The role of niche complementarity in the strengthening of the diversity-ecosystem functioning relationship over time

Species-rich communities exhibit higher levels of ecosystem functioning compared to species-poor ones, and this positive relationship strengthens over time. One proposed mechanism for this phenomenon is the reduction of niche overlap and thus, competition within plants or consumers. To explore how niche differentiation affects the plant diversity-productivity relationship, we combined bio-energetic population dynamics and food-web assembly models. Our findings reveal that increased niche complementarity of plants can steepen the relationship if it does not increase intraspecific competition, while increasing complementarity among consumers during community assembly can also have a positive effect but with considerable variability. The study highlights the importance of trait variation among and within species, and the interplay between intra- and interspecific competition strength in shaping the functioning of ecosystems over time. These results offer insights into the mechanisms behind the diversity-functioning relationship and have implications for ecosystem management and conservation efforts.