OPEN-PIT COAL MINES: ANTHROPOGENIC STRESSORS AND VEGETATION SUCCESSION

In the spoil heaps, i.e. in the waste dumps of the soil removed in open-pit coal mining, the emergence and development of spontaneous vegetation is a prerequisite for "bringing them to life", i.e. for development of flora and fauna. Here, the diversity of plants is the result of locally different conditions - often extreme ones ( such as drought and overheating of the surface, toxicity of the substrate, erosion, etc.). At initial stages, phytocenoses, which are not rich in the number of species and which usually have a dominant edificator species, emerge here. The abiotic stress in the spoil heaps is a regular and predictable phenomenon. The theory of primary strategies, represented by the relations of stress, disturbance and competition, was applied. A general diagram of succession development of vegetation in the spoil heaps in the North Bohemia has been prepared; the basic concept is the concept of C-S-R strategies here. The stress-tolerant taxa are determined by the conditions of these anthropogenic areas, i.e. these species are diagnostic indicators for an environment strongly burdened with stress factors (S-strategists). On the other hand, there are species well adapted to unpredictable disturbances (R-strategists); these often include field weeds and ruderal plants. Competitive C-strategists grow in the relatively stable habitats of spoil heaps areas. They are able to resist stress and disturbance only with difficulties. The C-S-R life strategies represent intersections based on the principle of the compromise of profits and losses.