Placing Nature

Culture And Landscape Ecology

Joan Nassauer, Joan Nassauer

• Publisher: Island Press
• Year: 2013
• ISBN:
  9781610910996
• Topic: Architektur
• Subtopic: Architektur Allgemein

Landscape ecology is a widely influential approach to looking at ecological function at the scale of landscapes, and accepting that human beings powerfully affect landscape pattern and function. It goes beyond investigation of pristine environments to consider ecological questions that are raised by patterns of farming, forestry, towns, and cities.

Placing Nature is a groundbreaking volume in the field of landscape ecology, the result of collaborative work among experts in ecology, philosophy, art, literature, geography, landscape architecture, and history. Contributors asked each other: What is our appropriate role in nature? How are assumptions of Western culture and ingrained traditions placed in a new context of ecological knowledge? In this book, they consider the goals and strategies needed to bring human-dominated landscapes into intentional relationships with nature, articulating widely varied approaches to the task.

In the essays: novelist Jane Smiley, ecologist Eville Gorham, and historian Curt Meine each examine the urgent realities of fitting together ecological function and culture philosopher Marcia Eaton and landscape architect Joan Nassauer each suggest ways to use the culture of nature to bring ecological health into settled landscapes urban geographer Judith Martin and urban historian Sam Bass Warner, geographer and landscape architect Deborah Karasov, and ecologist William Romme each explore the dynamics of land development decisions for their landscape ecological effects artist Chris Faust's photographs juxtapose the crass and mundane details of land use with the poetic power of ecological pattern.

Every possible future landscape is the embodiment of some human choice. Placing Nature provides important insight for those who make such choices -- ecologists, ecosystem managers, watershed managers, conservation biologists, land developers, designers, planners -- and for all who wish to promote the ecological health of their communities.

PART I

Urgent Realities

1 | Human Impacts on Ecosystems and Landscapes

EVILLE GORHAM

Outside Cheryl’s Window, SOHO district, New York City (November 1994).

The Bad River, Copper Falls State Park near Mellen, Wisconsin (April 1993).

EVILLE GORHAM is an ecologist at the University of Minnesota who specializes in studies of acid rain, aquatic chemistry, and the ecology and biogeochemistry of wetlands. A member of the National Academy of Sciences and a fellow of the American Academy of Arts and Sciences and the Royal Society of Canada, he has served on numerous national and international committees concerning acid rain, wetlands, and global warming.

We are essentially inseparable from the earth, from its creatures, and from each other. We are they, and they are us, and when any one person, species, or ecosystem is impoverished, we are all impoverished.

—Donella Meadows, “A Reaction from a Multitude”

DURING EARLY HUMAN HISTORY, caring for the land was unnecessary; as a part of the natural world it took care of itself. Later, with the development of agriculture, caring for the land meant the maintenance of soil fertility by farmers. Later still we added the prevention or mitigation of local water and air pollution to our evolving concept of care. Now it is becoming increasingly clear that human societies, if they are to survive and prosper, must care, and care deeply, for the planetary ecosystem as an integrated whole.

Human Impacts on the Biosphere

The planetary ecosystem, often called the biosphere, forms a thin envelope about 10 miles deep around the outer part of the earth’s crust, where solid, liquid, and gaseous phases (the lithosphere, hydrosphere, and atmosphere) are intermingled. The reasons for our concern about the health of the biosphere are not far to seek. When we look at other species of large mammals, such as the various kinds of seal, deer, and dolphin, we see that their populations worldwide do not exceed a few millions or at most tens of millions. Before the development of agriculture, the global human population was of a similar magnitude, perhaps 5 million, so that its impact on the life-supporting capacity of the biosphere was very small. Now, with the human population increased a thousand-fold and exceeding 5 billion, supplemented by more than 4 billion large domesticated mammals—cows, pigs, sheep, goats, camels, and water buffaloes—that impact has become so large that it threatens to disrupt and degrade the biosphere in a number of important ways.¹ Indeed, we are now at a point where some scientists believe that we have already exceeded considerably the capacity of the global ecosystem to maintain for all its different peoples a reasonably adequate (i.e., Western) standard of living. Arthur Westing, for instance, of the International Peace Research Institute in Oslo, has estimated that carrying capacity to be about 2 billion people, much less than the more than 5 billion present inhabitants and the 8 billion or so projected by the year 2020.² At the average living standard of the Third World, the carrying capacity might be about 10 times higher, 20 billion—based on per capita energy use as an index of environmental impact.

