Plant communities on oil-contaminated ruderal sites in the Lopejská basin, district Brezno

Abstract

The paper deals with three plant communities with mono-dominance of the species Carex hirta, Melilotus albus and Calamagrostis epigejos, occurring within a territory affected by activity of an oil-processing plant, situated in the geomorphological unit Lopejská kotlina basin, in district Brezno. We describe their species composition, ecological conditions and taxonomic characteristics in relation to soil contents of non-polar extractable substances (NE) in localities loaded by hazardous waste material - acid oil residue. All the examined plant communities are developed under influence of oil substances in soil. In most cases, concentrations of non-polar extractable substances considerably exceed the maximum allowable limit - 500 mg kg-1. In sites with dominance of Carex hirta species, the concentrations of oil substances range from 5,517.6 to 8,090.1 mg kg-1. The plant community with dominance of Melilotus albus species is less influenced by waste materials in case of locality Predajná I. Much higher concentrations were found in locality No. 3 inside the oil processing plant area (2,125.5-3,822.5 mg kg -1). The similar results were obtained for the community with dominance of species Calamagrostis epigejos. The highest content of oil substances in soil made 6,992.6 mg kg-1. The NE concentrations in soil are so high, that the species Carex hirta, Melilotus albus and Calamagrostis epigejos can be considered as very resistant to pollution by oil substances.