Biodiversity trends for Germany using repeated habitat mapping data

Abstract

Identifying the winners and losers of biodiversity change requires systematic monitoring data. Since such data is rare, biodiversity trends could be derived from heterogeneous data. In this thesis, I used repeated habitat mapping data from 1977-2021 from the German federal states Schleswig-Holstein, Hamburg, and Baden-Württemberg to derive temporal trends of habitat types, plant species, and plant species within different habitat types. Most protected habitat types decreased in area. Consistently in all states, I found negative trends for species of heaths and semi-natural grasslands, moist to wet grasslands, and coastal and marine habitats, and for endangered species. In contrast, species of scrubs, copses and field hedges, and non-native species increased. Within habitat types, characteristic species mostly declined, while woody species spread in open habitat types. This implies ongoing habitat degradation and emphasizes the need for intensified action to stop the biodiversity crisis.