The manuscript “Functional identity regulates aboveground biomass better than trait diversity along with abiotic conditions in global forest metacommunities” is a high-quality paper, well written, with significant contributions and novel results, which I recommend for publication. Understanding the multiple drivers of tree community assembly helps us plan conservation and restoration strategies and predict the impact of global climate changes. Furthermore, in this article, the authors tested important hypotheses in ecology using appropriate analysis with structural equation models, evaluating how multiple factors (biotic and abiotic) affect ecosystem functioning along global forest metacommunities. First, I read hypotheses (which I use in my studies as well). Second I analyzed the data that the authors provide using the R code. In this way, I was able to corroborate the results that test the hypotheses. Finally, I evaluated the methods, introduction and discussion, which are systematically structured. However, please, the authors must considerer these important suggestions:

C1. Please check throughout the manuscript that different words or terms are used to refer to the same meaning; however, readers may be confused with different definitions. I understand that the intention is to make reading more flexible and correspond to the same meaning.
Example1: Abiotic and biotic factors; abiotic and biotic drivers, abiotic and biotic pathways; abiotic conditions; abiotic and biotic determinants. However, please, if they are all different, then define more clearly in your introduction and methods. Please review other terms and definitions throughout the manuscript.
Example2: Abiotic hypothesis: I can only read in figure 1, while in figure two hypotheses are presented (niche complementarity or mass ratio). I understand that it has been explained, but I think can be highlighted. Indeed, what work does this hypothesis support? Climate stability affects Dominant latitudinal diversity gradient (LDG)?

C2. Please, it is important to deepen and explain with more details both in the introduction and discussion the balance between acquisitive and conservative strategies along the climatic gradient according to the proposed hypotheses. The author can dedicate a paragraph for the introduction and explain it better in the discussion. For example, functional traits (and diversity) can determine species persistence against strong environmental filters along a resource-use strategies gradient or climatic gradient. Please, flow this paper like an example: Maracahipes et al. Perspectives in Plant Ecology, Evolution and Systematics 34 (2018) 17–25. In the introduction of this paper, this gradient acquisitive and conservative strategy is clearly defined. This same logic must be maintained in the discussion to relate to the proposed hypothesis (niche complementarity or mass ratio).

The authors follow the reviewers' suggestions. The article is an important contribution to ecology

The authors present an important contribution

Congratulations for the effort and important contribution