Abstract
In grassland biodiversity experiments the positive biodiversity–ecosystem functioning relationship generally increases over time. However, there is still a large gap in our understanding of the underlying short-term evolutionary processes. Research has shown that differential selection in monoculture vs. mixed-species communities can lead to rapid evolution. We assessed whether selection history altered productivity, biodiversity effects and species complementarity within newly assembled monocultures and 2-species mixtures using five plant species selected for twelve years in such a biodiversity experiment in mixture or monoculture and plants without such a selection history. Plants without past community selection history produced the lowest community biomass and showed the weakest biodiversity effects. Furthermore, we found that twelve years of selection history in monocultures or species mixtures differentiated plants into monoculture- and mixture-types within species. In newly assembled mixtures, plants with a selection history in mixtures performed better than plants with a monoculture selection history. Biodiversity effects were generally positive but, contrary to expectation, not stronger for mixture types. In addition, biodiversity effects were both influenced by trait differences among plants and community-weighted means, but these relationships were largely independent of selection history. Our findings indicate possible mechanisms underlying the rapid evolution of adapted subtypes within a species in grasslands. Uncovering these mechanisms contributes to our understanding of the biodiversity–ecosystem functioning relationship, which has the potential to influence species conservation practice.
Footnotes
↵2 Email: sofia.vanmoorsel{at}ieu.uzh.ch
Emails of other authors (in order): contact{at}mwschmid.ch, terhi.hahl{at}ieu.uzh.ch, debra.zuppinger{at}ieu.uzh.ch, bernhard.schmid{at}ieu.uzh.ch