How community adaptation affects biodiversity-ecosystem-functioning relationships

It is increasingly clear that evolutionary dynamics determine biodiversity-ecosystem functioning (BEF) relationships, as evidenced by experimental evolution studies. However, the direction of changes stays unclear. Here we use a modelling approach to compare random communities, with no trait evolutionary fine-tuning, and co-adapted communities, with traits at a co-evolutionary equilibrium, in terms of emerging biodiversity-productivity, biodiversity-stability, and biodiversity-invisibility relationships. Community adaptation impacted most BEF relationships, causing as much as slope inversions compared to random communities. Biodiversity-productivity relationships were generally less positive among co-adapted communities, and less driven by sampling effects. The effect of community-adaptation, while modest regarding invasion resistance, was striking regarding invasion tolerance: co-adapted communities retained greater invasion tolerance at high diversity. BEF relationships are thus contingent on the history of ecosystems and their degree of community adaptation. Observations from short-term experiments or recent perturbations may not be safely extrapolated into the future, once eco-evolutionary feedbacks will have taken place.