【作者】 单娜娜；

【导师】 文启凯； 潘伯荣； 罗明；

【作者基本信息】 新疆农业大学 ， 土壤学， 2001， 硕士

【摘要】 在极端干旱的塔克拉玛干沙漠腹地，利用咸水(矿化度4～5g/l)在流沙上建立人工植被，改善了生态环境促进了风沙土的成土发育，在生物、物理、化学诸因素的作用下，风沙土的理化性质发生着变化；土壤微生物的数量、组成、生理类群及生化活性发生了变化；同时土壤微量元素的含量、形态与分布也显示了一定的规律性，分析结果如下：(1) 流沙上微生物数量很少，生物活性极弱，植被建立后，受人为措施和植被等因素的影响，微生物数量及活性都有显著增加。土壤微生物数量随着植被生长年限的变化和植被类型的不同发生着相应的变化。(2) 人工绿地土壤微生物总数中细菌占绝大多数，其次是放线菌，真菌的数量最少。细菌中芽孢杆菌占一定比例。(3) 人工绿地建立后土壤微生物生理群数量有所增加，氨化细菌数量最大。筛选出了一部分产淀粉酶的细菌。(4) 人工绿地土壤微生物数量秋季比夏季略有增加。(5) 人工绿地几种主要固沙植物根际微生物数量远远大于根外，根际效应极为显著。(6) 人工绿地中的土壤全量微量元素与流沙对照相比变化不大，有效态微量元素大于流沙对照，这也表明了风沙土成土发育仍处于初级阶段。流沙母质中各微量元素含量较低是各处理土壤微量元素含量低的决定因素。(7) 人工绿地土壤微量元素的含量随植被类型、生长年限和剖面层次的变化而呈现一定的规律性。更多还原

【Abstract】 In the center of Taklimakan desert in the extremely arid region , Artificial vegetation has been set up by saline water (4～5g/l),which have reformed ecological environment ,enhanced the form of Blown Sand Soil .The Blown Sand Soil properties have changed much. The soil microorganism amount and activities have improved . The contents and distribution of soil microelements follow certain regularity in the process of soil-forming. Our researches showed: (1)There are a small quantities of microbes and a low microorganism activities in drifting sand dunes .After the Artificial vegetation has been set up ,the soil microbial population is in large number and varied with the forest ages ,the microorganism activities have a remarkable improvement .(2)The amount of bacteria is highest, the secondary is actinomycies ,the last is fungus .In bacteria ,bacillus have a high percent.(3)After the Artificial vegetation has been set up, the amount of physiological group of the microorganism have a greatly improved. The amount of ammonifiers is largest. The large number of bacteria can produce amylase.(4)The amount of microorganism in summer were different from autumn. (5)The sand-fixing plants planted on drift sand dunes have well-developed rhizosphere microorganisms. The amount of rhizosphere microorganisms is more than beyond it. (6)The total contents of afforestation plots are not significant differences with drift sand dunes; Available contents of plots are higher than drift sand dunes. The development of Blown Sand Soil is still on primal period. The contents of soil microelement of each plots are low, which reason is the low contents of drifting sand. (7)The contents of soil microelement of afforest plots are increased with ages. In the plots of same age, the content of grassplot is the most.更多还原