Conservation and restoration of calcareous grasslands: a concise review of the effects of fragmentation and management on plant species

Worldwide, the most species rich plant communities at small scale (< 10 m super(2) grid) are some types of temperate grassland communities, and of these, the calcareous grasslands of temperate Europe are the most diverse. Calcareous grasslands were once widespread in the hilly calcareous regions of Western Europe but due to changes in agricultural practices (either intensification or abandonment of grazing by sheep and cattle, and the consequent succession towards forest) their extent has decreased dramatically and the remaining areas have become extremely fragmented. In this review we discuss the reported effects of decreasing habitat quality and habitat quantity on plant community composition of calcareous grasslands. Available evidence reveals the strongly negative consequences of both of these processes on plant species, both at the community level as at the population level. It seems, however, that especially the effects of fragmentation on plant species richness on the one side and the effects of management and fragmentation on biotic interactions on the other are still poorly understood and that more research is necessary.