Managing towards extinction: Diverging developments of plant and ground beetle assemblages following restoration of calcareous grasslands

Central European calcareous grasslands are particularly rich in species, harbouring an endangered flora and fauna. In this study, we analyse how invertebrates, like ground beetles, react on vegetation changes in these habitats. We ask if and how species of both groups may react on local environmental changes associated with conservation management regimes. For this reason, vascular plant and ground beetle communities were assessed at six semi-natural calcareous grasslands in Luxembourg before (1988–1992) and after (2008–2010) restoration had started. All studied grassland sites are protected as nature reserves and managed to preserve an open and diverse plant species composition. Our data indicate diverging trends for plant and ground beetle composition: Richness and abundance of species increased for plants and decreased for ground beetles, particularly for forest and Red List species. Functional diversity of plants and ground beetles remained stable, although the abundance of nitrogen-loving plant species increased. In ground beetles, we identified increased proportions of species with strong habitat associations. These findings underline that plant species, in particular typical calcareous grassland species, benefited from ongoing conservation management, while many ground beetle species, mostly the non-grassland specialists, suffered under the applied management regimes. These results highlight the general dilemma in nature conservation of how to prioritise management regimes in situ.