杨扇舟蛾和杨小舟蛾危害对意大利214杨高光谱特征的影响

杨扇舟蛾和杨小舟蛾是危害意大利214杨的主要食叶害虫. 为了研究杨扇舟蛾和杨小舟蛾危害对意大利214杨高光谱特征的影响,并为遥感监测意大利214杨杨扇舟蛾和杨小舟蛾提供基础光谱数据,该文于2003年5—8月以6年生意大利214杨为材料,在杨扇舟蛾和杨小舟蛾危害意大利214杨落叶率为48%时，分别测定试验和对照区冠层、叶片的高光谱数据及相应的生化参数(叶绿素含量、类胡萝卜素含量、含氮量和含水率等),应用微分光谱及数理统计中的t检验方法对数据进行分析.结果表明,意大利214杨受杨扇舟蛾和杨小舟蛾危害后,冠层和叶片的光谱反射率均变小,冠层和叶片光谱的红边具有“双峰"现象；冠层光谱在可见光～近红外波段有较高的灵敏度和辨识能力,敏感波段为449.1～466.1 nm、798.6～801.4 nm和826.8～833.9 nm；冠层和叶片的红边(REP)均呈“蓝移"现象,红边斜率和红边面积变小；冠层试验和对照的REP分别为719.3和725.0 nm,叶片试验和对照的REP分别为709.4和719.3 nm. 杨扇舟蛾和杨小舟蛾危害意大利214杨后,叶面积、叶绿素a含量、叶绿素b含量、总叶绿素含量、类胡萝卜素含量、叶片含氮量和叶片含水量均显著减少. 

Impact of Clostera anachoreta and Micromelalopha troglodyta insect-induced damage on the hyperspectral features of Populus × canadesis cv. 'I-214'

Clostera anachoreta and Micromelalopha troglodyta are the two primary defoliators feeding upon the leaves of Populus×canadesis cv. ‘I 214’. The purpose of this investigation is to determine the impact of C. anachoreta and M. troglodyta insect induced damage on the hyperspectral features of P.×canadesis cv. `I 214’ and to provide basic data for remote sensing monitoring. The experiment was carried out at the canopy and leaf levels in six year old stands at the induced damage and control plots from May to August in 2003 The hyperspectral reflectance and biochemical and physiological parameters consisting of photosynthetic pigments, nitrogen and relative water content were measured when P.×canadesis cv. `I 214’ defoliation rate was 48% caused by insect damage. The raw hyperspectral data, their derivatives, and t test were used. The results showed that the spectral reflectance of P.×canadesis cv. `I 214’ insect induced damage by C. anachoreta and M. troglodyta decreased regardless of the leaf or canopy level. There were double red edge peaks. The canopy spectral reflectance had high sensitivity and discrimination in the visible NIR region. The sensitive ranges included 449.1-466.1 nm, 798.6-801.4 nm, and 826.8-833.9 nm. The red edge positions(REP) in canopy and leaf spectral reflectance shifted to blue, and the slope and area of red edge decreased. The REP of test and CK of the canopy were 719.3 and 725.0 nm, respectively, the REP of the leaves of test and CK were 709.4 and 719.3 nm, respectively. In addition, after P.×canadesis cv. `I 214’ being damaged byC. anachoreta and M. troglodyta,the leaf area, concentrations of chlorophyll a, b and total chlorophyll, carotenoid, leaf nitrogen content and relative water content all decreased evidently.