Data from: Taxonomic evenness-area relationships for plant and soil microbes on tropical islands: Patterns and potential mechanisms

Island area is widely known to affect taxonomic richness across trophic
levels. However, the effect of island size on species evenness, which
quantifies the species abundance distribution, has yet to be explored
across taxa, especially for tropical island ecosystems. In this study, we
surveyed 20 tropical islands with areas ranging from 2 ha to 406 ha and
minimal human disturbance, then measured the taxonomic evenness of both
aboveground plant and belowground soil microbial communities. We found
that, like the positive area-richness relationship, the taxonomic evenness
of the plant community also increased with island area, indicating more
stable plant communities on the larger islands. However, the island area
did not affect the taxonomic evenness of soil bacterial or fungal
communities. Furthermore, the effects of island area on the taxonomic
evenness of the plant and soil bacterial communities were mediated through
soil factors (e.g., soil pH and salinity). Overall, the contrasting
area-evenness relationships among taxonomic groups highlight the
importance of dissecting potential mechanisms underlying multitrophic
community dynamics; more comprehensive explanations of biodiversity
patterns will have critical implications for biodiversity conservation.