Autotrophic communities’ diversity in natural and artificial water-bodies of a river estuary — A case-study of the Dnieper–Bug Estuary, Ukraine

Abstract

Spatial distribution of plant communities in the human-modified aquatic ecosystem within the Dnieper–Bug Estuary is marked by discrete-continuous patterns. Continuity is caused by hydrological interconnection between the subsystems, and discreteness — by habitat diversity. For higher aquatic plants, the continuity aspect consists in overgrowth of emergent plants all-round the shoreline in both subsystems. The discreteness aspect is noticed in presence of floating-leaf plants’ and submerged plants’ belts in the natural subsystem only (the lake) and their absence in the artificial one (the sand quarry). For algal communities, continuity is observed in predominance of the same divisions in both subsystems. Discreteness manifests itself in higher taxonomic and floristic diversity of algae in the natural subsystem, than in the artificial one. The process of hydrological interaction between phytoplankton and epiphytic algae is another important mechanism sustaining continuity of algal communities.