How do soil microbes exert impact on soil respiration and its
temperature sensitivity?
Abstract
Understanding how soil microorganisms influence the direction and
magnitude of soil carbon feedback to global warming is vital to predict
future climate change. Although microbial activities are major
contributors to soil respiration (RS) and its temperature sensitivity
(Q10), the mechanisms underpinning microbial influence on RS and Q10
remain unclear. In this study, structural equation modeling (SEM) was
conducted to illustrate that bacteria mainly affect RS by shifting beta
diversity (denoted NMDS ordinations) instead of richness. In contrast,
Q10 values are governed by the richness and NMDS ordinations of
bacteria. We also found that soil water content (SWC) was the factor key
to changing bacterial properties (P < 0.05, R2 ≥ 0.33).
Network analysis demonstrated that only Proteobacteria were positively
associated with RS (P < 0.05, R > 0.5).
Illuminating the mechanisms underpinning the influence of soil microbes
on RS and Q10 values is fundamental to understanding mechanistic
soil-climate carbon cycles.