不同演替阶段典型树种幼苗对酸胁迫响应的高光谱监测

通过在为期2a的可控酸雨试验下对处于不同演替阶段的典型树种幼苗的高光谱测定,得到不同梯度酸雨下各树种的叶片光谱反应曲线及相应叶片的生理生化参量.对测定的3种树种的叶片叶绿素含量及一阶导数光谱进行分析,发现随着酸雨浓度的增加,处于演替前期的先锋树种马尾松的幼苗叶绿素含量呈现增加趋势,而处于演替中、后期的木荷和青冈幼苗叶绿素含量则呈现减少趋势;随着试验时间的推移,马尾松的红边位置呈现"红移"趋势,其中pH2.5处理下的"红移"趋势较明显;而木荷和青冈的红边位置则呈现不同程度的"蓝移"趋势.较长时期高浓度酸胁迫对先锋树种马尾松的幼苗生长有一定促进作用,而对演替中期和后期树种木荷和青冈幼苗生长则主要表现为抑制作用.

Evaluation of stress in the seedlings of succession typical species induced by acid rain using hyperspectral remote sensing

In order to revealing the influence of acid rain stress in succession species, the hyperspectral traits of three seedlings of Pinus massoniana、Schima superba and Cyclobalanopsis glauca were measured during two years. There were three acid rain stress treatments, include pH5.6、pH4.0 and pH2.5. The hyperspectral information is helpful to reveal the relationship between chlorophyll concentration and spectral reflectance in succession species under acid rain influence. The results indicated (1) Chlorophyll concentration of Pinus massoniana seedling in earlier succession stage showed the increased trend with the increasing of the simulated acid rain density, however the seedling of Schima superba and Cyclobalanopsis glauca, which are in middle and late succession stages showed the Chlorophyll concentration are decreased; (2) Along with the test period, the peak wavelength of red edge for the seedling of Pinus massoniana shifted to longer wavelengths but while Schima superba and Cyclobalanopsis glauca shifted to shorter wavelengths; (3) It may promote the seedling of Pinus massoniana growth and impacted the seedling of Schima superba and Cyclobalanopsis glauca growth with the high density and longer period acid rain stress.