Effects of diversity and dispersal on the functional performance and stability of bacterial communities

Natural communities are open systems and consequently dispersal plays a central role for the diversity, composition, functioning and stability of communities at the local scale. It is, however, still unclear how effects of dispersal differ depending on the diversity of local communities. Here we implemented an experiment where we manipulated the diversity of complex bacterial communities using a dilution-to-extinction approach as well as dispersal from a regional species pool to test how dispersal rates and diversity interactively affect the magnitude of functional parameters (average community growth rates, respiration rates, substrate utilisation ability) and abundance as well as their predictability in response to a perturbation.