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Natural and anthropogenic transformations of water and marsh vegetation in Lake Zbęchy (Wielkopolska Region)

Gołdyn H., Arczyńska-Chudy E., Pińskwar P., Jezierska-Madziar M.

Oceanological and Hydrobiological Studies

2008

Vol. 37, No.2

77-87

Lake Zbęchy is situated in the General Chłapowski Landscape Park, which is the model of a rural area that has been subjected to agricultural pressure for many years. Over a thirty-year period (1976-2006) serious changes in the plant associations of Lake Zbęchy have occurred. The maximal depth of plant occurrence decreased from 3.6 m in 1976 to 2 m at present. The area overgrown by submerged macrophytes decreased from 13 to 0.2 ha. The community of Nitellopsidetum obtusae that dominated the belt of submerged plants during the 1970s has entirely disappeared from the lake. The decreasing phytolittoral area in the lake is the result of progressive lake eutrophication and water pollution. The transformations of reed and sedge communities are of a partially natural and partially anthropogenic character. The ecological status of the lake has deteriorated significantly. The ecological state of the lake in 1976 was good according to the Water Framework Directive. Currently, it is sufficient, but the ESMI value of 0.21 only slightly exceeds that of a bad ecological state (0.20-0.00). The level of lake development in the succession process was between mature and aged in 1976; now it is classified as definitely aged.

Effect of land-water ecotone on changes in heavy metal content in waters of agricultural area

Szpakowska B., Karlik B., Gołdyn H.

Polish Journal of Ecology

2003

Vol. 51, nr 2

137-142

Concentrations of zinc, cadmium and lead in ionic forms and in forms bound to humic substances isolated from ground and surface waters of drainage catchment were analysed. Higher total concentrations of examined metals were found in ground waters as opposed to surface waters. Particularly clear difference was observed in case of cadmium. Mean concentrations of cadmium in ground waters amounted to 0.92mig l^-1, whereas in surface waters 0.50 mig l^-1. Similar tendency of higher heavy metals concentrations in ground waters as compared to surface waters was also observed in case of their ionic forms. Due to strong complexing properties organic matter can bind large amounts of metals and therefore influence bioavailability of the metals for aquatic organisms. Moreover the distribution of metals in aquatic environment depends on the presence of such biogeochemical barrier like belt of meadow, which can modify metals migration.