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Practical Ecology for Planners, Developers, and Citizens introduces and explains key ecological concepts for planners, landscape architects, developers, and others involved in planning and building human habitats. The book is tailored to meet the needs of busy land use professionals and citizens seeking a concise yet thorough overview of ecology and its applications. It offers clear guidelines and a wealth of information on how we can protect species and ecosystems while at the same creating healthy, sustainable human communities.
Throughout the book, the authors make ecological concepts accessible to readers with little or no scientific background. They present key ideas and information in simple and pragmatic terms, and provide numerous graphics to help explain important concepts. They also offer exercises for the reader to practice ecologically-based planning and design, along with a list of resources for practical information on ecology and conservation.
Practical Ecology for Planners, Developers, and Citizens will raise the level of ecological understanding among land use professionals and citizens, and is an invaluable new resource for anyone concerned with human land use and its environmental impacts.
This book will be most useful for professional land use planners, designers, and developers, including landscape architects and civil engineers and all those involved in designing ecologically sound projects. Resource managers, land use planners, students, and researchers will also welcome it for its clear and concise presentation of ecological concepts."
"A man, a plan, a canal, Panama."
Palindrome describing the creation of the Panama Canal
"I returned, and saw under the sun, that the race is not to the swift, nor the battle to the strong, neither yet bread to the wise, nor yet riches to men of understanding, nor yet favor to men of skill; but time and chance happeneth to them all."
Ecclesiastes 9:11, King James Bible
Over the past few millennia, humans have spread to cover the globe. In the process, we have changed more of the earth, more profoundly, than any species before us. We have altered the face of the planet by building a canal between the Atlantic and Pacific oceans, reestablishing a connection that had not existed for more than 2 million years; by cutting vast forests at all latitudes; and by changing the global climate. As human communities grow, we shape nature. With our advanced technologies, however, we often forget that nature shapes us as well.
As we extend ourselves across the landscape, we plan. Sometimes our plans are explicit and carefully thought out documents, while other times they are implicit thoughts, such as, "If I create a farm here, it will be productive for several years," or "If we build a town here, it will be a safe place to live." Plans give us a secure feeling about the future and reinforce our sense that we can control the landscapes where we live. Drawings and carefully crafted words describe what a given site or region will look like if the plan goes into effect—but these plans can be misleading in two ways.
First, most plans focus primarily on the site or area for which they are planning. While they may consider roads and other aspects of human society outside the study area, they rarely consider ecological issues beyond the boundaries. A certain piece of terrain is either in the study area (and included in the plan) or out of the study area (and typically ignored). In fact, most plans show virtually nothing that is outside the planning area or site, as if it were an island floating in space (see Figure 1-1).
Second, the planning and design process is often built on the assumption that human beings fully control the future of the study area. A carefully produced plan is a prediction that verges on being a contract: the plan tells residents of an area what their subdivision or community will become if the plan is followed. As a result, plans typically depict only one or, at most, a handful of future states. The science of ecology, on the other hand, recognizes that "time and chance happeneth to them all." Yes, we can plan and predict, but despite the seeming solidity of our plans' words and images, we cannot guarantee what the future of a site holds. The world of nature is full of chance events, and the mere passage of time brings its own changes as well.
The following two case studies explore the relationship between planning—a wholly human enterprise—and the workings of nature. As these examples illustrate, planners, designers, and developers would do well to consider the effects of time, chance ecological events, and ecological processes occurring beyond their planning area. By taking these factors into account, we can develop plans that reap major benefits and avoid major problems. By ignoring these factors, we run the risk of costly or tragic consequences as nature runs its course.
New York City's Water
Beginning in the mid-nineteenth century, New York City developed one of the best municipal water supplies in the world in terms of quality, reliability, and innovative management. Every day, the city's water system supplies 9 million people with 1.3 billion gallons of potable water. The water comes from a system of nineteen reservoirs and lakes fed by a 1,969-square-mile (5,099 square km) watershed that extends more than 100 miles (160 km) north of the city. Perhaps most remarkable of all is that the foundations of this system were laid nearly two centuries ago, in 1835. Today, almost all of New York's water still comes from upstate watersheds, and the main treatment that it receives is simply chlorination to kill the pathogens that are sometimes present at low levels.
In 1989, the U.S. Environmental Protection Agency (EPA) promulgated the Surface Water Treatment Rules, which grew out of the Safe Drinking Water Act of 1974. Under these rules, New York City would have had to begin filtering its entire water supply for the first time. The filtration plants, according to the City, would have cost $6 to $8 billion to build and would have doubled the price of water for city residents. Instead, throughout the early and mid-1990s, the City and the EPA worked out an alternative to filtering the main water supply: the City would protect and improve water quality by helping towns in the watershed upgrade their sewage treatment facilities and by protecting thousands of acres of land in critical portions of the watershed. As of this writing, the City has purchased or obtained conservation easements on over 50,000 acres (20,000 ha) of land in the upstate watersheds. The City alone has committed over $290 million for the land acquisition program, and city, state, and federal contributions to all facets of the watershed program total $1.4 billion.
