Study on leaf reflectance and red edge characteristics of Chinese fir (Cunninghamia lanceolata) caused by acid rain with hyperspectral remote sensing

摘要

The purpose of this study is using hyperspectral data to detect the reflectance differences of Chinese fir (Cunninghamia lanceolata) which are sensitive to acidic stress and have been under different degrees of acid deposition stress for a long time. The hyperspectral reflectance for Chinese fir leaf is measured by Fieldspcc Pro FR under three simulated acid rain levels (pH2.5, 4.0 and 5.6) during three years in order to monitor the response of leaf. The results indicated: (1) chlorophyll concentration of Chinese fir increased with the increasing of the simulated rain acidity in the late experimental period; (2) the 1 st derivative values increased at the green edge (480-540nm) and red edge (680-760nm) with pH increasing; (3) the RVI550 and GNDVI values did differ significantly at pH2.5 and 5.6 treatment; (4) red edge position was found moving to longer wave bands with increasing rain acidity along with the experimental time; (5) there are significant differences vale at blue 510nm and 690nm wavelength between different treatments that can be used to be an useful parameters to distinguish the severity of acid deposition. The research also indicated that the hyperspectral parameters can be used to monitor the acid rain stress on trees.