ENVIRONMENTAL AND RESOURCE CAPACITY OF FOREST PLANTATIONS ON RAVINE GULLY LANDS IN THE MIDDLE VOLGA REGION

Abstract

The research is carried out in response to the need of enhancing the environmental and resource capacity of landscapes and abandoned agricultural lands by means of establishment of forest plantations for the environmental and socio-economic benefits of the rural population. The work aims to evaluate environmental and resource capacity of forest plantations on gully lands of the Middle Volga region and their optimization, ensuring maximum economic and environmental effects. The object of the study are pure and mixed forest species established in 1968 using a variety of schemes on soddy podzolic loam sand soil and located in the central part of the Mari El Republic on the gully ravine lands of the Managa river basin. Digital empirical material was processed using traditional mathematical statistics using PC and standard application packages. The research results proved that forest plantations on the gully ravine lands of the Mari El Republic feature a very high resource capacity: completely dry forest stand biomass of pure 45-year old pine stands amounts to approximately 316.8 t/ha, its energy efficiency amounts to 6,000 GJ/ha, which is equivalent to 140.7 tons of oil. One hectare of forest plantation consumes annually 12.9 tons of carbon dioxide and disengages 9.3 tons of oxygen. The stem timber stock at this age is 624 m3/ha, and the stock of large and medium timber at this age reaches 364m3/ha. The market value of the stand provided it is harvested at this particular moment amounts to 1.189.000 rubles per ha, under the average annual increment of 26.41thousand rubles/ha. Productivity, viability and root value of the existing mixed pine-spruce-birch plantations is considerably lower. As a result of the research carried out, it has been determined that the productivity of pure pine forest and large-scale wood yield in many ways depend on its initial density, which should not exceed 1.5-2 thousand trees per ha on ravine gully lands. The research features mathematical equation, which reveal the impact of row spacing  on taxation parameters of the middle tree and productivity of plantations. The authors draw a conclusion that under such conditions it is reasonable to produce highly productive mixed oak and linden plantations. Pine should be mixed with larch, and spruce should be mixed with linden.