首页 >> 推荐阅读 >> 正文

译:Stretching city limits (2)

来源: 时间:2010-10-10 12:04:00 点击:

Jared Green: Climate change is expected to cause mass migrations of animal and plant species. What design solutions can aid migration?


In the conclusion of a two-part interview with Jared Green, Kristina Hill forecasts a changing relationship between urban dwellers and local wildlife – and argues clever landscape design has a crucial role in species preservation.

Kristina Hill: The most important planning and design strategies for biodiversity involve first protecting the land that has been conserved to date in two ways. Number one, by adding buffer zones to their edges, within which development is restricted or prevented. This is especially important on northern-aspect slopes, where characteristic regional species are more likely to persist in an era of increasing dryness and temperature extremes. Second, educating the public about the importance of reducing the negative impacts of what landscape ecologists call “the matrix” – which includes all the developed landscapes outside the reserves.

This is a strategy ecologists sometimes call “reducing matrix hostility”. It basically means that even developed landscapes can contribute to the overall ability of a region to support sensitive species that lived there before development occurred. When each developed parcel manages the quality and quantity of its storm-water runoff, for example, it contributes to a healthier landscape with sustained regional biodiversity. Improving air quality can make it possible for insects to locate and pollinate plants in developed landscapes. Reducing noise on roadways can benefit frogs that use sound in mating behaviour in wetlands nearby. Building wildlife over- and under-passes can allow animals to migrate and disperse through heavily developed landscapes.

In addition, climate change creates an imperative to add corridors and stepping stones at all spatial scales. As the ecologist Stuart Pimm has pointed out, it’s more efficient for species to move up by hundreds of feet of elevation as a way of staying cooler than it is to move tens or hundreds of miles north to get the same benefit. But going up in elevation is like walking the plank, because it means there is less area available as the species go up and the solution is limited by the maximum height of the hills or mountains available.

The biggest questions involve timing. If species characteristic of a region start to die out, will species that could survive the new seasonal conditions be able to get there, find suitable locations, and successfully reproduce before they die out in their own regions? When will the species that are their food be available locally? When will new predators, parasites and competitors also move in? It’s a very complicated four-dimensional chess game.

JG: In downtown Chicago and other cities, coyotes and other wildlife have been found digging through dumpsters in the subway and inside supermarkets. What kind of designs can aid animals that have taken up urban living because of changes in their natural environments?

KH: That’s an interesting question, from a strategic point of view. Species that are already thriving in urban environments or begin to do so in the future may not need our help, since they are finding ways to survive by themselves in human-dominated environments. They may, however, provoke new attitudes, ethical debates and management relationships. I think that’s the really interesting part – will our cultural attitudes towards these animals change? Perhaps even our sense of what it means to be human among other species may change. What would happen if an animal that represents a threat to our children becomes able to thrive in urban areas?

Coyotes are probably expanding their urban populations not just because of lost habitat outside cities, although that may be a factor in some areas, but also because of changes in their behavioural traits. They are becoming habituated to human presence as they increasingly subsist on a diet of wasted human food and cats. Juvenile animals learn from their mothers and their peers how to find food and den sites, and what dangers to avoid. They’re also learning that toddlers are not dangerous, and may be prey. Over the next few decades, we may have to learn to design deterrents and exclosures – fences or something equally effective — that keep coyotes out of areas where small children play, rather than design habitat for coyotes in cities. We may eventually even need to hunt coyotes to keep their urban populations small, and remind them that humans should be avoided.

Will urban people learn new things about their relationship to other species? It’s hard to fully appreciate how much that could change our self-image as urban people, over a long period of interaction.

JG: Storm-water overflow from cities presents a major problem for natural fish habitat in surrounding areas. You have cited projects in Seattle that can help ensure fish eggs don’t get flushed away during rainstorms. How can infrastructure be designed to be wildlife-friendly?

KH: Before I give examples to answer this question, I want to point out that “infrastructure systems” include the point-of-use of resources (inside buildings, for example, where electricity is consumed) in addition to the transmission networks that convey resources from a place of abundance to a place of scarcity in relation to demand. These systems also include the landscapes that support the place of abundance, both inside and outside urban areas, headwaters and tributaries that drain to reservoirs, for instance. Our focus on the networks for conveyance – pipes, overhead powerlines, highways and seawalls – when we conceive of infrastructure has drastically reduced our ability to imagine options for making cities and their supporting regions more resilient.

If infrastructure projects protect vulnerable people – especially poor families – and special places, like north-facing slopes, or headwaters of stream systems or estuary “nurseries” for fish and shellfish, that’s the first performance issue. The second is that these projects should contribute to the renewal of basic resources (soil fertility, air quality, water quality, etc.) and not reduce the supply of these. Finally, the third is that they should contribute to re-tooling our ways of moving things around, so that we are more resilient to extreme environmental events and increasing fuel costs.

