Formation of a sierozolshan forest on lands out of agricultural use

Long-term non-use of old-grassland is a prerequisite for the formation of closed forest stands of different ages and, as a consequence, leads to the natural overgrowth of gray alder and birch. Alder is one of the most common second-order tree species of the Leningrad Region, which, despite the presence of valuable economic features, is practically not grown in special pure stands and has a reduced commercial value. Therefore, for the first time in the conditions of Leningrad region of the Kastenskii district forestry we carried out a comprehensive study of the natural formation of alder on the lands out of agricultural use. The tasks under consideration include the study of processes of formation of a stand of gray alder on post-agrogenic lands, reconnaissance survey, analysis of the main forest characteristics of gray alder by quantitative and qualitative indicators, as well as the species diversity of vegetation in the sample area. The obtained results of the study of the formation of gray alder forest on the lands out of agricultural use in the southern taiga subzone allow us to state that environmental conditions affect the seasonal growth of gray alder, and the main diseases, running chronically at this stage of development, do not lead to a decrease in the taxation characteristics of the stand. The land has preserved an arable horizon with high natural fertility. The area is well suited for natural regeneration of spruce and growing pine, but biological features, treeless spaces, maximum light and minimal competition allows for now successful spread of gray alder. On the object of research in the form of living ground cover is dominated by hedgehog, grasses, red clover, willow- herb, woodruff, willow-herb, St. John’s wort, goldenrod and field horsetail, where the total projective coverage of the dominant species composition exceeds 50 %. These results of alder surveys can be used in solving a number of tasks: to assess the raw material value, the ecological role of homogeneous stands, as well as the productivity potential of forest post-agrogenic biogeocenoses.