浅析城市绿化中的生态问题.doc

/ /浅析城市绿化中的生态问题一、美于城市绿化的定位A positioning and us in the urban greening近年来，人们对城市绿化在城市建设中功能的认识，已经由是可有可无的点缀、装饰提高到具有城市形象的美化、文明的象征及生态环境的改善等多种功能的认识。这是一个很大的进步，城市绿化也因此受到各级领导重视，它的地位得到了很大的提高。但是，城市绿化主要功能究竟是什么？我们认为有必要从本质上。来认识，才能有助于对它正确定位。In recent years, people to the understanding of the function in the construction of urban greening in the city, already is the ornament of dispensable, adornment to have the image of the city beautification, the symbol of civilization and the improvement of the ecological environment and other functions. This is a great progress, urban greening has been leaders at all levels attach great importance to, its status has been greatly improved. But, what is urban greening main function? We think it is necessary from nature. To get to know, can help to correct positioning for it.城市绿化是伴随着城市化的进程而产生的一个破坏自然的过程的逆向过程；因为原有的大片森林被砍伐，大量农田被占用，代之以柏油马路、钢筋水泥、混凝土结构的建筑物和桥梁，这些无生命的城市基础设施，构架了城市人群生存的空间。因此，城市绿化是把被破坏的自然通过人工再创造的“第二自然”，也是一个与城市化进程同时产生的逆向过程，所以绿地系统应是城市人工生态系统中极为重要的组成部分。城市绿地在植物群体的生长发育的过程中动态地改善了城市的生态环境，提高了人们的生活质量，并成为保护生物多样性的基地；城市绿地系统在整个城市中起着最活跃、最积极的作用是任何其它城市基础设施所不能取代的。因此，城市绿化最主要的功能应该定位在生态上，而在发挥生态功能的同时，绿化也必然能展示其形态美和动态美，成为美化城市的有生命的景观；在文化领域中缘文化早就是我国传统文化的重要部分，它有着悠久的历史，具有民族的及地方的特色，成为当前精神文明的重要内容。因此，城市绿化的主要功能定位在生态上，同时兼有其它多种功能，是完全符合城市可持续发展的战略方针及方向的。Urban greening is accompanied with the process of urbanization, resulting in a reverse process of destruction of nature; Because the original forests have been cut down and lots of farmland occupied, replaced by asphalt, concrete, reinforced concrete structure buildings and Bridges, the inanimate city infrastructure, architecture is the urban population living space. Therefore, urban greening is the destruction of nature by artificial to create second nature , is a with the urbanization process at the same time produced by the reverse process, so the green space system should be a very important component of urban artificial ecosystem. Urban green space in the process of plant community growth dynamically to improve the urban ecological environment, improve peoples quality of life, and become the base to protect biodiversity; Urban green space system in the citys most active, most positive role was not replace any other urban infrastructure. As a result, the most main function of urban greening should locate on the ecosystem, while in play ecological functions at the same time, green also inevitably can show their beauty and dynamic beauty form, become beautify the city landscape of life; Edge in the field of culture and culture is an important part of traditional culture in China long time ago, it has a long history, ethnic and local characteristics, has become one of the important content of spiritual civilization. Therefore, the main function of urban greening positioning on the ecology, and other functions at the same time, is completely in line with the strategy and direction for the sustainable development of city.二、城乡协调发展是城市绿化的指导思想Secondly, the coordinated development of urban and rural areas is the guiding ideology of urban greening100余年前（英）霍华德发表明日的田园城市一文，该文是作者在工业快速发展，形成了城乡对立，并由此产生了一系列社会问题的背景下，提出了为了人民必须城乡协调发展的田园城市规划思想：城市和农村要给予人民社会的爱和自然的爱。霍华德认为一个中心城市必然有与它相联系的卫星城市群落，即大都市圈的规划构思；认为城市各分支系统一住宅、工厂、道路、绿地、学校等通过重新有序组合，更能自我完善，自我生存，更具活力；城乡应视为一个整体，城市周围的农村则是其支撑系统，它们的土地分配比例应为1：5，城市为1，农村为5.由此，城市绿地系统规划也应该参照上述思想，使农村在绿地建设面积上、数量上大于城市数倍才能同样成为城市的支撑系统，同时在城市或城镇外围以永久性绿带来隔离，防止城市摊大饼式的向外扩展，而城市中央应有大型的绿地，如美国纽约中央公园、伦敦中心自然公园等思想。霍华德田园城市规划思想不仅对城市总体规划的构思有实用价值，也对绿化的规划有直接的和现实的指导意义。