Leaf optical properties in Myosotis scorpioides agg. and Veronica anagallis-aquatica

The purpose of the thesis was to examine optical properties of two amphibious plants – Myosotis scorpioides agg. and Veronica anagallis-aquatica. We studied morphological and biochemical properties of leaves and measured reflectance and transmittance spectra. We analysed ten aquatic and ten terrestrial samples of leaves of both species and made the comparison among them. Leaf reflectance and transmittance were measured in the range between 280 and 824 nm. Leaf mass per area, density and size of leaf stomata and trichomes were determined. Leaf structure was analysed and contents of chlorophyll, carotenoid, anthocyanin and UV-absorbing substances were measured. The results showed differences in reflectance and transmittance spectra. In leaves of aquatic plants we detected higher transmittance levels. Terrestrial form of M. scorpioides agg. and aquatic form of V. anagallis-aquatica had higher reflectance in the most of the spectrum range. Optical properties are influenced by the most biochemical and morphological factors mostly negatively correlated with leaf transmittance and reflectance spectra. Most of the relations between leaf properties and reflectivity were obtained by UV, yellow and red range of the spectrum, while the transmittance is typical for the whole spectrum