【作者】 蔡春菊；

【导师】 彭镇华； 王成；

【作者基本信息】 中国林业科学研究院 ， 森林生态学， 2004， 博士

【摘要】 本文在分析城市森林发展历程及建设现状的基础上，总结了国内外城市森林发展的经验和我国城市森林发展中的问题，系统阐述了我国城市森林的发展动向，并重点论述了城市森林的潜在发展空间和发展规划问题。并以扬州市为案例，采用遥感与实测相结合、定性与定量相结合的方法，系统分析城市森林景观格局、结构与功能及其存在问题，量化了城市森林发展指标、建成区城市森林空间利用现状及发展潜力。在此基础上，参照城市总体规划，完成了扬州城市森林发展规划，并为我国经济发达地区中小城市的城市森林发展提供了依据。主要研究结果： 1．明确了城市森林发展是一个动态的、开放的发展过程，具有明显的尺度性，城市森林的发展受城市地区乃至外围区域景观格局的影响。在宏观区域尺度上，是中国森林生态网络体系中重要组成要素，是改善区域生态环境的重要内容；在城市景观尺度上，城市森林是城市中有生命的基础设施，是城市环境可持续发展的保障，是实现“人与自然和谐发展”的重要纽带；在城市森林组成上，又是以自然景观为依托、以树木为主体建立起来的近自然森林生态系统，是协调城市空间、改善城市生态环境、突出城市个性的重要手段。 2．我国城市森林发展时间不长，问题较多，但为保证我国城市森林持续健康发展，当务之急需要解决： ①完成与城市发展同步的城市森林生态规划。从宏观上合理布局城市森林，为解决未来城市发展中环境负效应预留出必要的城市森林发展空间。文中立足城市发展过程，系统分析了我国城市森林规划中存在问题及解决对策；全面总结城市森林数量控制依据，建立了以结构指标为主体，满足城市森林现状及分布格局、规划控制、发展评价等不同阶段和目的的评价指标。 ②挖掘城市森林发展潜力空间，提高空间利用效率，确保城市森林实现功能和效益最大化。针对我国城市绿化用地不足等的问题，详细论述城市绿化发展的潜力空间，强调科学布局城市森林，确保城市林木健康生长，是实现生态功能的最大发挥、营造高质量城市绿色空间的根本出路。 3．以遥感卫星影像为数据源，GIS与景观格局分析相结合，对扬州市域土地利用格局及森林景观进行分析，得出：景观类型总体发展不平衡，整个扬州区域是以水田和城镇与农村居民点以及水域等少数景观类型为主体构建起来景观格局；其它景观类型面积小，连通性差，破碎化程度高；森林资源总量贫乏，破碎化程度高，分布不平衡，78.54％的片林集中分布在小范围的丘陵区。受城市建设扬州城市森林发展研究等人为活动强烈干扰的影响，市区水体、林地、沼泽地等自然景观破碎化程度明显升高;建成区城市绿化总体水平较高，但布局上不均匀，小型斑块所占比重大，破碎化度高;植物配置生态关联性不强，总体上森林的作用还不强。 4.利用TM6热红外遥感影像和NDvl指数图，结合实地测定，从城市森林的降温效应和森林空气负离子浓度两方面研究城市森林功能。结果显示:城区热中心明显，热场存在明显的梯度分布;城市热辐射值与NDvi指数表现为显著线性负相关:城市森林改善城市热环境决定于城市森林总面积和大面积片林的数量;城市森林面积越大，以高大乔木为主体构成的近自然林，改善小环境效果越明显;而以草地和移植大树及新栽树木为主体，短期内人为组合成的所谓的“森林”，既使表观上绿化覆盖度高，但从生态功能发挥上，远不及近自然林。 5.首次对城市森林绿化空间利用率进行量化，实测城区森林群落植物生长，建立主要绿化树种的生长模拟方程，并探讨了扬州城市森林绿化空间发展潜力。计算扬州建成区城市森林空间利用率为24.19%，不同类型绿地的空间利用率 由高到低的次序为:公园>防护绿地>道路绿地>生产绿地>单位绿地>小区绿化。绿化空间占有率与常用的绿地率在表征城市绿化水平上反差较大，相比之下，绿化空间占有率比绿地率更能评价出城市绿化质量优劣，同时提出了绿地率评价城市绿化的不足，强调了城市森林建设中绿化大乔木的作用。现有城市绿地中，87%的绿地面积还存在不同程度的空间发展潜力。 指出高大乔木在城市绿化中所占比例是决定城市绿化空间发展潜力的决定性因素，人为修剪严重影响树冠体积和功能发挥。建议扬州城市森林逐步建立起以乡土大乔木为主体、布局合理、特色鲜明、多元配置的城市森林模式，将有效提高城市绿化空间利用。 6.采用碳氧平衡法、氧气需求法、热中心补偿法、生态闭值法和现状反推法5种方法量化了扬州不同尺度范围城市森林最小需求指标，确定了以森林面积和林木覆盖率为主的建设指标，明确了区域城市森林的开放发展对策。 7.在城市景观格局分析、生态环境问题分析和城市森林结构与功能研究的基础上，全面把握城市生态格局和生态建设需求，以林网化一水网化为规划理念，突出“水乡生态”与“历史文化名城”两大特点，点、线、面结合，在市域范围内提出了“两带、两片、三网”的城市森林总体布局，实现2020年扬州市域森林覆盖率达20%;市区以古运河为文脉，提出“一环、四楔、两廊、多核”的建设布局，规划完成后，实现市区绿地率达45%，绿化覆盖率50%的?更多还原

