Central European dry grasslands: processes of their development and possibilities for their maintenance

(Semi-)dry grasslands represent an important component of the traditional cultural landscape within Central Europe. Because of their species-richness, they are of substantial interest to conservation biologists. They are exposed to various threats and therefore, this habitat type in general and many of its related species have become endangered. The present study aims at understanding past processes of the development of (semi-)dry grasslands and at investigating possibilities for their maintenance. Moreover, in combination with a functional understanding of species assemblages, possibilities for the development of effective conservation and restoration strategies are sought. On the one hand, postglacial migration processes were analysed exemplarily for the typical dry grassland species Eryngium campestre by means of molecular analyses. On the other hand, present conservation and restoration possibilities within the Middle Rhine region that aim at preserving the traditional cultural landscape were investigated. Here, the question was whether cost-efficient alternative management practices are suitable for the sustainable development of xerothermic slopes in the Middle Rhine valley. Prescribed burning and tank track management (strong mechanical soil disturbance) were compared to manual clear cutting and succession in different stages of succession and within different slope areas. Vegetation changes were also analysed on the level of plant functional traits in order to enable a comparison and transferability to other sites. Furthermore, germination response to fire simulation was investigated, as germination response to fire might have important influence on vegetation development following fire.