A metacommunity is a set of local communities between which there is an exchange of individuals (dispersal). Differentiation in traits and in species (as a result of natural selection/species selection) within each community affects surrounding communities through dispersal. We are interested to find out the relationship between genetic diversity and species diversity in this regional context of a metacommunity. In a field survey we will compare genetic variation of molecular markers and quantitative traits in a specific zooplankton species (Daphnia magna) with variation of traits and species composition of the zooplankton community. The calculation of specific parameters (Fst, Qst and community analogues Fst and Qst) will allow us to do an analysis of the between-habitat variation in the various variables which gives us more insight in the factors that influence the covariation between genetic diversity and species diversity.