Grazing-induced biodiversity loss impairs grassland ecosystem stability at multiple scales

Livestock grazing is a major driver shaping grassland biodiversity, functioning, and stability. Whether grazing impacts on grassland ecosystems are scale-dependent remains unclear. Here, we conducted a sheep-grazing experiment in a temperate grassland to test grazing effects on the temporal stability of productivity across scales. We found that grazing increased species stability, but substantially decreased local community stability due to reduced asynchronous dynamics among species within communities. The negative effect of grazing on local community stability propagated to reduce stability at larger spatial scales. By decreasing biodiversity both within and across communities, grazing reduced biological insurance effects and hence the up-scaling of stability from species to communities and further to larger spatial scales. Our study provides the first evidence for the scale-dependence of grazing effects on grassland stability through biodiversity. We suggest that ecosystem management...

家畜放牧是塑造草原生物多样性、生态系统功能与稳定性的核心驱动因子。目前学界仍未明确放牧对草原生态系统的影响是否存在尺度依赖性。本研究在温带草原开展绵羊放牧实验，以检验不同空间尺度下放牧对生产力时间稳定性的影响。研究发现，放牧可提升物种种群稳定性，但由于群落内物种种间异步动态减弱，显著降低了局域群落稳定性。放牧对局域群落稳定性的负面影响进一步传导，最终导致更大空间尺度下的生态系统稳定性下降。放牧通过降低群落内部及群落间的生物多样性，削弱了生物保险效应（biological insurance effects），进而阻碍了稳定性从物种种群到群落、再向更大空间尺度的尺度推绎（up-scaling）过程。本研究首次证实了放牧通过调控生物多样性，对草原稳定性的影响存在尺度依赖性。我们认为，生态系统管理……