Архив метки: sand massifs

WATER REGIME TYPES OF THE SAND MASSIFS OF THE DON RIVER

Arid Ecosystems

UDC 631.432

Kulik A.K., Balkushkin R.N. WATER REGIME TYPES OF THE SAND MASSIFS OF THE DON RIVER // Arid Ecosystems. 2022. Vol. 28. № 4 (93). P. 37-45. | PDF

Issues related to the study of soil-hydrological features of sandy massifs become relevant in conditions of arid climate and insufficient moisture for plants. The purpose of the research is to study the types of the Don River sandy massifs water regime. In the period from 2003 to 2021, route and stationary (laying of water-regime sites) studies were carried out on the territory of the sandy massifs of the Don River and its tributaries. Laboratory work was carried out at the hydrological complex of the FSC of Agroecology RAS, which includes 8 large-sized lysimeters and 18 vegetation sites. During the year, infiltration on open sands averages 70% of the total amount of precipitation. The greatest runoff to groundwater is observed on the Upper Don sandy massifs. According to lysimetric studies, the average annual intensity of intra-soil runoff, under conditions of fallow, is maximum on sandy soils and averages 0.73 mm/day, on sandy loam – 0.65 mm/day, on light loam — 0.37 mm/day. At the same time, in the second half of the year sandy loam soils are able to discharge more water into the groundwater than sandy and loamy soils. In most cases, the non-washing type of water regime is observed on the third terrace of sandy massifs with deep groundwater (>8 m) and on heavier soils in granulometric composition. In areas with ground water that is accessible to the stand roots, there is a daily pulsation with a general decrease in the level, since the night water intake does not compensate for the transpiration flow. Seasonal fluctuations in the groundwater level on the Don sands average 40-60 cm, but can reach 90 cm.

Keywords: sand massifs, water regime, soil-hydrological constants, intra-soil runoff, lysimeters.

Funding.The work was carried out within the framework of the state task FNFE-2022-0011 «Development of a new methodology for optimal management of biological resources in agricultural landscapes of the arid zone of the Russian Federation using system-dynamic modeling of soil-hydrological processes, a comprehensive assessment of the impact of climate change and anthropogenic loads on agrobiological potential and forest conditions».

DOI: 10.24412/1993-3916-2022-4-37-45

EDN: VVRFAS

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