Procesy zarastania Pustyni Błędowskiej

Abstract

The Błędów Desert is situated in the eastern part of the Silesian Upland (fig. 1). The area is characterized by the massive occurrence of sand-gravel compositions. The origin of the Błędów Desert had nothing to do with climate conditions: the effective cause was the strong development of the extractive industry which started in the region in the Middle Ages. The surrounding forests turned the main fuel source for the developing mining and metallurgical industry. Therefore, areas of the Błędów Desert were completely deforested. Until recently, the desert belonged to one of the largest inland areas of blown sand in Central Europe. In 70s, the region was in the range of depression sink action of zinc lead ores mines in Olkusz but, in spite of the fact, the process of growing up intensified. So, bore sand areas and deflation fields are presently rare and covered with bushes, sods or even woods. Different stage of plant succession have been observed in the for selected transects (Przełom, Centuria, Żródlisko Białej - fig. 2, tables 1-4) of the total length of about 8 km and territory of 160 000 m2. The phytosociological, ecological and soil investigations were conducted in the surface of transects in order to find the regularity of plant succession and link them with soil processes. On the selected transects, the presence of 16 plant associations (7 non forest and 3 forest asemblages - tables 5-15)) as well as 6 plant communities with undefined phytosociological range has been recorded. During the research, the author showed that the typical association Spergu/o morisonii-Corynephoretum canescentis with replaced by Festuco-Koelerietumglaucae. In the sand areas in the Błędów Desert, 106 vascular plan species were represented with predominating hemicryptophytes (fig. 3). From on ecological point of view, all the plant have adapted to life in warm, dry, full lighted habitats deficient in organic materials. In this work, attention was paid to the role of several species biogroups (Pinus sylvestris. Salix acutifoHa, S. arenaria, Betuia pendu/a, Juniperus communis - photos on the cover) in the processes of growing up in the Błędów Desert, as well as sand fixing, which is owing to artificial afforestation and the introduction of Eiymus arenarius. It was also stated that sandy ground did not interfere with vegetation of the following species: Salix acutifotia, S. arenaria. Corynephorus canescens and Koeleriaglauca, which took part in the formation of aeolian hills (fig. 4, photos 1, 2). Moreover, two types of succession - primary and secondary - have been found in the distinguished transects. The primary type of succession consist of the following stages: stage of encroachment plants (I), stage of sodding (II), stage of bushes (III), stage of biogroup formation (IV), and stage of afforestation (V) (fig. 5). The results of this work indicate the important role of wind and animals in spreading new species from the surrounding areas. Besides, in the area of the following plant associations: Algae, Poiytrichum pHiferum, Koeleria glauca. Salix acutifoiia, S. arenaria and Pinus sylvestris, soil studies were conducted and individual characteristics of soil compositions under the above mentioned communities have been shown (figs 6, 7, tables 16-28).