This is an impressive, and very interesting study that provides important information about the roles of functional trait diversity (intraspecific and interspecific) for linking the response of aboveground biomass to species richness across forest strata in a subtropical forest considering also the effect of nutrient soil (in both richness, aboveground, and functional trait diversity). This information is useful to guide conservation and management efforts. The study presents relevant scientific questions and uses appropriate statistical approaches. I allow myself to do an integral analysis of the paper; it is very consistent in approach, theoretical framework, and results.