绿道规划可持续性的探索

Envisioning for Sustainable Approach in Greenway Planning
Interview with Prof. Jack Ahern

编者按：由美国马萨诸塞大学风景园林与规划系筹办、中国《风景园林》杂志社任支持媒体的2013年法布士国际绿道会议①于2013年4月14日美国马萨诸塞州阿莫斯特圆满落下帷幕。大会以绿道的多尺度体现、绿色生态网络的新解决方法、绿色基础设施的运用等为主题。来自23个国家的绿道专家、学者参与了会议，发表了他们对于绿道现状及发展的见解并分享了他们在参与的各个国家的绿道建设时积累的经验。法布士会议的主要发言人杰克 · 埃亨（Jack Ahern）教授以国际视角谈论了绿道现状的议题。本刊社长何昉先生也作为中国绿道建设和景观规划的代表在会议上做了精彩的发言。

会后，本刊特约美国马萨诸塞大学风景园林专业研究生、助教、2013年法布士绿道国际会议演讲者之一的黄伊伟对杰克 · 埃亨教授进行了访谈，探索他眼中绿道规划的未来走向。杰克 · 埃亨教授是美国风景园林师协会（ASLA）常任理事、美国风景园林教育委员会(CELA)常任理事、美国马萨诸塞大学国际项目副教育长、美国马萨诸塞大学风景园林专业终身教授。

采访及撰稿：黄伊伟
Interviewer and Author: HUANG Yi-wei

《风景园林》：您能简要地谈谈美国绿道规划的历史进程么？

杰克 · 埃亨：绿道是一个很新的概念，从“环境保护运动”时被提出到现在仅仅20到30年的历史。那时人们开始了解规划中生态的重要性，也开始了解景观中连通的重要性。随后绿道的概念由本地组织、环保团体、当地规划师“自下而上”的开始发展起来。他们建立了连接公园、栖息地、娱乐场所、自行车道的系统，并将其命名为 “绿道”。随后这个词开始成为流行文化的一部分，变得越来越被人熟知。人们开始对这个概念感兴趣，绿道也随之发展起来。正因为绿道是个非常简单而且容易被人理解的概念， 所以一些建成的案例使人们对绿道的兴趣也更为浓厚。

查尔斯·利特尔的《美国绿道》②介绍了整个“绿道运动”的历史，也给出了他自己对于绿道的定义。而当我在做关于绿道的研究时，我尝试分析各个不同的人对于“绿道”的解释，然后尝试为“绿道”下一个我认为比较全面的定义——它需要包括连接性、多功能性以及可持续性。在这之中，还是有很多变化的，比如一个自行车道就可以是一个绿道。这是一种只专注于娱乐性和交通性的绿道形式。

《风景园林》：在其他一些国家，有些绿道的建设只专注于自行车道。这样的绿道是为了连通城市与郊区，他们主要强调交通功能，但是生态功能就不是那么重要。绿道可以只强调其中一个功能么？还是建立一个绿道需要考虑所有的功能？

杰克 · 埃亨：在我看来都可以。它可以是一个不拥有生态效应的自行车道。而辩证地来看，它其实也有生态效应。 如果有更多的人骑自行车，那么就有更少的人使用私家车, 于是污染会减少，温室气体也会减少，也就不用再建那么多的高架桥。所以间接来看，自行车道也有生态效应。

不过我认为对于风景园林工作者和规划者来说，增加绿道的多功能性是很重要的。因为如果它可以提供更多功能，它便更有可能可持续地发展。如果它只是一个自行车道，那么拆掉它非常简单。但是如果它是一个连接了野生动植物栖息地，或者连接了雨水管理系统的自行车道，那么现在我们有很多理由不能拆掉它。有一些人会因为它对栖息地的贡献而珍视它，有一些人又会因为它的水利功能想保护它。如果把这些理由都放在一起，你就有了一个强有力的支持，而这些支持会让这个绿道存在得更久。就好像波士顿的“翡翠项链公园”， 它不仅仅提供游玩的功能，还有对水利功能的贡献，也许这也是其中一个它能留存到现在的原因。

