Abstract: In May-September 2006, soil cores were sampled from the grasslands returned from cropland and under different management modes in Wuchuan County of Inner Mongolia by using soilcutting ring (50 mL), and the meso- and micro-fauna were isolated by dry- and wet funnel methods to study the effects of different management modes of grassland after returned from cropland on the meso- and micro-faunal communities, aimed to provide references for the evaluation of returning cropland to grassland. A total of 19845 meso and micro-fauna were collected, belonging to 6 phylum, 8 classes, and 8 groups. The dominant groups were Nematode and Enchytraeidae, accounting for 81.37% and 15.68% of the total individual numbers of the meso- and micro-fauna, respectively. As compared to that in cropland, the individual number of Nematode in the grasslands returned from cropland and under different management modes increased significantly (P<0.05), especially in the grassland planted with Helianthus tuberosu +Artemisia sp. However, the individual number of Enchytroidae, Acarina, and Collembola had less increase. After returning to grassland, no significant differences were observed in the vertical distribution of meso- and micro-faunal communities, but the Acarina in the grassland planted with Medicago sativa had an increase in surface gathering. Our results suggested that in the study area, all the management modes of grassland after returned from cropland were beneficial to the restoration of Nematode. In the management of the grasslands returned from cropland, more attentions should be paid to the reservation and accumulation of ground litters to promote the restoration of Acarina and Collembola.

Key words: soil nutrient, spatial prediction, Kriging, regression model., vegetation type