Data from: Seasonal assembly of nectar microbial communities across angiosperm plant species: Assessing contributions of climate and plant traits

Plant-microbe associations are ubiquitous, but parsing contributions of
dispersal, host filtering, competition, and temperature on microbial
community composition is challenging. Floral nectar-inhabiting microbes,
which can influence flowering plant health and pollination, offer a
tractable system to disentangle community assembly processes. We
inoculated a synthetic community of yeasts and bacteria into nectars of 31
plant species while excluding pollinators. We monitored weather and, after
24 hours, collected and cultured communities. We found a strong signature
of plant species on resulting microbial abundance and community
composition, in part explained by plant phylogeny and nectar peroxide
content, but not floral morphology. Increasing temperature reduced
microbial diversity, while higher minimum temperatures increased growth,
suggesting complex ecological effects of temperature. Consistent nectar
microbial communities within plant species could enable plant or
pollinator adaptation. Our work supports the roles of host identity,
traits, and temperature in microbial community assembly, and indicates
diversity-productivity relationships within host-associated microbiomes.