Abstract: In order to discuss the effects of land use/cover changes on soil faunal communities in agro-pastoral transitional zone, grasslands, sandy land, croplands, and shrublands were selected as objects in Horqin sandy land. The soil macro-faunal communities were investigated, together with the ground herbaceous vegetation and soil properties. Results were showed that there were 27 families and 43 groups captured, belonging to 10 orders of soil animals. Tenebrionidae, Melolonthidae larvae and Formicidae dominated the soil macro-faunal communities, and the number of these three groups was 41.79% of total individuals. Grasslands reclamation for croplands or desertification due to heavy grazing increased soil bulk density and pH, while decreased soil organic carbon and total nitrogen content. When the shrubs replanted in the shifting sandy lands, soil moisture could be improved and soil bulk density was decreased to some extent, resulting in the heterogeneity of shrublands. In tendency, grassland desertification had significant impacts (negative) on the number of Melolonthidae larvae and Formicidae. Soil macro-faunal density, richness and Shannon index significantly decreased during desertification. But the re-vegetated shrubs in shifting sandy land could increase the number of Tenebrionidae, and improve soil macro-faunal diversity. Comparably, grasslands reclaimed to croplands had slight impacts on soil macro-faunal communities. It implied that the grasslands under exclosure to control desertification, re-vegetation by shrubs and returning croplands to shrublands and grasslands all could improve soil conditions, and soil macro-faunal diversity. These measures were beneficial for the effective restoration and conservation of fragile ecosystems in agro-pastoral transitional zone.

Key words: Agro-pastoral transitional zone, Land use/cover changes, Soil macro-fauna, Community structure

摘要： 在北方农牧交错区东段科尔沁沙地选择草地、沙地、农田和林地4种土地利用覆盖类型,采用手拣法调查不同类型样地大型土壤动物群落特征,分析土地利用覆盖变化对大型土壤动物群落的作用及其影响因素。结果表明:4种土地类型生境共获得10目27科43个类群,其中拟步甲科(Tenebrionidae)、鳃金龟科(Melolonthidae)幼虫和蚁科(Formicidae)为优势类群,个体数占总个体数的41.79%。草地开垦为农田或过度放牧沙化后土壤容重增加且碱性增强,土壤养分损失,而流动沙地种植人工灌木林后可在一定程度上降低土壤容重并增加土壤水分,增强生境的异质性。草地沙化后直接影响优势类群鳃金龟科幼虫和蚁科的个体数分布,显著降低了大型土壤动物多样性;大型土壤动物个体数、类群数和Shannon指数在沙地生境显著低于草地生境;流动沙地人工种植灌木林后可增加拟步甲科个体数的分布并提高大型土壤动物群落的多样性;但草地开垦为农田对大型土壤动物多样性的影响相对较低。因此,对草地进行围栏封育、防治土壤沙化以及流动沙地人工种植灌木林等退耕还林还草措施均可改善土壤环境,保护和维持大型土壤动物多样性,有利于农牧交错区生态系统的有效恢复和保护。

关键词: 农牧交错区, 土地利用覆盖变化, 大型土壤动物, 群落结构