High-resolution mapping of trees loss and regrowth across Germany and Denmark, 2018-2023

Accurate and timely monitoring of forest dynamics is essential for understanding carbon fluxes, managing natural resources, and detecting early signs of ecosystem change. However, satellite based assessments often overlook small-scale changes, especially in regard to trees outside forests (TOFs) and early forest regrowth stages, leading to a possibly biased national reporting. In this study, we present an end-to-end framework to map canopy height dynamics at high spatial (3 m) and temporal (annually from 2018–2023) resolution across Germany and Denmark. Leveraging PlanetScope imagery with lidar data and deep learning models, we produce annual canopy height and canopy cover maps, forest morphology classes (contiguous forest, trees outside forests, and forest gaps), and assess both tree loss and regrowth. Over the study period, we found that trees were lost on 8164 km² and gains were observed over 683 km², which is a loss to growth area ratio of 12:1. Our results reveal that disturbances have caused substantial fragmentation of contiguous forest in Germany, emphasizing the importance of high-resolution monitoring in capturing canopy cover dynamics.