Role of spatial and environmental factors in shaping the rotifer metacommunity in anthropogenic water bodies

In spatially heterogeneous habitats, local communities may be shaped by both local biotic and abiotic factors and by regional factors (dispersal of individuals among habitats). In recent years, ecologists have been increasingly interested in measuring how much the structure of local communities is explained by spatial variables and by non-spatial environmental variables. We analysed the effects of biotic and abiotic factors on rotifer communities in 12 anthropogenic water bodies in the Silesian Upland. The studies were conducted in two groups of water bodies which were of differing dimensions: group A — seven water bodies situated very close to each other (between 50 and 500 m), group B — the water bodies from group A as well as 5 other water bodies situated 2 km away, which were at greater distances from each other (about 1–3 km). Apart from this, genetic variation was assessed in 3 populations of Brachionus plicatilis Müller to estimate the level of gene flow between them. A characteristic feature of anthropogenic water bodies is a high variation in environmental conditions, so they are specific and difficult habitats for many organisms. Our study shows that environmental factors played a major role in shaping the local rotifer communities in heterogeneous anthropogenic water bodies with respect to salinity. Results of this study suggest, however, that in neighbouring water bodies, dispersal is very important for maintenance of local species diversity. A medium level of genetic variation between populations of B. plicatilis indicates that gene flow occurs irrespective of the distance between local populations.