Аутекологічні особливості та характеристика еконіш діатомових водоростей (Bacillariophyta Karsten) пониззя р. Ворскла

Abstract

The species diversity of diatoms in the lower reaches of the Vorskla River, which belong to the territory of the Regional Landscape Park "Nizhnovorsklyansky", is analyzed. The material for the work comes from algological samples collected in the lower reaches of the Vorskla River in the spring and autumn periods. A section of about 7 km of the lower reaches of the Voskla River, a section of the Vorskla Bay and the Kamyanke Reservoir, floodland water bodies, swamps and wetlands were surveyed. Collection of algae samples was carried out from different ecology groups. Samples were processed in live and fixed state using the method of direct microscopy. A total of 288 taxa were identified. An analysis of the autecology of 133 representatives of diatoms in relation to the main environmental factors (temperature, acidity, salinity) has been carried out. The obtained digital data were processed by generally accepted methods of statistical research. Based on Ellenberg scales, phytoindication methods are used to characterize the ecological niche and to clarify the nature of the interaction between the main ecofactors of the noted representatives of <i>Bacillariophyta</i>. Based on the analysis of the values of the range of variation of ecofactors, the range of the optimum zone for the studied species was established, and according to the tolerance amplitude (BP) they were divided into 4 classes (stenotopic, hemistenotopic, hemieurytopic and eurytopic). It is established that the ecological niche of the studied taxa is characterized by a shift towards a neutral environment in terms of acidity (6.5 ≤ рН ≥ 7.5) and salinity 0–2‰. Groups of stenotopic species to the temperature, salinity and acidity of the environment, which can be sensitive indicators of changes in these environmental factors, have been identified. According to the results of hierarchical clustering, the affinity of the studied indicator species was established. Clusters that unite a complex of species characterized by similar values of ecological amplitude to the leading environmental factors were formed.