Data from: Towards a better ecological understanding of metacommunity stability: A multiscale framework to disentangle population variability and synchrony effects

1. Despite great progress in our understanding of the mechanisms governing
ecosystem stability in local communities, we still lack knowledge at a
larger spatial scale. Studying the stability of metacommunities requires
assessing the temporal stability and synchrony of populations across space
and organizational levels. Previous attempts to disentangle these effects
have provided limited ecological interpretations, and conceptual
improvements are needed to identify the underlying ecological processes.
2. We propose an extended framework aiming at disentangling simultaneously
the relative effects of population stability and different types of
synchronies on metacommunity stability. We adapted previous methods of
decomposing stability into a new set of indices associated with clearer
ecological hypotheses. Particularly, we provide synchrony indices that are
not affected by statistical properties of the metacommunity but focus on
species responses to environment, demography, and interactions. We applied
this framework to a unique dataset describing the sorted biomass of
individual plant populations, across 12 communities of a species-rich
meadow, and for 16 years. The communities were sampled in different
treatments of fertilization and dominant removal to evaluate the effect of
environmental heterogeneity on stability. 3. We found higher stability at
a larger spatial scale, mainly due to statistical averaging (portfolio
effect). The variability of individual populations was an important
determinant of the stability of the whole metacommunity. Consistent with
the hypothesis of a common response to environmental conditions, we found
that the fluctuations of populations were mostly synchronized (within and
between species) at a large spatial scale and tended to destabilize the
metacommunity. On the other hand, opposite fluctuations (anti-synchrony)
between populations occurred at the local scale, probably due to local
species interactions. 4. Synthesis Our framework appears as a powerful
tool to test how ecological processes occurring simultaneously at
different spatial and organizational scales affect the stability of
metacommunities. This study advances our ecological understanding of the
processes underlying the stability of species-rich environments. --