放牧和刈割对内蒙古典型草原大型土壤动物的影响

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

采用连续3年全季节放牧、3种季节性轮牧、秋季刈割和不利用对照6种处理,研究了内蒙古典型草原大型土壤动物群落特征.调查在春、夏和秋3个季节进行,共捕获大型土壤动物597只,隶属于2门4纲11目,49个类群.结果表明:全季节放牧导致土壤动物的个体密度、生物量和多样性降低;而刈割的影响相对较轻,土壤动物的个体密度、生物量和多样性甚至有提高趋势.3种季节性轮牧处理中,夏季和秋季放牧2次处理对土壤动物群落个体密度、生物量和多样性等指标的负面影响较轻.刈割管理对退化典型草原大型土壤动物群落的恢复较为有利;夏季和秋季放牧2次处理对大型土壤动物群落的负面影响较轻,是较理想的草地可持续管理措施.

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 Mon- golia 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 season grazing, whereas the effects of mowing on community significantly decreased under the full soil macrofauna were relatively mild, with the in- dividual density, biomass and diversity indices of soil macrofauna community even showing an in- creasing trend. The seasonal grazing in summer and autumn had the least negative effects on the in- dividual density, biomass and diversity indices of soil maerofanna community among three seasonal grazing treatments. The results suggested that mowing might facilitate the restoration of soil macro- fauna community for degraded steppe grassland, and the seasonal grazing in summer and autumn had the least negative effects on soil maerofauna practice for a sustainable grassland communities, which was possibly the best grazing practice for a sustainable grassland use.