《风景园林》：在法布士国际绿道会议中，您在演讲中提到了很多关于气候变化的现象。在您看来，绿道规划会对气候变化问题提供帮助吗？

杰克 · 埃亨：是的。它有潜力做到。它不会是解决气候变化的答案，不过它会有助于我们解决气候变化问题。我们来想一想，绿道可以提供交通形式的多种选择。在一个像中国这样的国家，想要通过绿道来解决所有的交通问题是不可能也不现实的。十几亿人口不可能只通过自行车上班或者购物。但是，如果有一定比例的出行可以通过自行车实现，而骑自行车并不会产生温室效应气体，那么这就是其中一种减缓气候变化的方式。人们少开车，温室气体的排放量就不会上升，气候变化会趋于平稳。这是其中一种方法。另外，绿道也可以和一些能够减缓气候变化的项目相连。有很多海边的城市希望通过建造新的，更能抵御洪水、飓风或者台风的海岸线，这样的海岸线是线性的，而绿道，本来就有可以通过建造被赋予防御洪水的功能，还可以为它（海岸线）提供其他的功能，比如交通、动植物栖息地等等。这是另一种方式。同样的，绿道的构成包含很多树木，绿道能帮助让城市绿起来，增加绿荫覆盖率，也能减少城市热岛效应。所以这些不同的方法有一些可以减少气候问题，我们叫它缓解策略；或者是适应气候变化造成的结果，叫做适应策略。

《风景园林》：在这次会议中，有很多来自不同国家的专家学者, 比如说意大利、希腊、中国等等；而您也曾在您的论文中多次提到其他各国的绿道案例，比如说荷兰、葡萄牙的绿道系统。那么在您看来，绿道会因为融合各个国家的文化而变得各不相同么？

杰克 · 埃亨：是的。绿道有一个很重要的功能就是文化资源和文化特性的展现。所以绿道应该来源于文化，也应该反映所在国家的文化。绿道并不是一个美国的独有概念然后强加在中国或者欧洲的国家上，它其实是一种策略。在我的的一篇论文《绿道作为规划策略》③中，它拥有建立绿色网络的规划功能。当你把绿地变成一个绿色网络后他们会工作得更好，也能提供能多的功能。

《风景园林》：在一篇关于朱利叶斯 · 法布士的采访中，他提到说“绿道是更加自然的过程，而非人工化的概念。”

杰克 · 埃亨：我很同意，因为环境并不是随机的。在自然环境中，有一些地域的环境价值高，也有一些地域的环境价值不那么高。这些高环境价值的地域大部分都在廊道中。这是一个来自威斯康辛州菲利普-路易斯的著名实验：他在整个州的地图中标记不同的资源——防洪图、栖息地、历史保护区、濒危物种等等，当他把所有这些地图重合在一起，他发现大部分的资源都集中在廊道上。所以说，当你保护了这些重要的廊道，你其实是在用最少的土地来达到最高的生态效益。绿道本来就趋向于遵循原就是线性的景观和特征。比如海岸线、河谷、山脊。我在广东深圳看到的绿道就是遵循着山脉而建。广东的绿道对野生动植物很有生态益处，同时也为人们提供了视觉享受。当你爬到山顶，你可以看到整个城市。所以当你连接这些山脊顶，你可以将它变为一条绿道。

《风景园林》：在我们探讨广东绿道之前，您能为我们简单地谈一下新英格兰绿道规划④么？在法布士国际绿道会议上，很多专家是初次了解这个规划项目，而他们也表现出了很大的兴趣。他们认为这个项目取得了很大的成功。

