Is Causal Ecological Biogeography a Progressive Research-Program

Various spacial and temporal time scales need to be taken into account in the interpretation of biological events. Omission of these aspects can lead to purely descriptive studies of changes in faunal assemblages, which are severely limited in scope. Terrestrial molluscs, which are very sensitive to environmental and climatic changes, provide a good example to illustrate this problem. Using an ecological biogeographic approach, a review of mollusc assemblages from holsteinian tufas in western Europe is presented. The analysis permits the definition of the Lyrodiscus biome, which corresponds to a temperate mixed forest community which developed under a particularly warm oceanic climate, and never occurred in Western Europe since that time.