Understanding the mechanisms that drive community assembly in
species-rich tropical forest remains a fundamental challenge in ecology.
Here, we integrated trait dimensions, metabolomics, and phylogeny to
test whether interspecific variation over multivariate trait dimensions
contribute to coexistence among Euphorbiaceae species. We measured 41
functional traits related to resource acquisition, photosynthetic
capacity, hydraulic safety and efficiency, and defense in all 26
Euphorbiaceae species in a 20-ha forest dynamics plot in tropical
southwestern Yunnan, China. Network analysis revealed that a small
number of traits with high network centrality reflected variation in
ecological strategy among the Euphorbiaceae. Further, we observed
significant turnover with respect to these high-centrality traits over
environmental gradients at distinct spatial and temporal scales. Whereas
resource-utilization traits and the habitat associations they mediate
exhibited consistent phylogenetic signal. Phylogenetic divergence in
chemical defenses likely represents an additional trait dimension that
enhances local diversity of closely related Euphorbiaceae in
southwestern China.