The burden of genetic diversity

In general, species with large ecological amplitudes are equipped with high genetic diversities. In contrast, more specialised species with narrow ecological amplitudes show low levels of genetic diversity. Generalist species are mostly rather marginally affected by recent land-use changes; specialist can be supported by specific conservation measures. We argue that, in the light of Conservation Genetics, species being ecologically intermediate between these two extremes are the most seriously affected ones by recent environmental changes. Such species which formerly occurred in large population networks have to sustain their high level of genetic variability via gene flow. Today, species from the latter group are negatively affected by rapid habitat collapses causing sudden lacks of population interconnectivity. Therefore, species with intermediate habitat demands and originally high genetic diversity might be at highest risk due to inbreeding depressions.

► Generalists are only marginally affected by recent land-use changes o Real specialist species can be supported by specific conservation measurements. ► Species being ecologically intermediate among these two extremes are the most seriously affected ones by recent environmental changes. ► Therefore, species with intermediate habitat demands and originally high genetic diversity might at high risk due to inbreeding depressions.