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In woodlands, land use legacy, but also present habitat management can influence biodiversity and ecosystem functions in various ways. However, little is known about how former and current land use interact in woodlands with different habitat continuity and tree age. The aim of this study was to investigate the impact of both habitat continuity and tree age on ground beetles. We performed a field study in the nature reserve “Lüneburger Heide” (Germany). The study area comprised ancient woodland embedded in a matrix of recent woodland. We defined four woodland types by combining ancient and recent woodland with young and old trees and analysed five replicate plots within each of the resulting four woodland types. Habitat continuity, tree age as well as the combination of both of these factors had no significant impact on ground beetle species diversity, abundance, biomass, and evenness with most woodland species occurring on near to all of the four types of woodland plots. Four species, however, showed a significant preference for one of the specified woodland types studied. Our findings provide evidence that all woodland-inhabiting ground beetles of this region are able to colonize new habitats in the continuous woodland matrix, at least, up until a distance of 2.3 km. We call for a heterogeneous woodland management and increasing habitat connectivity to protect both species with a preference for ancient woodland sites and/or old trees and those species which prefer early successional stages.

Ancient woodlands differ from recent woodlands by numerous abiotic and biotic factors, including soil properties. Several animal species are more abundant in ancient than in recent woodlands, but this has been only rarely tested for saprophagous taxa and not at all for dung beetles, which are common in temperate woodlands. Beside habitat continuity, tree age can have also an effect on woodland inhabiting animals, especially on saprophagous taxa. To analyze the effects of both habitat continuity and tree age we studied dung beetles in a continuous north-west German woodland with baited pitfall traps on basis of a factorial design. We compared species diversity (Shannon-Wiener-Index and Pielou's Evenness), catching rates, biomass and community composition of dung beetles. With only 18 recorded species from 20 study plots, dung beetle communities were species-poor and dominated by one large tunnelling species. The main result is that catching rate and biomass of dung beetles were higher in ancient woodlands, which was due to the particularly high catching rate of the most dominant tunnelling species and one dweller species. Tree age alone had a minor impact, but affects significantly one rare species. Diverging habitat quality of ancient and recent woodlands likely explains differences in the communities of dung beetles in woodlands of different habitat continuity. Old trees in recent woodlands could not compensate for habitat continuity of ancient woodlands.

Bumble bees play an important role as pollinators of many crop plants and wild flowers. As in many wild bees, their abundance and diversity have declined in recent years, which may threaten the stability of pollination services. The observed decline is often linked with the loss or alteration of natural habitat, e.g., through urbanization, the conversion of natural habitat into largely sealed areas (concrete) inhabited by humans. The effects of urbanization on bumble bees remain as yet controversial with both positive and negative effects reported. We investigated how habitat isolation through increasing areas of concrete, as well as the diversity, abundance, and community composition of floral resources, determine bumble bee abundance and diversity in cities. We found plant species diversity and abundance to be more important than the amount of concrete in driving the abundance and species richness of common bumble bees in a German city. Moreover, plant species composition, i.e., the presence of specific plant species and families (e.g., Fabaceae), played a prominent role. In particular, flower-rich parks and gardens can offer a continuous food supply for bumble bees and attract bumble bee foragers even to isolated patches in the city center. Bumble bees play an important role as pollinators of many crop plants and wild flowers. As in many wild bees, their abundance and diversity have declined in recent years, which may threaten the stability of pollination services. The observed decline is often linked with the loss or alteration of natural habitat, e.g., through urbanization, the conversion of natural habitat into largely sealed areas (concrete) inhabited by humans. The effects of urbanization on bumble bees remain as yet controversial with both positive and negative effects reported. We investigated how habitat isolation through increasing areas of concrete, as well as the diversity, abundance, and community composition of floral resources, determine bumble bee abundance and diversity in cities. We found plant species diversity and abundance to be more important than the amount of concrete in driving the abundance and species richness of common bumble bees in a German city. Moreover, plant species composition, i.e., the presence of specific plant species and families (e.g., Fabaceae), played a prominent role. In particular, flower-rich parks and gardens can offer a continuous food supply for bumble bees and attract bumble bee foragers even to isolated patches in the city center.