【Abstract】 Urban Forests are receiving more and more countries’ recognition throughout the world. Based on the reviews of Urban Forest studies, this dissertation analyses developing process and construction status of Urban Forest. By summing-up construction experiences of Urban Forest both in China and at abroad and by putting forward the main existing problems, the author expounds systematically on developting trends, with stressed discusses on spatial potency for constructing and planning Urban Forest. The case study is in Yangzhou city. With the combined technique of 3S and measurements on the spot, in the method of qualifying and quantifying, the landscape patterns, structures and ecological functions of Urban Forest in Yangzhou City are systematically analyzed, and the existing problems are put forward as well. In this dissertation, the total developing indexes of Urban Forest are quantified, and the special-utilization status and potential space for Urban Forests in built-up area are studied. Based on the above studies, and with reference to the lately finished urban development planning and with respect to the environment background needs, the author accomplishes Urban Forest developing planning in Yangzhou city of its own characteristics. The study will provide good reference to Urban Forests developments of small and medium cities in economically well-developed regions of China. The main results are as follows:1. Urban Forests development is a dynamic and opening process. It is influenced by urban environment and outer landscape patterns. Urban Forests have typical scale characteristics. On the macro region scale, Urban Forests are one of the most important elements and significant contents of Chinese forest Eco-network system. On the landscape scale, Urban Forests are the vital and basic establishment of city, and guarantee of urban environment sustainable development. Meantime, the buildup of Urban Forests as trees as main body, relying on nature landscape, can not only improve urban ecological environment, but also stand out city features, with urban landscape inline.History of Urban Forests development in our country is about fifteen years. There have being appeared some problems during the development course. But two important questions are to be solved urgently to assure a healthy and sustainable development of Urban Forest in China.(1) Simultaneous development of Urban Forest ecological planning and urban construction. In order to solve the negative affect caused by urban development, Urban Forests are required to be allocated scientifically on macro-scale and reserves enough expandable space ahead of schedule. In the article, the author summarizes existing problems and countermeasures in Urban Forests planning. Based on the reviews of Urban Forest area control, the dissertation establishes indicator system, dominated by Urban Forests structural indexes, adaptive to multi-aims evaluation of landscape patterns, planning control and development process in different stages for sustainable development of Urban Forest in our country.(2) Exploring the potential space and improving the space utilization for the best Urban Forest functions and benefits. The shortage of urban greening land use has restricted Urban Forest development. How to take full advantage of Urban Forest space is the most important question. The ultimate way out is to build the high quality Urban Forest through scientific layouts and well protection of trees in good growth condition.3. With ETM image as data resources, combined with GIS and analysis of landscape pattern in Yangzhou city, the dissertation studied the land use pattern, forest landscape attributes. The result indicates that the overall development of landscape is out of balance. A few huge patches such as paddy field, city and county patches and water area mainly occupy the whole region. Other landscape types have little proportion in area but poor in linkage and high in fragmentation. The total forest resources in Yangzhou city are deficient and imbalanced. 78.5 percent of Woods con更多还原