Faunal diversity of Fagus sylvatica forests: A regional and European perspective based on three indicator groups

Abstract

While the postglacial history of European beech (Fagus sylvatica) and the plant species composition of beech forests in Central Europe are fairly well understood, the faunal biodiversity has been less well investigated. We studied three groups of mostly sedentary organisms in beech forest at regional and European scales by combining field studies with a compilation of existing literature and expert knowledge. Specifically, we examined the relationship between host tree genera and saproxylic beetles, and the diversity and composition of forest ground-dwelling molluscs and ground beetles in relation to the abundance of beech. At a west central European scale (Germany), where beech has a “young” ecological and biogeographical history, we found 48 primeval forest relict species of saproxylic beetles associated with beech, 124 ground beetles and 91 molluscs inhabiting beech forest, yet none exclusive of west central European beech forests. High levels of faunal similarity between beech and other woodland trees suggested that many of the beech forest dwelling species are euryoecious and likely to originate from mid-Holocene mixed broadleaf forests. Beech forests of the mountain ranges in southern and east central Europe, which are ecologically and biogeographically “old”, were found to harbour distinct species assemblages, including beech forest specialists (such as 10 carabid species in the Carpathians) and narrow-range endemics of broadleaf forest. The observed biodiversity patterns suggest differentiated conservation priorities in “young” and “old” European beech forest regions.

Keywords

• beech forests, faunal biodiversity, carabidae, conservation priorities, ecological history, habitat continuity, mollusca, primeval forest relicts, saproxylic beetles