Evaluating the capabilities of Sentinel-2 data for large-area detection of bark beetle infestation in the Central German Uplands

Abstract

An increase in forest damage caused by the European spruce bark beetle (Ips typographus L.) has recently been observed in many Central European forests such as the forests of the Central German Uplands. For these regions, which are highly vulnerable due to their tree species composition and an increasing frequency of extreme weather events, the availability of time- and cost-efficient monitoring procedures is of particular importance. Thus it was the objective of our study to evaluate the potential of Sentinel-2 data for large-area detection of bark beetle infestation. Using change detection, infestation maps were produced for the Saxon Switzerland National Park Forest District (SAXS) and the Black Forest National Park (BFOR). An accuracy assessment provided a user’s accuracy of 97% (SAXS) and 88% (BFOR), respectively. The calculation of the producer’s accuracy (AP) resulted in 34% (SAXS) and 4% (BFOR). However, when small infestation areas were excluded from stereoscopic reference data, AP increased up to 52% (SAXS) and 40% (BFOR), respectively. Taking these findings into account, our study highlights both the high value of Sentinel-2-based change detection for area-wide bark beetle monitoring and its limitation to large contiguous infestation areas.