Osmanov M.M., Amaeva F.Sh., Abdurakhmanova A.A. HYDROBIOLOGICAL RESEARCH OF THE TEREK-CASPIAN COASTAL AREA // Arid ecosystems. 2021. V. 27. № 2 (87). P. 106-111 | PDF
Structure of zooplankton communities in the Terek-Caspian coastal region of the Caspian Sea under the conditions of flow regulation of the river Terek and its passage through the Uch-Kosinsky channel are researched. Hydrobiological material collected in the waters of the Terek coastal region of the Caspian sea was used. The long-term data of zooplankton distribution in the studied region, which reflect the nature of the influence of various factors, as fluctuations in the level regime, arid climate, the mass development of the Azov-Blacksea invader Acartia tonsa (Dana, 1849) and the trophic press of another invasive species Mnemiopsis leidyi (A. Agassiz) after passing the river runoff Terek in a new direction. The influence of these factors mainly affected the autochthonous fauna of the waters of the Terek coast. It was shown that previously leading native species Calanipeda aquae dulcis and Eurytemora grimmi for a long period were in the background and only in recent years C. a. dulcis, due to a decrease in the press of the ctenophore Mnemiopsis leidyi, becomes a subdominant form in the zooplankton of the studied water area of the Caspian Sea.
Keywords: The Caspian Sea, Uch-Kosinskiy channel, arid climate, zooplankton, species diversity, Copepoda, invasive species.
Merkusheva M.G., Badmaeva N.K., Boloneva L.N., Lavrentieva I.N. LEYMUS CHINENSIS (Trin.) Tzvelev) IN THE WESTERN TRANSBAIKALIA: STRUCTURE OF COMMUNITIES, PRODUCTS AND BIOCHEMICAL COMPOSITION DURING CLIMATE ARIDIZATION // Arid ecosystems. 2021. V. 27. № 1 (86). P. 86-96. | PDF
The phytocenotic characterization of communities with Leymus chinensis growing on different types of soils of the meadow steppe, steppe floodplain, and halophytic meadows of Western Transbaikalia is considered. The botanical composition revealed glycophytes – 28 species, halotolerant glycophytes– 17 and halophytes – 6. It was established that the genus Leymus includes 3 species: Leymus chinensis, L. buriaticus, L. littoralis. The botanical composition of communities with Leymus chinensis of Western Transbaikalia is represented by 51 species, 20 families, and 40 genera. The species composition is represented mainly by the steppe complex with different xerophytic species belonging to the Asian type of range. In the biomorph, the main share falls on rhizome species, and the proportion of young infants is also significant. The similarity between the species composition is in the interval “weak – average”, which is due to the significant participation of families and genera with low species richness. The primary production communities with Leymus chinensis is 1029–2370 g/m2×year; the aboveground phytomass almost completely forms Leymus chinensis. The biochemical composition, feed value and protein ratio of the edible dry matter are determined by the growing conditions, but on the whole they comply with standard indicators.
Keywords: Leymus chinensis, communities, species diversity, production, biochemical composition, feed value, Western Transbaikalia, climate aridization.