Laser-induced fluorescence of birch, pine, and aspen trees was studied. The
fluorescence of birch leaves, excited with a Xe-Cl laser at a wavelength o
f 308 nm, was measured under laboratory conditions. A persistent directly p
roportional dependence was found between the measured fluorescence signals
and the chlorophyll content. An apparatus for measuring laser-induced fluor
escence under field conditions was designed. Deciduous trees were found to
have a wider range of fluorescence variability when compared to conifers, w
ith the fluorescence intensity increasing in the leaves of deciduous trees
before the autumn fall of leaves, during leaf yellowing. It is concluded th
at the method of lidar probing can be used for identifying tree species and
assessing the condition of leaf and needle canopies.