Howard (British), more than 100 years ago, published the rural cities of tomorrow, this article is the author in the rapid industrial development, formed the urban and rural areas, and under the background of the resulting a series of social problems, put forward to the people have to the coordinated development of urban and rural areas of rural urban planning ideas: urban and rural areas to give peoples social and natural love. Howard thought a city centre must have satellite city community associated with it, namely, the planning idea of metropolis circle; Think a city branch system houses, factories, roads, green space, schools, etc by orderly combination, self improvement and self existence, more dynamic; Shall be regarded as a whole urban and rural areas, rural is its support system around the city, their land allocation proportion should be 1:5, city is 1, rural 5. As a result, urban green space system planning should also refer to the above thoughts, make the rural area, the number is greater than the urban green space construction several times to also become a support system of the city, at the same time in the city or town in permanent green brings isolation, prevent city booth pie type of outward expansion, while the central cities should have a large green space, such as New Yorks central park, natural park, in central London, etc. Howard rural urban planning thought not only has practical value to the overall urban planning conception, also for greening planning has a direct and realistic significance.三、构建城乡一体化的生态绿网为缓解城市的大气污染特别是热岛效应。Three, building urban and rural integration of the ecological green network to ease the atmosphere pollution of the city heat island effect in particular.发挥城乡绿化的整体性和系统性的功能，大城市（特别是特大城市）的绿化建设应以绿色廊道（简称“绿廊”）建设为主体。绿廊指的是从农村开始，经过城市的中心区穿越热岛再进入农村；沿途将“园”（指块状绿地）、“楔”（指楔形绿地）、“环”（指环状绿带）、“廊”（指绿色廊道）连接成生态绿网。绿廊的宽度不小于50m，其中可包括建筑物（但不含成群的高层建筑）、道路和河流；绿廊应以常缘阔叶树种为主、有建筑物处应有多层次的立体绿化（屋顶的及垂直的绿化），使之成为高绿量的绿带，其绿化覆盖率不低于50%，绿廊间距以23km为宜；绿廊的布设原则，一是整体性指城乡一体化，二是方向性绿廊应顺应本地区盛行的风向设置；三是针对性一方面绿廊应把现实的和规划的大型绿地（公园、居住区绿地、单位附属绿地等）连接起来；另一方面应有意识穿过城市生态环境负荷重、热岛效应严重及旧区改造等地区，使之真正担负改善城市生态环境质量的责任；四是可行性绿廊布设应沿河沿路，可操作性强且可水绿结合推动河道及道路的整治。Play a holistic and systematic function of urban and rural greening cities (especially in megacities) greening should take the green corridor construction (hereinafter referred to as the green corridor) as the main body. Refers to the green gallery began, the rural via central zone of the city through the heat island and then into the countryside; Along the way will garden (refers to the massive green space), the wedge (refers to wedge green space), the ring (ring green belt), gallery (point to) of green corridor connects into ecological green network. Green corridor width not less than 50 m, which may include building (but not including) groups of high-rise building, roads and rivers; Should with margin broad leaved tree species often give priority to the green gallery, there are buildings should be multi-level three-dimensional green, roof and vertical greening), make it become the high green green belt, the greening coverage is not lower than 50%, the spacing between the green gallery with 2 3 km advisable; The layout principle of the green gallery, one is integrity refers to the integration of urban and rural areas, 2 it is directional pergola should conform to the prevailing wind direction setting the region; Three is focused on the one hand, the green corridor should be realistic and planning of large green space, parks, residential green space, units affiliated green space, etc.) connected; On the other hand should have consciousness through the city ecological environment load weight, heat island effect is serious and old district reconstruction and other regions, make it really improve the urban ecological environment quality of responsibility; Four is feasibility of green corridor layout should be along the road along the river, strong operability and aqua green regulation of river and road.