【作者】 吴迪；

【导师】 王天厚；

【作者基本信息】 华东师范大学 ， 生态学， 2011， 硕士

【摘要】 长期以来,日益上升的人口压力导致人类对土地的需求也日趋扩大,而对湿地资源的掠夺式开发利用和工业废水的污染带来的环境问题不仅造成了湿地生物多样性的丧失和湿地环境的日趋恶化,也大大降低了生态系统的稳定性,并使湿地成为退化最严重的生态系统之一。为了缓解湿地退化对人类生存环境和生物多样性造成的损害,人工的湿地恢复成为了一种重要的方法。湿地恢复是指通过生物、生态技术或生态工程对退化或消失的湿地进行修复和重建。目前多个国家已经开展了湿地恢复理论和方法的研究,但从生态系统角度出发,综合环境因素、生物多样性因素及社会因素进行湿地恢复评价及恢复技术探讨的研究还比较欠缺。淀山湖区域是黄浦江上游重要的水源地,提供了水源涵养和水质净化、土地资源储备、生物多样性保育等功能。为了应对该区域日益严重的环境恶化问题,贯彻《上海市“十一五”规划纲要》中关于黄浦江上游水源地的保护计划,开展了以大莲湖为核心的“上海西郊淀山湖湿地生态恢复区”湿地修复工程。本研究于2008年12月——2010年6月,在大莲湖修复示范区,通过对比修复工程前后土地利用方式、植被、生物多样性(鸟类两栖及爬行类)、水质及人口社会等指标的差异,定量评估工程的修复效果；选取水质和两栖动物两个影响湿地环境和生物多样性的重要指标进行重点分析,找出影响水质和两栖动物多样性的关键因子,并在此基础上提出湖滨带湿地环境修复和生物多样性保育的技术和策略。大莲湖湖泊湿地受损现状在淀山湖甚至太湖流域都具有典型性,因此该修复试验研究的展开将为淀山湖区域以及太湖流域湖滨带湿地的修复提供科学依据和典型示范。本研究主要结论包括：1)从土地利用和植被的情况来看,随着工程的实施,实验区内土地利用由主要以人工养殖鱼塘和林地为主的人工湿地(人工鱼塘占50%,林地占25%),转变为以开放性水域和乔灌草相结合的半自然状态下的自然湿地(明水面面积占30%,各类植被群落占50%,人工鱼塘完全消失),植被从只有片段化林地转变为乔木、灌木丛、草本植物及各类水生植物相结合的格局。实验区由以前人类主导的人工鱼塘湿地转变成了半自然状态下的自然湿地,生态系统的生境结构和植被的配置更加符合自然湿地的要求,为生物多样性的恢复提供了良好的基础。2)从鸟类变化来看,施工之前,实验区内共记录到鸟类65种,隶属11目27科；在工程一年后共记录到鸟类71种,隶属11目32科；工程后鸟类群落多样性和均匀性比工程前有了显著提高,优势度指数有所下降；从鸟类生态类群组成来看,涉禽和鸣禽在工程前后都是优势群,在工程后修复的目标鸟类——雁鸭类新增加6种,并新纪录到猛禽2种,并在2009年9月份发现上海市新分布物种白胸翡翠4只。这说明工程后的生境和植被配置能更好地起到鸟类生物多样性保育的效果。3)从两栖爬行类变化情况来看,工程后记录到两栖动物2科3属5种共902只,显著多于工程前的558只,并且五种蛙类的数量都比工程前提高；爬行类共调查到3科7种,工程后个体总数(29只)也多于工程前(27只)。4)对水质主要指标的具体变化分析,修复后水体中叶绿素a (Chla)、含氮指标、总磷(TP)、化学需氧量(COD)、溶解氧(D0)等指标均有显著下降(P<0.05),说明经过改造后水中有机物的浓度显著下降,氮、磷等营养物质的排放也得到了一定的控制。5)对生态系统的健康评价,2008年该区域结构健康指标、功能健康指标和综合评价得分分别为9.75、1.7和11.45,2010年评价得分依次为14.26、9.25和23.51。2008年该区域生态健康水平处于非常差的状态,2010年由于修复措施的逐步实施,生态健康程度正得到改善,处于良好但还不理想的状态；随着该地区人类活动压力的逐渐减小(2010年压力得分21.34)和政府法规和管理措施(2010年响应得分18.4)的逐步完善,其各种生态功能也将会得到更为充分的体现。6)影响水质的关键因子,叶绿素、化学需氧量等指标与Tp呈显著正相关,而与TN无显著相关性,说明在该地区Tp是主要的限制因子。因此在以后的工作中应适当控制含磷物质的排放,尤其是控制居民生活污水及农药化肥等点源及非点源污染物的直接排放；底泥在修复过程中会对水质产生极为关键的影响,因此在以后的修复工程中应该适当控制修复地区底泥的深度,以减少营养物质的释放源；水生植物的存在也使影响水体中氮磷水平的重要因素。7)对两栖动物的生境选择分析,人工次生湿地中两栖动物的种类和数量都明显少于自然湿地；人类干扰因素对泽蛙、黑斑蛙和饰纹姬蛙都具有显著的负相关关系；另外裸地面积对中华蟾蜍的数量有显著影响,泽蛙和饰纹姬蛙比较偏好于复杂的生境,金线蛙主要受水面积和水生植被的影响；另外人为捕捉也是黑斑蛙等蛙类数量减少的重要原因。更多还原

