Quantifying the contribution of community trait mean and diversity to ecosystem functioning

Hundreds of experiments conducted over the last decades demonstrate a positive relationship between species diversity and ecosystem functions. Following good experimental practice, most of these studies have manipulated species richness artificially by assembling communities randomly. Yet, natural communities along ecological gradients often show niche-based responses to selection gradients, and species extinction order is generally not a random process. Such responses are commonly trait-mediate,d and the effects of communities on ecosystems’ functions also depend on species traits. In an effort to disentangle the relationship of trait mean value and diversity with ecosystem functioning, we revisited a community assembly mesocosm experiment that simulated habitat heterogeneity and a typical gradient of productivity to test how body size diversity and composition of cladocerans responded to such gradients and whether and how such trait responses impacted top-down control of unicellular a..., , , # Zooplankton community trait mean value rather than diversity determines ecosystem functioning

[https://doi.org/10.5061/dryad.nzs7h4502](https://doi.org/10.5061/dryad.nzs7h4502)

The dataset consist in a subset of the data from a metacommunity assembly experiment performed by Declerck et al. (2007; [https://doi.org/10.1890/07-0048.1](https://doi.org/10.1890/07-0048.1)). In our study, a multifactorial combination of nutrient concentrations and habitat complexity levels was performed using cattle tanks (200-L) under semi-standardized outdoor conditions (ARENA outdoor experimental area, Heverlee, Belgium). The experiment lasted 32 days following a 34-day inoculation/acclimatation period. In the experimental design, for each level of habitat heterogeneity (i.e., with and without artificial macrophytes) by nutrient concentration (i.e., 0, 10, 100, and 1000 µg L-1), five replicates were used, resulting in a total of 40 cattle tanks. For further details about the experimental design, see De...,