Assessing the physiological state of woody plants by parameters of chlorophyll fluorescence in the bark of annual shoots

The relative yield of variable chlorophyll fluorescence in the bark of annual shoots of woody plants was measured with a portable pulse-modulated fluorometer designed for this purpose at the Department of Biophysics (Biological Faculty, Moscow State University). Experiments were performed to study the response of this parameter to external influences (treatment with an herbicide, water loss, etc.). The results demonstrated the possibility of reliably recording the parameters of fluorescence in the annual shoots of various woody plants without damaging these shoots. It is concluded that measurements of chlorophyll fluorescence in the bark of woody plants can be used for analyzing changes in the physiological state of tree stands under the effects of natural and anthropogenic factors.