ESTIMATION OF VEGETATION PHOTOCHEMICAL PROCESSES:AN APPLICATION OF THE PHOTOCHEMICAL REFLECTANCE INDEXAT THE SAN ROSSORE TEST SITE

摘要

The Photochemical Reflectance Index (PRI) hasrnbeen proposed as a tool for the estimation of leafrnand canopy light-use efficiency and photosynthesisrnfrom remote-sensing data. The application of thernindex is based on more than fifteen years ofrnspectroscopic studies at the leaf level, which supportrnit with a sound physiological basis. In the presentrnstudy, the correlation between PRI andrninstantaneous light-use efficiency was estimatedrnacross a range of vegetation types in the SanrnRossore Regional Park, a CHRIS-P corernsite. The relationship was also tested over an entirernseason for a pine forest in the Park where carbonrnfluxes have been monitored by eddy-covariancernover the last five years. Seasonal changes inrnphotosynthetic potential were also monitored at thernsite, in order to test the correlation with PRIrnreported in the literature. In September 2004,rnestimates of canopy PRI from CHRIS images wererncompared with leaf-level measurements from 13rnplots corresponding to different vegetation types.rnThe results were used to extrapolate leaf-levelrninformation to the entire scene.