PROPORTION OF QUANTITATIVE INDICATORS OF MICROARTHROPOD COMPLEXES IN SOILS OF THE SOUTHERN PART OF THE TYUMEN REGION
The article presents the materials of the study of the relationships between the complexes of microarthropods (oribatid-co-bulb and acaridic-astigmatic) in three different types of soils (podzolic, chernozem and gray forest) in the south of the Tyumen region. A comparative analysis of the quantitative indices of the complexes has been carried out, and several factors affecting the formation of indicators of their numbers have been identified. Carrying out a comparative analysis of the quantitative parameters of the oribotical-collembolic and acaridium-astigmatic complexes of microarthropods in podzolic soils and chernozem soils showed that the number of microarthropods on podzolic soils exceeded the indices of chernozem soil by more than 10,000 items per m<sup>2</sup>. According to the study results on gray forest soils, it was noted that the total number of both investigated microarthropod complexes is 4 times lower than in chernozem and podzolic ones. A possible explanation was that only the upper layers (about 8 cm deep) of the gray forest soil were saturated with the root mass of the plants, which in turn was the habitat of microarthropods; further, the deeper into the soil, the less the number of roots, and, accordingly,the less the quantity of food base for microarthropods. It was also found that the largest number of microarthropods of both investigated complexes was reached on podzolic (more than 17 600 specimens/m<sup>2</sup>) and chernozem soils (more than 16 300 specimens/m<sup>2</sup>). The smallest number of microarthropods was recorded on gray forest soils (up to 6 500 specimens/m<sup>2</sup>). The maximum indices of the abundance of the oribotical-colembolic and acaridium-astigmatic complexes on all types of soils were noted in May and September. For the period of the conducted researches, the oribatidic-collembolic complex was the dominant in number, the most significant indicators of which were found in areas with podzolic soils in the autumn (15 392 ind./m<sup>2</sup>).