Ways of strengthening positive influence of forest ecosystems on the ecological state of the environment in Rivne region

Abstract

There has been made an analysis of forest land areas in Rivne region. If has been marked that under the influence of the climatic conditions which are due to the geographic location of  the region, there have formed two types of forest land areas on ifs territory : Polissia and Forest-steppe. The northern part is occupied by Polissia which is characterized by a low flat relief and a moderate conti-nental   climate with mild winters and warm, humid summers. Among arboreal species, the prevail-ing one is pine common (Pinus sylvesfris). If is the main forest-forming species in this region where highly productive and ecologically stable stands have formed on soddy podzolic sandy – and sandy loam soils with different moisture levels. The Forest-steppe zone whit its moderate continental cli-mate is located to the South of Polissia stretching from the northern border of the Volyn Upland to the southern border of the region. The great variety of soils and climatic conditions of the Volyn Up-land results in alternations of forest stands with prevailing hardwood species and steppe areas. As a result of active anthropogenic transformation of landscapes in Rivne region, the correlation between their components has changed substantially. Farming lands occupy the most part of the region amounting to the highest index (65.7 percent) in the forest-steppe zone while being 34.0 per cent in Polissia. Forest stands, of which one fifth is made up of forest of the former collective farms, occupy 31.2 per cent of forest land area in the region. They are characterized by low quality, insignificant density and inadequate stability. It should be noted, however, that the forest stands are distributed unevenly here, which diminishes considerably their positive effect on the environment. The forest percentage is the highest in Polissia while the territory of the forest-steppe being the least forested. As our research shows, the intensive farming in the forest-steppe zone has the most adverse effect on the environment. The most part of the eroded soils is concentrated here. This results from low forest percentage, the broken relief, a lack of the complete system of protective forest, weakness of the stands due to substantial proportion of low productive and of low-density forest of the former collec-tive farms as well as breaching age structure of Derzhlisfond (state forest) stands. It was reveald that the age structure of Rivne region forests is uneven and significantly disrupted. According to statisti-cal data for forest resources inventory in the year 2002 (common pine and common oak which are the main forest-forming species) middle-aged stands prevail here (34.2 per cent - community forest, 42.7 per cent state forests). The intensive anthropogenic transformation of the landscapes in Polissia for-est-steppe zone in the past supports the growing ecological role of forest, in the environmental stabi-lization, which, in its turn, brings about the requirement that the existing forest stands should be con-served and new stands be planted. An important role in maintaining the proper ecological state of the environment is assigned to massive, highly productive and high-density climax stands which, along with the intensive accumulation of organic matter, play water-regulation role in the rivers, purify the air, water and soils. They are an active producer of oxygen and make the microclimate milder, they prevent soil erosion and accumulate moisture as well as being good protection from winds etc. One way to optimize the age structure of state-run forest in this region is to hand over, either in part or in full, the community forests to Derzhlis fond (state forest fund) with their subsequent reconstruction. Simultaneously with the optimization of the stands age structure it is necessary that the optimum forest percentage of agrolandscapes should be formed creating protective forest stands within the limits of estimated needs. The goal of forestry measures directed toward the optimization of forest percentage in Rivne region is to produce a positive effect of forest stands (forest strips, forest mas-sifs and small forest massifs) on the environment as well as reducing negative effects (soil erosion, catastrophic floods, land-sliding, water and air pollution).