Antropogenic transformation of protective forest plantations under the influence of negative factors
In the areas of intensive exploitation of natural resources, the environment including forests is under considerable loading, which causes the damage of plant and soil cover, sustainability and productivity of ecosystems, landscape structure and stability. At the same time, forests are able to accumulate information on the environmental factors that shape the landscape development, living conditions of the vital activity of human and other living beings. The most informative indicators are the phytocenosis structure consisting of certain tiers, consortium, food chains, species composition of these and other structural components and the state of functional relationships between them and the integral characteristics - biological stability and performance. But still there is not enough knowledge at the ecosystem level that makes it difficult to adequately describe the negative consequences of the damage and predict them. The aim of the study was to find out the features of worsening sanitary conditions, the structure damage and the development of protective forest plantations with various functions depending on the positional application and anthropogenic factors. The research was carried out by the example of the sparsely wooded southern area of Kyiv region, particularly the green area of the town Bila Tserkva, within a radius of 30 km, which was studied. The trial were laid in 17 forest belts and forest areas of different taxation characteristics in their neighbourhood strip along the transport routes: the railway route Bila Tserkva-Kyiv and the highways Kyiv-Odessa, Bila Tserkva-Fastiv, etc. Taxation, agrarian forest improvement and sanitary assessment of the forest belts were carried out using the methods of forestry by species and the tiers of the stand. The suburban forests around Bila Tserkva cover an area of 4.52 thousand ha and are represented by several land plots. The system of shelter belt linear configuration of the agricultural landscapes, along rivers and transport routes is developed. It is mainly presented by middle-aged, hard-leaved, two-tier stands, formed by several wood species with developed understory and undergrowth. They form around the town and arboretum «Olexandria» a network of eco-corridors. The plot of land called «Tovsta» (2.06 ha) is located in the north of Bila Tserkva. The weakened stands of Quercus robur L. accompanied by species satellites prevail there. The understory is well developed and consists of bird-cherry, European hazelnut, black elderberry, etc. The living over-soil cover has been formed by the typical forest species. However, Impatiens parviflora DC. is widely spread (52 %), Chelidonium majus L. is common, that indicates an anthropogenic damage of forest ecosystems. The southern part of the forest area of over 13 km<sup>2</sup> during the 19th and 20th centuries turned into the residential areas «Gaiok» and «Pionerska» and farmlands. This probably caused its fragmentation and certain degradation. The arboretum «Olexandria» is also located in this area. The most devastating anthropogenic damage is observed on the edges (within 40 m) of the land plot «Tovsta», which are closer to the towns and villages. In some places the landfill areas are up to 750 m<sup>2</sup>. Collecting birch sap results in considerable damage. However, high performance and resistance in the conditions of the land plot is revealed by exotic introducent Phellodendron amurense Rupr., performing better than linden and ash. It can be seen in the urban forest belts of elm and sycamore maple. However, without proper care it is displaced by the native species. When the serried wood tent is high (over 0.85), self-seeding and oak undergrowth and its satellites are poorly developed in most stands, Robinia pseudacacia L. is barely survived. Sometimes there is no second tier in oak satellites. Elm has the worst state in the undergrowth and the second tier. Acer platanoides L. has a healthy state and renews the best. There is a land plot called "Tomylivska dacha" (1.85 ha) located in the south of Bila Tserkva along the highway Kyiv-Odesa. Sparse pines have the average recreational digression in the area of 0-30 m from the edge in lane diversion road. The narrow leaved forest belts are also damaged, A. saccharinum L. is severely weakened. People not often visit thick oak stands growing in the high parts of the land plot. Overgrown Urtica dioica L. is even less attractive in the damp and wet areas of the floodplain of the river Ros. There have not been found the recreation traces, but black alder dries within a 50-meter strip from the highway. Elm often dries in many protective forest belts, especially along the highway Kyiv-Odesa. In the narrow forest belts the situation is even more difficult compared to the forest land plots. On the one hand, they are more accessible to people, on the other - they are often over-thickened due to lack of proper forest care. Acer negundo L. (up to 40 % of the stand) is common there. However, it also dries at the average age and such stands degrade. The occupation of more than half of the territory by the ruderants shows the destruction of plantations. Due to the development of urban transport network and economic activity in the green area of Bila Tserkva, the sanitary conditions are worsening, the structure and development of the massive and linear protective forest stands of different functions disrupted depending on the spatial distribution of species and anthropogenic factors are being damaged. The degree of phytocenosis transformation depends on the distance from the transport routes, settlements, access to recreational and other uses. Compared to dense deciduous plantings or wet alder stands, more attractive to people birch and pine stands are currently under greater recreational load. The antropogenic transformation of forest stands manifested itself through unauthorized construction works, networks of roads and trails, trampling, and sometimes destruction of the living over-soil cover, weeding, clogging by household and construction debris, mechanical damage, weakening and wilting of trees.