A unified framework for partitioning the drivers of stability of ecological communities

Abstract

AimIdentifying the drivers of ecological stability is critical for ensuring the maintenance of ecosystem functioning and services, particularly in a changing world. Different ecological mechanisms by which biological communities stabilize ecosystem functions (i.e. “stabilizing effects”) have been proposed, yet with various theoretical expectations and debated conclusions. Here we propose a unified framework that aims at reconciling, and combining, different approaches to reliably test the strength of three stabilizing effects on the temporal constancy of ecosystem functions: the effects of (a) dominant species, (b) species asynchrony, and (c) diversity.InnovationCompared to existing developments the approach allows, for the first time, disentangling these three stabilizing effects at the level of individual communities. So far this was not possible, and conclusions depended on indirect tests and comparative analyses across communities. We also propose a graphical representation of the relative contributions of the three stabilizing effects on a ternary plot, allowing us to easily compare communities sampled in various ecological contexts in a standardized space.Main conclusionsOur study answers the current need for a unified framework to link theoretical concepts on the temporal stability of ecological communities to data analysis. The present development promises flexible tests for a deeper understanding of the ecological stabilization of biodiversity and the relative importance of its components.

Why are plant communities stable? Disentangling the role of dominance, asynchrony and averaging effect following realistic species loss scenario

“…This reveals a certain, although relatively weak, contribution of dominant species to overall community stability. The contribution of dominants to community stability has been further confirmed by the fact that the removal of the one most dominant species in the same locality (see Lepš et al, 2018), decreased the dominance and increased the averaging effect (Segrestin et al, 2024).…”

“…We used the difference between the average species CV (CV e ) and abundance-weighted mean species CV ( CV) as a quantification of dominance effect (Segrestin et al, 2024;Thibaut & Connolly, 2013) and showed that the extent of variability attributable to differences in species abundance accounts for approximately 15% in more diverse communities. This reveals a certain, although relatively weak, contribution of dominant species to overall community stability.…”

“…To test the effect of diversity loss on each component of the community stability we used the framework described in Segrestin et al (2024). All indices were calculated using the comstab R package (Segrestin et al, 2024).…”

“…To test the effect of diversity loss on each component of the community stability we used the framework described in Segrestin et al (2024). All indices were calculated using the comstab R package (Segrestin et al, 2024). In short, we partitioned the community CV c into the stability of an average species and three stabilizing effects: the dominance, asynchrony and averaging effects, as follows:…”

“…Specifically, a community composed of stable populations is likely also to be stable. On the other hand, low stability of populations can be compensated by three stabilizing mechanisms, still resulting in a high community stability: (1) stabilization due to dominant species (dominance effect) and stabilization due to temporal compensations between species related to (2) species asynchrony and (3) to the averaging effect (Segrestin et al, 2024).…”