ABSTRACT Although numerous studies have explored the mechanisms underlying the diversity‐productivity relationship (DPR), a comparative understanding of whether complementarity or selection effects play a dominant role is still lacking. We quantified the contributions of complementarity or selection effects to the DPRs of submerged macrophytes in Lake Erhai, China. We treated the contributions of species richness and dominant species dominance to productivity as complementarity or selection effects and excluded the effects of water depth. We then developed a new statistical analysis to quantify the contributions of complementarity or selection effects to their DPR. Such an approach would enhance the mechanistic interpretation of DPR patterns, a key objective of the present study. Our results showed a positive correlation between productivity (expressed as biomass) and species richness, after excluding the water depth and quantifying the comprehensive direct and indirect effects of species richness, dominant species dominance, and water depth on community productivity. The DPR pattern is greatly disturbed by factors such as water depth, which must be excluded when interpreting patterns in DPR. Furthermore, the contributions of complementarity and selection effects to patterns in DPR can be adequately partitioned using our constructed statistical analysis procedure once these influencing contributions are excluded. While the statistical analysis procedure works well in our field DPR experiment, it will inspire more scientists to quantify complementarity or selection effects on community productivity in future DPR studies.
Wu et al. (Sun,) studied this question.