琅琊山区主要树种冠层光谱年际变化研究

森林树木的生理机制和生态结构随年份变化，该变化通过其冠层光谱特征在一定程度上有规律的表现出来。掌握森林树木光谱特征随年份变化的规律，既有利于遥感解译，也为多树种的识别与分类、生物化学成分估测等提供一定的科学依据。本研究利用高分辨率光谱仪对研究区7个主要落叶树种和7个主要常绿树种的不同年份冠层光谱特征进行测量，分别获取4个不同年龄段的光谱曲线，并计算出一阶导数曲线，从而深入分析不同落叶树种、不同常绿树种在不同年份和相同年份的光谱特征变化规律，比较各树种在可见光波段和近红外波段的光谱差异变化，以找出最适宜多树种识别的最佳年份和最佳波段。结果显示：落叶树种和常绿树种的冠层光谱特征随年份变化表现出一定的规律性，光谱反射率随年龄增加而升高;光谱变化差异均在近红外波段最为明显，此波段是进行多树种识别的最佳波段。

Changes of Forest Canopy Spectral Reflectance with Seasons in Lang Ya Mountains

The physiological mechanism and ecological structure of forest trees can change with the changes of years. In a certain extent, the changes were expressed through the canopy spectral features. The mastery of changing rules about spectral characteristics of trees over the years is benefit to remote sensing interpretation and provide scientific basis for the classification of different trees. The study adopted high-resolution spectrometer to measure the canopy spectral characteristics for seven major deciduous trees and seven evergreen trees to gain the spectrum curve of four different ages and calculate the first derivative curve. The analysis of changing rules about spectral characteristics of different deciduous trees and evergreen trees and the comparison of changes about spectrum of various trees in the visible and infrared band could find the best year and best band for identification of trees. The results showed that the canopy spectral reflectance of deciduous and evergreen trees increases with the increase of age. And the spectral changes of two species were most obvious in the near infrared band.