[Effects of grazing and mowing on macrofauna communities in a typical steppe of Inner Mongolia, China].

The dynamic features of the ecosystem components under different human activities are fundamental for understanding the ecosystem change mechanisms and developing sustainable mana-gement system. For the vast temperate steppe ecosystems in northern China, there existed many studies on the effects of animal grazing and mowing on plant and soil microbial communities, but not the soil fauna communities. We investigated the soil macrofauna communities of a typical Inner Mongolia steppe grassland under 6 utilization treatments (1 full season grazing, 3 different seasonal grazing, 1 autumn mowing and 1 control of no grazing or mowing). The investigation was conducted in spring, summer and autumn after 3-year's grazing or mowing treatments. We collected 597 soil animals, which belonged to 2 phyla, 4 orders, 11 classes, and 49 groups. The individual density, biomass and diversity indices of soil macrofauna community significantly decreased under the full season grazing, whereas the effects of mowing on soil macrofauna were relatively mild, with the individual density, biomass and diversity indices of soil macrofauna community even showing an increasing trend. The seasonal grazing in summer and autumn had the least negative effects on the individual density, biomass and diversity indices of soil macrofauna community among three seasonal grazing treatments. The results suggested that mowing might facilitate the restoration of soil macrofauna community for degraded steppe grassland, and the seasonal grazing in summer and autumn had the least negative effects on soil macrofauna communities, which was possibly the best grazing practice for a sustainable grassland use.