935 
of toxicants, etc.) and species differentiation. Taking these factors into 
account is of great importance for interpreting not only lidar data, but also 
any other fluorescent techniques (e.g. solar-stimulated fluorescence measure 
ments). The second group of factors is defined by the features of powerful 
pulsed laser excitation, mostly by the saturation of Chl-a fluorescence, 
caused by singlet-singlet annihilation of excitons within light-harvesting 
complexes. 
On the one hand, the linkage between functional state of the object and 
in vivo Chl-a fluorescence complicates quantitative assessments of object 
characteristics (for instance - phytoplankton Chl-a concentration in water 
column or Chl-a content in leaves). On the other hand, it provides the 
potentials for development of lidar techniques, capable of remote monitoring 
the parameters related to physiological status of the objects and ongoing 
photosynthesis, as well as bioindication of environmental impacts. 
8 . - REFERENCES 
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Chapelle E.W., McMurtrey III J.E., Kim M.S., 1991. Identification of the 
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