杰克 · 埃亨：也不尽然。新英格兰绿道规划是1999年马萨诸塞大学设计的。总的来说这是一项 “自下而上”的工程。他们聚集了来自不同州的人们，然后绘制出了所有的绿色资源。因为有的时候工作在一个地方的人们并不知道其他的人在做什么。所以这一举措帮助人们更好地了解发生在周边的其他项目，让人们了解到绿道的效益，也让人们看到大尺度绿道连接的可能性和重要性。而其中一些项目得以继续，比如说马萨诸塞州西部的康涅狄格河流绿道规划。我们州政府的环境署，现在的娱乐和环境保护部门，致力于设计康涅狄格河流绿道州立公园已长达20年。他们总是会走出去看一看在康涅狄格河畔有哪些可以被保护的区域。但是新英格兰绿道规划并不那么成功，是因为它是一个非官方的规划。它是一个自下而上的基层的规划，从没有被这些州政府官方采用。一个绿道能真正实施，是需要两个方向的共同作用的。它需要“自下而上”，需要这些本地的规划师去设计游线、连接栖息地，然后政府可能会说：“这很重要，我们更宏观地来看，我们可以拨款，我们来把它推广下去。” 所以仅在马萨诸塞州州内来说，康涅狄格河流绿道规划是一个好的例子。但是当我们上升到整个新英格兰地区时，并没有人继续完成这个工作让这个规划完整。

《风景园林》：在中国，如果想要建设一条绿道，主要需要的是“自上而下”的策略。

杰克 · 埃亨：对。我认为广东绿道是“自上而下”的。这是很一个有意思的对比。

《风景园林》：在您看来广东绿道的建设成果如何呢？而它在未来又会面临怎样的挑战？

杰克 · 埃亨：看到这个结果我还是很惊叹的。广东绿道的建设投入了大量资金和精力，在短时间内完成了很多工程。我认为，这是很重要的，也是令人激动的。这个项目很可取，因为中国的一切都发展得很快，那么中国在环境保护上的快速发展也变得更重要——我们需要加快脚步，因为机会正在消失。当新的城市建设开始启动，高速路、水陆管网建成后，有些机会就会消失了。这个（广东的绿道建设）非常迅速，而且是自上而下的。

我认为，如果有一些挑战的话——当然这是我不太清楚的——我认为挑战可能是这个绿道如何被本地组织或者是非政府组织所支持。 比如说自行车爱好协会，他们就可以帮助维护绿道，也可以继续拓展绿道，因为他们知道绿道的好处，或者是钓鱼爱好者、登山爱好者，又或者是鸟类爱好者。如果这些有着不同爱好的人们能因为绿道聚集起来，那么你就构建了一个民众参与和支持的观念。而这些是非常有帮助的，因为他们让这个想法得到延续。再过50年，还有多少人们会谈论绿道？我们不得而知。但是如果更多的人们参与进来，那么这个想法会延续更久。而等到这个提议在政策上都得到了认同，那政府也许会说：“我们需要绿道”。那么这一切都会自然发生了。如果没有这些本地组织的支持，10到20年之后，也许政府就不会这么说，那么绿道这个概念就被遗忘了。

《风景园林》：在整体全球环境背景下，您如何看待绿道的未来发展呢？绿道会在发展中国家产生更大的影响么？

杰克 · 埃亨：我们希望是这样的，因为绿道是能让城市变得可持续化的答案之一。这不是因为我喜欢绿道，而是因为绿道可以提供使用价值。而这个使用价值也可以被称为生态系统功能。人类都依赖于它。如果城市想要长期处于健康，它一定要有干净的空气、清洁的水源，而这也需要绿色生态设施去完成。绿道可以成为其中的一部分，其他类型的绿色设施也可以成为一部分。但是绿色基础设施有时是散布在城市各个地方而没有连接的。而生态教会我们的道理是有连接的地方生态效益才高，有系统有网络的地方才有效率。所以同样面积的土地连接它会对人类提供更大的功能和帮助。如果你只有10%的绿地，确保它是连接的而不是散落的也同样重要。而不幸的是，在发展中国家，人们思考更多的是短期发展。他们还没有眼光，或者智慧，或者知识，来让他们想得更远。他们需要存活，比如南美的棚户区、非洲的非正规建设和贫民窟、中国的城中村，这些都是快速建设并且环境资源几乎丧失的地方，因为那里的人们不明白环境的重要性。这样的情况下教育和政府的支持就非常重要。其中在贫民窟人们不保护绿地的原因是没有人让他们这么做。