通过绿廊纵横布设形成的生态绿同才能发挥农村对城市的支撑系统的功能，达到以绿制热、以绿净污，达到改善城市生态环境的目的，这也是落实霍华德城市规划思想的重要举措。Through vertical and horizontal layout form the green gallery of ecological green with to develop the function of rural supporting system of city, to achieve green heating green clean dirt, achieve the purpose of improving urban ecological environment, it is important measure of urban planning implementation of Howard thought.以上海为例，在外环线以内的绿廊布局，其方向为近南北向和近东西向，交织成网，近南北向和近东西向绿廊各9条，主干绿廊共6条，内环线以内的三纵、三横主。干道一致，应首先实施。绿廊纵横于城乡、浦西浦东、环内环外，绿廊相互交织成一个具有整体、系统性的生态绿网，它们的建成将把郊区和海上的冷湿空气带进城市，又能对城区热中心进行分割疏解。In Shanghai, for example, within the outer ring of the green corridor layout, its direction is nearly north-south and nearly east-west, interwoven into a network, nearly north-south and nearly east-west pergola each article 9, the trunk green gallery, a total of six, three vertical and three horizontal main within inner ring. Trunk road is consistent, should be implemented first. Existed in urban and rural areas the green gallery, pudong and puxi inner ring ring, pergola interwoven into a whole, the systematic ecological green net, they will built in the suburbs of the cold wet air and sea brought into the city, and the heat center split relief in urban areas.四、区系结构和群落结构Four, the floristic structure and community structure城市绿化的基础是植物，而植物是自然界中的一员，如何运用植物材料再现城市中的“第二自然”，是长期存在没有妥善解决的问题。其最主要的原因是，人和自然的关系没有处理好。虽然谁都能接受“人与自然和谐相处”的口号，但在城市绿化的实践中，是人居于自然之上还是尊重自然，顺应自然规律真正做到人和自然关系很和谐呢？是个值得深思的问题。Urban greening is the basis of plant and plant is a member of the nature, how to use plant materials represent the citys second nature, is a long-standing not properly solve the problem. Its the main reason is that failure to deal with the relationship of between man and nature. Although anyone can accept the slogan of harmony between man and nature, but in practice, urban greening is above nature and respect nature, comply with the laws of nature actually do the relationship between man and nature is very harmonious? Is a problem worthy of thinking deeply.植物生长的分布区域有明显的地带性，它随地理区域、气候带、地貌等不同而有区别。我国幅员辽阔，地形复杂，形成了不同的气候带，中国的植物分布（简称植挪就可分成温带、暖湿带、亚热带、热带等八个植被区划，我国各个城市均处于不同的植被区划地区范围之内。所选用的植物应该尊重其具有地带性的特性。然而在城市绿化的历史上却常常发生跨越地带的错误，大量引种最后遭到多次失败的教训，在一些大中城市中并不少见。以上海为例，大规模引种了适应在较高纬度的华北地区生长好的加拿大杨及二次引种适应在低纬度华南地区生长的检树，结果均全军覆灭。事实上，上海地处中亚热带北缘，为常绿阔叶与落叶阔叶混交林的过渡地带，根据前几年对上海城市绿化最常见的乔木和灌木树种调查，前者有68种，后者有105种，上海可用于绿化的植物材料都是很丰富的，当前应该深入到江、浙一带属本地带的区域去挖掘、去发现，先引到城市环境中来种植，成功的就可推广应用，这样才能体现上海城市绿化的特色。Plant growth have obvious zonal distribution area, its different over a geographical area, climate, landscape, etc. And theres a difference. Chinas vast, complex terrain, has formed the different climatic zone, plant distribution in China (hereinafter referred to as Noah can be divided into temperate, warm wet zone, subtropical, tropical. eight vegetation regionalization, cities in China are in different vegetation regionalization region scope. The selection of plants should respect its zonal characteristics. However, in the history of urban greening