The post-mining (Zn, Pb) open pit under study (local name “Krążek”) is situated in the Silesian Upland (50°17’N, 19°27’E) in an area abounding in zinc-lead ores. The open pit, 7.5 ha in area and 30 m deep, was designated for reclamation. Reclamation work started in 1999 and consisted in filling the excavation with foreign (nonlocal) material, and planting pine and oak. It was completed in 2002. Studies of the vegetation colonizing the open pit were carried out in 20 permanent plots (25 m²) representing two types of imported soil substrate (sandy, clayey) in the years 2003–2005. They were based on 60 phytosociological relevés made according to Braun-Blanquet’s methods. In the studied open pit, 178 vascular plant species, spontaneously colonizing the newly created substrate, were found. Only 43 species were present in every year of the study. Most frequent were sporadic species (130), occurring in less than 20% of the relevés. The plants of the reclaimed area represented different ecological groups. Species associated with human-transformed sites (e.g. Solidago canadensis, Tussilago farfara) were the most numerous, but their number decreased with time during the study. Species connected with seminatural (meadow) sites (e.g. Achillea millefolium, Daucus carota) and natural (xerothermic and sandy grassland) sites (e.g. Hypericum perforatum, Poa compressa, Corynephorus canescens) were less frequent, but their number increased with time during the study. Six groups of species connected with the soil substrate type (sand – Rumex acetosella, Cardaminopsis arenosa; clay – Ranunculus repens, Medicago lupulina) and the colonization period (2003 – Atriplex patula, Polygonum lapathifolium, Polygonum hydropiper; 2004–2005 – Calamagrostis epigejos, Leontodon hispidus) were distinguished. Species composition changed over the study period. In the clayey plots these changes were more apparent than in the sandy ones. The numbers of species were lower, the diversity indexes slightly lower and the evenness indexes slightly higher in 2003 than in later years (2004–2005). The initial stages of colonization of the open pit were characterized by the presence of mostly nonlocal ruderal species (Melandrium album, Matricaria maritima, Atriplex patula) which originated from the bank of diaspores in the soil brought to the open pit and from seeds introduced during the reclamation work. Local plants contributed little to the colonization process. Ecological restoration methods in areas degraded by mining activity are discussed; the use of local soil material containing the local bank of diasporas and soil microorganism associations is recommended.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.