthorSmith, T.AuthorSmith, T.Wall, D.Hogg, I.Adams, B.Nielsen, U.Virginia, R.Year2012JournalPedobiologiaVolume55Number2Pages75-81DOI10.1016/j.pedobi.2011.11.001URLhttps://www.scopus.com/inward/recor.....0642c08e1627f5fd559c15502Keywordsabundanceenvironmental factorglobal warminghabitat typenematodepermafrostpHphysicochemical propertypopulation structuresalinitysoil faunasoil propertysoil texturesoil typespatial distributionterrestrial ecosystemthawingwater availability, Antarctica, rank5Author KeywordsCold desertEcologyFrozen soilsGlobal changeHabitat suitabilityNematode

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TypeArticleCitationSmith, I., Gough, A., Langhorne, P., Mahoney, A., Leonard, G., Van Hale, R., Jendersie, S. and Haskell, T. (2015) First-year land-fast Antarctic sea ice as an archive of ice shelf meltwater fluxes. Cold Regions Science and Technology, 113: 63-70 doi:10.1016/j.coldregions.2015.01.007 IdentifierSmith2012bRelevancerank5

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Hogg, I.