A large body of research shows that biodiversity loss can reduce ecosystem functioning.
You don’t say. Several years ago we half-heartedly attempted to summarize the literature here a couple of times. We’ve sort of given up on that of late: there’s just too much of it. But there is a fundamental problem with this literature…
…much of the evidence for this relationship is drawn from biodiversity–ecosystem functioning experiments in which biodiversity loss is simulated by randomly assembling communities of varying species diversity, and ecosystem functions are measured.
Fear not, though, help is at hand. The two quotes above are from the abstract of a paper bearing the following title.