Rakhimov Matnazar Shomurotovich, National University of Uzbekistan named after Mirza Ulugbek Tashkent E-mail: raximov.matnazar@mail.ru Azimov Djaloliddin Azimovich, AS RUz, Institute of Zoology Tashkent city E-mail: ushakarbaev@mail.ru
ECOLOGICAL - TAXONOMICAL ANALYSIS OF COLLEMBOLANS OF THE NORTHEAST OF UZBEKISTAN
Abstract. Paper is devoted to the ecological and faunistic analysis of the collembolans unit of the Northeast region of Uzbekistan. In the agrocenoses of apple orchard, wheat and surrounding ecosystems, 40 species of collembolans have been identified. Of these, 29 species were found in agrocenoses (apple orchard and wheat), and 40 (in natural communities). We observed the same pattern in a huge population density in the cenoses studied. It is significantly more in natural communities (12386 copies per 1 m2 of soil) as compared with agrocenoses (6980 copies per 1 m2 of soil). The horizons of the surface layer (10-20 cm) of soil are most densely populated by collembolans. Keywords: collembola, agrocenosis, soil, seasonal dynamics, sample, wheat, Uzbekistan.
of soil small arthropods, soil samples were taken from three points of each investigated agrocenosis and surrounding ecosystem in layers of three horizons (0-10, 10-20, 20-30 cm). In total, we received 405 samples in a fivefold repetition.
The extraction of collembolans from soil samples was carried out in the laboratory using an eclectic method. The extrusion of collembolans from substrate was carried out using a modified Berlese-Tulgren apparatus. Permanent preparations in liquid phora are prescribed [2; 4]. The counting and determination of the taxonomic affiliation of collembolans was performed under MBS-9 binocular microscope. The digital material was statically processed. A quantitative account of the number of collembolos was carried out on the basis of counting them in 1 dm3 of the soil sample. Based on the data obtained, recalculation was carried out for 1m2 for each soil layer. Digital material is statistically processed (N. M. Cher-nova B. R. [4], Striganova [3]).
Results and discussion. Analysis of the collected material showed that in wheat agrocenoses, an apple orchard and the surrounding ecosystem of the Parkent district of Tashkent region live 40 species of collembolans from 6 families belonging to Collembola order.
The number of species constituting these complexes in the studied cenoses is not the same. Since the apple orchard identified 29 species, wheat field 17, the surrounding ecosystem, 40 species. Representatives of the families Isotomidae (14 species), Onychiuridae (17), Entomobryidae (7) and Neanuridae (5 species) dominated.
From found 40 species of collembol, 17 species: (Li-pura sibirica, Lipura groenlandica, Brachystomella maritima,
Introduction. The springtails order (Collembola) is a relatively small, well-defined group of predominantly soil animals - one of the most ancient taxa of land arthropods, which retained a plesiomorphic level of organization. Collembolans are one of the leading groups of arthropods in the saprotrophic complex in soil biota. The significant role of collembolans in soil biodynamic is due to their abundance, taxonomic richness, and the rapid change of generations. They are very sensitive to ecological conditions and quickly respond to environmental alterations that allows the use of collembolans for bio monitoring of contaminated and disturbed ecosystems [1; 3; 5].
Research of collembolans fauna in specific regions gives a complete picture of the taxonomic composition of certain groups, their interrelations in biogeocenoses, and their role in the circulation of substances in nature. Therefore, the research of taxonomic composition, distribution, quantity, biology, ecology of especially significant soil-forming species of collembolans in various agrocenoses and surrounding ecosystems is of great scientific practical importance.
The aim of our research is to determine the taxonomic composition of collembolans, the study of the seasonal dynamics of the number of individual groups of soil organisms in the biogeocenoses of the Northeast of Uzbekistan.
