Mitigating the loss of biodiversity is a challenge for policy and conservation given current unprecedented rates of environmental change. Among environmental change, climate and land-use change related to agricultural intensification and land abandonment prevail as dominant drivers. Agricultural abandonment may cause an increase of woody encroachment and ultimately lead to the expansion of forests. In threatened habitats in Switzerland (e.g. fens, dry meadows), woody encroachment may lead to a decline in vascular plant diversity. In this project, we will quantify the relationships between woody encroachment, habitat diversity and plant species diversity. Modelled vegetation height based on historical aerial stereo images, covering 40 years of woody encroachment and forest expansion, will be combined with existing biodiversity data. This allows for a spatially explicit assessment of the relationship between woody encroachment and the dynamics of habitat and plant species diversity.