Transit, parks and new shoreline structures that provide habitat while protecting property and utilities all look like better investments using the criteria I’ve noted above. To me, being “wildlife-friendly” isn’t the point – it’s about supporting ecosystem resilience, with humans recognised as an integral component of those ecosystems. Empirical observations and models support the conclusion that many species will become extinct or rare because of climate disruptions and increased urbanisation over the next several centuries, no matter what designers do today. The real trick is to act ethically as human beings in the midst of those larger trends, advocating to protect what we can and increase our ecosystem-level resilience over time.

The port of Antwerp [in Belgium] has implemented a strategy that provides an interesting example for infrastructure and wildlife. Biologists and planners collaborated there to identify a “habitat backbone” system of permanent wetlands to support habitat for natterjack toads. But they added the idea that port landscapes with shifting, temporary uses can also play an important role in providing temporary habitat, as part of what landscape ecologist Richard Forman once called the “shifting mosaic” of a landscape. It’s possible that many other species could be supported in and around urban areas by providing both a core habitat area and temporary zones available in different seasons or in different years.

The Bay Area Conservation and Development Commission in San Francisco is studying ways to respond to increases in sea level while supporting species that live in the Bay, using a mix of artificial marshes and hardened shoreline structures. The Dutch are experimenting with a strategy they call the “sand motor”, in which they would place dredged sand in an artificial mini-peninsula along their coast and allow the processes of wave action and along-shore currents to redistribute it as massive sand dunes to protect their coast. I believe that this sort of “cyborg landscape” strategy, combining artifice and natural processes, holds the most promise for supporting biodiversity while achieving human goals – not the least of which might be gaining an aesthetic that appreciates processes and change. If humans see change as beautiful, adaptation will be easier.

(译文如有出入请联系本会,来源于chinadialogue)

译  文:

规划城市适应气候变化(2)

  在杰瑞德•格林访谈的结论部分,克里斯蒂娜•希尔预言,城市居民与当地野生动植物之间的关系会不断地发生变化。她认为,明智的景观设计在物种保护上起重要作用。


  杰瑞德·格林(以下简称“格”):气候变化有可能会导致动植物物种的迁移。什么样的设计解决方案可以为这种迁移提供帮助呢?

  克里斯蒂娜·希尔(以下简称“希”):对于生物多样性来说,最重要的规划和设计战略是首先通过两种方式保护目前所保存的土地资源。第一种方式:在这些土地的边缘增加缓冲区,在缓冲区内,限制甚至禁止土地开发。这对于北向坡面尤其重要,因为当面临干旱和极端气温的时期,地区特有物种极有可能在这样的地区生存下来。第二种方式:教育公众,使其认识到降低景观生态学家所说的“矩阵”的负面效应的重要性。“矩阵” 包括保护区之外所有被开发的景观。

  生态学家们有时称这一战略为“减轻矩阵的敌意”。它的基本含义是,景观即便被开发了,也仍然能够提高某一地区保护开发前曾在此地出现过的敏感物种的整体能力。比如说,当每个已开发的地区能够管理其暴雨径流的质量和数量,它就为保持具有可持续的区域物种多样性的景观地貌做出了贡献。提高空气质量可以帮助昆虫在被开发的景观地貌中找到植物,并给植物授粉。降低公路上的噪音可以使湿地附近利用声音辅助交配活动的青蛙受益。为野生动物建设专用的地下通道或者高架通道可以帮助动物们穿越过度开发的景观地区进行迁移或者分散。

  此外,在气候变化的驱使下,在各个空间尺度上增加走廊和石阶成为迫在眉睫的任务。正如生态学家斯图亚特·皮姆所指出的那样,为了保持凉爽,物种向上迁移几百英尺要比向北迁移几十或几百英里的效率要高得多。但是,向高处迁移如履薄冰,因为这意味着随着各个物种向上迁移,可利用的面积越来越小,这一方案受制于山脉的最高高度。

  时机是最大的问题。如果一个地区的物种特性开始消亡,那么那些能够适应新的季节条件的物种能够坚持到目的地、找到合适居住的场所、并成功地繁殖后代吗?它们能够在当地获得食物吗?新的捕食者、寄生生物、竞争者何时能够到达?这如同一个非常复杂的四维象棋游戏。

  格:在芝加哥以及其他一些城市的市中心,人们发现地铁、超市的垃圾桶被土狼等野生动物挖穿。什么样的设计能够帮助到那些由于自己栖息的自然环境改变而过起了都市生活的动物?

  希:这个问题从战略的角度来看很有趣。那些已经或者将要在都市环境中滋润地生活着的物种或许不需要我们的帮助,因为他们自己能够在人类主导的环境中找到适合自己的方式生存下来。然而,他们或许会让我们产生一种全新的态度、引起伦理道德方面的争论、以及导致新的管理关系的产生。我认为这是真正有趣的部分 – 从文化的角度而言,我们对这些动物的态度会发生改变吗?甚至于,在众多物种中,我们作为人类究竟意味着什么的感觉都会发生变化。如果一种对我们的孩子构成威胁的动物能够在城市里安家落户,那么将会发生什么?

