Habitat fragmentation of semi-natural grasslands : Impact on species richness, trophic interactions and population genetics

Eidesstattliche Versicherungen und Erklärungen isolated remnants (Young et al. 1996).Thus "habitat fragmentation" combines the effects of the two factors "isolation" (habitat connectivity) and "habitat loss".The relationship between habitat area and species richness is called the species-area relationship, and has been demonstrated for numerous species guilds (Rosenzweig 1995).Today, habitat loss and fragmentation are known to be major Objective and key elements of this thesisUsing data from numerous semi-natural grasslands, this study focuses on the consequences of habitat fragmentation on butterfly and plant species.First of all the impact of habitat connectivity (isolation) and habitat loss on species richness of specialist and generalist butterfly and plant species will be examined (Chapter 5).Second, trophic interactions of the herbivore P. coridon with its larval food plant (host) and its parasitoids are analyzed to investigate effects of habitat fragmentation (Chapter 6).Thereupon a genetic analysis using microsatellites addresses the consequences of habitat fragmentation on the genetic diversity and differentiation of populations of the butterfly P. coridon (Chapter 7).