Changes in soil oxidase activity induced by microbial life history strategies mediate the soil heterotrophic respiration response to drought and nitrogen enrichment

作者：Weirong Zhuang, Yong Li, Xiaoming Kang, Liang Yan, Xiaodong Zhang, Zhongqing Yan, Kerou Zhang, Ao Yang, Yuechuan Niu, Xiaoshun Yu, Huan Wang, M. An, Rongxiao Che · 发表于：Frontiers in Microbiology · 年份：2024 · DOI：10.3389/fmicb.2024.1375300 · 被引用次数：21 · 研究领域：Microbial Community Ecology and Physiology、Soil Carbon and Nitrogen Dynamics、Gut microbiota and health

Drought and nitrogen deposition are two major climate challenges, which can change the soil microbial community composition and ecological strategy and affect soil heterotrophic respiration (Rh). However, the combined effects of microbial community composition, microbial life strategies, and extracellular enzymes on the dynamics of Rh under drought and nitrogen deposition conditions remain unclear. Here, we experimented with an alpine swamp meadow to simulate drought (50% reduction in precipitation) and multilevel addition of nitrogen to determine the interactive effects of microbial community composition, microbial life strategy, and extracellular enzymes on Rh. The results showed that drought significantly reduced the seasonal mean Rh by 40.07%, and increased the Rh to soil respiration ratio by 22.04%. Drought significantly altered microbial community composition. The ratio of K- to r-selected bacteria (B K:r ) and fungi (F K:r ) increased by 20 and 91.43%, respectively. Drought increased hydrolase activities but decreased oxidase activities. However, adding N had no significant effect on microbial community composition, B K:r , F K:r , extracellular enzymes, or Rh. A structural equation model showed that the effects of drought and adding nitrogen via microbial community composition, microbial life strategy, and extracellular enzymes explained 84% of the variation in Rh. Oxidase activities decreased with B K:r , but increased with F K:r . Our findings show that drought decr...