Microbial community resistance is associated with soil carbon degradation under warming condition in dryland agroecosystems

Abstract

Soil microorganisms play a critical role in regulating carbon cycling, particularly under the influence of climate change. Understanding the relationship between the ecological stability of belowground communities and soil carbon cycling under warming conditions is essential for predicting global soil carbon storage. In this study, we conducted a large-scale soil microcosm experiment using 25 paired maize and rice ecosystems distributed along a latitudinal gradient across China to explore how microbial communities in these two cropping systems respond differently to climate warming and how these responses affect soil carbon cycling. In maize soils, we observed that microbial diversity resistance was positively correlated with mean annual temperature (MAT). Moreover, both microbial diversity resistance and community resistance were higher at lower latitudes in maize soils. These low-latitude maize soils also exhibited greater microbial co-occurrence network stability and stronger phylogenetic conservation under warming conditions. However, these patterns were not observed in rice soils. Interestingly, in maize soils, community resistance was negatively correlated with the variation in organic carbon degradation-related functions under warming. Furthermore, the original organic carbon content in these soils was positively correlated with microbial community resistance and negatively correlated with functional variation in organic carbon degradation. Taken together, our results highlight the critical role of habitat in shaping microbial responses to warming, and suggest that soil microorganisms can regulate their metabolic processes to mitigate soil carbon loss under global change scenarios.