Authors: Welle, Torsten; Franke, Jonas;

In 2018, 2019 and 2020, periods of droughts and pests such as the bark beetle have particularly hit conifer monocultures hard in Germany and revealed how vulnerable many forest are. Additionally, forest fires and the expansion of open-cast mining (coal, gravel, sand, etc.) have contributed to forest damage and forest loss. Since the droughts of recent years, the abundance of bark beetles and other calamity factors highly differed between regions, the extent of forest damage varies greatly. A yearly in-field forest status assessment at fixed sampling plots is realized to identify how severe this forest damage is in Germany. Since this assessment cannot be done at full coverage, a satellite-based monitoring system is needed to map the forest damage and forest loss at high resolution and country-scale.
In order to address this need, the “Forest Monitor Germany”, which uses a long time series of Sentinel-2 data with 10m spatial resolution to assess changes in the forest status, was developed (https://map3d.remote-sensing-solutions.de/waldmonitor-deutschland/#). Established vegetation indices were calculated based on time series and trend analyses were applied in order to identify positive or negative changes in forest stands in regard to forest biomass and foliage water balance.