Regional effects and local climate jointly shape the global distribution of sexual systems in woody flowering plants

Understanding the evolution and maintenance of plant sexual diversity needs to incorporate both regional processes and local climate factors across large geographic scales. Using data of woody flowering plants from a global set of large-scale forest plots and multinomial logistic regression, we quantified regional effects on the proportions of dioecious, monoecious, and hermaphroditic species and their abundance while incorporating evolutionary history and local climate factors. Our results showed that plants were more likely to be dioecious than hermaphroditic in Oceania and tropical Asia but were more likely to be monoecious than dioecious in Europe and North America compared with tropical Africa. We further found that plants were more likely to be monoecious than dioecious in island communities. Plants were more likely to be monoecious than dioecious in areas with high precipitation but were more likely to be dioecious than monoecious in areas with high precipitation of coldest quarter. Our results suggest that both regional processes and local climate factors play important roles in shaping the geographic distribution of plant sexual systems, providing a baseline for predicting future changes in forest communities in the context of global change.