One of the most striking features of the agreement between the EPA and the city is the joint official recognition that nature can perform critical ecosystem services for humans. Instead of insisting on building giant filtration plants, the parties recognized that, through proper management, nature may be able to provide drinking water that is as safe as water provided by purely technological means. In addition to drinking water benefits, this watershed-based approach is helping protect rural landscapes just a couple of hours from New York City. Many farms will remain in business, and people are allowed to hike, fish, and hunt on much of the land that the city purchases.
In the early nineteenth century, the City of New York recognized that its water resources would become limiting, and the municipality looked beyond its borders to create a remarkable water supply system. At the end of the twentieth century, the city again looked beyond its borders—and beyond the confines of human technology—to envision a future in which humans protect natural areas in ways that help both humans and countless nonhuman organisms living across the landscape. This example offers the following lessons:
Sometimes we are better served by letting nature provide necessary services than by using technology to fulfill our needs. When we protect and maintain healthy ecosystems, humans can reap significant health and economic benefits.
By setting aside parcels of nature for one purpose—in this case, to provide safe drinking water—both human and ecological communities may benefit in other ways. The watershed lands protect the rural character of dozens of communities as well as high-quality habitat for the region's native species.
While looking beyond the boundaries of a site can help identify the benefits and services that nature provides, taking a broad view can also help one avoid some of the problems that nature can bring, as the next case study illustrates.
Fire in Colorado
Several years ago, some friends of ours purchased a house in Pine, Colorado. This small community, nestled beside and within the Pike National Forest, has become a bedroom community for Denver as the capacity of the highways into the city has expanded. The mountain ridges surrounding Pine are covered with maturing pine forests that are not only lovely to look at but also contain a surprisingly intact ecological community that includes black bear, elk, mule deer, coyotes, and even mountain lions—all less than an hour's drive from Denver. This ecosystem offers aesthetic and recreational amenities that have undoubtedly contributed to Pine's recent popularity among home buyers.
This ecosystem, however, is not entirely benign. Although the setting of our friends' house appears quite suburban, with several houses visible nearby, mountain lions are enough of a danger that many children do not play outside at dusk or dawn. But the single most notable species in this ecosystem is not one of the large mammal species but rather the Ponderosa pines (Pinus ponderosa) that dominate the landscape. And the single most notable process in the ecosystem is fire.
Left alone, Ponderosa pine forests typically burn lightly and frequently, with ground fires removing underbrush while leaving mature trees intact. However, in areas where fires have long been suppressed and underbrush has been allowed to accumulate, as is the case throughout much of the American West, fires burn heavily. As they engorge themselves on the dense growth left unpruned by the now-disrupted fire regime, they become massive, destructive crown fires capable of killing even the largest trees.
In June 2000, the Hi-Meadow Fire roared through the subdivisions and forests of Pine with impunity. The 10,800-acre (4,400 ha) fire destroyed fifty-eight structures, including several houses that could be seen from our friends' deck, but firefighters stopped the blaze thirty feet from their house (see Color Plate 1). The fires around Pine offer several critical lessons:
Understand the ecological processes of the place you are planning or designing. Developers creating new subdivisions in Ponderosa pine forests, and local planning commissions that approve these subdivisions, need to understand how the local ecosystems function. The same lesson applies to ecosystems across the continent.
Context is critically important. What is outside the boundary of a site can add tremendous value—economic, ecological, recreational, or aesthetic—to the site, but it can also threaten health, safety, and property.
Always consider the array of possible futures for the land around a site. This includes changes that may be brought about by humans, those that might occur naturally, and those that may occur through a combination of human and natural causes.
Plan with a measure of humility. There are forces in nature that we may not be able to control.
The examples of New York City and Pine demonstrate that when we plan for the future, we need to look beyond the edges of our properties—which the planners of New York's water system certainly did, but which the designers of the subdivision in Pine did not do adequately.
Different Ways of Thinking about the Future
Planners, designers, ecologists, and conservationists all concern themselves with how specific landscapes will look and function in the future, and many of these professionals attempt to shape the future in different ways. But each profession approaches its work from a different background and with a different set of issues in mind, and each tends to view the world in a very different way (see Table 1-1). Developers who build houses in a wetland know that they may be penalized under the laws of humans and that some houses may end up with wet basements because of the laws of hydrology. Planners, in contrast, might be most concerned with how development in the wetland will affect the lives of humans, some of whom live far downstream from the wetland. Ecologists and conservationists would be more likely to focus on the effects of such development on nonhuman organisms, many of which spend only a small part of their lives in the wetland.
