Forest@ (Jan 2007)
Pedunculate oak forests (Quercus robur L.) survey in the Ticino Regional Park (Italy) by remote sensing
Abstract
Pedunculate oak forests (Quercus robur L.) in the Ticino Regional Park (Italy) show sensible damage conditions due to different environmental stresses: insect attacks, summer drought and air pollution. Knowing whether oaks are healthy or stressed can provide useful information in order to conserve the forest ecosystems and avoid the lost of valuable natural resources. Environmental stresses can affect tree biochemical and structural variables, such as the concentration, composition and efficiency in light harvesting of foliar pigments, and the Leaf Area Index (LAI). Interest in the use of these variables for forest condition assessment has recently increased because they can be indirectly estimated from remote observations at leaf and canopy level. In particular, in this research we found that total chlorophyll (Chl) concentration, a biochemical variable related to crown discoloration rate, was the most suitable variable for the detection of pedunculate oak decline in the Ticino Park. A regression analysis between Chl concentration and optical indices computed from hyperspectral MIVIS data was performed in order to estimate Chl concentration from remote observations. The good correlation between field measurements of Chl concentration and MIVIS optical indices allowed the development of a model to map Chl concentration across the Ticino Park forested area. Promising results demonstrated that remotely sensed data can provide an accurate estimation of Chl concentration and indicated the potential of this technique for forest condition monitoring.