【Abstract】 From the 20th century, because of the fast increasing of human population, the demand of people with developing land is increasing accordingly, and consequently this development of land use with predatory exploitation and environmental problems caused by industry pollution has brought many disaster problems and instability to the wetlands, now wetlands becomes one of the most degraded ecosystems. In order to relieve the deterioration of the human living environment and the decrease of biodiversity, wetland restoration is being carried out as an important compensation method for wetland protection. Wetland restoration is to repair and reconstruct the degraded or disappeared wetlands by using biological, ecological techniques and ecological engineering methods. By now, many countries have begun researches on the theology and methodology of wetland restoration, but studies that combining the environmental, biological and social factors to evaluate and summarize the restoration effect and restoration techniques are still a shortcoming.Dianshan Lake region is an important water source in the upstream of the Huangpu River, providing many ecological functions like water conservation, water purification, land resource reservation, biodiversity conservation and so on. In order to relieve the environmental problems here, and put the water resource protection plan in this area into effect, a wetland restoration pilot project was carried out centering on Dalian Lakeside area, and some scientific studies concerning about the restoration of ecological environment and the protection of biodiversity were also developed in the same time. From August 2008 to Match 2010, parameters including land use pattern, vegetation, bird populations, amphibian populations, reptile communities, water quality and some social parameters were collected in the restoration area to assess the effects of the project; water quality and amphibian population were chosen as two important factors that affect the wetland environment and biodiversity to find out the key factors that affect the water quality and amphibians population, and then some restoration techniques and strategies concerning about wetland environment and biodiversity protection were put forward. The current situation of degraded Dalian Lakeside wetlands is also very typical around the Taihu Lake basin, so the development of the restoration project will offer scientific support and typical demonstration for the development of wetland restoration in Dianshan Lake and Taihu Lake basin.The study results were as follows:1)During the restoration period, this demonstration area which was dominated by intensive fish ponds (50%) and woods (25%) was reformed into a much more complicated landscape with open water (30%), multi-vegetation communities (50%) and with no fish ponds left anymore. A diverse ecological area which was characterized by vegetation succession with forest, shrub, herbaceous plants and aquatic plants was established instead of small fragmentation of patch woods before the project. This human-controlled fish pond wetland changed into a semi-nature wetland, also the change of the ecological foundation is good for the biodiversity conservation.2) On the part of bird population,11 orders,27 families and totally 65 species were recorded before the pilot project; 1 year later llorders,32 families and totally 71species were recorded, and also 11 species of water birds,10 species of terrestrial birds were newly found in this area; The total number of species and individual in the bird communities showed increase although not significantly (P>0.05), eleven new species were recorded after project, the Shannon-Wiener index (H’) and Pielou index (J) also showed a significant increase after restoration, the total number and species of the targeted species-Geese and Ducks got a significant increase (6 species new recorded), also two species of Raptors were newly recorded and new distribution bird-Halcyon smyrnensis was found here after the project. In a word, the habitats and vegetation distribution can give a positive impact on the conservation of bird community.3) On the part of amphibians and reptiles, after the pilot project, two families three genera five species and totally 902 individuals of amphibians were recorded, significantly higher than 558 individuals before project, also the number of each kind of amphibians after the project were higher than that of before project; totally 3 families 7species of reptiles were recorded, and the individuals after the project was higher than that of before project.4)Based on the analysis of water quality parameters, after project, the content of chl.a, TN, NH4+,NO3-, TP, COD, DO significantly lower than that of before project(p< 0.05). That means after the project, the pollution sources has been a certain control and the density of organics decreased significantly.5) According to the characters of Dalian Lake wetland ecosystem, a set of ecosystem health assessment has been developed. In 2008, the structure health index, function health index and comprehensive health index were respectively 9.75,1.7 and 11.45, and in 2010 these three index were 14.26,9.25 and 23.51 correspondingly. In 2008 the health level of this area was in a very bad condition, and due to the implementation of the repair measures in 2010, the health of the ecosystem improved a lot, but still not in a best condition; as the stress of human activity(pressure index in 2010 was 21.34) decreasing gradually and the improvement of management and regulations from the government(response index in 2010 was 18.4), the functions of Dalian Lakeside wetland will become more effective. 6) By analyzing the key factors that affect the water quality, some details are as follows:the content of chl.a and COD showed a significant positive correlation with Tp instead of TN, so Tp was the most important limiting factor in this area. From this point, waste water from residential area, industry area and agriculture region should be controlled to prevent organics with P element entering into the water directly; also the bottom sediment played a very important role in the purification of water quality, so the depth of sediment should be controlled appropriately to reduce the release of organics; aquatic plants were also a factor that affected the balance between N, P.7) By analyzing the habitat selection patterns of amphibian population in Dalian Lake wetland, some detailed results are as follows:the numbers of species and individuals were lower in the constructed wetlands than that in the natural wetland; factor of human disturbance showed a negative correlation with the distribution of Rana limnocharis, R. nigromaculata and Microhyla ormata; and the numbers of Bufo gargarizans positively correlated with proportion of barren (P<0.05) compared with other variables; Rana limnocharis and Rana limnocharis preferred the more complicated habitats, proportion of water area, proportion of vegetation impacted on the number of R. plancyi positively (P<0.05); in addition, the capture of human was also an important reason for the decrease of R. nigromaculata population.更多还原