In this graduation thesis we studied optical properties of leaves of the selected species of plants. We were interested in how structures on the leaves surface (cuticle and trichomes) affect light reflectance. Ten plant species were chosen. For this reason we removed either cuticle or trichomes. We measured reflectance with and without cuticle in the first group of plants, and with and without trichomes in the second. Leaf reflectance was measured in the range from 280 nm to 880 nm. Comparison of the results showed that chosen plant samples have some spectral properties in common, mostly low reflectance in visible spectrum (380-700 nm) with peak in green range of visible spectrum (550 nm), and high reflectance in NIR area (700-880 nm). We found out that samples were very variable, therefore the importance of structures on the leaf surface structures was not confirmed in all cases. The influence at chosen plant species with removed cuticle was higher then influence of removed trichomes. Cuticle influenced light reflectance in particular in UV and NIR spectra. Trichomes significantly influenced the light reflection in visible and NIR spectrum at Crepis capillaris. The age of leaves did not affect the reflectance, as the measured reflectance was very similar in two age classes.
|
