Data from: Biotic stability mechanisms in Inner Mongolian grassland

Biotic mechanisms associated with species diversity are expected to
stabilize communities in theoretical and experimental studies but may be
difficult to detect in natural communities exposed to large environmental
variation. We investigated biotic stability mechanisms in a multi-site
study across Inner Mongolian grassland characterized by large spatial
variations in species richness and composition and temporal fluctuations
in precipitation. We used a new additive-partitioning method to separate
species synchrony and population dynamics within communities into
different species-abundance groups. Community stability was independent of
species richness but was regulated by species synchrony and population
dynamics, especially of abundant species. Precipitation fluctuations
synchronized population dynamics within communities, reducing their
stability. Our results indicate generality of biotic stability mechanisms
in natural ecosystems and suggest that for accurate predictions of
community stability in changing environments uneven species composition
should be considered by partitioning stabilizing mechanisms into different
species-abundance groups.