Walory przyrodnicze przeobrazonego eksploatacja Torfowiska Wysokiego Karaska

Paper presents the results of the 1992 studies of Karaska Bog, one of the largest continental raised bogs in Poland. The object of research was to determine the impact of four decades of peat extraction on natural environment of the bog, to identify in particular: - impact of extraction on various elements of the bog ecosystem, - potential of extensive raised bog subjected to industrial-scale exploitation to preserve its nature values, - natural regeneration capacity of the peatbog. Investigation results helped to establish the origin and evolution of the peatbog as well as its interrelations with the surrounding area. The following four stages of development were distinguished: I - silting up of the water reservoir by lake sediment. II - final colonization of the lake by sedge-moss and raised bog-sedge communities responsible for accumulation of fen and transitional peat. III - accretion of highly decomposed raised bog Eriophorum-Sphagnum peat generated by oligotrophic peat-forming communities associated with water regime based on precipitation. IV - development of raised bog Sphagnum communities accompanied by accumulation of poorly decomposed raised bog tussock peat. Condition of vegetation and soils in Karaska Bog was found to be as follows: - condition of vegetation: - areas with natural or near-natural vegetation - jointly 55 %, - visibly dehydrated areas featuring secondary plant cover - 28 %, - heavily dehydrated areas destroyed by exploitation largely devoid of vegetation - 17 % total bog area - soils: - peat-swamp soils - 39 %, - peat-moorsh - 50 %, - post-extraction sites -11%. It was concluded that extensive raised bogs are relatively invulnerable to diverse impact of peat extraction. They retain much of their nature value and demonstrate high capacity for self-regeneration. As such they should be seen as sites not wholly lost to the natural environment. Consequently, it is advisable for each site of this type to assess its eligibility for nature-reserve type of protection