Plant-microbe interactions in tropical and subtropical ecosystems.

Microbes regulate many dimensions of plant performance with multiscale implications for plant fitness, competition, coexistence, and ecosystem functioning. Yet, this fascinating and diverse arena of study has been limited to a few thematic areas, ecosystems, and regions. In particular, despite growing evidence that microbes may be critical players in the dynamics of plant communities in tropical and subtropical ecosystems, these regions remain poorly represented in studies of plant-microbe interactions. Such geographical gaps limit our ability to draw general inferences to comprehend how microbial effects on plant community dynamics may vary with context and, by extension, respond to global environmental change. In this special section of the American Journal of Botany, we bring together a diverse set of research on plant-microbe interactions from tropical and subtropical ecosystems. These papers explore intraspecific variation of soil microbial communities, the context dependency of host-specific assembly of microbial communities on plants, and the new and exciting frontier of the microbiome of epiphytic plants. We hope that this compilation will fuel deeper forays into the many dimensions of plant-microbe interactions in megadiverse tropical and subtropical forests.