PECULIARITIES OF THE FLORISTIC COMPOSITION AND CHARACTER OF OVERGROWTH OF SMALL NON-FLOWING LAKES OF NARACH LAKE GROUP (BELARUS)

The flora of small non-flowing lakes of the Narach lake group located on the territory of the Narachanski National Park (Belarus, Minsk region, Myadelsky district) was studied. The taxonomic composition of the flora numbering 126 species of vascular plants belonging to 85 genera from 42 families was revealed. Three plant species which are included in the list of protected taxa in Belarus were found – Liparis loeselii (L.) Rich. (Lake Shestakovo), Aldrovanda vesiculosa L. (Lake Shestakovo) and Isoëtes lacustris L. (Lake Beloe). Based on the annotated list of species presented in the work, taxonomic, geographical, ecological-coenotic and ecobiomorphological analyzes of the flora of water bodies were performed. According to the taxonomic and environmental structure, the flora of the studied lakes is shown to be traditional for this territory. The differences in the flora of the studied lakes are mainly due to their trophic status and, to a lesser extent, due to the diversity of biotopes and the nature of the anthropogenic load. Information on the nature of overgrowing of these water bodies is provided.

The Effect of Human Impact on the Water Quality and Biocoenoses of the Soft Water Lake with Isoetids: Lake Jeleń, NW Poland

Soft water lakes with isoetids (SLI) are ecosystems prone to degradation due to the low buffer capacity of their waters. One of the main threats resulting from human impact is eutrophication due to agriculture, catchment urbanization and recreational use. In this paper, changes in the water chemistry and transformation of biocoenoses of one of the largest Polish SLI, Lake Jeleń, over the past 30 years are presented. The lake is located within the borders of a city, and a significant part of its catchment is under agriculture and recreation use. The physicochemical (concentration of nutrients, organic matter, electrical conductivity, oxygen saturation and water pH) and biological parameters (macrophytes and phytoplankton) were measured in summer 1991, 2004, 2013 and 2018. Since the beginning of the 1990s, a gradual increase in the trophy of the lake has been observed as indicated by increased nutrient availability, deterioration of oxygen conditions and a decrease in water transparency. The alterations of water chemistry induce biological transformations, in particular, an increase in phytoplankton abundance (4-fold increase of biomass in epilimnion) as well as a gradual reduction in the range of the phytolittoral (from 10 to 6 m), a decrease in the frequency of isoetids, Lobelia dortmanna and Isoetes lacustris, and expansion of plant species characteristic for eutrophy.

About the reasons for the rare plant species disappearance in the Upper Volga region

The problems of the extinction of aquatic plant species in Ivanovo region glacial lakes are discussed. As a result of research a sharp decrease in the number of rare hydrophytes (Elatine hydropiper, Isoetes lacustris, I. echinospora, Sparganium gramineum) has been established. The reasons are complex, they are associated with the eutrophication of ponds, heavy metals soil pollution, uncontrolled recreational loads and Elodea canadensis invaded into lake ecosystems. The ecological niche of Sparganium gramineum in the lakes is occupied by S. × longifolium, the hybridogenic origin of which is proved by modern molecular genetic analysis.

Protection of Rare Plant Species during the Development of Oil Fields in the South of Western Siberia (Tyumen Region, Russia)

The article provides a description of the vegetation and information on the discovery of plant species subject to protection, as revealed during the examination of the territory of licensed oil production sites located in the Uvatsky district of the Tyumen region (Western Siberia). The vegetation cover of the territory is represented by a combination of plots of dark-coniferous grass-shrub-green-moss forests, derivative communities in their place, pine-shrub-sphagnum marshes and floodplain meadow-shrub vegetation. The localities of 7 rare species subject to protection at the state and regional levels were discovered, including 2 species of lycopods (Isoetes lacustris, I. echinospora), 2 species of ferns (Dryopteris filix-mas, Phegopteris connectilis), 1 species of angiosperms (Nuphar pumila), mosses (Neckera pennata) and lichens (Lobaria pulmonaria). To preserve the discovered habitats of protected species, the necessary changes were made to the layout of the oil production facilities.

ISOETES LACUSTRIS (ISOETACEAE) - НОВЫЙ ВИД ДЛЯ ФЛОРЫ РЕСПУБЛИКИ МАРИЙ ЭЛ, "Ботанический журнал"

В оз. Чуркан впервые в Республике Марий Эл найден Isoites lacustris, в дополнение к единственному ранее известному в регионе представителю рода I. echinospora. Видовая принадлежность нашей находки подтверждена с помощью сканирующей электронной микроскопии и молекулярно-генетических данных. Кратко рассмотрены распространение вида и вопросы его охраны.