Loss of characteristic species of open habitats across Germany detected by repeated mapping of protected habitats

Identifying the winners and losers of biodiversity change within different habitat types requires systematic monitoring data. However, such data are particularly scarce at the regional scale, with species trends rarely reported. While systematic data are still lacking, species trends could be instead derived from previously untapped sources. To do so, we make use of plant species occurrences records that were recorded in repeated habitat mapping programs in Germany. We derive temporal trends in plant species from data of three German federal states from 1977 to 2021, both across all habitat types per state and within habitat types. Consistently negative trends were found across all states for species preferring heaths and semi-natural grasslands, moist to wet grasslands, and coastal and marine habitats, including many endangered species. Consistently positive trends were found for species preferring scrub, copses and field hedges, and for non-native species. Moreover, trends within habitat types showed negative trends for species characteristic of most open habitat types, with many of those habitats showing a woody encroachment. While trends varied among states, the overall patterns were very similar. These consistent trends mirror findings in other countries and point to ongoing habitat degradation and common drivers of biodiversity change in Germany. Our findings contribute to the main goals set by the EU Biodiversity Strategy with our species trends serving as monitoring of biodiversity, that can help to improve the management of protected habitat types and nature restoration.