【作者】 呼格吉勒图；

【导师】 杨劼；

【作者基本信息】 内蒙古大学 ， 生态学， 2012， 博士

【摘要】 湿地生态系统处于陆地生态系统和水生生态系统之间的过渡区,湿地面积占全球陆地面积的5.4%,但其重要性绝不亚于森林生态系统和海洋生态系统。尤其对于水资源短缺的我国半干旱区沙地而言,湿地被称为沙地中的“植被岛”,它不仅是沙区人类赖以生存的主要空间,也对维持沙区生态平衡具有重要意义。毛乌素沙地是我国半干旱区主要沙地之一,也是一个十分特殊和敏感的生态过渡区。因此,本研究以内蒙古自治区境内分布的毛乌素沙地湿地为研究对象,分析湿地植物区系组成、植物群落分布及其影响因子、植被动态变化及其对植物多样性、地上生物量和土壤有机碳储量的影响,从不同尺度上探讨毛乌素沙地湿地植被特征与生态功能,研究结果如下：1.毛乌素沙地湿地面积为4486.54km2,占毛乌素沙地面积的18.75%。湿地类型以湖滨低地、丘间低地和滩地为主,随着海拔高度的增加,分布的湿地类型依次为：河漫滩→湖滨低地→丘间低地和滩地。2.毛乌素沙地湿地植被不仅具有隐域性特点,并且带有深刻的地带性烙印。毛乌素沙地湿地植被植物科的分布区类型以世界分布为主,属和种的的分布区类型以温带分布为主,种的分布区类型与鄂尔多斯高原典型草原(东胜梁地和准格尔黄土丘陵)种的分布区类型相似,东亚成分的作用明显强于草原成分。与湿润半湿润区的黑龙江流域湿地植被比较,毛乌素沙地湿地植物群落类型以草甸为主,而黑龙江流域湿地植物群落类型以沼泽为主。3.毛乌素沙地湖滨低地和丘间低地植物群落均有带状分布特点,但影响湖滨低地和丘间低地植物群落带状分布的环境因子有差异。水分和盐分是影响湖滨低地植物群落分布的主要环境因子,而水分和土壤机械组成(粒级为0.05-1μm)是影响丘间低地植物群落分布的主要环境因子。4.毛乌素沙地湿地面积萎缩、盐碱化、破碎化现象严重。从1986到2007年毛乌素沙地湿地面积减少了618.53km2,盐碱地面积增加了163.48km2,景观破碎化指数上升了0.000023。这是毛乌素沙地气候因素(气温上升、蒸发量增强)和人为因素(固沙活动、农田开垦和人工造林等)共同作用的结果。5.湿地作为毛乌素沙地宝贵的资源,在维持生物多样性、生产干物质和碳循环等方面起着不可替代的作用。湿地共有野生维管植物323种,占毛乌素沙地野生维管植物的72.1%,而且湿地植物多样性明显高于同一区域沙地和梁地；湿地植被草本层生产力为310072.43t,占毛乌素沙地植被草本层生产力的68.98%；湿地植被0-30cm土层土壤有机碳储量为5735.93t,占毛乌素沙地植被0-30cm土层土壤有机碳储量的46.29%。柳湾林物种丰富度、地上生物量和0-30cm土层土壤有机碳含量显著高于毛乌素沙地其它植物群落(P<0.05)。6.虽然毛乌素沙地湿地具有重要的生态功能,但是,同时面临着湿地面积萎缩、盐碱化、破碎化和功能下降等一系列生态问题。因此,要实现毛乌素沙地湿地资源的保护与可持续利用可以采取以下对策：(1)提高民众的湿地保护意识；(2)保障湿地生态用水；(3)加强湿地保护的科学支撑。更多还原

【Abstract】 Wetland ecosystem is located at the ecotones between terrestrial ecosystem and aquatic ecosystem. Wetland area accounts for5.4percent of global land area, but its importance is no less than the forest ecosystem and marine ecosystem. Especially for the water depletion semi-arid region sandy land in China, it is known as "vegetation island" in the sandy land. It is not only the main space of human survival in the sand areas, and also very important for the maintenance of ecological balance in the sand areas. Mu Us sandy land is a major sandy in semi-arid inland region of China, and is a very special and sensitive ecotone. So, this paper took the wetland of Mu Us sandy land in Inner Mongolia as the research object, analyzed the floristic composition of wetland, distribution of the plant community and its influencing factors, vegetation dynamics change and its impact on plant diversity, aboveground biomass and soil organic carbon storage, and also discussed the characteristics and ecological functions of vegetation of wetland in Mu Us sandy land from the different scales. The main results are summarized as follows:1. The area of wetland in the Mu Us sandy land is about4486.54km2, which is18.75%of the Mu Us sandy land. The wetland types are represented by inter-dune lowlands, lake lowlands and beaches. The distribution series of wetland types with increasing altitude was flood plain→lake shore lowlands→inter-dune lowlands and beaches.2. The wetland vegetation in the Mu Us sandy land not only has the intrazonal characteristics, also has the obvious brand of the zonal vegetation. The world distribution family is the main family in the plant family distribution types, but the temperate distribution genera and species are the main genera and species in the plant genera and species distribution types. The plant species distribution type of wetland in the Mu Us sandy land is more similar to the typical steppe in the Ordos Plateau (Dongsheng ridge, and the Junger loess hills), the effects of East Asia elements are stronger than the Steppe elements. And comparied with wetland vegetation of Heilongjiang River valley in humid and semi-humid region, the main plant community type of wetland in the Mu Us sandy land is meadow, but the main plant community type of wetland in the Heilongjiang River valley is swamp.3. The plant communities of lake shore lowland and inter-dune lowland in the Mu Us sandy land has a zonal distribution featuers. However, there are differences between the influencing environmental factors of the zonal distribution of plant communities of lake shore lowland and inter-dune lowland. The distribution of plant community on the lake shore lowland is affected by water and salinity gradient, and that on the inter-dune lowland is affected by water and soil mechanical composition (size fraction is0.05～μm).4. The shrinking, salinization and breaking of wetland is more and more serious in the Mu Us sandy land. The wetland area has been reduced by618.53km2, the saline land area has been increased by163.48km2and the landscape fragmentation index has been increased by0.000023from1986to2007. This is resulted from a combination of climatic factors and human factors such as temperature rise, evaporation enhancement, the Dune stabilization practice, forestry planting and agricultural land reclamation.5. As a valuable resource in the Mu Us sandy land, wetland plays an irreplaceable role in the maintenance of biodiversity, production of dry matter and the carbon cycle. There are323wild vascular plants in the wetland, accounting for72.1% of that in the Mu Us sandy land, and wetland plant species diverssity is significantly higher than the sandy land and ridge of the same region. The herb layer production of the wetland vegetation is310072.43t, accounting for68.98%of that in the Mu Us sandy land, soil organic carbon storage (0-30cm) in wetland is5735.93t, accounting for46.29%of that in the Mu Us sandy land. The species richness、aboveground-biomass and soil organic carbon storage (0-30cm) of the osier bed was significantly higher than other plant community in the Mu Us sandy land (P<0.05).6. In spite of the wetland in the Mu Us sandy land has an important ecological function, it also faces ecological problems as shrinking, salinization, breaking and functional degradation. Therefore, the protection and sustainable utilization of wetland resources in the Mu Us sandy land may be implemented by the follow countermeasures:(1) Raising awareness of wetland protection;(2) Guaranteeing wetland ecological water;(3) Strengthening scientific support of the wetland conservation.更多还原