Transformation and Simplification of Aquatic Vegetation Structure and Reoligotrophication of a Lake During the Last 40 Years

Abstract The recovery or reconstruction of aquatic vegetation has recently been reported as a result water quality improvement after anthropogenic eutrophication. objectives this study were: to investigate long-term trends in abundance relation decreasing fertility and present new directions changes the submerged structure, species richness, biodiversity Lake Kuźnickie (western Poland) with perspective last 40 years (1978–2018). is an example taking place without any additional reclamation measures, except reduction nutrient discharge into lake from its direct catchment. Currently, represents mesotrophic status. Trophy State Index evidenced decrease lake’s compared previous decades. manifests significant total phosphorus concentration. An analysis spatial phytolittoral rush between 1978 2018 by over 2 ha. In period 1978–2018, structure underwent reconstruction. charophytes play much greater role years, contributing maintenance high quality. Moreover, endangered charophyte Lychnothamnus barbatus recovered. Concurrently, however, richness decreased. At present, only four dominate lake, including two L. , Nitellopsis obtusa vascular plants Ceratophyllum demersum Myriophyllum spicatum . Over changed eutrophic dominated codominant contribution charophytes. characterized good quality, optimal for development vegetation, especially