often occur across the areas of errors, introduction last lesson by many failures, in some large and medium-sized cities are not uncommon. In Shanghai, for example, large-scale introduction adapted to grow in the high latitudes in north China to Canada and secondary introduction Yang tree at low latitudes grow in south China, the results were all found. In fact, Shanghai is located in the subtropical north rim, evergreen broad-leaved and deciduous broad-leaved mixed forest transition zone, according to a few years ago in Shanghai urban greening trees and shrubs of the most common tree species, the former has 68 species, which has 105 kinds of plant materials can be used for greening in Shanghai are very rich, the current should be go to jiangsu, zhejiang area with a local area to dig, to find, first to urban environment to grow, success can be applied, so as to reflect characteristics of Shanghai urban greening.植物在城市绿化的立地条件中发挥其功能，还必须遵循“适地适树”的生态原则，这个原则包含两个内容：一是指必须应用地带性植物；二是指必须适应城市特殊立地条件的植物种。这里重点指后者。如行道树先要按地带性原则选定树种，再要它在立地条件最差环境生长发育，但对它的功能要求却最高。人们常强调后者，而不注意创造有利于行道树生长发育人工可以改善的立地条件，对于因此而生长欠佳的树种又不能用两分法评价，而是一有缺点就全盘否定。所以，在一些城市存在着随便更换行道树种的问题，如在上海的一条道路，解放以来换的树种就达十余种之多，甚至连世界著名行道树种之一的法国梧桐，也因其“冠”“法国”两字在五十年代末被认为是崇洋了媚外，曾一度被否定，当时外省市公。郑付情地大批运走，在那里发挥了良好的绿化功能。这就是为什么行道树种从南到北不少城市几乎都以“四大件”当家，即法国梧桐、雪松、广玉兰、香樟，使城市绿化面貌显得很单调，而长成大规格的行道树却寥寥无几的根本原因，历史事实证明，只要对城市特殊立地环境及养护管理稍加改善，在一般的城市中，可以选种的行道树种至少有十余种，可以更好地发挥其绿化功能。再有，从园林绿化设计风格上也很难看到各地曙二自然“的特色。近年来；建筑业的欧陆风刮到了城市绿化中来，不管大城市、小城市都风行从国外进口草种大铺草坪，在有的地方甚至拔掉大树铺草坪，在人们心目中城市绿化的现代化就等于铺设草坪。我们不否认城市需要一定数量的草坪创造开敞绿色的空间，为市民提供良好的活动场所这是必要的。经过实践，人们开始意识到过多的草坪不仅因其生态效益小于同面积上种植的树木，而且投入和以后的管护工作量均大大超过后者，因此，多种乔木的决定是非常正确的；还要在主要景点移栽些大规格的乔木以显示大城市美丽的形象，也是需要的。但是，大规格甚至特大规格的乔木是在自然界人。十年才形成的自然资源，将其移栽到城市的特殊环境中来，要求保证成活而且还要求保持原来高大的树干和宽阔的树冠的外形就一定要有严密的技术措施和足够的资金。因此，根据我国的资源、资金、技术力量等实际情况应该严格控制数量，防止再次刮风。Plants in urban greening plays its function, site conditions must also follow to the optimal tree ecological principle, this principle includes two contents: one is the zonal plant must be applied; The second is refers to the special site conditions of the plant species must adapt to the city. Here mainly refers to the latter. Such as roadside zonal principle, according to the selected tree species, the first to have it in the site conditions of the worst environment growth, but for its functional requirement is the highest. People often emphasized the latter, and do not pay attention to create conducive to the growth of trees artificial can improve the site conditions, for which poor growth of tree species and cannot use dichotomy evaluation, but will negate the shortcomings. In some cities, so, there is literally replace the doers of the word tree species of problems, such as a road in Shanghai, since the liberation in alone more than 10 kinds of tree species, and even the world famous French phoenix tree, one of the doers of the word tree species, and also because of its crown French two words in the 50 s is considered to be the worship of foreigners had been negative, the other provinces and cities. Zheng pay sentiment and a large number of away, played a good greening function there. Thats why trees almost all cities from south to north, with four big charge, namely, French phoenix tree, cedar, magnolia, camphor, make the urban greening landscape appears very monotonous, and grow into the root cause of the large size of only a few trees, historical facts have proven that as long as a little improvement on special site environment and urban