Наукові праці Лісівничої академії наук України (Jun 2020)
Features of anthropogenic impact of forest management on water purity in mountain forest watercourses
Abstract
Harvesting in the mountains has a significant impact on the forest environ-ment. This is especially evident during ground skidding due to forest soil trans-formation both directly within the harvesting area and at skid trails. In the pro-cess of construction, the skid trails, the solidity of the soil is brokenand with an increase in the steepness of the slope, the volumes of operational erosion are con-siderably increased. In the case of multiple passages of skidding tractors on the trails, deep tracks are formed, through which during intense precipitation or during snowmelt occurs surface run-off leading to the foot of the slope. It is accompanied by the simultaneous removal of forest soil particles which, when they enter nearby for-est streams, lead to their pollution. Many researchers have come to the conclu-sion, that the main factor that affects the water quality is the sediment, which in the process of forestry activities enters to watercourses from forest roads and skid trails. In view of the foregoing, the issue of studying the features of the forest man-agement impact on water quality is relevant. Therefore, four-year studies were conducted at two forest catchments in the state enterprise «Osmolodа Forestry». It purpose was to define the effect of forest management on water pollution. This will allow further development of measures to prevent the entry of soil erosion products into forest streams. The influence of technogenic factors inherent in forestry activities, including logging, on water quality was determined by con-ducting field and analytical studies to determine the turbidity of water in rivers of small forest catchment. The method of quantitative determination of turbidity, essence of that con-sists in establishment of height of column of muddy water, was thus used. Its ap-plication is regulated by the State standard and is often used in practice. On the basis of the results, graphs showing the changes in turbidity in the riverbeds dur-ing the week and separately during the working day have been constructed. There is a clear trend of water turbidity increasing of during the working period (Mon-day to Friday) and a significant decrease on weekend (Saturday, Sunday). Both rivers are also characterized by increased turbidity from morning hours to mid-afternoon and its gradual reduction towards the end of the working day. At the same time, the restoration of water transparency by 20 hours to its morning level is not observed. This is due to the time it takes to reach the water sampling site. More studies are needed to fulfil to identify the different types and levels of water pollution caused by forest management and the factors that cause them. It will allow to create the conditions for establishing a system for assessing the water quality in forest catchments and developing appropriate decisions for its improvement. The main ones should be technical measures that reduce soil ero-sion and prevent the entry of surface water from forest infrastructure elements in to watercourses.
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