Specific remnants of old iron-ore extraction sites as islands of plant species richness

In the Old-Polish Industrial Region (Southern Poland, Central Europe), specific remnants of former iron-ore extraction occur. These interesting post-mining habitats influence the plant cover which emerges on them. In this paper, I analyzed the impact of the former iron-ore mining on the increase of plant species richness in forest communities. I analyzed the floristic composition of 100 phytosociological releves (plots) made in the mining areas, their surroundings and 100 associated soil samples. I found that within the island communities developing in the former mining fields, there was a considerable increase in the number of species of native flora (in comparison with communities of nontransformed areas). This increase in species richness is caused chiefly by the increased proportion of species characteristic of the syntaxa from the Querco-Fagetea class - species exclusively attached to the mesophilous forest communities developing in gob piles whose limits are marked by the material extracted and scattered around in ancient times. My research suggested that in this case, mining activity exerted a positive influence on the biodiversity in forested areas, improving the quality of soils and creating mesophilous forest communities growing on remnants of former iron-ore extraction, which are specific islands among acidophilous forest communities growing in the non-transformed areas.