A Review of Strong Evidence for the Effect of Functional Dominance on Carbon Stocks in Natural Forest Ecosystems

Natural forest ecosystems are very important because of their potential and primary role in carbon (C) sequestration. However, it is not very clear that whether Functional Trait Diversity (FTD) enhances C stocks in them due to the trait values of the most abundant species (the mass ratio effect; measure as a Community Weighted Mean (CWM) and/or the variety of trait values (the niche complementarity effect; measure as a Functional Divergence (FD) within an ecosystem. In this study, I reviewed the most recent, critical, empirical and original research studies about FTD-C stocks relationship to understand the effects of CWM and FD on C stocks in natural forest ecosystems. The results of their studies suggest that strong dominance by tall and conservative species, rather than a set of coexisting species with diverse heights and exploitative nature, results in greatest C stocks in natural forest ecosystems. Thus, functional dominance (CWM effect) rather than FD effect has strong influence on C stocks in natural forest ecosystems. In conclusions, these evidences reflect that presence of dominant species will finally diminish functional divergence. Therefore, further research is needed to include the abiotic and biotic factors of an ecosystem in the conceptual model to critically test the FTD model of C stocks for full understanding.