ABUNDANCE AND BIODIVERSITY OF INVERTEBRATES IN BROWN SOILS OF NATURAL AND AGRICULTURAL ECOSYSTEMS

The invertebrates' abundance and biodiversity of virgin and arable brown soils in the central zone of the Republic of Moldova have been investigated. Invertebrates sampling was carried out from test cuts by manual sampling of soil layers to the depth of soil fauna occurrence. The virgin brown soil in the natural ecosystem is characterized by a high abundance, biomass and biodiversity of the edaphic fauna compared to the soil under long-term agricultural use. A characteristic feature of the natural brown soils is the high concentration of invertebrates and Lumbricidae family in the upper layers of soils. Indicators of the edaphic fauna in soil profiles decreased with the depth. The relations between trophic levels are stronger in brown soils under forest, and trophic pyramids are more stable in the typical brown soil than in the luvic brown soil. The number and biomass of invertebrates in arable brown soils are lower by 2.8-3.4 times and by 2.2-7.5 times compared to brown soils of natural ecosystems. The number of edaphic fauna families decreased from 10-11 to 4-7. The disruption of trophic connections between invertebrates has been observed.