Illuminating Forest Health: Validating Space-Based Plant Fluorescence from the Ground Up

This innovative ESA project transforms the Pfynwald research site into a comprehensive ground-truthing laboratory for the FLEX (Fluorescence Explorer) mission, which maps global plant health and photosynthetic activity from space. By measuring sun-induced fluorescence (SiF) - the subtle glow emitted by vegetation during photosynthesis - at multiple scales from individual leaves to drone flights, the project validates FLEX's satellite observations and builds robust models connecting this fluorescence signal to actual carbon uptake by forests. Operating in a unique forest environment with controlled water availability treatments, the research combines continuous monitoring systems with intensive measurement campaigns to decode the complex relationships between plant stress, photosynthesis, and the fluorescence signals that FLEX detects from orbit. The results will not only validate FLEX mission products but also enhance our understanding of forest ecosystems' role in the global carbon cycle.