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题名	塔克拉玛干沙漠北缘荒漠河岸植物群落对水分和氮素输入的响应
作者	李宁
学位类别	博士
答辩日期	2008
授予单位	中国科学院．新疆生态与地理研究所
导师	田长彦，中国科学院新疆生态与地理研究所
关键词	塔克拉玛干沙漠
其他题名	The response of the plant community to the water and nitrogen inputting in the desert river bank at the north edge of Taklimakan Desert
中文摘要	为理解咸水和不断增加的干沉降所带来的氮素输入对荒漠生态系统植物群落特征的影响及荒漠生态系统稳定性的效应与机理，于2004-05年在塔克拉玛干沙漠北缘的荒漠河岸开展野外定点试验，研究不同水平的氮素和咸水对土壤性质、地上植被群落、土壤种子库及种子库与地上植被关系的影响等问题，以期为河道输水植被恢复过程中水分和氮素的贡献及其交互作用的机理提供理论依据。主要结论如下： 输入水分和氮素显著提高土壤养分和土壤含水量，并降低土壤pH值。咸水灌溉引起表层土壤含盐量的波动性变化以及土体含盐量的增加。水分和氮素对荒漠植物群落密度和组成有显著影响。随着水分输入增加群落密度增加，但不同物种对水分和氮素响应的敏感程度不同。群落的植被覆盖度和净初级生产力随着水分和氮素的增加而增加。水分和氮素通过改变不同生活型或物种的密度、覆盖度、净初级生产力，从而使一年生草本植物的综合优势度增加，而灌木和多年生草本则呈下降趋势。塔克拉玛干沙漠北缘土壤种子库属于持续土壤种子库中的类型Ⅳ，在时空上表现出相应的分布规律。水分和氮素的输入对土壤种子库的物种组成、季节动态以及分布特征没有显著影响，但显著增加种子库的库容。结果表明，水分和养分作为荒漠生态系统中最重要的生态因子，显著影响荒漠生态系统重植物生存环境、物种多样性特征以及荒漠生态系统的稳定性，具体表现为水分和氮素输入增加初级净生产力和覆盖度，水分和氮素输入对一年生草本影响比多年生草本和木本植物生长更为明显。因此在实践过程中要充分认识到水分和养分对荒漠生态系统的作用，合理有效地利用水分和养分资源来维护荒漠生态系统的稳定性。In order to understand the influences to the desert ecosystem plant community characteristics and the mechanism of the desert ecosystem stability of the salt water and nitrogen inputting which come from the increasing subsidence, the experiments were carried out in the river bank at the north edge of Taklimakan Deserts from 2004 to 2005. The influences of different level water and nitrogen inputting were researched thoroughly, including the soil characteristics, the community characteristics of overground vegetation, soil seed bank and the interrelationship between the seed bank and the overground vegetation, which could provide the theory basis for the contributions of moisture content and nitrogen and the correlation mechanism of them in the course of vegetation recovery with the river. The results were summed up as the following: The input of water and nitrogen improved the soil nutrient content, moisture content, reduced the pH significantly. The input of salt water brought the fluctuated change of surface soil salt content and the salt content increase of the whole soil. Water and nitrogen affected the plant community density and the structural composition significantly. The density increased significantly along with the increasing of water inputting, but the sensitivities of different species responding to the water and nitrogen were different. The plant community coverage and NPP increased along with the increasing of water and nitrogen inputting. Water and nitrogen change the superiority of different life form or one species in the community by inflecting their population density, coverage and NPP. The superiority of annual herbs increased while the superiority of perennial herbs and the shrubs had the decreasing tendency because of the inputting of water and nitrogen. The soil seed bank at the north edge of Taklamakan Deserts belongs to persistent soil seed bank, which displays the corresponding rule in the spatial and temporal distributing. Water and nitrogen had no significant influences to the species composition, spatial and temporal distributing characteristics and the seasonal dynamic rule of soil seed bank, but increased the size of the soil seed bank significantly. Above results indicated that the water and nutrient, as the most important ecological factors of the desert ecosystem, influence plant survival environments, the species biodiversity characteristics as well as the stability of the desert ecosystem tremendously. Therefore the function of water and nutrient to the desert ecosystem should be realized fully in practice and use the water and nutrient resources to defend the stability of desert ecosystem reasonably and effectively.
语种	中文
学科主题	植物生理学
公开日期	2010-11-12
页码	共115页
内容类型	学位论文
源URL	[http://ir.xjlas.org/handle/365004/8144]
专题	新疆生态与地理研究所_中国科学院新疆生态与地理研究所(2010年以前数据)
推荐引用方式 GB/T 7714	李宁. 塔克拉玛干沙漠北缘荒漠河岸植物群落对水分和氮素输入的响应[D]. 中国科学院．新疆生态与地理研究所. 2008.

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