《风景园林》：所以我们（风景园林工作者）的角色是让政府知道他们这样做是正确的。

杰克 · 埃亨：对。这是我们风景园林系在做的事情，也是我们在新英格兰绿地规划中倡导的。我们希望能倡导这样的想法，然后解释给人们听，不是用“这是规定你必须遵从”的自上而下的方法，而是去启发人们让他们知道自己自发地去做。如此，政府无需强制施压给人们，人们会自觉遵守，因为他们知道什么才是重要的。（完）

 

Landscape Architecture: Can you briefly describe the history of the greenway planning process in the U.S ?

Jack Ahern: “Greenways” is a recent term, maybe 20-30 years old, developed from Environmental Movement, when people learned about ecology in planning, and started to understand the value of connectivity in the landscape. Then the greenway idea emerged mostly from the “bottom up”-from local organizations, environmental groups, local planners. They make a system to connect parks, habitats, recreation areas and bike trails, and they called it a greenway. So the word start to be used in popular culture, and it caught on. People became interested in this idea and then it started to grow. Because it’s a simple idea that people could understand and as example start to be completed, interest was raised for the idea. A good reference for this is the book by Charles Little, called the “Greenways for America”, and he describes the history of the greenway movement and he gives some of his definitions of greenways. When I did research on greenways, I tried to analyze the definitions of different people, and I try to propose my own definition of the elements that I believe greenways should include, which include connectivity, multi-functionality and the connection with sustainability. Then within that, there is a lot of variations, a bike trail can be a greenway. That’s a greenway that focused mostly on recreation and transportation.

Landscape Architecture: Some of the greenways in other countries just focus on the bike trails; the greenway has been used to connect the urban area to the suburban area, which concentrates more on the transportation aspect. But what about the ecological aspect, can greenway just focus on one aspect? Or building a greenway has to take every aspect into consideration?

Jack Ahern: I think it can go either way. It has value to have a bicycle trail, with no ecological function. Arguably, it has an ecological function. If more people ride bicycles, less people ride cars. Less pollution less greenhouse gas for climate change, then there is no need to build so many highways. So in indirectly, a bike trail has ecological benefits. But I think it’s important for designers and planners to think about the possibility to add different functions to greenways so that they can provide multiple functions. When greenways can provide multiple functions, they are more likely to be sustainable. If it is only a bike trail, it’s very easy to remove it. But if it is a bike trail connects to wildlife habitat, or it connects to storm water management, now there are a lot of reasons for that Greenway. Some people will appreciate it, for the habitat, some for the water functions. If you put them together, you have a strong base of support, and that it’s more likely to keep the greenway active for a long time, like the Emerald Necklace. It is not only a recreational park; it also has a hydrology function. So that’s probably one of the reasons that it is still there.

Landscape Architecture: In the Fábos Conference, you gave a speech mentioned a lot of problems on climate change. Do you think greenway planning can really function in climate change?

