A concise collection of contributions which focuses on the global decline of animal and plant species. Scientists from the various disciplines of biology mainly explore how environmental alterations (e.g. size and distribution of biotopes) affect the structures of populations and interactions between populations. Topics comprise aspects of population genetics, dynamics, demography and evolution, which are carefully summarized and discussed. The given data is based on experimental field and laboratory work on animals and plants as well as theoretical research. These contributions aim at demonstrating how the knowledge presented in this book can be actively applied to species conservation and which partly political decisions are necessary to effect a change. This book is of great interest to all those who are actively or administratively concerned with species conservation.