Understanding stability across ecological hierarchies is critical for landscape management in a changing world. Recent studies showed that synchrony among lower-level components is key to scaling temporal stability or variability across two hierarchical levels, whether spatial or organizational. For instance, ecosystem variability can be expressed as the product of species-level variability and the synchrony among species, and the variability of a metapopulation can be expressed as the product of the variability and spatial synchrony of its component local populations. While these studies have provided insights into the stability of local communities and metapopulations, landscape management calls for a synthetic framework to understand stability in complex communities at large scales, e.g. metacommunities. Such a framework is important for clarifying the scaling properties and ecological drivers of metacommunity stability. That said, it is far from trivial to reach such a synthetic framework when taking into account the spatial heterogeneities in real-world ecosystems. Here we develop a partitioning framework that bridges variability and synchrony measures across spatial scales and organizational levels in heterogeneous metacommunities.
Results/Conclusions
In this framework, metacommunity variability is expressed as the product of local-scale population variability and two synchrony indices that capture the temporal coherence across species and space, respectively. We develop an R function “var.partition” and apply it to five types of desert plant communities to illustrate our framework and test how diversity shapes synchrony and variability at different scales. As the observation scale increased from local populations to metacommunities, the temporal variability of plant productivity was reduced mainly by factors that decreased species synchrony. Species synchrony decreased from local to regional scales, and spatial synchrony decreased from species to community levels. Local and regional species diversity were key factors that reduced species synchrony at the two scales. Moreover, beta diversity contributed to decreasing spatial synchrony among communities. Our new framework offers a valuable toolbox for future empirical studies to disentangle the mechanisms and pathways by which ecological factors influence stability at large scales.