Summary

The current longterm study on amphibian populations and landscape ecology is located in the area of Bonn (Northrhine Westfalia, Germany) in a typical european agricultural landscape. It continues two previous studies starting in 1988 and 1993. The main subject of this longterm investigation is the development of amphibian populations in natural and artificial ponds. The combination of capturing and marking animals in the field, genetical methods (enzyme electrophoresis) and analysis of important population parameters like age structure (skeleton chronology) and reproductive success make it possible to estimate the stability of populations of the species examined (Smooth Newt, Alpine Newt, Crested Newt, Common Frog, Agile Frog, Marsh Frog, Pool Frog, Edible Frog and Common Toad). This data are used for analysis of migration rates and isolation of subpopulations and modelling of population size and species composition. Additional information on environmental factors like land use, microclimate, water chemistry and waterlevel dynamics of ponds can help to understand the dynamics in species composition and dominance.
These longterm observations and analysis of factors mentioned above can help to work out the key factors for sustainable, more or less species rich population of amphibians in agricultural landscape.