【作者】 谷东起；

【导师】 夏东兴；

【作者基本信息】 中国海洋大学 ， 海洋地质， 2003， 博士

【摘要】 潟湖是由沿岸沙嘴、沙坝或滨外坝等围拦海湾、河口或其它浅海水域而形成的半封闭或封闭性地貌体，是重要的海岸湿地类型之一。潟湖湿地具有极高的生态、资源、环境、科研、休闲旅游价值，是高生产力、高生物多样性的生态系统。和国外的大型滨外坝——潟湖湿地不同，我国的潟湖湿地一般面积较小，相对而言环境演变较迅速，因此潟湖湿地又是进行湿地形成演变和湿地退化研究的绝佳场所。 山东半岛濒临渤海和黄海，海岸线长而曲折，潟湖湿地资源丰富，共发育有潟湖湿地近60个。根据潟湖湿地的水文特征，将其划分为咸水潟湖、半咸水潟湖、淡水潟湖和干出潟湖四种类型。经计算，自虎头崖到岚山头的港湾海岸岸线全长2021.4km，潟湖岸线总长580.4km，占岸线长度的28.7％，远高于全球平均值。由于自然演变和人为盲目开发利用，目前潟湖湿地生态环境恶化趋势日益严重，湿地资源遭受到极大的破坏并濒于消亡。潟湖湿地退化所引发的一系列生态环境问题已经成为制约区域经济发展的一大障碍。研究潟湖湿地的发育过程，探讨环境退化原因，分析潟湖湿地退化下的生态环境效应，并提出可持续发展策略，对于保护和合理开发利用潟湖湿地资源具有重要意义。 朝阳港潟湖位于山东半岛东北角，是山东半岛诸多潟湖中所遭受到的人为干扰活动最强的潟湖湿地之一，潟湖近期演变比较剧烈，湿地退化较严重。本文以其为重点研究对象，以2002年现场调查为基础，结合历史资料，分析了朝阳港潟湖湿地的生态环境状况；对所取岩芯做了沉积物粒度分析、孢粉分析、微体古生物分析，同时结合测年数据，研究了朝阳港潟湖在垂向上所指示的沉积环境信息，探讨了朝阳港潟湖的形成和演变规律；根据景观生态学原理，研究了近几十年来朝阳港潟湖湿地的景观格局变化，并分析了人为作用在潟湖湿地景观变化中所起的作用；探讨了导致潟湖湿地退化的主要原因及其影响机制，综合评价了潟湖湿地的退化程度；分析了朝阳港潟湖湿地退化下的生态环境效应，提出了湿地退化的防治对策和可持续发展建议。 朝阳港渴湖湾口朝北，由一条狭窄的水道与外海相通，面积约1300hm2。朝阳港渴湖水体较浅，平均水深在lm以内，渴湖中部是宽广平缓的潮滩，组成物质主要是细砂，向潮滩边缘泥质成分渐多，在渴湖边缘发育有沼泽。四周陆地地貌为剥蚀低丘和准平原。受水分、盐度和土壤特性的影响，湿地植被群落类型较少，渴湖湿地生境较为简单，湿地自我调节功能和抗外力干扰能力十分弱，生态系统极不稳定，显示出高脆弱性。 经数据统计，山东半岛的大多数渴湖是在6000一400Oa B.R间开始发育的。根据钻孔资料揭示，在5000一4000a B.P.左右，朝阳港附近地区气候温暖、略湿，抱粉组合以栋属一松属一篙属一水龙骨科一禾本科为主，并含有少量淡水介形虫，沉积环境为半咸水渴湖沼泽环境;在4000一1 500 a B.P.年间，气候温暖，此时植被以栋属一松属一篙属一黎科一禾本科一刺球藻为主，软体动物为菲律宾蛤仔、异白樱蛤、古氏滩栖螺和多形滩栖螺，沉积环境为经常受海水淹没的潮间带环境;1500 aB，P.之后，气温略为下降，植被以松属一栋属一篙属一黎科一水龙骨科为主，沉积环境为渴湖沼泽相沉积环境，和前阶段相比海面相对稳定或略微下降。 朝阳港渴湖湿地的演变过程可以划分为四个阶段:(1)古海岸线形成阶段。(2)水下沙坝发育阶段。(3)青矶岛连岛坝发育阶段。(4)现代渴湖湿地发育阶段。在20世纪中期青矶岛基本与陆地相连。青矶岛连岛坝形成后，坝后渴湖被分割为朝阳港渴湖和小海渴湖两个渴湖，朝阳港渴湖口门处次生沙嘴不断发育，渴湖口门进一步封闭。 景观生态学是湿地研究的热点领域之一。在景观生态学研究中，景观格局与变化过程是主要研究内容。根据朝阳港渴湖湿地的开发与利用状况，选取1954年、1971年、1983年三期1:5万地形图和2002年现场调查资料，利用GIS技术对朝阳港渴湖湿地的景观格局变化进行了分析。在朝阳港渴湖湿地中，自然景观主要为渴湖浅滩、沼泽湿地和河口湿地;人工景观主要是养殖池、盐田和农用地。从1954年到2002年，朝阳港渴湖的自然湿地逐渐被改造为人工湿地，人工湿地面积增加了532腼2，湿地景观格局发生了很大的变化，景观多样性和均匀度增加，优势度下降。从1954年到2002年，朝阳港渴湖总体斑块密度从0.0174个爪mZ增加到0.0346个小mZ;廊道密度从0.6954m小mZ增加到22.0564m小mZ，景观破碎化程度呈递增趋势，显示出人为干扰程度的不断增强态势。 当前山东半岛渴湖湿地正面临着面积萎缩和生态环境恶化等严重问题。在导致渴湖湿地退化的诸多因素中，围垦、污染、城市建设、渴湖淤积、海岸侵蚀和海面上升等是主要因素。这些环境因素对渴湖湿地的作用方式和影响程度是不同的，而渴湖湿地在这些影响因素作用下的退化程度也不尽相同。根据综合评价指数法等方法，对山东半岛的6个渴湖湿地的退化程度进行了定量评价。评价结果显示，朝阳港渴湖是环境退化比较严重的渴湖湿地之一。导致渴湖湿地退化的最主要、最直接的原因是人为因素，而自然因素对湿地的作用往往因人为因素的?更多还原

