Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China.
School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA.
Ecology. 2022 Nov;103(11):e3792. doi: 10.1002/ecy.3792. Epub 2022 Jul 24.
The frequency and severity of extreme weather events are increasing and expected to increase more in the future, together with global change. However, how extreme events and global change factors interactively influence community structures and ecosystem processes is largely unknown. Here, we investigated the responses of the temporal stability and resilience of aboveground net primary productivity (ANPP) of an alpine meadow to an extreme flooding event under different treatments of experimental drought and clipping. We found that ecosystems that were exposed to drought treatments for 3 years significantly decreased the temporal stability of community productivity but increased resilience to flooding, whereas their resistance to or recovery from flooding did not change. Neither clipping nor its interaction with drought altered the responses of these community stability metrics to flooding. Drought treatments significantly decreased plant species richness and asynchrony and dominant species stability, leading to a decrease in temporal stability and an increase in resilience in response to the extreme flooding event. The study also revealed that the change in species asynchrony was the dominant impact pathway determining the responses of resilience and temporal stability to flooding. Our results highlight that alpine grassland that experiences a multiyear drought may aggravate the instability of community productivity to extreme climatic events by reducing species asynchrony.
极端天气事件的频率和严重程度正在增加，并预计随着全球变化而进一步增加。然而，极端事件和全球变化因素如何相互作用影响群落结构和生态系统过程在很大程度上是未知的。在这里，我们调查了实验干旱和刈割处理下高寒草地地上净初级生产力（ANPP）的时间稳定性和弹性对极端洪水事件的响应。我们发现，经历了 3 年干旱处理的生态系统显著降低了群落生产力的时间稳定性，但对洪水的弹性增加，而它们对洪水的抵抗力或恢复力没有变化。刈割及其与干旱的相互作用都没有改变这些群落稳定性指标对洪水的响应。干旱处理显著降低了植物物种丰富度和非同步性以及优势种稳定性，导致对极端洪水事件的时间稳定性降低和弹性增加。该研究还表明，物种非同步性的变化是决定弹性和时间稳定性对洪水响应的主要影响途径。我们的研究结果强调，经历多年干旱的高寒草地可能会通过降低物种非同步性来加剧对极端气候事件的群落生产力不稳定性。
