Designing Greenways: Sustainable Landscapes for Nature and People

Designing Greenways: Sustainable Landscapes for Nature and People

by Paul Cawood Hellmund, Daniel Smith
     
 

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How are greenways designed? What situations lead to their genesis, and what examples best illustrate their potential for enhancing communities and the environment? Designing greenways is a key to protecting landscapes, allowing wildlife to move freely, and finding appropriate ways to bring people into nature. This book brings together examples from ecology,… See more details below

Overview

How are greenways designed? What situations lead to their genesis, and what examples best illustrate their potential for enhancing communities and the environment? Designing greenways is a key to protecting landscapes, allowing wildlife to move freely, and finding appropriate ways to bring people into nature. This book brings together examples from ecology, conservation biology, aquatic ecology, and recreation design to illustrate how greenways function and add value to ecosystems and human communities alike. Encompassing everything from urban trail corridors to river floodplains to wilderness-like linkages, greenways preserve or improve the integrity of the landscape, not only by stemming the loss of natural features, but also by engendering new natural and social functions. From 19th-century parks and parkways to projects still on the drawing boards, Designing Greenways is a fascinating introduction to the possibilities-and pitfalls-involved in these ambitious projects. As towns and cities look to greenways as a new way of reconciling man and nature, designers and planners will look to Designing Greenways as an invaluable compendium of best practices.

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Editorial Reviews

The Nature of Cities

"Designing Greenways remains valid as a great contribution and provides a practical guide for planners, landscape architects, educators, students, citizen groups and conservationists to move from theory to action."
Natural Areas Journal

"Designing Greenways presents a practical, applied approach to greenway design within a context of sound science...Greenways are shown to be an excellent vehicle for environmental education and environmental art...Designing Greenways is a well-written scientific and social survey that describes how greenways can be a part of sustainable landscapes."
Landscape Ecology

"The ample use of figures and photographs to support the text makes the book eminently readeable. Tables provide fingertip summaries of data. ...the early chapters...provide clear and complete synopses of the history of greenways and the benefits of preserving swaths and stringers of the landscape for ecological and social benefits. This is the sort of book that will become, over the years, a dog-eared favorite in many land use planners' personal or professional libraries."
Chicago Botanic Garden Lenhardt Library's Current Books

"the reader will appreciate the need for well-designed green corridors that improve the quality of life."

Product Details

ISBN-13:
9781597265959
Publisher:
Island Press
Publication date:
07/10/2006
Sold by:
Barnes & Noble
Format:
NOOK Book
Pages:
288
Sales rank:
1,094,240
File size:
5 MB

Read an Excerpt

Designing Greenways

Sustainable Landscapes for Nature and People


By Paul Cawood Hellmund, Daniel Somers Smith

ISLAND PRESS

Copyright © 2006 Paul Cawood Hellmund and Daniel Somers Smith
All rights reserved.
ISBN: 978-1-59726-595-9



CHAPTER 1

INTRODUCTION: GREENWAY FUNCTIONS, DESIGN, AND HISTORY


Greenways and Landscape Integrity: An Overview

Greenways are being designated in cities and countrysides throughout North America and elsewhere. Sometimes these conservation areas are a response to environmental problems, such as flooding or degrading water quality. Other times their creation is an act of pure vision—people imagining a better community—one where people and natural processes coexist more closely. Often, despite this recent popularity, people fail to recognize the full range of contributions greenways can make to society and the environment. It is as if open spaces, especially in metropolitan areas, have been thought of as just so much generic greenery, mere backdrops for people's activities.

In this chapter we suggest why greenways are deserving of their newfound popularity and how their functions can be enhanced, but also consider their limitations. We discuss how the greenway concept came to be, how it has been defined, and how its spatial form and content have varied. We also highlight the significant social and ecological functions of greenways, in advance of a fuller discussion of greenway ecology and design in subsequent chapters.


