Data_Sheet_2_Individual species and site dynamics are the main drivers of spatial scaling of stability in aquatic communities.CSV

IntroductionAny measure of ecological stability scales with the spatial and temporal extent of the data on which it is based. The magnitude of stabilization effects at increasing spatial scale is determined by the degree of synchrony between local and regional species populations.
MethodsWe applied two recently developed approaches to quantify these stabilizing effects to time series records from three aquatic monitoring data sets differing in environmental context and organism type.
Results and DiscussionWe found that the amount and general patterns of stabilization with increasing spatial scale only varied slightly across the investigated species groups and systems. In all three data sets, the relative contribution of stabilizing effects via asynchronous dynamics across space was higher than compensatory dynamics due to differences in biomass fluctuations across species and populations. When relating the stabilizing effects of individual species and sites to species and site-specific characteristics as well as community composition and aspects of spatial biomass distribution patterns, however, we found that the effects of single species and sites showed large differences and were highly context dependent, i.e., dominant species can but did not necessarily have highly stabilizing or destabilizing effects on overall community biomass. The sign and magnitude of individual contributions depended on community structure and the spatial distribution of biomass and species in space. Our study therefore provides new insights into the mechanistic understanding of ecological stability patterns across scales in natural species communities.

引言
生态稳定性的任一度量指标，均随其所依托的数据的空间与时间覆盖范围而变化。空间尺度增大时，稳定效应的强度由局域与区域物种种群间的同步程度决定。

研究方法
本研究将两种新近开发的量化稳定效应的方法，应用于三套环境背景与生物类群均存在差异的水生监测数据集的时间序列记录。

结果与讨论
本研究发现，随空间尺度增大而产生的稳定效应的量级与整体模式，在本次研究所涉及的物种类群与生态系统间仅存在细微差异。在三套数据集的所有案例中，通过空间异步种群动态（asynchronous dynamics）实现的稳定效应的相对贡献，均高于基于物种种群间生物量波动差异的补偿动态（compensatory dynamics）所带来的贡献。然而，当将单个物种与样点的稳定效应与其物种特异性、样点特征、群落组成以及空间生物量分布格局的相关属性进行关联分析时，本研究发现单个物种与样点的效应存在显著差异，且高度依赖于具体环境背景。换言之，优势种虽可对群落总生物量产生高度稳定或高度去稳定的效应，但并非必然如此。单个贡献的符号与强度，取决于群落结构以及生物量与物种的空间分布格局。因此，本研究为理解自然物种群落中跨尺度的生态稳定性格局的内在机制提供了全新视角。