| Zusammenfassung: | The upper timberline in the West Carpathians has been most intensively attacked by grazing and, to a lesser extent, by charcoal burning or by other human activity. The shepherds attacked it especially during the Valach colonization in the 15th and 16th centuries. Because the Valachs practiced summer grazing at high altitude, above the forest belt, they were deforesting the mountains not only from the mountain foot upward but also downward, lowering the timberline. Grazing and deforestation intensity and accompanying lowering of the timberline can be related primarily to the petrographical composition of the substratum, soil, relief conditions, vegetation, and ownership. In general, the best conditions for alpine grazing are found on the basic substrates, rich in minerals, with a thick and coherent soil cover and smooth slopes with few rock outcrops. After deforestation floristically poor associations develop on the more acid substrates which are less suitable for grazing. The bilberry (Vaccinium myrtillus L.) does not tolerate tramping by cattle and it is replaced by the grass Nardus stricta L. forming floristically monotonous and very poor meadows of hard grass (Nardetum strictae) which is also less suitable for grazing. On the carbonate substrata, especially on widespread dolomite and limestone, floristically rich pastures, which are highly suitable for sheep, develop following deforestation. Thus deforestation has proceeded most extensively on areas underlain by carbonate rocks resulting in a lowering of the timberline by 200 to 300 m (in some places by much more than this) below the level of the climax timberline. The most depressed timberline occurs in the Krivánska Malá Fatra (Small Fatra), the White Tatras (Belanské Tatry) and the West Tatras (Západne Tatry), in the carbonate part of the High Tatras (Vysoke Tatry), and of the Low Tatras. The relief and geomorphological conditions are important factors influencing the impact of man upon the timberline. The shepherd is attracted to smooth periglacial ridges such as those characteristic of the Small Fatra and Great Fatra (Vel'ká Fatra), which are not very far from the timberline. During the 20th century the timberline has been influenced by recreational activities, especially by winter sports. Thick and long-lasting snow cover and periglacial relief provide good conditions for skiing. On grassy surfaces covered with grazing plant communities, water penetrates very slowly into the soil. In the region of timberline total precipitation is high and evaporation is low; slopes are smooth, grassy, and steep, so that runoff is rapid. Trampling by cattle destroys the plant cover and gives rise to rapid erosion. Deforested smooth and grassy slopes provide conditions for increased avalanche activity. The mountain areas most menaced by avalanches, where the timberline was especially lowered by grazing are the Great Fatra, the Mesozoic part of the Krivánska Small Fatra, the White and West Tatras, and in part the Low Tatras (Nízke Tatry). Reduction of the above-mentioned undesirable phenomena is urgently needed. At timberline, it is possible to improve the forest and water economy, to develop the winter sport areas, and also to practice grazing. However, in order to understand the landscape processes as a basis for efficient land-use planning, it will be necessary to undertake a theoretical reconstruction of the climax or natural timberline.
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