Research Of The Litter Decomposition Rules Of Caragana Microphylla And Changes Of Soil Microbial In Alpine Desert Area

As the world’s special geographical unit,its ecological environment problems received extensive attention all over the world.Qinghai republican basin is one of the serious desertification area of the qinghai-tibet plateau,large areas of artificial sand-fixation vegetation distribution here.It has great significance to research the restoration and succession process of the artificial sand-fixing vegetation for understand of ecological system function and maintain stability and promote the vegetation restoration.In this study,we take the lobular caragana artificial sand-fixation vegetation as the research object which distributed in the republican basin ShaZhu Yu sand experiment stations,select 1964, 1977, 1991, 2003 and 2011, five differents vegetation restoration areas to set up experimental sample areas to research the lobules of caragana litter decomposition and the change rule of soil microorganisms with the method of ecology as well as the method of Denature Gel Gradient Electrophoresis(DGGE).The result showed that:1. The older the tree is,the faster the litter decomposes, decomposition rate of the litter which between the cluster is faster than that under the clusterscluster in this study; elements content of soil and litter on the rise as a whole along with the increasing length of sample recovery;2.he number of bacteria > actinomycetes > fungi quantity in soil microbial components in study areas.the higher the plantation’s age is, the the numbers of bacteria are greater and under cluster’s numbers are higher than which between the clustre;3.Microbial quantites are negatively related to the carbon content significantly or extreme significantly;Nitrogen content of litters are significantly negative correlation with alkaline hydrolysis nitrogen and available phosphorus in soil;Soil organic matter,alkaline hydrolysis nitrogen and available phosphorus of the correlation in soil reached the significant level or extremely significant level.4.The diversity of soil bacteria mainly influenced by climate factors,in high temperature and rainy summer, the flora diversity is higher, with the temperature decrease, diversity decreased obviously. There is no significant difference between the sample area of flora diversity in the different forest age.As time changes, microbial flora structure gradually stabilized which under cluster.The microorganisms in soil are mostly uncultured,the strains of long existing in the study area are mainly Sphingomonas sp., pedobacter sp. and a kind of uncultured bacterium with ID:KF927533;As the litter decomposes, the species of microbes in soil with the changing of time.The interaction effect between litter and soil microbial has an important role on the improvement of the soil physical and chemical properties and the stability of the ecosystem.Microbes can affect the growth of plants and litter decomposition process indirectly through the way of quantity and types of changes.