The Lichen Indication of Pollution of Western Volga Delta

The research is focused on the delta area of the Volga river. Our study was conducted during the period from May to September in the years 2011 and 2012. We examined about 80 trees Ulmus laevis and Fraxinus excelsior. Ten species of lichen belonging to the familes Teloschistaceae, Rhysciaceae, genera Caloplaca, Xanthoria, Physcia, Lepraria were found in the control biotope. During the study period, all trees were characterized by a high degree of projective cover from 45.7 % to 96.2 % in 2011 and from 47.1 to 100 % in 2012. Lichens growing in the area of conventional control had bright color of the thallus. The index value of clean air was 14.8 in 2011 and 14.1 in 2012. The studied sites were divided into three areas: area of the severe pollution, area of the average pollution and favorable area.