  或许土狼群在都市里不断壮大并不仅仅是因为它们在郊区的栖息地不复存在。尽管在某些地区这确实是一个因素。但是,也有可能是由于它们的行为习惯也发生了变化。它们对人类的出现已经逐渐的习以为常,因为它们越来越依赖人类食物残渣和猫为食。动物幼崽从它们的母亲和同伴身上学习如何寻找食物和栖息之地、如何躲避危险。它们也了解到小孩子并不危险,而且或许是一顿美味。未来的几十年内,我们也许不得不学习设计障碍物和围栏 ——栅栏之类的东西 – 从而保护儿童玩耍的场所不受到土狼的侵袭,而不需要为土狼在城市里设计栖息地。或许我们最终不得不采取猎杀土狼的方式以控制它们在城市中的数量,并让它们明白应该对人类敬而远之。

  城市里的人们会从他们跟其他物种之间的关系中学到新的东西吗?在长期的互动过程中,我们很难完全明白我们作为都市人的自我形象会如何被改变。

  格:来自城市的暴雨洪灾给周边地区的鱼群自然栖息地带来了很大的问题。你曾经提到过西雅图有一些可以帮助确保鱼卵不被暴雨冲走的项目。我们应该如何设计出对野生动物友好的基础设施呢?

  希:在我举例回答这个问题之前,我想指出“基础设施系统”除了包括将资源按照需求从资源丰富的地方传输到资源稀缺地的传输网络,还包括使用点的资源(例如:使用电力的建筑物内)。这些系统还包括保护城市内外资源丰富地的景观地貌,例如:向水库排水的源头和支流。当我们构想基础设施的时候,我们将重点放在了管道、空中输电线、高速公路、防波提等传输网络上,这严重地降低了我们的想象力,使我们很难构想出能够使城市及其周边保护地区具有更强抵御能力的方案。

  如果基础设施项目能够为容易受灾的群众——尤其是贫困家庭,以及特殊地区,例如北向坡面、水域体系的源头、以及鱼类和贝类位于河口的“幼儿园”等提供保护,那么这就是第一个表现方面的问题。第二个问题是这些项目应该为基础资源的恢复(土壤肥力、空气质量、水源质量等)做出贡献,而不是减少这些资源的供给。最后,第三个问题是它们应该有助于改变我们的应对方式,当我们面对极端的环境事件、以及不断增加的燃油成本时,我们具有更强的恢复能力。

  交通、公园、新的海岸线结构一方面提供栖息地,另一方面也能够为财产和公共事业设施提供保护。用我上面提出的标准来衡量,这些似乎都是更好的投资。对我来说,“对野生动物友好”并不是关键,关键是能够为生态系统的恢复提供支持,并将人类作为那些生态系统不可分割的一个组成部分。经验观察和分析模型均支持这样一个结论:无论今天的设计者做什么,许多物种都将由于未来几个世纪的气候破坏和城市化扩张而灭绝或者变得稀有。真正的办法是在这些更广泛的趋势当中,按照人类伦理道德的标准去行事、提倡保护我们所能保护的,并逐渐增强我们生态系统级别的恢复能力。

  (比利时)安特卫普港已经实施了一个战略,为基础设施和野生动植物提供了一个有趣的范例。生物学家和规划师共同在那里寻找一个永久湿地的“栖息地支柱”体系,从而为黄条蟾蜍的栖息地提供支持。但是他们又有了新的想法,认为作为地貌生态学家理查德•福尔曼所说的地貌“动态镶嵌”的一部分,间或使用、或临时使用的港口地貌也可以在提供临时栖息地方面扮演重要的角色。通过提供一个核心的栖息地区以及在不同季节或者不同年份提供临时区域,许多其它物种也可以在城市及城市周边地区获得保护。

  旧金山海湾地区保护和发展委员会正在研究如何通过人工湿地及海岸线固化结构相结合的手段在保护海湾地区物种的同时应对海平面上升。荷兰正在试验他们所谓的“沙地运动”战略。他们将挖掘出的沙子沿着海岸线铺在一个人工半岛上。这些沙子在海浪运动及沿岸流的作用下,重新分布,形成许多大型的沙丘,从而可以保护他们的海岸。我认为,这种将人工和自然相结合的“半人工景观”战略是最有希望在满足人类的目标的同时保护生物多样性的手段。至少,这一战略从变化和过程中感受到了美的存在。如果人类能够从改变中发现美,那么适应变化就会容易得多。

 

 

浙江正泰公益基金会 浙ICP备11034570号 2000-2011 THE COMMONWEAL FOUNDATION OF CHINA
浙江省杭州市下城区中山北路598号西子花园柳莺苑11B 热线电话:0571—89710110 89710106 邮编310014 电子邮箱:dtxd@ztgy.org