TYPOLOGICAL STRUCTURE OF FORESTS IN THE DESNA CATCHMENT AREA

A general characterization of the catchment area of the River Desna is given. The Desna catchment area is located in two forest zones of Ukraine - Polissia, and Lisostep. According to the results from the analysis of the forest inventory database of PA Ukrderzhlisproekt, the planted areas of the Desna catchment area have been distributed by forest site types, forest types, tree species. To analyze the typological structure of the Desna catchment area, the sites belonging to the catchment area have been selected from the standwise forest inventory database of PA Ukrderzhlisproekt. The total area of the stand sample is 395.3 thousand hectares. The catchment area boundary has been determined using MapInfo Professional 12.5 and a vector map of Ukraine. The forest areas are distributed by administrative regions as follows: Chernihiv Region (62 %), Sumy Region (31 %), Kyiv Region (7 %). The forest resources of the Desna catchment area are characterized by a wide variety of types of forest sites covering almost the entire Ye.V. Alekseev’s and P.S. Pogrebnyak’s edaphic grid. In each group of forest site types, the foresters have identified different numbers of forest types. Pine forests (bors) are represented by five, pine – fir/oak forests (subors) - by eight, pine forests with birch, aspen and oak participation (composite subors) – by twenty eight and oak groves (dubravas) – by eighteen types of forest. In total, 59 types of forest are identified, including four - arid, thirteen - fresh, eighteen - sodden, nineteen - wet and five - bog. The most common types of forest within the area of the study subject are as follows: fresh fir/oak forest (subor) (40 %), fresh lime/oak/pine forest (composite subor) (9 %), sodden fir/oak forest (subor) (7 %), fresh pine forest (bor) (7 %). Among the tree species, the following species predominate common pine (60 %) and common oak (15%). The weighted average forest inventory indicators of natural and artificial pine forests in the conditions of fresh oak/pine forest (subor) in the Desna catchment area have been determined and analysed. It has been established that natural pine forests, as pertaining to reserves (per 1 m3•ha-1) up to the 5th age class, predominate over artificial pine forests, and, in contrast, as for the 6th to the 13th and further age classes, the artificial pine forests predominate over the natural ones. While planning, organization, and forest management in compliance with watershed and landscape principle, one should take into account the following varieties: forest types, types of forest stands, categorization of forest protectability in the watersheds of Desna River.