Print PageEcosystem stability in a variable world depends on the diversity of form and function in a community. This type diversity is the product of evolution and the evolutionary history represented by co-occurring species has been shown to be an important predictor of ecosystem function. If evolutionary history is a surrogate for ecological differences, then greater evolutionary diversity should buffer ecosystems against environmental variation and result in greater stability of ecosystem function. We calculated measures of plant community diversity that incorporate evolutionary information for a long-term biodiversity-ecosystem function experiment at Cedar Creek, Minnesota. We calculate a detrended coefficient of variation in aboveground biomass production, and examine how evolutionary diversity explains variation in stability.
Results/Conclusions
Our results indicate that communities where species are equivalently related to one another are more stable than communities where evolutionary relationships are imbalanced. Two hypotheses could potentially explain this result. First is that there are some evolutionary lineages that have inherently greater stability in biomass production than others and greater evolutionary distances reduce the chance of sampling only unstable groups (evolutionary selection effect). Using tests of phylogenetic signal, we failed to find evidence for closely-related species having correlated stability. The second hypothesis is that greater evolutionary distances between co-occurring species result in greater stability because they are more likely to be ecologically different (evolutionary complementarity). We found that species were less likely to be stable when they were in communities with only closely-related species. Ecosystem stability is affected by the diversity of form and function in communities and accounting for evolutionary relationships can reveal how such diversity may affect stability.
