Galstyan Gayane Armenovna RussiaSaratovSaratov State University, 83, Astrakhanskaya Str., Saratov, 410012, Russiapost-graduate studentgga-90@mail.ru Author's articles Study Presence of Lichens on Tree Trunks in Saratov as an Indicator of Air Pollution Analysis of the Atmoecological Situation in Saratov and an Assessment of its Possible Development