Greenways Vary Widely in Type and Name

Greenways are bands on the landscape, designated for their natural or recreational resources or other special qualities. Greenways—known by a variety of monikers (table 1.1)—straddle waterways, traverse ridgelines, and sometimes cut across the landscape independent of topographic features. They range from narrow urban trail corridors to winding river floodplains to very wide, wildernesslike landscape linkages. Although they exist in varied landscapes, from cities to farmland to commercial forests, historically they have most frequently been created in suburban areas. All greenways have in common their linearity and official designation, or at least popular identification, as distinct areas of the landscape with recognized qualities.

People have been setting aside greenways of various sorts for more than one hundred years. In North America in the late 19th and early 20th centuries, parkways—early prototypes for greenways—were created to connect urban parks. During the same period, broad greenbelts were designed to encircle some cities and limit urban sprawl. In the 1960s, citizens, ecological planners, and landscape architects recognized the need to protect waterways and other corridors that included a high concentration of important natural features. More recently, natural scientists and conservationists have considered the significance of corridors for wildlife management and biodiversity protection. Social scientists have explored how greenways affect things such as economics, community and civic life, and social interaction among diverse users. At the same time, citizens, alarmed by the rapid loss of open space to development, have expressed strong desires for opportunities for outdoor recreation near where they live.

Ideally, greenways are corridors of land and water (and networks of such corridors) designed and managed for multiple purposes, such as nature conservation, recreation, stormwater management, community enhancement, social equity, and scenery protection, with an overall aim of sustaining the integrity of the landscape, including both its natural (biophysical) and social components. The term greenway has gained wide acceptance among landscape architects, greenspace planners, conservationists, and citizen groups. But the terms used to identify greenways and other greenspaces are used imprecisely. This confusion is apparent in the range of terms shown in table 1.1.

Networks of greenways are sometimes known as green infrastructure—"interconnected networks of green space that conserve natural ecosystem values and functions and provide associated benefits to human populations." In Europe greenway networks, along with the nature reserves they connect, are likely to be known as ecological networks, even if their purpose is more than just nature conservation. In this book we primarily use the terms greenway, the more encompassing greenspace (rather than the vague open space, green infrastructure, and ecological networks.


Greenways Help Retain or Re-Create Important Landscape Functions

A greenway exists within a landscape. Many landscapes today, especially those on the urbanizing metropolitan fringe, are being transformed dramatically. With these transformations there is a great opportunity to intervene to sustain more of a landscape's unique qualities or integrity—its cultural and natural richness—by designating greenways.

What is vital to sustaining landscape integrity is not just the overall quantity of land area lost or conserved. The pattern or configuration—and especially the connectedness—of what remains is extremely important. This is where greenways can play a role. If implemented carefully, greenways can help conserve some landscape connections and functioning.

When people designate a greenway they nominate it for special status in the landscape. They are saying that they value this special corridor because it plays, or, with restoration, could play important roles in the community. With the designation, they commit to managing that greenway for its overall health or integrity. They recognize that the greenway is not something distinct from the landscape; it is integral to the landscape. With this perspective they easily see that a greenway never provides just one function, such as recreation along a bike path, but it always, even if unintentionally, does many things at the same time, such as nature conservation, floodwater management, and water quality protection. A greenway is most effectively designed and managed, then, when all of these dimensions are recognized and coordinated.

When a landscape is largely free of development, the mosaic of patches and corridors and their surrounding matrix are naturally filled with connections and interactions. Water ebbs and flows. Wildlife moves to fulfill a range of needs. But as people build communities and supporting infrastructure, they tend to disrupt and restrict these flows, sometimes intentionally. They may attempt to dampen disturbances, such as wildfires and floods, to reduce impacts to human lives and development. But often, alterations to the landscape are so gradual and incremental that their cumulative effects go unnoticed, in a "tyranny of small changes."

