Таксономічна структура мікрофітобентосу русанівського каналу (м. Київ)

Abstract

Досліджено видовий склад мікрофітобентосу Русанівського каналу, розташованого на території м. Києва. Знайдено 131 вид водоростей, представлених 142 внутрішньовидовими таксонами (з номенклатурним типом виду включно), які належали до 6 відділів, 9 класів, 20 порядків, 34 родин та 56 родів. Встановлено, що в таксономічній структурі мікрофітобентосу основна роль належить представникам відділів Bacillariophyta, Chlorophyta та Cyanoprokaryota.

Исследован видовой состав микрофитобентоса Русановского канала, расположенного на территории г. Киева. Обнаружен 131 вид и 142 внутривидовых таксона водорослей с номенклатурным типом вида включительно, которые относились к 6 отделам, 9 классам, 20 порядкам, 34 семействам и 56 родам. Установлено, что в таксономической структуре микрофитобентоса основная роль принадлежит представителям отделов Bacillariophyta, Chlorophyta и Cyanoprokaryota.

Water bodies of the urbanized territories of Ukraine are subjected to ever enhanced anthropogenic impact, which causes significant degradation of their ecological and sanitary state, the quality of the aquatic habitats and the health of population as well as the quality of water resources for economic use. Microphytobenthos is an important and integral component of the water ecosystems of natural and artificial water bodies and watercourses, it is involved in the formation of the water quality and the biological productivity of water bodies as it is an active agent of the self purification process. This paper presents the result of the research of the taxonomical structure of microphytobenthos of the Rusanovka channel – an artificial watercourse, located in the left bank of the Dnieper River within the Kyiv city boundaries. It runs through the territory of the Rusanovka housing area and is connected hydraulically with the Rusanovka side arm of the river section of the Kaniv reservoir. The channel was constructed in the second half of the 60s of the 20th century during the construction of the housing estate. Its length is 2 km 700 m, width – 40 m, depth – 3–4 m; channel’s bed is fully lined with concrete slabs. Flowage during the day is uneven and depends on the diurnal oscillations of the flow rate and water level, which are due to peak mode of operation of Kyiv hydroelectric power station. Therefore there is the accumulation of silt in the channel, which leads to intensive overgrowing of coastal areas by the higher aquatic vegetation. Now the Rusanovka channel is used for recreational purposes. The purpose of the research was to establish the taxonomical structure of the microphytobenthos of the Rusanovka channel. Such investigations have been carried out for first time. Researches of the taxonomical structure of microphytobenthos of this artificial watercourse was carried out in the spring, summer and autumn of 2014–2015. Sampling was carried out by a sampling device “Mikrobentometr T-E” in the areas free from thickets of the higher aquatic vegetation, which formed a thin layer of mobile silt. Algological samples were conserved by 4% solution of formaldehyde, and laboratory processing was carried out according to methods, which are used in hydrobiological studies of water surface. Permanent preparations were produced for determination of the species composition of diatoms. The Ukrainian and European determinative keys were used for algae identification. On the basis of field studies microphytobenthos of the Rusanovka channel comprised 131 species (142 species and intraspecific taxa) of 6 types, 9 classes, 20 orders, 34 families and 56 genera. The structure analysis showed, that the most significant role in terms of diversity played the representatives of types Bacillariophyta, Chlorophyta and Cyanoprokaryota, followed by types Euglenophyta, Chrysophyta and Charophyta, whose share in the total number of species was insignificant. At the level of classes the greatest contribution was made by Bacillariophyceae, which belong to the type Bacillariophytа; Chlorophyceae – type Chlorophyta; as well as Hormogoniophyceae and Сyanophyceae, type Cyanoprokaryota. At the level orders domination was allocated as follows: Naviculales, Fragilariales, Cymbellales (class Bacillariophyceae) and Sphaeropleales (class Chlorophyceae); at level of families – Naviculaceae, Surirrelaceae, Fragilariaceae (Bacillariophyta) and Scenedesmaceae (Chlorophyta), at level of genera – Navicula, Gomphonema, Nitzschia and Desmodesmus, Scenedesmus respectively. The analysis of seasonal aspects of the species richness of microphytobenthos showed, that the number of species was the highest in autumn, and in summer it was the lowest. The taxonomical structure of microphytobenthos in all seasons was formed mainly by diatoms. Types Euglenophyta, Chrysophyta and Charophyta were represented by the lowest number of species.