Study On The Features Of Soil Animals Community In The Ecotone Of Grassland And Farmland In The Middle Area Of Inner Mongolia

The northern foot of Mountain Daqing in the middle area of Inner Mongolia is semi-grassland and semi-farmland region,which has typical landscape features of grassland and farmland crisscross. In this region,four typical habitats that are farmland,quitted farmland,artificial woodland and desert steppe were selected for study on the composition features of soil animals community , the correlation between soil anomals and soil environmental essential factors and the role of soil animals in the material cycle of the compound ecosystem of grassland and farmland etc. The results showed that soil animals in the ecotone of grassland and farmland in the middle area of Inner Mongolia belong to 5 phylum,7 class,13 order,43 famility. Large size soil animals belong to 2 phylum,4 class,11 order,42 famility.The dominant groups are imagos of Carabidae,Formicidae and larvaes of Curculionidae. Small-middle size soil animals belong to 5 phylum,6 class,9 order,7 famility.The dominant groups is Nematoda. Four habitats involved for study stand for the main ultilizing styles of land. because of the different ultilizing style of land ,the natural condition and the structure of soil animals community in four habitats are obviously different. In the respect of density distribution,density of Large size soil animals in desert steppe is higher than that in farmland,that in farmland is higher than that in artificial woodland and that in artificial woodland is higher than that in quitted farmland. Density of small-middle size soil animals in artificial woodland is higher than that in farmland,that in farmland is higher than that in desert steppe and that in desert steppe is higher than that in quitted farmland. In the respect of number of groups,the number of groups of large size soil animals in artificial woodland is more than that in quitted farmland and desert steppe,that in quitted farmland and desert steppe is more than that in farmland. Number of groups of small-middle size soil animals in quitted farmland is more than that in farmland and desert steppe and that in quitted farmland and desert steppe is more than that in artificial woodland. In the respect of composition of the dominant groups,the dominant groups of large size soil animals in farmland are imagos of Carabidae,Formicidae and larvaes of Curculionidae. The dominant groups in quitted farmland are larvaes of Carabidae,imagos of Carabidae and larvaes of Empididae. The dominant groups in artificial woodland are Formicidae and larvaes of Anthomyiidae. The dominant groups in desert steppe are larvaes of Curculionidae. The dominant groups of small-middle size soil animals is Nematoda. In the respect of vertical distribution,Density and the number of groups of small-middle size soil animals gather mainly in 5-10cm layer of soil in farmland and it is different from the character of the surface gathering of soil of large size soil animals vertical distribution in farmland as well as vertical distribution of soil animals in the other habitats. In the respect of biodiversity of soil animals,biodiversity of large size soil animals in artificial woodland is higher than that in quitted farmland,that in quitted farmland is higher than that in desert steppe and that in desert steppe is higher than that in farmland. Biodiversity of small-middle size soil animals in artificial woodland is higher than that in farmland,that in farmland is higher than that in quitted farmland and that in quitted farmland is higher than that in desert steppe . In the respect of composition of guild,the dominant groups of large size soil animals infarmland are plant-ate and prey-ate groups. The dominant groups in quitted farmland are rottenness-ate and prey-ate groups. The dominant groups in artificial woodland are mixture-ate and rottenness-ate groups. The dominant groups in desert steppe is only plant-ate groups. The dominant groups of small-middle size soil animals is mixture-ate groups. Density and the number of groups of large size soil animals and small-middle size soil animals present different varied regularity in different habitats with seasonal changes. Through the analysis of the correlation between density and the number of groups of soil animals and soil environmental essential factors,showed that the correlation between density and the number of groups and soil environmental essential factors is obvious.And soil pH affect both density and the number of groups largerly. Chemical elements are enriched highlier by large size soil animals in their bodies. And chemical elements enrichment put in order is:K>Ca>Mg>Fe>Na>Zn>Mn>Cu . In four habitats,the contents of chemical elements enriched in bodies of large size soil animals in artificial woodland are the highest and those in farmland are the lowest.