Jack Ahern: It has potential to do that. It’s not going to be the solution, but it can contribute to the solution. If we all think about it, greenways can provide alternatives modes of transportation. In a country like China, you can’t have the greenway handle all the transportation. It’s not realistic to think about that. More than one billion people cannot all on bicycles to going work and shop. But a certain percentage of trips can be on bicycles, and that does not produce any significant greenhouse gas. So that’s one way in terms of mitigation of the causes of climate change. People driving fewer cars, then less greenhouse gas is going up. Then climate change can be stabilized. Greenway can also be connected to climate mitigation projects. A lot of coastal cities are looking to build new shorelines that are less susceptible to damages from storms- from flooding, from typhoons or hurricanes. The shoreline becomes a linear feature, and greenway, by having the feature that’s built provide for flood protection, you can add other functions to it-transportation, habitat, that’s another way that they can help. Also in effect greenway can include a lot of trees, the greenways help to green the city, increase the percentage of the tree canopy and that will also reduce the urban heat island effect. So all these different ways can contribute to either reducing the problem of climate change, that’s called mitigation or adapting to the result of climate change, that’s called adaptation.

Landscape Architecture: In this conference, many experts are coming from different countries, like Italy, Greece, China etc.; and you mentioned a lot of case studies in your papers like the Netherland greenways and Portugal greenways. So do you think greenway will become diverse when it mixes with other countries’ culture?

Jack Ahern: Yes. One of important functions of greenways is the cultural resources and cultural identity. So the greenway should come from the culture and should reflect the culture of the country. It is not an American idea that should be imposed in China or European countries. It is rather a strategy- that’s what I called in one of my papers “Greenway as the Planning Strategy” -it’s a way to do planning to provide the function of a network that’s a green network. When you can connect green areas into a green network and they function better and provide more functions.

Landscape Architecture: And in one of Julius’s Interview, he mentioned that “the greenway is a more natural process. It is made by nature not by artificial methods”.

Jack Ahern: Exactly. And the reason for that is because the environment is not random. The environment has areas of high environmental value, and areas with values that are not so high. And the areas of high environmental values tend to be located in corridors. This is a famous study by Phil Lewis from Wisconsin where he made the map of the whole state and he mapped all the resources from flood plans, to habitat, to historic locations, and to rare species. When he overlaid these, he found out that most of them are concentrated in corridors. Therefore, by protecting those corridors, you are protecting a high percentage of valuable landscapes and you can achieve the most benefit by the least amount of land. So the greenways mostly tend to follow features of the landscapes that are already linear. Like coastlines like river valleys, and like ridge tops. The greenway I saw in Guangdong province in Shenzhen follow along the top of the mountains. That has important ecological functions for wildlife. It also provides visual benefits, when you up high, you have a nice view of the city. And when you can connect those ridge tops, then you can turn that into a green way.

Landscape Architecture: Before we get into the Guangdong greenway, can you talk a little bit about the New England Greenway Vision Plan? Many experts in this conference are first to know this vision plan, they are excited about it and they think it is a huge success.

Jack Ahern: Yes and no. Yes, the New England Greenway plan was produced in 1999 by Umass. They did mostly bottom up grass root work. They have people worked in every state, and they mapped all the greenway resources. Because sometimes people would be working in one place, they wouldn’t know what somebody over here was doing. So they help people to learn about other projects, and they help people to understand the value of the greenway, and they help people to see the possibility and importance of making a larger scale of connection. And some of this has continued, and a good example is in Western Mass, the Connecticut River Greenway. Our state Environmental Management Department, now it is called (Department of) Conservation and Recreation, they have been making the Connecticut River Greenway State Park for twenty years. They are always going out and looking for land along the Connecticut River Corridor to protect.

But the New England Greenway is not so successful, because it is a non-official plan. It was a grass root bottom up plan, but it was never adopted by all of the States officially. If you need the greenways really work, you need both. You need bottom-up, you need local planners to build trails, to connect habitat, and then you can have the State says: “oh, this is important, let’s look at the bigger picture and let’s give some money to this and let’s try to improve it.” So the Connecticut River is a good example, inside one State, only in Massachusetts. But when we jumped into New England, there is nobody really continuing to look into that and make that happen.

Landscape Architecture: In China, if you want the greenway idea to be happened, you need mostly “top-down” way.

Jack Ahern: Yes, I think the Guangdong Greenway is more “top-down”. That’s an interesting comparison.

