Temporal stability of ecosystem functioning is a measurement of how variable an ecosystem function is through time, and this can increase the predictability and reliability of ecosystem services. Stability of local communities is determined by both the stability of its component species and the degree these species are synchronized through time. Yet, understanding the drivers of stability at larger spatial scales is important for land management and policy decisions. We used species-level abundance data from 62 plant communities across five continents to test a recent hierarchical framework – which partitions the stability of metacommunities into stability and asynchrony at smaller spatial scales (e.g., local communities, species) – to address two major questions: (1) What is the relative importance of stability and synchrony within and among local communities for determining metacommunity stability? (2) How much does asynchrony among local communities enhance stability of meta-communities?
Looking across the 62 metacommunities, we found that stability and asynchrony of local communities explained 63% and 24%, respectively, of the variance of metacommunity stability. Additionally, we found that species stability and asynchrony filtered up – through the stability of local communities – to explain 41% and 29% of metacommunity stability. When we quantified the stabilizing effect of asynchrony among local communities, we found that it accounted for a two-fold increase in stability when scaling from local communities to metacommunities. We traced this stabilization effect to species’ populations fluctuating asynchronously across space, perhaps stemming from physical and/or competitive differences among local communities. Based on these findings, we suggest that spatial heterogeneity should be a major focus for maintaining the stability of ecosystem services at larger spatial scales.