THE INFLUENCE OF MOTOR TRANSPORT POLLUTION ON THE GROWTH OF EUROPEAN LARCH

Abstract

The results of an 18-year monitoring of the growth of European larch (Larixdecidua Mill.) in the zone of influence of the Moscow Ring Road (MKAD), one of the largest highways in the European part of Russia with a load of about 9 thousand cars per hour, are presented. The studies have been carried out on three trial plots located at 15, 35 and 100 m (control) from the highway. The morphometric parameters of European larch were determined 4, 8 and 18 years after planting four-year-old seedlings. Significant inhibition of European larch growth near the MKAD was revealed by height, trunk diameter, and crown parameters. The largest negative impact of the MKAD on its growth was manifested in the first 4 years after the creation of forest crops. The area of influence of the motorway on larch stands is about 40 m. Dendrochronological analysis of larch wood has showed that the total annual growth in the control section is significantly higher than in the area near the highway. Moreover, the growth of early wood in the area near the Moscow Ring Road is on average 23% higher than in the control one, the growth of late wood in the control area exceeds the growth in the area near the Moscow Ring Road by 34%. An analysis of the radial increment of European larch wood has showed that the growth of early wood is most closely related to the total amount of rainfall in May, June and July (correlation coefficient r = 0.33), of late wood to the amount of heat in August and September (r = - 0.44)