Warming effects on grassland soil microbial communities are amplified in cool months

作者：Jiesi Lei, Yuanlong Su, Siyang Jian, Xue Guo, Mengting Yuan, Colin T. Bates, Zhou Jason Shi, Jiabao Li, Yifan Su, Daliang Ning, Liyou Wu, Jizhong Zhou, Yunfeng Yang · 发表于：The ISME Journal · 年份：2024 · DOI：10.1093/ismejo/wrae088 · 被引用次数：20 · 研究领域：Soil Carbon and Nitrogen Dynamics、Microbial Community Ecology and Physiology、Rangeland and Wildlife Management

Global warming modulates soil respiration (RS) via microbial decomposition, which is seasonally dependent. Yet, the magnitude and direction of this modulation remain unclear, partly owing to the lack of knowledge on how microorganisms respond to seasonal changes. Here, we investigated the temporal dynamics of soil microbial communities over 12 consecutive months under experimental warming in a tallgrass prairie ecosystem. The interplay between warming and time altered (P < 0.05) the taxonomic and functional compositions of microbial communities. During the cool months (January to February and October to December), warming induced a soil microbiome with a higher genomic potential for carbon decomposition, community-level ribosomal RNA operon (rrn) copy numbers, and microbial metabolic quotients, suggesting that warming stimulated fast-growing microorganisms that enhanced carbon decomposition. Modeling analyses further showed that warming reduced the temperature sensitivity of microbial carbon use efficiency (CUE) by 28.7% when monthly average temperature was low, resulting in lower microbial CUE and higher heterotrophic respiration (Rh) potentials. Structural equation modeling showed that warming modulated both Rh and RS directly by altering soil temperature and indirectly by influencing microbial community traits, soil moisture, nitrate content, soil pH, and gross primary productivity. The modulation of Rh by warming was more pronounced in cooler months compared to warmer one...