Landscape Architecture: And how do you think the outcome of Guangdong Greenway? And what challenges it might face in your point of view?

Jack Ahern: It’s very impressive to see the result. And there is a lot of money and a lot of pressure to do it very quickly. So a lot was happening on that. And I think, that’s important and exciting. That is commendable because things are happening so fast in China, then it is important to make environmental protection happen fast-to keep up because opportunities disappear when new development comes, highways are built, rivers are put into pipes, the opportunities can disappear. It’s going very fast, and it’s top-down. And I think the challenge-and this is where I don’t know-I think the challenge is for that greenway to be supported by more local groups. Inside the cities and maybe NGOs-people who would like to ride bicycles, they can help to maintain the greenway, or to keep expand it, because they know it. Or people interested in fishing, or people interested in hiking, or people who would like to watch birds. If you can get all these different people together around the idea of greenway, then you are building popular involvement of supporting the idea. And this will help because the idea has to be sustainable. In fifty years, will people still talk about the greenway or not? We don’t know. If more people are involved, more likely, they will! And then if the political, the moment that the idea is politically interesting, the government is saying we have to have greenways. And so, it’s happening. In 10 or 20 years, the government might not say that, then the idea can be forgotten, if it does not have the grass root support.

Landscape Architecture: What do you think is the future development of the greenway in terms of the whole global environment? Will the greenway planning have more impacts in developing countries?

Jack Ahern: We hope so, because the greenways are part of the solutions to make city sustainable. Not just because I like greenways, but because greenways can provide functions. And the functions can also be called ecosystem services. And everybody depends on those. If cities are trying to be clean and healthy throughout the long term, it has to have clean air, it has to have clean water, and it need green infrastructure to do that. Greenways can be a part of that, and other types of green infrastructures can be part of it. But green infrastructures can be random and distributed all over the city, not connected. That’s what ecology has taught us that there is a value of connectivity, and there is a value of systems and networks. And when the same amount of green space is connected, it can provide more functions and services to people. It’s more efficient. If you have 10% green space, it’s very important that it’s connected rather than fragmented.

So unfortunately, in the developing world, people think more short term. They don’t have the vision or the wisdom or the knowledge to think long term. They need to survive. Like favelas in South America, informal development and slums in Africa, and urban villages in China, these are examples of rapid developments where environmental resources tend to be completely absent, because people don’t understand the value of them. Education and government support is very important. One of the reasons that people in slums don’t protect green areas is because nobody makes them.

Landscape Architecture: So our (the landscape architects) role is to persuade the government that it is right to do so.

Jack Ahern: Absolutely. That’s what we do in our department, and that’s what we did in the New England Greenway Plan and we try to articulate the vision and explain to people and not as a top-down-here is the law you have to follow this-but to inspire people so that they want to do it themselves. And then it’s not the government just pushing people, but it’s people doing it on their own, because they know why it’s important. (END)

 

注释：

① 法布士国际绿道规划大会以“美国绿道之父”朱利叶斯·法布士教授（Julius Fábos ）之名来命名，每3年举行1次，是以风景园林和绿道规划为主题，以齐聚来自本地以及全球各国专家研讨为目的的聚会。

② 英文原名 “Greenways for America”, 作者Charles E. Little. The Johns Hopkins University Press.

③ 英文原名 “Greenways as a Planning Strategy”, 见Landscape and Urban Planning, Special Greenways Issue. 33:1-3, pp. 131-155.

④ 新英格兰地区由位于美国的东北部的康涅狄格州、马萨诸塞州、伏蒙特州、新罕布什尔州、罗德岛州和缅因州所组成。新英格兰绿道规划原名 “New England Greenway Vision Plan”. 是1999年马萨诸塞大学风景园林与规划系在庆祝美国风景园林师协会100周年庆典时提出的概念性规划。网址为：http://www.umass.edu/greenway/index.html