Monitoring Climate Extreme Impacts on Whole Forest Stands in Near Real-Time: A Remote Sensing and Dendrometer Pilot in Central-West Europe

The extreme droughts between 2018 and 2022 showed how vulnerable European forests are to a warmer and drier climate. WestWARD responds to this challenge by establishing a pilot network of forest monitoring sites across Central-West Europe.

Our goal is to capture how trees react to climate stress in real time.

At the heart of WestWARD are state-of-the-art dendrometers. Installed on all trees above 10 cm in diameter, these sensors track water storage and growth continuously. With ~80 dendrometers per site, we monitor forests at the ecosystem level rather than just a handful of trees. This high-frequency “ground truth” is then linked with Sentinel-2 satellite data, creating early-warning indicators of tree stress that can be scaled across Europe.

The project focuses on three core signals:

Phenology: detecting shifts in leaf-out and growth phases.
Drought stress: monitoring tree water deficit as a key stress indicator.
Growth: measuring daily stem growth to understand climate sensitivities.
By spanning a gradient from subalpine to continental climates across Germany, WestWARD captures how different soils, species, and climates shape forest resilience. The six “super-sites” also benchmark against networks like TreeNet and Wald-Puls, ensuring comparability and scalability.

With its integration of AI, novel software, and near real-time monitoring, WestWARD provides the critical missing link between tree-level physiology and forest-scale satellite observations. It is a decisive step toward European-wide forest health monitoring, raising public awareness and guiding sustainable forest management.