Key microorganisms mediate soil carbon-climate feedbacks in forest ecosystems

Soil microorganisms are known to significantly contribute to climate change through soil carbon (C) cycle feedbacks. However, it is challenging to incorporate these feedbacks into predictions of future patterns of terrestrial C cycling, largely because of the vast diversity of soil microorganisms and their responses to environmental conditions. Here, we show that the composition of the bacterial community can provide information about the microbial community-level thermal response (MCTR), which drives ecosystem scale soil C-climate feedbacks. The dominant taxa from 169 sites representing a gradient from tropical to boreal forest mainly belonged to the phyla Actinobacteria and Acidobacteria. Moreover, we show that the MCTR in warm biomes and acidic soils was linked primarily to bacteria, whereas the MCTR in cold biomes and alkaline soils was primarily associated with fungi. Our results provide strong empirical evidence of linkages between microbial composition and the MCTR across a wide range of forests, and suggest the importance of specific microorganisms in regulating soil C-climate feedbacks. (c) 2021 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.

Automated summary

Soil microorganisms play a significant role in climate change through soil carbon cycling feedbacks, with their composition providing insights into microbial community-level thermal responses; The association between microbial composition and thermal response varies in different biomes and soil conditions, with bacteria playing a key role in warm and acidic environments while fungi are more important in colder and alkaline soils; The study highlights the importance of specific microorganisms in regulating soil carbon-climate feedbacks across a wide range of forests.