Influence of anthropogenic factors on anatomo-morphological and physiological indices of needles of common pine trees

Abstract

The article presents the results of the influence of anthropogenic factors on the changes in anatomo-morphological and physiological features of the structure of pine needles (Pinus sylvestris L.) growing in different habitat conditions in Kstovo, Nizhny Novgorod region. Necrosis and desiccation of needles in places with the most intensive motor transport traffic exceeded the control variant by 30.0-72.0 %, respectively. The experimental variant showed changes in the anatomical structure of pine leaf: epidermis thickness increased (by 60%), the area of assimilation tissue decreased by 34.6%, the diameter of resin passages decreased (by 5.0%) and their number (by 60.0%), the distance between conductive bundles (by 26.7%) and their diameter (by 37.8%), compared to the control variant. Under conditions of anthropogenic load, changes in the pigment composition of pine needles were observed: the content of chlorophyll a decreased by 9.1%, chlorophyll b - increased by 29.1%, carotenoids did not change, compared to the control variant. Thus, the results obtained expand the understanding of morphology, anatomy and pigment composition of needles of common pine growing under urban conditions. Quantitative changes in these indicators depend on the growing area.