拉萨河流域不同土地利用方式下土壤动物的群落特征

Characteristics of soil fauna communities in different land use patterns in the Lhasa River basin

对拉萨河流域下游6个不同土地利用方式下土壤动物的群落特征进行了研究.结果表明:由于土地利用方式的不同,土壤动物群落组成存在一定的差异.节跳虫科、辐螨亚目、革螨亚目和甲螨亚目在6个群落中均为优势类群或常见类群,这些类群不仅数量大,分布也较为均匀,是该地区的广布类群;稀有类群在各群落中分布各异.土壤动物垂直分布具明显的表聚性,个体数表聚性更为突出,2个草场土壤动物的个体数量主要聚集在表层,4个农田垂直分布递减的较为缓慢,这与生境中的食物来源有关.割草场和青稞田土壤动物群落的多样性较高;土地利用方式的不同,土壤动物群落的相似程度亦不同,其中小麦田与青稞田、割草场与放牧场生境最为相似.

Characteristics of soil fauna communities in six different land use pattern soil were studied in downstream of the Lhasa River basin. The results show that there is some difference in the composition of soil fauna community of different land use pattern soil. Isotomidae, Prostigmata, Mesostigmata and Oribatida are dominant or common groups in six different land use soil. The quantity of these groups is more and they distribute evenly. They are widespread groups of investigation area. There is various in the distribution of rare groups in all land use pattern soils. The accumulation in soil surface of soil fauna from vertical distribution is obvious, especially the ir^dividuals number. The individuals of soil fauna in two grasslands mostly accumulate in the surface soil, while the decline rate of soil fauna in vertical distribution of four farmlands is relatively slow. The distribution of soil fauna may relate to food source from habitats. The diversities of soil fauna communities in both mowing pasture and barley field are high. The similarity of soil fauna community is various for the difference of land use pattern. Among six habitats, the composition of soil fauna communities in wheat field and barley field,mowing pasture and pasture is most similar.