Abstract:

This study analyzed the hyper-spectral characteristics of the canopy of Chinese fir under the anthracnose stress, and explored and built the hyper-spectral estimation models of the pigment content in canopy of Chinese fir under the disease stress, the results will promote the application of the hyper-spectral remote sensing-technology in the forest pest and disease monitoring. From April to June in 2011, the anthracnose of Chinese fir had been investigated at Youxian in Hunan Province, and the pigment content and the spectral reflectance of Chinese fir canopy which was under the different degrees of anthracnose stress had been measured. The correlation between the pigment contents, the first derivative data and the canopy hyper-spectral data of the relatively disease Chinese fir leaves were analyzed respectively. By regression analysis methods, a part of the samples were used for construction of the estimation model about pigment contents of disease Chinese fir, and the rest of the samples were used to test the model accuracy. The result showed that the visible light and near-infrared region were the sensitive region which were reflected and absorbed by the pigment in disease of Chinese fir; pigment content had the highest correlation with the first order differential spectra in red edge (695-754 nm), and the correlation coefficient of single band first order differential spectrum in 741 nm was the largest. And it also showed that the accuracy of Chla+b, Chla and Chlb contents was the highest estimated by power function model which used the difference vegetation index DVI[FD587,FD741] as the variable, the relative errors were less than 15%, the RMS error was in the range of 0.093 to 0.241. This study showed that significant difference of the spectral reflectance under the different degrees disease stress of Chinese fir anthracnose, and the hyper-spectral information could be used for estimating pigment contents in canopy of Chinese fir under the disease stress and the estimation precision was high.