Data from: Dispersal enhances beta diversity in nectar microbes

Dispersal is considered a key driver of beta diversity, the variation in
species composition among local communities, but empirical tests remain
limited. We manipulated dispersal of nectar-inhabiting bacteria and yeasts
via flower-visiting animals to examine how dispersal influenced microbial
beta diversity among flowers. Contrary to the prevailing view that
dispersal lowers beta diversity, we found beta diversity was highest when
dispersal was least limited. Our analysis suggested that this unexpected
pattern might have resulted from stronger priority effects under increased
dispersal. Dispersal is highly stochastic, generating variability in
species arrival history and consequently the potential for community
divergence via priority effects, in these and likely many other microbial,
plant, and animal communities. Yet most previous experiments eliminated
this possibility. We suggest that the positive effects of dispersal on
beta diversity, like the one we report here, may have been greatly
underappreciated.