Biodiversity and Forest Management: the case of brachypterous ground beetles of Sessera Valley beech forests (NW Italian Alps)

European beech forests are of particular importance for biodiversity, although relatively little is known about how beech forest management impacts on invertebrate communities. We focused on a group of localized, medium and large-bodied brachypterous ground beetles inhabiting beech forests in the north western Italian Alps. The study site, located in the Sessera Valley, is part of Natura 2000 ecological network. In particular, the site houses Carabus olympiae, classified as a priority species in Annexes II and IV of the ‘‘Habitats Directive’’ (92/43/EEC). We used baited pitfall traps to sample the carabid community and investigate the influence of beech forest management history [i.e. over-mature coppices (OC) and coppices in conversion to high forests (CCHF)], climatic, topographic and microhabitat characteristics on ground beetle diversity, measured as total relative abundance, species richness, Shannon diversity and abundance of the endangered endemic species Carabus olympiae. Moreover, we used radiotelemetry to evaluate C. olympiae movements in differently managed beech forest stands. The diversity of forest specialist carabids was higher in OC and in forest stands characterized by a higher mean temperature and lower relative humidity. Moreover, we detected a positive response of several diversity variables to coarse wood debris cover or volume, herb cover, and the standard deviation of tree diameter. Currently, OC seems to be a more favorable habitat for forest carabids, including C. olympiae, although succession over time can lead to a progressive homogenization of the vegetation structure, with negative consequences for the conservation of the forest carabid assemblage. Preliminary observations on C. olympiae movements seem to suggest they move more linearily in recently coppiced stands. Based on our results, we suggest that the traditional management of beech coppice and its conversion to high forest should be modified by including practices aimed at promoting structural and microhabitat diversity such as retention of large trees, creation of canopy gaps, retention of coarse wood debris and the preservation of ‘islands’ of older trees in the managed stands. The research was supported by a European grant (EU LIFE+ Project NAT/IT000213).