Spectroradiometer measurements in the laboratory and in the field to analyse the influence of different damage symptoms on the reflection spectra of forest trees

The objective is to characterize the influential parameters on the reflection spectra measured over forest trees with different damage symptoms. To meet this objective spectroradiometer measurements of leaves, twigs and trees with comparable damage symptoms were carried out both in the field and in the laboratory. The spectroradiometer measurements have been carried out between 0.4μm and 2.2μm in 56 bands over spruce (Picea abies), pine (Pinus sylvestris, Pinus strobus) and beech (Fagus sylvatica). The evaluation of the data showed that the influence of leaf parameters on the reflection spectra are minor compared to the external parameters of the natural biosphere, like illumination, shadow and background. It was also proved that the near infrared region in particular is extremely sensitive to the amount of shadow in the stand and to the illuminated background.