Plant litter decomposition is a central process in the carbon (C) cycle and sensitive to ongoing anthropogenic nitrogen (N) fertilisation. Previous syntheses evaluating the effect of N fertilisation on litter decomposition relied largely on models that define a constant rate of mass loss throughout decomposition, which may mask hypothesised shifts in the effect of N fertilisation on litter decomposition dynamics. In this meta‐analysis, we compared the performance of four empirical decomposition models and showed that N fertilisation consistently accelerates early‐stage but slows late‐stage decomposition when the model structure allows for flexibility in decomposition rates through time. Within a particular substrate, early‐stage N‐stimulation of decomposition was associated with reduced rates of late‐stage decay. Because the products of early‐ vs. late‐stage decomposition are stabilised in soils through distinct chemical and physical mechanisms, N‐induced changes in the litter decomposition process may influence the formation and cycling of soil C, the largest terrestrial C pool.

中文翻译：

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全球试验性施氮会加速，然后减慢凋落物的分解

植物凋落物分解是碳（C）循环的核心过程，对正在进行的人为氮（N）施肥敏感。先前的评估氮肥对凋落物分解影响的综合研究很大程度上依赖于模型，该模型定义了整个分解过程中恒定的质量损失率，这可能掩盖了假设的氮肥对凋落物分解动力学的影响。在本荟萃分析中，我们比较了四个经验分解模型的性能，结果表明，当模型结构允许随时间变化的分解速率具有灵活性时，氮肥持续加速早期分解，但减慢了后期分解。在特定的基质中，分解的早期N刺激与晚期衰变速率降低相关。因为早期与早期的产品