maintenance management, in general, in a city can cultivate the trees, there are at least more than 10 kinds of can better play to its green function. Again, from the landscape design style is hard to see on the start around the second nature . In recent years; the construction of Europe land wind scraped city virescence, no matter popular in big cities and small cities are imported from abroad the lawn grass big shop, shop in some places even pulled out the tree lawn, the modernization of urban greening in peoples heart is to lay the grass. We do not deny that cities need a certain number of lawn create open green space, provide good places for citizens that is necessary. In practice, people began to realize that much of the lawn not only because of its ecological benefit is less than the area planted with trees, and investment and future work of the management are significantly higher than the latter, therefore, a variety of trees decision is very correct, but also in the main attractions in transplanting some large size tree to display the city image of beauty, is needed. However, large size and large specification of trees is in the nature person. Ten years to form the natural resources and to transplant it into the citys special environment, demands to ensure survival but also keep the original tall tree trunks and wide canopy appearance must have strict technical measures and enough money. Therefore, according to the actual situation of resource, capital, technical strength of should strictly control the number, to prevent the wind again.当前，有些城市提出把“森林引进城市”的口号，我们认为这个口号更加贴近自然“，更易被城市的人们所接受。”森林“不是一株株大树的机械总和；而是乔木、灌木、草本、地被组成的植物群落，它们与微生物、动物及周围环境共同组成一个系统的和有机的整体。这种森林型的植物群落占用土地少，能充分利用地下和地上部分的自然资源（如光、热量、水分、矿物质等），在同样的空间叶面积指数最多、绿量最大，所产生的生态效益最高。因此，在人多地少的大城市中是最适宜的。At present, some cities put forward the slogan of forest in city, we think it is more close to the slogan natural, are more likely to be accepted by urban people. Mechanical combined forest is not the skeletons of the tree; but arbor, shrub and herb, and composition of plant community, they with microorganisms, animals and the surrounding environment to form a system and an organic whole. This type of forest plant community occupy less land, can make full use of underground and overground part of natural resources (such as light, heat, water, minerals, etc.), leaf area index in the same space, green quantity is the largest, most have the highest ecological benefits. Therefore, in much fewer people in the big cities is the most appropriate.如何实施把“森林引进城市”的措施呢？不是真的把一座森林搬进来，而是应该到属本地带的自然界去调查植物群落的种间组成及其空间结构，再在城市内调查保留有15年以上历史的人工或自然植物群落；通过分析总结，提炼出符合项极群落原理的植物群落，在城市绿化的规划设计中逐步形成以稳定的、优化的植物群落为基本单元。因为它们不仅有本区域41植物地带性的特征，而且，绿量高、生态效益显著，又能为动物提供栖息、繁植的场所，成为生物多样性的基地，还为城市中人们创造一个回归自然的美好意境。How to implement the measures of forest in city? Not really put a forest, moved in, but should go with a local nature of the investigation of plant community species composition and spatial structure, and within cities survey reserves have more than 15 years history of artificial or natural plant community; Through the analysis summary, extracted conforms to the biggest community of the principle of plant community, gradually formed in the planning and design of urban greening in stability, optimization of plant community as the basic unit. Because they not only have 41 plant zonal region features, and high quantity of green, ecological benefit is remarkable, and provide habitats for animals, numerous plants, and b