Compositional Stability of the Bacterial Community in a Climate-Sensitive Sub-Arctic Peatland.
The climate sensitivity of microbe-mediated soil processes such as carbon and nitrogen cycling offers an interesting case for evaluating the corresponding sensitivity of microbial community composition to environmental change. Better understanding of the degree of linkage between functional and compositional stability would contribute to ongoing efforts to build mechanistic models aiming at predicting rates of microbe-mediated processes. We used an amplicon sequencing approach to test if previously observed large effects of experimental soil warming on C and N cycle fluxes (50-100% increases) in a sub-arcticSphagnumpeatland were reflected in changes in the composition of the soil bacterial community. We found that treatments that previously induced changes to fluxes did not associate with changes in the phylogenetic composition of the soil bacterial community. For both DNA- and RNA-based analyses, variation in bacterial communities could be explained by the hierarchy: spatial variation (12-15% of variance explained) > temporal variation (7-11%) > climate treatment (4-9%). We conclude that the bacterial community in this environment is stable under changing conditions, despite the previously observed sensitivity of process rates-evidence that microbe-mediated soil processes can alter without concomitant changes in bacterial communities. We propose that progress in linking soil microbial communities to ecosystem processes can be advanced by further investigating the relative importance of community composition effects versus physico-chemical factors in controlling biogeochemical process rates in different contexts.
Department of Ecological Science, Vrije Universiteit AmsterdamAmsterdam, Netherlands; Research Group of Plant and Vegetation Ecology, Department of Biology, University of AntwerpAntwerp, Belgium.
James T
JT
Weedon
Ecology and Biodiversity, Department of Biology, Utrecht University Utrecht, Netherlands.
George A
GA
Kowalchuk
Department of Ecological Science, Vrije Universiteit Amsterdam Amsterdam, Netherlands.
Rien
R
Aerts
Department of Ecological Science, Vrije Universiteit Amsterdam Amsterdam, Netherlands.
Stef
S
Freriks
Department of Molecular Cell Physiology, Vrije Universiteit Amsterdam Amsterdam, Netherlands.
Wilfred F M
WF
Röling
Department of Ecological Science, Vrije Universiteit AmsterdamAmsterdam, Netherlands; Institute of Environmental Sciences, Leiden UniversityLeiden, Netherlands.
Peter M
PM
van Bodegom
16S DNA; 16S RNA; bacteria; climate change; peatlands; seasonality; soil nitrogen; soil organic carbon