If we assume that development is, to some extent, inevitable in many metropolitan areas, greenways do more than stem the tide of loss of natural features. They also help to create new, positive social functions in the midst of what might otherwise be haphazard development patterns (figure 1.1). Just as water and wildlife move and flow in the landscape, there are myriad social connections in the landscape that increase with greater human presence. Greenways create opportunities to steer these new connections in socially positive ways. In addition to their obvious recreational uses, properly designed and managed greenways can tie diverse neighborhoods together in ways that increase civic interaction and expand and deepen people's sense of community. The linearity of greenways allows them to wind through a variety of neighborhoods, making them more accessible than nonlinear greenspace and contributing to goals of social equity. Especially where communities take responsibility for design and management, greenways can help strengthen the capacity for collaboration and overall democratic process. As with greenways' biophysical functions, however, these benefits are not a given but require thoughtful investigation and planning.

Although greenways share certain general characteristics, the diversity of greenway types and forms, combined with geographic differences, means that different greenways may function very differently ecologically and socially. Ecologically, greenways can protect natural areas and diminish the isolating, disruptive effects of habitat fragmentation on wildlife and water resources. Their effectiveness on both of these counts, however, will vary according to factors such as their width, shape, location, and context. From a social and community perspective, greenways can provide important places for recreation, help maintain the scenic quality of landscapes, or serve as regional separators between towns and cities.


Consider Landscape Integrity

Although there is widespread concern today about environmental degradation, there is considerable difference of opinion as to how to gauge that degradation or even measure the quality or health of landscapes in general. Biological diversity (or biodiversity) and ecological integrity, health, fit, and sustainability are several of the concepts offered as possible landscape metrics or goals. Each term addresses various aspects of goodness or quality of the environment, and how changes made by humans affect that quality. With many of these terms, such as biodiversity, the focus is, and the primary goals relate to, nature and natural processes. Sustainability, by definition a broader concept, deals with both socioeconomic and natural features. Sustainability is sometimes described as looking at the "triple bottom line" of economic, environmental, and social conditions of systems. English landscape architect Ian Thompson conceived of sustainable design as incorporating "ecology, community, and delight," with the last of the three terms referring to the beauty of the landscape and the prospect of creating art with the environment. Sustainability and sustainable development have been adopted as goals by a number of conservation organizations and projects, drawing suspicion from some biologists, who are concerned about introducing economic advancement into an evaluation of conservation activities.

In considering which concept to suggest here for greenway designers, we felt that each of the earlier mentioned approaches has merit, but none was as comprehensive and as practical as needed for real-world, multiobjective greenway projects. Therefore, we propose a broader concept we believe holds promise as a goal appropriate for greenway creation and management, a concept we call landscape integrity. Although this term has sometimes been used with a meaning more focused on natural systems, the pairing of these two words suits the broader goal of ecological and social quality for greenways.

To evaluate landscape integrity is to consider the overall quality or health of the landscape, including ecological and social functions. It includes the health of plants and animals, and other qualities embodied in the term ecological integrity, as well as social functions related to economic, recreational, and aesthetic resources, improving the quality of social and civic interaction, and ensuring equitable access to public spaces and the benefits, both economic and intangible, they offer. A place with strong landscape integrity has a good representation of ecological and cultural resources and a strong sense of place. There is a good fit between people and place and opportunities for both to flourish. Natural processes are sustained, while humans have access to jobs, housing, and services. There is environmental justice, civic interaction, and opportunities for people to participate in decisions that affect the landscape.

As a start, Richard Forman's suggested measures of ecological integrity can appropriately be thought of as part of landscape integrity. He recommends pursuing near-natural conditions of:

• plant productivity;

• biodiversity;

• soil/soil erosion; and

• water quality and quantity.


With the broader concept of landscape integrity, Forman's above-listed natural conditions can be complemented with social issues that contribute to a sense of place, such as historical, cultural, and recreational resources. It is also crucial to examine the socioeconomic impacts of greenway conservation, such as influences on communities, civic interaction, and environmental justice.

