Data for Former cropland enhances tree cover and connectivity but homogenizes landscapes across Europe

Changes in the landscape structure of trees can profoundly influence ecosystem functioning and biodiversity patterns. However, the combined effects of farmland abandonment, forest management intensity and natural disturbances on tree landscape structure across Europe remain poorly understood, particularly due to the lack of systematic, landscape-scale indicators that go beyond tree extent alone. Here, we develop an integrated framework quantifying tree cover, connectivity and structural heterogeneity, and apply it to assess their dynamics across Europe from 2001 to 2021. We further evaluate the relative roles of forest management regimes, farmland abandonment, natural disturbances, climate and human pressures in shaping these changes. We find that European tree landscapes have undergone widespread increases in tree cover and connectivity over the past two decades, accompanied by a marked decline in structural heterogeneity across 23% of the land area, with the strongest trends occurring in southeastern Europe. Notably, former cropland areas are strongly associated with tree-cover expansion and increased connectivity, but simultaneously promote landscape homogenization. Our results reveal pervasive vegetation densification and homogenization, trends that may reduce the capacity of European ecosystems to sustain biodiversity. Restoring natural disturbance processes, including herbivory and fire, may therefore be critical to unlocking the full biodiversity potential of nature recovery in Europe.