Temporal and spatial variation of habitat conditions in the zonation of vegetation in the late stages of lake overgrowth

Abstract

The water and substrate properties in the vegetation zones characteristic of the late stages of lake overgrowth were determined. It was demonstrated that the spatial distribution of plant communities conformed with the spatial gradient of habitat conditions. With regard to water properties the largest differences between the zones were found in Mg²⁺, Ca²⁺, electrolytic conductivity and NH₄⁺. In the case of substrate the zones differed significantly in Ca²⁺, total Fe and organic matter content. The water properties varied greatly during the vegetative season in the successive zones. The temporal changes often proceeded at a different level of a given component or factor in most zones. The differences between the zones were, however, maintained. It appears that the plant communities can alter their habitats to a large extent. In the lake studied, the invasion of raised and transitional bog vegetation was observed. The process of dystrophy proceeded from the terrestrialized peripheral parts of the lake to the centre of the lake.