Prolonged exposure does not increase soil microbial community compositional response to warming along geothermal gradients

• Published in: FEMS Microbiology Ecology
• Main Authors: Radujković, Dajana, Verbruggen, Erik, Sigurdsson, Bjarni D., Leblans, Niki, Janssens, Ivan, Vicca, Sara, Weedon, James
• Other Authors: Auðlinda- og umhverfisdeild (LBHÍ), Faculty of Natural Resources and Environmental Sciences (AUI), Landbúnaðarháskóli Íslands, Agricultural University of Iceland
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press (OUP) 2017
• Subjects: Geothermal energy; Soil warming; Soil microbiology; Jarðvegur; Jarðhiti; Subarctic
• Online Access: https://hdl.handle.net/20.500.11815/1263; https://doi.org/10.1093/femsec/fix174

Global change is expected to affect soil microbial communities through their responsiveness to temperature. It has been proposed that prolonged exposure to elevated temperatures may lead to progressively larger effects on soil microbial community composition. However, due to the relatively short-term nature of most warming experiments, this idea has been challenging to evaluate. The present study took the advantage of natural geothermal gradients (from +1°C to +19°C above ambient) in two subarctic grasslands to test the hypothesis that long-term exposure (>50 years) intensifies the effect of warming on microbial community composition compared to short-term exposure (5–7 years). Community profiles from amplicon sequencing of bacterial and fungal rRNA genes did not support this hypothesis: significant changes relative to ambient were observed only starting from the warming intensity of +9°C in the long term and +7°C/+3°C in the short term, for bacteria and fungi, respectively. Our results suggest that microbial communities in high-latitude grasslands will not undergo lasting shifts in community composition under the warming predicted for the coming 100 years (+2.2°C to +8.3°C). This work was supported by Research Foundation–Flanders (FWO) [1293114N to JTW, 12B0716N to SV, 11G1615N to NIWL], Icelandic Research Council [163272-051 to BDS], Climate Change Manipulation Experiments in Terrestrial Ecosystems (ClimMani) COST Action [ES1308], the European Research Council grant ERC-SyG-610028 IMBALANCE-P and the University of Antwerp: University Research Fund (BOF). Peer Reviewed