Decoupled responses of soil bacteria and their invertebrate consumer to warming, but not freeze-thaw cycles, in the Antarctic Dry Valleys.

Autor: Knox MA; Department of Biology, Colorado State University, Fort Collins, CO, 80523, USA.; Hopkirk Research Institute, IVABS, Massey University, Private Bag 11-222, Palmerston North, 4474, New Zealand., Andriuzzi WS; Department of Biology, Colorado State University, Fort Collins, CO, 80523, USA., Buelow HN; Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA., Takacs-Vesbach C; Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA., Adams BJ; Department of Biology, Evolutionary Ecology Laboratories, and Monte L. Bean Museum, Brigham Young University, Provo, UT, 84602, USA., Wall DH; Department of Biology, Colorado State University, Fort Collins, CO, 80523, USA.; School of Global Environmental Sustainability, Colorado State University, Fort Collins, CO, 80523, USA.
Jazyk: angličtina
Zdroj: Ecology letters [Ecol Lett] 2017 Oct; Vol. 20 (10), pp. 1242-1249. Date of Electronic Publication: 2017 Aug 10.
DOI: 10.1111/ele.12819
Abstrakt: Altered temperature profiles resulting in increased warming and freeze-thaw cycle (FTC) frequency pose great ecological challenges to organisms in alpine and polar ecosystems. We performed a laboratory microcosm experiment to investigate how temperature variability affects soil bacterial cell numbers, and abundance and traits of soil microfauna (the microbivorous nematode Scottnema lindsayae) from McMurdo Dry Valleys, Antarctica. FTCs and constant freezing shifted nematode body size distribution towards large individuals, driven by higher mortality among smaller individuals. FTCs reduced both bacterial and nematode abundance, but bacterial cell numbers also declined under warming, demonstrating decoupled consumer-prey responses. We predict that higher occurrence of FTCs in cold ecosystems will select for large body size within soil microinvertebrates and overall reduce their abundance. In contrast, warm temperatures without FTCs could lead to divergent responses in soil bacteria and their microinvertebrate consumers, potentially affecting energy and nutrient transfer rates in soil food webs of cold ecosystems.
(© 2017 John Wiley & Sons Ltd/CNRS.)
Databáze: MEDLINE
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