Landscape integrity, as we propose it, is not a checklist of easily quantifiable factors, but instead, a broad set of essential items—focused reminders of the significant values that are behind a greenway project and the landscape to which it is integral. Conservationist Aldo Leopold advised readers of his 1933 book on wildlife management that the techniques given in the book "represent examples of how to think, observe, deduce, and experiment, rather than specifications of what to do." Similarly, we suggest that greenway designers use this working concept of landscape integrity as a guide to thinking, observing, deducing, and experimenting with greenway design and management.

By their very nature, landscapes are dynamic, and a landscape with integrity has room to accommodate—and even requires—changes for its health. For example, if channelization shunts floodwaters downstream, eliminating historic flooding of adjacent areas, then some trees or other organisms dependent on flooding may not be able to regenerate. Flooding, drought, and other disturbances may affect or even eliminate resources being conserved by a park or greenway. At times conservationists have taken a more static view of conservation, setting aside reserves with the assumption that resources would be accommodated within that area. Yet aspects of landscape integrity, including the resources that were the initial impetus for conservation, can be lost when landscape dynamics are compromised.

Landscape integrity cannot be effectively evaluated without examining an area of interest in its broader spatial and temporal contexts. This is because some ecological patterns are not obvious if they are considered within too narrow a time or space perspective. A broader perspective may reveal, for instance, that a greenway design may simply be shifting a problem, such as flooding, to a downstream location. Similarly, if greenways only exist in affluent neighborhoods, benefits for the larger goal of landscape intergrity may be compromised. Or, greenway managers may have future problems if fire, flooding, drought, or other regularly occurring natural disturbances are not anticipated in the design.

Greenways offer a strategic approach to conserving and enhancing landscape integrity by focusing on some of a landscape's most important connections and dynamics related to such objectives as wildlife conservation, stormwater management, water quality protection, recreation, and urban design. Because typically there is a coincidence of resources found along riparian corridors, conserving a skeleton of open lands along riparian and other corridors can be an effective way of conserving a disproportionately large amount of a landscape's important features. Not to be forgotten in conserving greenways, however, is that although they may be linear in nature, they must have adequate width if they are to sustain many resources.


Greenways Can Help Conserve Landscape Integrity

Although there is no simple, single recipe for designing a greenway, there are many useful principles and systematic steps that can contribute to successful greenway design and landscape integrity. Some general principles are presented in this chapter with more detailed guidelines interspersed throughout subsequent chapters. Because they highlight background issues and concerns, these guidelines should prove useful to greenway designers, although they will still need to ground the guidelines in local conditions and objectives.

Some of the most important, overarching principles for greenway design are:

• Greenway designers should strive to conserve and enhance the connectivity of natural features of the landscape and thereby contribute to landscape integrity, including connectivity of many sorts.

• Greenway plans should keep nature near where people live, no matter how urban the area. People, especially children, benefit from having access to nature nearby, even if that nature is not pristine.

• Greenways should be distributed as equally as possible, with special emphasis on low-income areas, so that their benefits are available for all.

• Most landscapes have both natural and cultural resources, and greenways should be designed and managed with these multiple objectives in mind.

• Greenways and systems of green infrastructure are as deserving of careful planning and management as are utility corridors, roads, and other forms of gray infrastructure.

• Unlike gray infrastructure, green infrastructure must be designed and managed with its ecological dynamics in mind. This may mean, for example, that greenway widths must be determined not only on what is within a greenway, but also what is adjacent to it.

• Greenways should reclaim degraded areas to accommodate natural processes and serve people's needs.

• Planners should design gray and green infrastructure at the same time so they do not degrade each other.

• Community gardens, farms, and forests should be included where possible within or adjacent to greenways.

• It may be more important to provide short connector trails than long-distance ones.

• Existing landscape lines such as canals or abandoned railroad corridors created for one purpose can have greenway potential today.

• A carefully planned greenway project with a broadly inclusive process could be an important vehicle for overcoming social conflict or aspects of environmental inequity.


(Continues...)

Excerpted from Designing Greenways by Paul Cawood Hellmund, Daniel Somers Smith. Copyright © 2006 Paul Cawood Hellmund and Daniel Somers Smith. Excerpted by permission of ISLAND PRESS.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.

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