Abstract Carbon (C) and nitrogen (N) are key to biogeochemical cycles in terrestrial ecosystems. Despite the negative effects of drought on multiple ecosystem processes, our understanding of the responses of C and N in plants, soil, and microorganisms to drought remains incomplete. Our meta-analysis of 379 observations from 79 studies revealed that the C and N concentrations and C:N ratios of plant organs, litter, and soil, and activities and stoichiometry of C- and N-acquiring extracellular enzymes all decreased under drought, while the microbial biomass C:N ratio increased. Moreover, the magnitudes of these responses generally increased with drought intensity and drought duration. These effects of drought were consistent across ecosystem types, including forests and grasslands. Our study underpinned the strong coherent responses of C:N stoichiometry to drought encompassing plants, soil, and microorganisms.

中文翻译：

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陆地 C:N 化学计量学对森林和草原植物、土壤和微生物干旱的相干响应

摘要 碳（C）和氮（N）是陆地生态系统生物地球化学循环的关键。尽管干旱对多个生态系统过程产生负面影响，但我们对植物、土壤和微生物中 C 和 N 对干旱响应的理解仍然不完整。我们对来自 79 项研究的 379 项观察结果的荟萃分析表明，植物器官、凋落物和土壤的碳和氮浓度和碳氮比，以及获取碳和氮的细胞外酶的活性和化学计量在干旱条件下均下降，而微生物生物量 C:N 比增加。此外，这些反应的幅度通常随着干旱强度和干旱持续时间而增加。干旱的这些影响在生态系统类型中是一致的，包括森林和草原。我们的研究支持了 C 的强烈连贯反应：