AimChronic directional climate changes in temperature and precipitation are predicted to increase the frequency of extreme climatic events (ECEs); however, their co‐occurring effects on the temporal stability of community productivity (i.e. ANPP stability) are still unclear. Here, we evaluate whether the increased frequency of ECEs reduces ANPP stability, and how it modulates the effects of chronic directional climate factors on ANPP stability in natural grassland.LocationTwenty‐two sites in Asia and 14 sites in North America.Time period1980s–2010s.Major taxa studiedHerbaceous plant.MethodsWe collected 36 long‐term observational and consecutive ANPP data (at least 10 years) and resampled yearly ANPP via a consecutive resampling method of nested time windows for each field. We used linear mixed‐effect models, partial regression analysis and structure equation models to explore the interactive effects of three climatic factors on ANPP stability and their associated intermediate processes of sensitivity, asymmetry, resistance and resilience.ResultsThe increased frequency of ECEs was observed within the long‐term rising temperature and elevating precipitation trend across sites in the past several decades. Elevating precipitation rather than rising temperature was the primary driver influencing ANPP stability. Elevating precipitation increased ANPP stability through increasing mean ANPP and decreasing the standard deviation (i.e. SD) of ANPP due to a decrease in sensitivity of ANPP to precipitation. The increased frequency of ECEs decreased ANPP stability mainly by increasing the SD of ANPP, and it reduced the positive effect of elevated precipitation on ANPP stability via a decrease in resilience.Main conclusionOur results demonstrated that recurrent and discrete ECEs had cumulatively negative effects on ANPP stability, and the decreased resilience was identified as the primary factor reducing the grassland community stability under long‐term climate change. This highlighted the potential risks of increased frequency of ECEs for grassland ecosystem functions.

中文翻译：

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极端气候事件发生频率的增加，通过降低恢复力，削弱了定向气候变化下天然草地的群落稳定性

目标：温度和降水的慢性定向气候变化预计会增加极端气候事件（ECE）的频率；然而，它们对群落生产力的时间稳定性（即ANPP稳定性）的共同影响仍不清楚。在这里，我们评估ECE频率的增加是否会降低ANPP的稳定性，以及它如何调节慢性定向气候因素对天然草地ANPP稳定性的影响。位置亚洲22个站点和北美14个站点。时间段1980年代-2010年代。研究草本植物的主要类群。方法我们收集了 36 个长期观察和连续的 ANPP 数据（至少 10 年），并通过每个田地的嵌套时间窗的连续重采样方法对每年的 ANPP 进行重采样。我们使用线性混合效应模型、偏回归分析和结构方程模型来探讨三个气候因素对ANPP稳定性的交互影响及其相关的敏感性、不对称性、阻力和弹性中间过程。结果观察到ECE频率增加过去几十年来各个地点的长期气温上升和降水量增加的趋势。降水量增加而非气温升高是影响 ANPP 稳定性的主要驱动因素。由于 ANPP 对降水的敏感性降低，降水量增加通过增加平均 ANPP 和降低 ANPP 的标准差（即 SD）来提高 ANPP 稳定性。ECE频率的增加主要通过增加ANPP的SD来降低ANPP的稳定性，并通过弹性的降低来降低降水量增加对ANPP稳定性的积极影响。主要结论我们的结果表明，经常性和离散的ECE对ANPP稳定性具有累积的负面影响，恢复力下降被认为是长期气候变化下草地群落稳定性降低的主要因素。这凸显了ECE频率增加对草原生态系统功能的潜在风险。