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Decoupled responses of soil bacteria and their invertebrate consumer to warming, but not freeze–thaw cycles, in the Antarctic Dry Valleys
Author(s) -
Knox Matthew A.,
Andriuzzi Walter S.,
Buelow Heather N.,
TakacsVesbach Cristina,
Adams Byron J.,
Wall Diana H.
Publication year - 2017
Publication title -
ecology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.852
H-Index - 265
eISSN - 1461-0248
pISSN - 1461-023X
DOI - 10.1111/ele.12819
Subject(s) - microcosm , microfauna , ecology , ecosystem , abundance (ecology) , biology , soil biology , global warming , soil ecology , ecosystem engineer , environmental science , climate change , soil water , soil organic matter , soil biodiversity , fauna
Abstract 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. FTC s and constant freezing shifted nematode body size distribution towards large individuals, driven by higher mortality among smaller individuals. FTC s 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 FTC s in cold ecosystems will select for large body size within soil microinvertebrates and overall reduce their abundance. In contrast, warm temperatures without FTC s 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.