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设置UV-B滤光减弱、UV-B辐射增强和自然光(对照)3组模拟大田试验,比较了不同UV-B辐射处理下,亚热带典型木本植物杨梅幼苗的叶绿素含量、光谱反射率及光谱特征参数,研究UV-B辐射变化对亚热带森林树种的影响.结果表明:增强UV-B辐射可降低杨梅幼苗的叶绿素含量,而降低辐射则会显著促进叶绿素的增加,并且这种胁迫反应于光谱反射率中.3种不同梯度UV-B辐射作用下,可见光部分光谱反射率间的差异主要集中在绿光反射峰及红边附近,同时红边所在波长位置“红移”.UV-B辐射对杨梅的胁迫在时间上具有积累性.用反高斯模型参数R0、λ0、λp、Rs、б指示杨梅受UV-B胁迫,以Rs最显著.不同UV-B辐射水平下植物叶片光谱反射率上的差异,可通过较窄波段光谱反射率或特定波长光谱反射率所构建的植被指数加以有效区分.
Three simulated field experiments were conducted to study the effects of UV-B radiation, enhanced UV-B radiation and natural light (control) on the chlorophyll content, spectral reflectance and spectra of the typical woody plants of subtropical. The results showed that enhanced UV-B radiation could reduce the chlorophyll content of M. bayberry seedlings, while the decrease of radiation could significantly promote the increase of chlorophyll content, and the stress response to the spectrum Reflectance.The spectral reflectance differences of visible light under the three kinds of gradient UV-B radiation are mainly concentrated in the reflection peak of red light and near the red edge, and the position of the red edge is “red shift”. UV- B radiation on the accumulation of time in bayberry with anti-Gaussian model parameters R0, λ0, λp, Rs, б indicated that the red bayberry under UV-B stress to Rs most significant under different levels of UV-B radiation plant leaf spectra The difference in reflectance can be effectively distinguished by the vegetation index constructed by spectral reflectance at a narrow band or spectral reflectance at a particular wavelength.