Stability of rocky intertidal communities in response to species removal varies across spatial scales

Improving our understanding of stability across spatial scales is crucial
in the current scenario of biodiversity loss. Still, most empirical
studies of stability target small scales. Here we experimentally removed
the local space-dominant species (macroalgae, barnacles, or mussels) at
eight sites spanning more than 1000 km of coastline in north- and
south-central Chile, and quantified the relationship between area (the
number of aggregated sites) and stability in aggregate community variables
(total cover) and taxonomic composition. Resistance, recovery, and
invariability increased nonlinearly with area in both functional and
compositional domains. Yet, the functioning of larger areas achieved a
better, albeit still incomplete, recovery than composition. Compared with
controls, smaller disturbed areas tended to overcompensate in terms of
total cover. These effects were related to enhanced available space for
recruitment (resulting from the removal of the dominant species), and to
increasing beta diversity and decaying community-level spatial synchrony
(resulting from increasing area). This study provides experimental
evidence for the pivotal role of spatial scale in the ability of
ecosystems to resist and recover from chronic disturbances. This knowledge
can inform further ecosystem restoration and conservation policies.