Архив метки: population

HAWTHORN Crataegus rhipidophylla Gand. IN THE ARID CONDITIONS OF THE REPUBLIC OF DAGESTAN

Arid Ecosystems

UDC 582.746:581.44(470.67)

Zalibekov M.D., Gabibova A.R. HAWTHORN Crataegus rhipidophylla Gand. IN THE ARID CONDITIONS OF THE REPUBLIC OF DAGESTAN // Arid Ecosystems. 2024. Vol. 30. № 2 (99). P. 67-72. | PDF

Hawthorn Crataegus rhipidophylla Gand. is a typical plant in the sparse woods of the piedmont region of the Republic of Dagestan, found in the lower, middle and upper mountain zones. Identification of patterns of intraspecific and interpopulation diversity (including the quantitative traits of annual shoots and their adaptive manifestation in the conditions of species introduction) allows determining the species’ optimum and adaptive potential to specific arid conditions. In this paper we present the results of an ecogeographical experiment on the altitudinal gradation of Crataegus rhipidophylla using its annual shoots as an example. In our research, we used a unique scientific setup “System of Experimental Bases Located along the Altitudinal Gradient (1100 and 1700 m ASL)”. We studied plants grown from seeds that were previously collected in arid ecosystems, under different conditions. We studied 10 quantitative traits and 1 qualitative trait (trichomes) of shoots and leaves to observe adaptive changes in an annual shoot under conditions of species introduction. The results were processed and evaluated by descriptive statistics, as well as by correlation, cluster and twofactor analysis of variance. We discovered the degree and structure of variability of quantitative traits of annual shoots and leaves, and the presence of population-geographical differentiation in such traits as “shoot length”, “number of leaves” and “number of prickles”, depending on the conditions of germination of collected samples. We determined the quantitative and qualitative differences between specimens. With increasing altitude, the increasing number of prickles and trichomes on the shoots and leaves can be considered as one of the adaptive mechanisms of vegetative organs to abiotic factors of the arid climate in the mountainous conditions.

Keywords: acclimatization, population, variability, ecological-geographical experiment, altitudinal gradient, factor influence, hawthorn, Republic of Dagestan.

Funding. This work was carried out as part of the state task No. 0206-2019-0007 “Geoclimatic
Peculiarities of Distribution and Description of Communities with Populations of Rare and
Resource Tree Species of the North Caucasus”.

DOI: 10.24412/1993-3916-2024-2-67-72
EDN: EMLDJM

COMPARATIVE ASSESSMENT OF THE CURRENT STATUS OF SEMI-ANADROMOUS AND AQUATIC FISH SPECIES IN THE NORTHERN PART OF THE AGRAKHAN GULF

Arid Ecosystems

UDC 597.55;639.2.053.2

Vasilyeva L.M., Rabazanov N.I., Sudakova N.V., Anokhina A.Z., Ramazanova D.M.,  Barkhalov R.M. COMPARATIVE ASSESSMENT OF THE CURRENT STATUS OF SEMI-ANADROMOUS AND AQUATIC FISH SPECIES IN THE NORTHERN PART OF THE AGRAKHAN GULF // Arid Ecosystems. 2023. Vol. 29. № 3 (96). P. 141-147. | PDF

Unfavorable hydrological regime in recent years contributed to negative changes in the species and age structure of ichthyofauna in the northern part of the Agrakhan Gulf. The article presents detailed data on species composition, age categories and morphometric indicators of semi-anadromous and freshwater fish species according to the results of surveys that were conducted in 2021. The comparative analysis of the results with the data of the previous years was executed, and the negative dynamics of changes of the studied parameters in modern conditions was established. There was a reduction in the species composition (from 14 to 9 species) of semi-anadromous fish, disappeared valuable in terms of commercial fishing (kutum, catfish, roach, tench and asp), significantly reduced the remaining preserved species. The average age increased, the proportion of older fish increased, and the number of younger fish decreased accordingly, indicating a decrease in the potential for growth. At the same time, freshwater, low-value fish species such as crucian carp, redfin, goose, etc. have growth trends in age and morphometric indicators.

Keywords: ichthyofaunal, semi-anadromous fish, water fish, Northern Agrakhan, species and age structure, morphometric indicators, juveniles, population, hydrological regime, valuable and low-value species.

Financing. The work was carried out for the state task, topic No. 122032200284-2 “The Structure of Populations of Commercial Fish Species and the State of Their Forage Base in the Coastal Zone of the Dagestan Coast of the Caspian Sea”, and as part of D.M. Ramazanova’s postgraduate work on the topic “The Current State of the Ichthyofauna in the Northern Part of the Agrakhan Bay” at the V.N. Tatishchev Astrakhan State University.

DOI: 10.24412/1993-3916-2023-3-141-147

EDN: BURDIY