Land use planners, designers, and developers usually work within unambiguous geographic boundaries and over relatively short time periods. In considering the future of a site, designers and developers generally assume that they can alter only land that is part of the development site and not neighboring parcels. Similarly, planners have jurisdiction only within the municipality, county, district, state, or province where they work and not in adjacent jurisdictions. Of course, many land use professionals do make an effort to consider the larger context. For example, planner Randall Arendt, in his book Growing Greener, suggests that designers create site context maps that extend 1,000 to 2,000 feet (300 to 600 m) beyond the boundaries of their parcels. But even this amount of context, which exceeds common practice, might not reveal important ecological processes that could affect the site under consideration—such as the Hayman Fire in Colorado, which ran seventeen linear miles (27 km) on June 9, 2002, needing only four minutes to spread half a mile (0.8 km) at one point.
By contrast, ecologists considering a piece of land would be aware of natural influences that exist outside the site's formal boundaries: physical processes, such as fire and wind, as well as biological impacts, such as pest outbreaks and invasive species. They would also consider how the landscape looked in the past and what it might look like in the future absent human intervention.
Another important difference among the professions is the certainty with which each anticipates future events. The planning and development processes involve several contractual and quasi-contractual relationships, unlike the practice of ecology, which involves none. A developer usually contracts with lenders and designers, and sometimes with landowners or future tenants, to create a specific building program on a site. In turn, the developer and the local government also have a quasi contract: developers can build within the community as long as they follow its zoning laws as well as building codes and other applicable regulations. These zoning laws are also the result of an implied contract between the community's residents and its planners and other officials to establish and maintain the community as a safe, healthy place to live.
Nature, in contrast, is not subject to contracts. In fact, ecologists hardly ever attempt to predict the future with certainty, and they are aware that the general rules they propose often hold true only in broad terms over long periods of time. Ecologists often say that the first law of ecology is "It depends." In thinking about the future, ecologists discuss what might happen or, at the strongest, what will probably happen. Ecological systems are too complex and contain too many interacting variables to allow us to be certain about the ecological future. Ecologists tell us that we need to know the history of a site and the natural patterns of ecological change for that landscape and the context of the site simply to understand the range of possibilities that might occur in the future. In this regard, ecological systems are much like the weather: at one level, they are deterministic and controlled by fundamental laws of physics and chemistry, yet they are too complex to allow humans to know every aspect of their workings. Instead, we infer and predict using a combination of observational and theoretical knowledge, improving our predictive power as time passes. With this level of ecological uncertainty, can a planner create an implied contract to keep members of the public safe within their ecological context?
Although it is impossible to capture all the nuances and complexities of these professions in such a brief space, the large differences in assumptions and approaches stand out clearly. There is nothing in the world of ecology and conservation—other than extinction—that is as clearly defined as a property boundary or a tax bill. But the certainty and finality of extinction drives much of the work of conservationists, for while a boundary or tax bill may be changed, extinction cannot.
Planning with Context in Mind
To appreciate the importance of considering a site's ecological context in space and time, let us return to Figure 1-1, in which we saw a hypothetical site as it exists today. The site contains fifty acres (20 ha), of which about thirty acres are currently farmland and fields, ten are forest, seven consist of a pond, stream, and wetland, and three are roads and buildings. Typically, developers and designers working on a site such as this will have considered the site's human context, such as the location of roads, schools, and nearby land uses, as well as such factors as zoning, property values, and the marketability of different development options. But what about the site's ecological context? Consider a series of three maps, each of which shows the site in a different ecological context (see Figure 1-2). These different contexts have profound implications for the site itself.
Excerpted from Practical Ecology for Planners, Developers, and Citizens by Dan L. Perlman, Jeffrey C. Milder. Copyright © 2005 Lincoln Institute of Land Policy. Excerpted by permission of ISLAND PRESS.
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List of Figures, Color Plates, and Tables
PART I. Humans, Nature, and Interactions
Chapter 1. Humans Plan
Chapter 2. An Introduction to Ecology and Biodiversity
Chapter 3. When Humans and Nature Collide
PART II. The Science of Ecology
Chapter 4. Change through Time
Chapter 5. Populations and Communities
Chapter 6. The Ecology of Landscapes
PART III. Applications
Chapter 7. Conservation Planning
Chapter 8. Nature in the Neighborhood
Chapter 9. Restoration and Management
Chapter 10. Ecologically Based Planning and Design Techniques
Chapter 11. Principles in Practice
Appendix A: Current Status of Biodiversity in North America
Appendix B: Data Sources