Search Results

You are looking at 1 - 2 of 2 items for

  • Author: Wojciech Ejankowski x
Clear All Modify Search
Open access

Wojciech Ejankowski and Tomasz Lenard

Abstract

According to the general classification of shallow eutrophic lakes, two alternative types are distinguished: phytoplankton-dominated and macrophyte-dominated lakes. The latter type is rare and currently endangered by human activity. In order to determine the effect of reduced inflow of surface water by an earth dyke on the lake trophic state, certain biological and physico-chemical parameters were evaluated. This work focuses on two lakes of similar morphometric characteristics situated in the agricultural landscape. The effect of the earth dyke on the trophic state was positively verified. The lake situated in the catchment basin, in which the inflow of surface water was reduced, was defined as meso-eutrophic, with a small amount of phytoplankton and high water transparency. The reference lake was highly eutrophic, with low water transparency and a large amount of phytoplankton. The water body surrounded by the earth dyke was macrophytes dominated (65% of the lake area), whereas the reference lake was a phytoplankton-macrophyte type (42% of the lake area). The trophic evaluation of a lake can be underestimated because of a significant amount of biogenic compounds accumulated in plant tissues. Thus, the values of Carlson’s indices in macrophyte-dominated lakes may not account for the total amount of nutrients in the water body.

Open access

Wojciech Ejankowski and Anna M. Iglińska

Abstract

Ejankowski W., Iglińska A.M.: Vegetation of humic lakes in relation to their trophic state. Ekológia (Bratislava), Vol. 33, No. 2, p. 160-170, 2014.

The vegetation of selected 24 humic lakes in Poland was studied to establish whether there was a link between the lakes’ vegetation and their trophic state. Based on literature data and field studies, the lakes were distinguished into two groups with regard to plant communities in the lakes and catchment basins. They were identified as dystrophic (DL) and humoeutrophic (HL) lakes according to their chemical and biological parameters. The two lake groups differed in terms of macrophyte structure: nymphaeids were common in DL, whereas helophytes in HL. The massive development of elodeids was also observed in HL. Vegetation in the catchment basins was mesotrophic in HL (Caricion lasiocarpae Vanden Bergh. ap. Lebrun et al., 1949), whereas in case of extremely nutrient-poor habitats in DL oligotrophic vegetation was found (Rhynchosporion albae Koch 1926 and Oxycocco-Sphagnetea Br.-Bl. et. R .Tx. 1943). The regionally determined variability of humic lakes in Poland was verified positively. Potential dystrophy indicators are discussed in this paper.