【Abstract】 Lagoon is one of the most important types of coastal wetlands, which is separated from open sea by sand spits, sandbars or barriers. It is also an important type of ecosystem with great values in terms of natural resource, tourism, environment and scientific research. Because of their smaller area and shallower water, lagoonal wetlands along Chinese coast are more sensitive and fragile to external environment loads than those large barrier bar-lagoon wetlands (such as those in North America), and they are favorite places for studying wetland formation, evolution and degradation.There are up to 60 lagoonal wetlands along Shandong Peninsula, they can be classificated into four types according to hydrologic characteristics: seawater lagoon, brackish lagoon, freshwater lagoon and drying lagoon. The total length of the lagoonal coastline in Shandong Peninsula is 580.4km, up to 28.7% of the coastline from Hutouya to Lanshantou. Lagoonal wetland possess very abundant resources and instinct ecosystems, which are under the threat of degradation by natural forces, such as global changes, and human’s inappropriate development activities. The degradation and loss of lagoonal wetlands have resulted in eco-environment problem and become an obstacle to regional economic progress. The study on lagoonal wetland’s formation, evolution, causes of wetland environmental degradation and their effect on eco-environment are very significant for lagoonal wetland resources protection.Located at the northeastern Shandong Peninsula, Chaoyanggang lagoon is one of those suffering from human forcing, and seriously experiencing degradation and loss of wetlands along Shandong Peninsula coast. A multi-principle field investigation was conducted in 2002, the collected data and historical information were used to study theecological environment of Chaoyanggang lagoon. Comprehensive core sample analyses were carried out back to the laboratory, including grain size analysis with Mastersizer2000 Laser grain size analyzer, spore-pollen and microfossils analysis of 27 samples, 14C dating of 2 samples. This information was used to study the sedimentary environment, formation and evolution of the lagoon. With principles of Landscape Ecology, the landscape pattern changes in the latest several decades were studied, as well as the human’s activities impact on landscape changes. The origin of this lagoonal wetland degradation was studied, and the level of the wetland degradation and loss was assessed. Based on the degradation and loss of the wetland, eco-environmental effects were analyzed and countermeasures were suggested for wetland protection and regional sustainable development.Chaoyanggang, surrounded by low hills, is a closed shallow water lagoon, connected to the open sea only through a narrow inlet. It is about 1300 hm2 in area and an average water depth less than 1 .0m. The center of the lagoon is wide shallow tidal flat, comprised by fine sands, and mud component increase outward, and the edge is salt marsh, mainly dominated with phragmites. Limited by hydrology, salinity and soil character, the wetland habitat structure is very simple, and only few vegetation communities can be found. Self-adjusting capability of this lagoon is weak and the ecosystem is very instable, vulnerable to outer disturbances.Most lagoonal wetlands along Shandong Peninsula were formed since 6000-4000 aB.R. According to core information, at 5000~4000a B.P., this area was warm and humid, sporopollen assemblages were dominated by Quercus -Pinus- Artemisia-Polypodiaceae - Gramineae, freshwater Ostracoda was also found in the core, indicating a brackish lagoon-marsh coastal sedimentary environment. Between 4000 and 1500 aB.R, the sporopollen assemblages were dominated by Quercus - Pinus - Artemisia -Chenopodiaceae - Gramineae - Hystrichosphera, Hystrichosphera, Mullusca, such as Ruditapes philippinarum, Macoma incongrua, Batillaria cumingi and Batillariamultiformis were found too, indicating a sedimentary environment submerged by tidal water frequently, and the clima更多还原