【作者】 王海星；

【导师】 张克斌；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2012， 博士

【摘要】 本研究基于宁夏盐池县四儿滩湿地的独特气候特征和生态特征,从群落尺度和景观尺度下分析研究湿地的动态变化,分析并讨论得出湿地动态变化的原因。为区域湿地气候研究和湿地植被保护、湿地过程研究和退化湿地修复研究打下坚实的基础。在群落尺度下的研究,通过生态学相关知识对这些植被数据进行整理并分析,对四儿滩湿地的植被群落进行植被特征指数的研究、植被群落聚类分析研究、生态位宽度和重叠度分析研究。通过这3方面在群落尺度下对湿地植被的动态波动变化进行分析并讨论。在景观尺度下的研究,从两方面入手：1.拍摄和整理样方的数码照片,得出各个样方的植被盖度。下载相应的遥感影像,提取各个样方对应的NDVI值。对植被盖度和NDVI值进行对比拟合分析,并讨论出两种湿地植被盖度调查方法的结果的相关性。2.选取了1999、2004、2010三期遥感卫星影像,运用马尔科夫链来预测2015年和2020年土地利用类型的变化(英文简称LUCC),对宁夏盐池县不同土地利用类型生态系统服务价值进行研究,本研究主要侧重于湿地,并得出以下主要结论：(1)研究区四儿滩的四条样线中东样线和北样线的植被各项指数要比南样线和西样线的植被各项指数高。影响样线植被各指数的主要因素是土壤含水量和生长季降雨量,除此之外,还有地势抬升程度不同和人类活动,造成了研究区四条样线间各植被指数的差异。(2)根据聚类分析和主成分分析的结果,结合湿地实地调查经验,总结出研究区四儿滩湿地的“三带”的主要植被。湿生带的3种主要植被分别为：盐爪爪(Kalidium foliatum).碱蓬(Suaeda salsa)和白刺(Nitraria tangutorum)。交错带的植被分别为：西伯利亚蓼(Polygonum sibiricum)、多裂骆驼蓬(Peganum harmala)、雾冰藜(Bassia dasyphylla)等8种。旱生带的植被分别为阿尔泰狗哇花(Heteropappus altaicus)、苦豆子(Sophora alopecuroides)、达乌里胡枝子(Lespedeza davurica)等8种。(3)分析“三带”主要植被的生态位宽度和重叠度可知：在湿生带内,碱蓬、白刺和盐爪爪生态位宽度大；在交错带内植物种类较多,它们大部分既稍喜湿润,又颇耐干旱,如雾冰藜、刺沙蓬(Salsola ruthenica)和沙鞭(Psammochloa villosa)生态位宽度大。旱生带中的植被阿尔泰狗哇花、苦豆子、披针叶黄华(Thermopsis shischkinii)等生态位宽度均有所增加。研究表明：生态位宽度大的植被,其与其它植被的生态重叠度不一定大,因此植被的生态位宽度和生态位重叠度的线性关系不明显。(4)利用数码照片对研究区湿地的植被的盖度值进行测度,与遥感卫片上的NDVI的值就行了回归分析,数码照片反映的植被盖度和INDVI值的拟合度较好,表明了在西北干旱半干旱地区湿地生态系统中,数码照片方法可以很好的反映植被盖度。(5)1999年-2004年研究区的湿地主要转出量为草地和耕地,转化为其它土地利用类型的相比之下较少。在1999年-2004年间湿地的转入主要也是由草地和耕地。1999年-2004年间湿地转出量大于转入量。2004年-2010年研究区的湿地主要转出量大部分足草地,2004年-2010年研究区湿地的转入量主要也是由草地和耕地。2004年-2010年间湿地转入量大于转出量。湿地的增加归功于近几十年国家对西北地区草地和湿地的保护政策。(6)研究区总生态服务价值从1999年到2020年呈先增后减的演变趋势。一级类型服务项中调节服务的生态价值最高,占总价值的50%以上,其次为支持服务、供给服务和文化服务；二级类型服务项中9个单项生态服务价值从多到少依次为：土壤保持、生物多样性保持、气候调节、水源涵养、废物处理、气体调节、景观调节、食物生产和原材料生产。不同土地利用的二级类型的生态服务主要以土壤保持、生物多样性保持和气候调节3项为主。食物生产和原材料生产的生态服务价值最低。总体各年间的林地和草地的贡献率是最大的,湿地在西北半干旱区的生态服务价值次之。更多还原