Materials and methods. To study the structure and number of populations of soil collembolans, soil samples were collected in agrocenoses, and stationary studies of their surrounding ecosystems were conducted in the "Karakalpak" farm in Parkent district of Tashkent region. The material for the study was collected in all seasons of the year in three points. To study the qualitative and quantitative composition
Section 1. Biology
Odonitella ewingi, Xenyllodes armatus, Onychiurus ramosus, Lipura armata, Pentacanthella decemoculata, Folsomina onychi-urina, Istoma producta, Cruptopygus antarcticus, Istoma minor, Istoma sensibilis, Istoma notabilis, Desoria saltans, Digeeria mus-corum, Parasira ornate), found in the soil layers of agrocenoses and natural ecosystems; 9 species (Achorutes inermis, Xenylla maritima, Tullbergiya tricuspis, Triaeana mirabilis, Pseudacho-rutes subcrassus, Micranurida pygmaea, Podura palustris, Isto-modellapusilla, Istoma communa) were characteristic only for the soils of natural ecosystems.
The results of studies on the seasonal dynamics of the number of collembolans in agrocenoses of apple orchard, wheat and the surrounding ecosystem are shown in the (table 1).
From table 1 it can be seen that the total number of collective balls is 8782 copies per 1 m2 of soil. The main population of collembolans is concentrated in the soil layer of 10-20 cm, the number of which reaches 4604 individuals on 1 m2.
The soil layer at a depth of 0-10 cm, the maximum populated in springtime is 10580 copies on 1 m2. With increasing soil depth, their number drops sharply.
Table 1. - Seasonal dynamics of the number of collembolans in agrocenoses of apple orchard, wheat and the surrounding ecosystem of Parkent district of Tashkent region
Depth Agrocenosis apple orchard Wheat agrocenosis Environmental ecosystem
IV* VIII X IV VIII X IV VIII X
0-10 cm 1600** 440 720 1600 580 840 5600 680 1840
10-20 cm 1680 2200 1680 7400 3200 5100 7100 6980 6100
20-30 cm 1200 2000 1560 3100 4300 2680 2460 3800 2600
Total 4480 4640 3960 12100 8080 8620 15160 11460 10540
* - months of the year;
** - on average per 1 m2.
In the soil tier of the apple orchard, the number of collembolans was not lower than 4360 copies per 1 m2 in the soil layer 0-30 cm. In all soil layers, they are distributed more evenly, where the number ranged from 440 to 1600 copies on 1m2 in a 10 centimeter layer of soil.
Under the conditions of wheat agrocenosis, the number of collembolans was 9.600 copies on 1 m2 of soil.
Collembolans inhabited all soil layers at a depth of up to 30 cm, their numbers in different layers ranged from 580 to 7400 copies on 1 m2 of soil. In springtime, a more dense settlement was observed (on average, 4033 copies per 1 m2). In the soil layer in the surrounding ecosystem collembolans make up an average of 12386 copies on 1 m2 of soil. The bulk of the population of collembolans was concentrated in soil layers of 10-20 cm, where their numbers reached 6.100 and 7.100 copies on 1 m2 of soil. In the spring season, a more dense settlement was also observed (on average, 5053 copies per 1 m2).
Thus, all soil tiers of the surrounding ecosystem of the studied agrocenoses were the most populated by collembolans.
Conclusions: Results of the research allowed finding out the ecological and faunistic analysis of the collembolans of the surveyed region. In the agrocenoses of apple orchard, wheat
and surrounding ecosystems, 40 species of collembolans have been identified.
From found 40 species of collembol, 17 species -Lipura sibirica, Lipura groenlandica, Brachystomella maritima, Odonitella ewingi, Xenyllodes armatus, Onychiurus ramosus, Lipura armata, Pentacanthella decemoculata, Folsomina onychiurina, Istomaproducta, Cruptopygus antarcticus, Istoma minor, Istoma sensibilis, Istoma notabilis, Desoria saltans, Digeeria muscorum, Parasira ornate, met in the soil layers of agrocenoses and natural ecosystems; 9 species-Achorutes inermis, Xenylla maritima, Tullbergiya tricuspis, Triaeana mirabilis, Pseudachorutes subcrassus, Micranurida pygmaea, Podura palustris, Istomodella pusilla, Istoma communwere characteristic only for the soils of natural ecosystems.
It has been established that the agrocenoses of apple orchard and wheat are much poorer by the species of collembolans than those in natural communities. Thus, in the agrocenoses, 29 species of collembolans were noted (6980 copies per 1 m2). In natural communities, however, there are 40 species respectively (12386 copies per 1 m2 of soil). The horizons of the surface layer (0-20 cm) of soil are most densely populated by collembolans.
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