Posted: 13 Nov 2017 06:55 AM PST read full ScienceDaily article here
Productivity and stability of forest ecosystems strongly depend on the functional diversity of plant communities. Researchers have developed a new method to measure and map functional diversity of forests at different scales — from individual trees to whole communities — using remote sensing by aircraft [paving] the way for future airborne and satellite missions to monitor global plant functional diversity.
Ecological studies have demonstrated positive relationships between plant diversity and ecosystem functioning. Forests with higher functional diversity are generally more productive and stable over long timescales than less diverse forests. Diverse plant communities ….can better cope with changing environmental conditions — an insurance effect of biodiversity. They are also less vulnerable to diseases, insect attacks, fire and storms.
Researchers from the UZH and the California Institute of Technology / NASA Jet Propulsion Laboratory have now developed a new remote-sensing method to map functional diversity of forests from small to large scales, independent of any predefined vegetation units or species information and without the need for ground-based calibration….
With airborne laser scanning, the scientists measured morphological characteristics of the forest canopy such as canopy height, foliage and branch densities. These measurements indicate how the sunlight is taken up by the canopy to assimilate carbon dioxide from the air and use the carbon to grow. In a canopy with a more diverse structure, light can better spread between different vertical canopy layers and among individual tree crowns, allowing for a more efficient capture of light. The researchers also characterized the forest with regards to its biochemical properties using airborne imaging spectroscopy. By measuring how leaves reflect the light in many spectral bands, they were able to derive physiological traits such as the content of leaf pigments (chlorophylls, carotenoids) and leaf water content…
“We can see, for example, if a tree is suffering water stress, and what resource allocation strategy a tree is following or how it adapts to the environment,”
Fabian D. Schneider et al. Mapping functional diversity from remotely sensed morphological and physiological forest traits. Nature Communications, 2017; 8 (1) DOI: 10.1038/s41467-017-01530-3