Non-monotonic and distinct temperature responses of soil microbial
functional groups of different origins and in different soils
Abstract
The fate of soil carbon (C) under climatic warming predominantly depends
on temperature sensitivity of soil microbial functioning, but it is
poorly understood. Using temporal measurements of soil respiration in an
incubation experiment with cross-inoculation of microbial communities to
contrasting soils, we constrained a microbial-explicit C model to infer
temperature responses of two general microbial functional groups:
fast-growing r- vs slow-growing K-strategists. We found that the two
groups exhibit distinct, non-monotonic temperature responses. Both
historical environment, under which the microbial communities were
originated, and current environment, under which the microbial
communities are colonized/adapted, significantly shape the temperature
responses of the two groups. Our findings highlight the importance of
combined effects of historical and current environment on microbial
decomposition for regulating soil C dynamics under warming. We suggest
that distinct, non-monotonic temperature responses of microbial
functional groups may cause pronounced feedbacks between soil C dynamics
and warming depending on climate-soil-microbe interactions.