Scientifica 2015 – Light and Biodiversity

Visitors were attracted by colourful plants showing a variation in leaf size, pigmentation, and leaf thickness of the displayed plant species. Many visitors followed the advice on a leaflet saying ‘Please touch’. Yes, reflectance does not only occur in wavelength ranges that humans can see with their eyes, but light is also reflected in spectral regions not visible to the human eye. Kids were allowed to cut leaves and carry them to a spectrometer to measure reflected light.

To help understand light interaction successfully the reflectance of living stones, a hairy cactus, bright green versus red leaves, white non-photosynthesizing leaf parts surrounded by green photosynthetically active areas, was measured. Artificial leaves showed missing liquid water absorption bands thereby deepening the visitors understanding of light interaction using reflectance.

The second stop of the booth highlighted light extinction by the assembly of a canopy to show 3 levels of plant functional diversity. Whereas the sparse tree canopies did transmit most of the incoming light, the denser grassland canopies absorbed a much higher light fraction.

Finally, visitors were directed towards the ‘sandbox’ where products derived from airborne imaging spectrometer data were displayed.

This step was nothing more than applying the knowledge on leaf and canopy reflectance previously acquired to the reflected light recorded at the airborne or spaceborne platform. The products displayed over the URPP Lägern site ranged from pigments to a digital elevation model.

Thanks to all the project members and to the WSL who provided us with small trees, we contributed a colourful, attractive booth, appreciated by many visitors. We had great interaction with the interested public, from very young kids to retired scientists, often ending in discussions about science and policy!

Gabriela Schaepman-Strub

Debra Zuppinger-Dingley