Rushes as a phytoindicator of a lake’s surrounding land use

Abstract

Rushes belong to the group of plants commonly found in water bodies, fulfilling many important functions. However, their presence depends both on features of the immediate surroundings and morphology of the lake. At the same time, rush presence can be an indicator of important features of the surrounding habitats. The aim of this study was to determine the impact of shoreline and buffer zone development on the attributes of rushes. Indications of lake features affected the rushes most strongly. We analysed 65 lakes located in the eastern part of Poland, within the boundaries of the Łęczna-Włodawa Lake District. The multidimensional analyses identified factors that most strongly determined the development of lake rushes in Polesie Lubelskie. The presence of peat bogs, scrubland communities, and wet meadows favoured the development of rushes. Among the morphometric characteristics of lakes, the depth and frequency of water mixing were significant, as well as the trophic level of the lake. Moreover, models describing scenarios for further development of rushes were developed. They predicted that the surface area of the rushes in the lake will increase (average of 0.288 ha) when the peatlands become overgrown 1 ha, and the share of dry (drained) meadows will increase (average of 0.996 ha) in the buffer zone. The increase in the density of rushes will take place if the share of buildings and scrub communities increases both in the buffer zone and shoreline area.