Spread of Acer negundo L. on the banks of the River Tok at the Orenburg oblast'.
The negative side of the distribution of the ash-leaved maple (Acer negundo L.) in the steppe zone of Orenburg oblast', as well as the factors reducing the biological diversity of woody vegetation are considered. The further displacement of native maple trees. The reasons for the aggressive capture of floodplain areas object of study are given. The scientific description of maple as a species is presented. The number of trees by selectively-enumeration method of 18 independent plots on 10 acres are considered. The route method of the studied trees is used for basic information about the nature of adult tree cover in the area. A very strong competition between the maple and the local woody flora, to which it is similar in their biological characteristics is discovered. From all studied trees (white poplar, bird cherry ordinary, white willow, small-leaved elm) competitive was only Populus alba L., as it was not discovered parasites and not identified any disease. The fastest growing trees in the studied plant communities are maple and white willow (Salix alba L.). The high susceptibility of trees to disease caused by Phellinus igniarius L. is connected with a close arrangement to each other. To prevent further deterioration of the environmental situation in the steppe it is prompted to enter a strict control of the size and dominance of maple in the steppe regions, to produce cuttings, to organize volunteer raids planting of willows and poplars in areas most dangerous to their displacement.