Архив метки: species diversity

EVALUATION OF CHANGES IN NATIVE VEGETATION COVER OF DUST SOURCES IN THE SOUTHWEST OF IRAN UNDER DIFFERENT IRRIGATION SYSTEMS AND RAINFALL PATTERNS IN SEEDLING CULTIVATION AREAS

Arid Ecosystems

UDC 633.2.033; 633.2.032; 633.2.038

Dinarvand M., Arami S.A., Sarab S.A.M. EVALUATION OF CHANGES IN NATIVE VEGETATION COVER OF DUST SOURCES IN THE SOUTHWEST OF IRAN UNDER DIFFERENT IRRIGATION SYSTEMS AND RAINFALL PATTERNS IN SEEDLING CULTIVATION AREAS // Arid ecosystems. 2022. V.28. № 1 (90). P. 28-41. | PDF

Efficient use of rainfall and water storage has fundamental importance for rehabilitation and improving rangelands in arid areas. In this study, we evaluated the changes in the natural vegetation cover of three regions (dust centers) of the south and southeast of Ahvaz under different irrigation systems and rainfall patterns following seedling cultivation. Observations were made on five 100-meter transects, each 50 meters apart, which were systematically established in the three selected areas. Around 180 fixed plots were installed along transects. In the two growing seasons of spring and autumn from 2018 to 2020, the coverage of native species was recorded. The Simpson and Shannon and dominance diversity indices were estimated using the PAST software. The results showed that in the selected areas, various irrigation methods along with rainfall caused significant positive changes in vegetation cover, the number of species, and diversity from 2018 to 2020. The results indicated a significant difference between the average dominance index, Simpson and Shannon indices, and vegetation cover, as well as the number of species in different years. This study has identified that due to the lack of water for surface irrigation, contour furrowing and pitting using an excavator is the best and cost-effective way to restore native species. In addition to creating a suitable hole for receiving irrigation water, this method provides better drainage of the area during the rainy season, providing a suitable substrate for the growth and germination of seeds of native plants.

Keywords: Khuzestan province, furrow, Shannon, Simpson, species diversity.

Financing. This article is taken from a research project “Evaluation the change of vegetation in a cultivated area of dust sources of Khuzestan province using of satellite images and field data” and its research sponsor is the Forest and Rangeland Research Institute of Iran (Project No. 2-46-09-018-000216).

DOI: 10.24412/1993-3916-2022-1-28-41

FEATURES OF THE SEASONAL DYNAMICS OF THE STRUCTURE OF PHYTOCENOSES ON THE SANDY LANDS OF THE SOUTH OF THE EUROPEAN TERRITORY OF RUSSIA

Arid Ecosystems

UDC 581.5

Vlasenko M.V., Trubakova K. Yu. FEATURES OF THE SEASONAL DYNAMICS OF THE STRUCTURE OF PHYTOCENOSES ON THE SANDY LANDS OF THE SOUTH OF THE EUROPEAN TERRITORY OF RUSSIA // Arid ecosystems. 2022. V.28. № 1 (90). P. 114-123. | PDF

Species diversity, yield, share participation and seasonal variability of species in natural and artificially created phytocenoses in the sandy lands of the southern European territory of Russia are considered. The role of the influence of moisture conditions on the formation of species diversity in different communities is explained. The Tsimlyansk sand massif was monitored using the methods of ecological and geobotanical surveys. It is established that the main mass in the phytocenoses of the Tsimlyansk sand massif is occupied by species from the family Asteraceae, Fabaceae and Poaceae. The herbaceous-shrub layer includes 183 species from 41 families. The Simpson index shows that for the territory of excessive moisture (II), the dominance of species of the Poaceae family is most pronounced. In areas of sufficient and variable moisture (III), moderate moisture (IV), as well as in areas of insufficient complex moisture and complex severely insufficient moisture under the sandy hillocks and moderate moisture in the grove and eroded sands (V), species of the Asteraceae, Fabaceae and Poaceae families dominate. The index of similarity of the species composition of the Jacquard shows that the most similar in terms of species diversity of the territory are: complex insufficient (Va) and complex severely insufficient moisture under the sandy hillocks and moderate moisture in the grove and eroded sands (Vb) – 90%; moderate moisture (IV) and complex severely insufficient moisture under the sandy hillocks and moderate moisture in the grove and eroded sands (Vb) – 89%; sufficient and variable moisture (III) and moderate moisture (IV) – 87%; excessive moisture (II) and moderate moisture (IV) – 87%. In the territory of moderate moisture (IV) in the studied phytocenosis, the largest mass was formed by cereals: Agropyron cristatum L., A. elongatum (Host) P. Beauv., Festuca valesiaca Gaudin, F. beckeri (Hack.) Trautv. and Poa pratensis L., Artemisia campestris L. and Galium verum L. predominated in various grasses. On average, the share of cereals in the community was 66.5%, the share of mixed grasses was 33.5%. In the territory of sufficient and variable moisture (III), the largest phytomass was also formed by species from the Poaceae family: Elytrigia repens (L.) Nevski and Agropyron elongatum (Host) P. Beauv., Agropyron cristatum L., Artemisia campestris L., Artemisia vulgaris L. and Artemisia arenaria DC had a great influence on the growth of phytomass. To stop the processes of degradation, improve the economic condition and increase the fertility of pasture ecosystems in large areas, it is proposed to fix mobile sands and restore pastures with the help of selected multicomponent grass mixtures. The experiment on studying the productivity of artificially created phytocenoses for restoring and increasing the productivity of natural pasture ecosystems was carried out on the vegetation sites of the lysimetric complex of the Federal Research Center of Agroecology of the Russian Academy of Sciences. The most promising on sandy substrates is a grass mixture with Agropyron cristatum L., Artemisia arenaria D.C., Medicaga sativa L. and a yield of 228.6-246.7 g/m2, as well as a grass mixture with Agropyron cristatum L., Agropyrom elangatum Host.P.B., Bromus inermis Leyss. and a yield of 184.4 g/m2.

Keywords: phytocenoses, species diversity, sand massifs, pasture ecosystems.

Financing. The work was carried out within the research No. AAAA19-119042290014-5 “Theoretical foundations of water resources management in the forest-agrarian development of arid territories of the Russian Federation on the basis of a dynamic model of the water balance of the region, mathematical modeling of the processes of formation and dynamics of groundwater and surface waters, assessment of the impact of climate change and anthropogenic loads on the agro-resource potential and forest-growing conditions”.

DOI: 10.24412/1993-3916-2022-1-115-124

HYDROBIOLOGICAL RESEARCH OF THE TEREK-CASPIAN COASTAL AREA

Arid Ecosystems

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.

DOI: 10.24411/1993-3916-2021-10156

LEYMUS CHINENSIS (Trin.) Tzvelev) IN THE WESTERN TRANSBAIKALIA: STRUCTURE OF COMMUNITIES, PRODUCTS AND BIOCHEMICAL COMPOSITION DURING CLIMATE ARIDIZATION

Arid Ecosystems

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.

DOI: 10.24411/1993-3916-2021-10140