【Abstract】 As the unique climate characteristics and ecological characteristicsof arid and semi-arid wetlands in Yanchi County, we want to have an overall understanding of dynamic change of wetland’s cause based on community-scale and landscape-scale. We have an overall understanding of dynamic changes of wetlands and lay a solid foundation for wetlands climate research, wetland conservation, process studies of wetlands and restoration study of degradation wetland.In community scale, there were three reaearchs such as vegetation biodiversity, vegetation community and niche breadth and niche overlap. We analysis and discuss the dynamic fluctuations of vegetation through these three aspects of community scale. In landscape scale, there were two works to do:1) to shoot and collect digital quadrat photos and the satellite images of the study area, we analysised correlation of two survey methodologies of wetland vegetation coverage.2) Based on three satellite images of1999,2004and2010. To predict LUCC of2015and2020through the use of the Markov chain, we mainly analysis and discuss ecosystems services value of LUCC, mainly about wetland. The conclusions are as following:(1) In Siertan vegetation indices of east and north line transect are higher than that of south and west line transect. The main reason of change of each vegetation indices are soil moisture and rainfall in growth season, in addition, terrains rise and human activities.(2) The main vegetations of "three strips" are summed up, according to results of cluster analysis and principal component analysis and experience of survey. There are three main vegetations in wet strip, respectively Kalidium foliatum, Suaeda salsa and Nitraria tangutorum. There are eight main vegetations in ecotone strip, respectively Polygonum sibiricum, Peganum harmala, Bassia dasyphylla and so on. There are eight main vegetations in arid strip, respectively Heteropappus altaicus, Sophora alopecuroides, Lespedeza davurica and so on.(3) Based on niche breadth and niche overlap, results are that:S. salsa, N. tangutorum and K. foliatum’s niche breadth are biggest in wet strip. There are many plant species in ecotone strip, lot of them could be resistant to moist and drought. B. dasyphylla, Salsola ruthenica and Psammochloa villosa’s niche breadth are bigger in ecotone strip. In arid strip niche breadth of H. altaicus, S. alopecuroides and Thermopsis shischkinii were increased. The reault of this research shows that niche breadth and niche overlap have not obvious linear relationship.(4) To make a regression analysis between vegetation coverage measured by digital photographs of the wetland and NDVI of satellite photos, the results showed that they have a high fitting degree. Furthermore, we know that vegetation coverage can be well reflected by digital photographs.(5) The wetland was mainly tranfered into grassland and farmland of1999-2004, other types of landuse made very small contribution. The wetland of1999-2004was generated from grassland and farmland. The tranfered amount is greater than the generated amount in1999-2004. The wetland was mainly tranfered into grassland of2004-2010; the wetland of2004-2010was generated from grassland and farmland. The generated amount is greater than the tranfered amount in2004-2010. On the recent decades wetland of the northwest increased due to protection policies making by government.(6) The trend of the ecosystem services value was first increased and then decreased from1999to2020. In the first-type services the regulating service (about50%) was the highest, followed by support services, supply services and culture service, from more to less there were9single ecological service value as follows:soil conservation, biodiversity conversation, climate regulation, water conservation, waste disposal, air regulation, landscape regulation, food production and raw material production. Among the secondary services, ecosystem services value are mainly soil conservation, biodiversity conversation, climate regulation, ecosystem services value of food production and raw material production is minimum. Generally, the contribution rate of woodland and grass is the largest in arid region of northwest of China, and followed by wetland.更多还原