Geographia Polonica (1992) vol. 60
Historic slope degradation above timberline in the Balkan Mts., Bulgaria
Geographia Polonica (1992) vol. 60, pp. 43-50 | Full text
Climatic amelioration in the Holocene resulted in a rise of the upper timberline in the Balkan Mts. (Stara Planina) up to 1800-1950 m a.s.l. Incorporation of the Balkan Peninsula in the Turkish Empire in the 14/15 centuries has opened the Muslim markets for mutton, skin and wool. As a result of grazing pressure, the upper timberline has been lowered by several hundred metres over the last 4-5 centuries. This exposed Pleistocene slope deposits to contemporary geomorphic processes. The results of these processes occur over the entire area above the timberline, but are in particular well developed between 1500-1700 m a.s.l. on slopes which were formerly afforested.In these areas small slumps or landslides are very common on fine grained slope deposits. On the debris-loamy slope deposits semi-circular niches, 5-8 m long, are common. As a result of upslope enlarging and capturing of adjacent niches, the grass ridges separating them become isolated "monadnocks". In the areas underlain by shales, on slopes with gradients exceeding 30°, soil slides are particularly common.Processes of slope degradation caused by the overgrazing exhibit various stages of development. Some areas are characterized by fresh relief forms, other by more subdued forms which are progressively colonized by vegetation.
, University of Silesia , Earth Sciences Faculty, ul Będzińska 60, 41-200 Sosnowiec, Poland