Вища водяна рослинність лесових «островів» Чернігівського Полісся

Abstract

The results of research on the higher aquatic vegetation of the water bodies of the loess «islands» in Chernihiv Polissia are presented. Higher aquatic vegetation occupies small areas (up to 6 %) on loess «islands». The plant communities have been identified. Plant communities have typical species composition and structure for Polissia vegetation. The classification scheme of plant syntaxons is based on the floristic-ecological approach. It was established that the higher aquatic vegetation of the loess «islands» reservoirs is represented by three classes: Lemnetea, Potametea and Phragmito-Magnocaricetea, belonging to five orders, 10 unions and 34 associations. The distribution of plant communities was clarified. The comparison of the higher aquatic vegetation classes representation of the loess «islands» water bodies in the Chernihiv Polissia was carried out. The greatest phytocenotic richness and diversity is noted in the Phragmito-Magnoсаricetea class, while the least is observed in the Lemnetea and Potametea classes. The Lemnetea class communities occur mainly in shallow water in the water bodies of all loess «islands». The vegetation of free-flowing aquatic plants belonging to the Lemnetea class is mostly represented on the territory of the Berezna-Mena-Sosnytsia and Ripky-Chernihiv loess «islands». This is due to the larger hydrological network on these loess «islands». The Potametea class communities are distributed only on three loess «islands» of the Chernihiv Polissia. Mykhailo-Kotsyubinsky loess «island» has the smallest area among the «islands», the most transformed landscapes and a small number of water bodies. Therefore, there are no Potametea class communities here. In conditions of high humidity and high mineral nutrition, the communities of the Phragmito-Magnocaricetea perennial herbs develops, first of all, of the Magnocaricetalia order. The significant distribution of Phragmito-Magnocaricetea communities is due to the presence of favorable conditions for their development: low-lying areas of floodplains that are periodically flooded, coastal shallows with significant fluctuations in the water level during the growing season. A comparison of the syntaxonomic diversity of the higher aquatic vegetation classes was carried out. The centers of phytocoenotic richness were determined. The reservoirs of the Mykhailo-Kotsyubinsky loess «island» are characterized by the least syntaxonomic diversity. There are no centers of phytocenotic opulence here.