The effects of population growth have been greatly enhanced by a vast increase in the per capita use of energy—for industry, agriculture, and transport—by people in developed countries such as the United States. They use hundreds of times as much energy per capita as people in the poorest countries of the world, for instance, Ethiopia and Nepal, whose consumption is, nevertheless, much greater than that in the most primitive hunter-gatherer societies. Because that energy is derived largely from fossil fuels, we have seen a toxification of our environment by acid rain, mercury, and other trace elements abundant in coal and oil, and we face the prospect of severe “greenhouse” warming of the climate by carbon dioxide released to the atmosphere following the combustion process.

Humans have also become great earthmovers, so that collectively they must now be regarded as a major geological agent, causing immense destruction of habitats. For example, tremendous transformations have been wrought in landscapes as American agribusiness has displaced the family farm. In this connection, industrial production of nitrogenous fertilizers from the nitrogen present in the atmosphere has doubled the nitrogen circulating through the biosphere, which is affecting in major ways nitrogen cycles—and other ecological processes—far from the farm fields to which the fertilizer is applied. Likewise, toxic pesticides and herbicides, several of them molecules so newly invented by agricultural chemists that microbial decomposers have not yet evolved metabolic techniques to destroy them effectively, have been spread widely throughout the biosphere. Chlorofluorocarbons, an industrial class of molecules also newly invented as refrigerants and spray-can propellants, have been even more widely dispersed, reaching the stratosphere and destroying a part of the ozone layer that protects us from damaging ultraviolet radiation.

Humans have transported, often inadvertently, so many plants and animals around the globe that substantial fractions of the species in a given region have been introduced. In the eastern United States, for example, the proportion of nonnative plants is 20 percent. Such introductions have often caused serious disruption in local ecosystems, as is currently the case with invasion of North American wetlands by the European purple loosestrife and of waterways by the zebra mussel. Largely through destruction of habitats, humans are causing a holocaust of species extinction seen only five times in the history of the earth, the last of them about 65 million years ago in response to a massive asteroid impact at the boundary between the Cretaceous and the Tertiary periods.We also face dangers from the obverse of species extinction, that is, from genetic engineering and its applied offshoot biotechnology, which is just now beginning a phase of rapid expansion. Many scientists believe that adequate safety measures have yet to be devised for the release of genetically altered organisms into unconfined environments.³

Finally, if we look with Stanford ecologist Peter Vitousek and his colleagues at the terrestrial production of organic material by plant photosynthesis, we find that a large part of it (40 percent) is now either used directly as food, fodder, and wood products by humans (3.5 percent), lost owing to human activities such as conversion of forests to agriculture and desertification (12 percent), or co-opted by altering natural communities for human purposes such as agriculture and forestry (24 percent).⁴ Such activities often have a strong impact on the cycles of carbon, nitrogen, phosphorus, sulfur, and other elements whose balanced interactions are essential to maintaining the smooth functioning of the biosphere. They also lessen considerably the diversity of plants and animals that is equally essential to biospheric function. It is clear from a consideration of these and many other impacts, including inadvertent, indirect, synergistic, and cumulative effects of the activities mentioned, that human beings are altering the structure and function of the biosphere very significantly in many ways that scientists have only recently been able to measure and understand (figure 1).⁵

Land Use and Its Regulation

What does all this mean for our stewardship of the biosphere? First and foremost it means that we must reconsider many of the social and economic policies that have contributed to ecological degradation. Having done so, we must craft new policies that will preserve, insofar as possible, the life-support systems of the biosphere. Whether we can in fact have “sustainable development” worldwide or will eventually find it to be a facile and cruelly deceptive oxymoron remains to be seen; certainly the policies that will bring it about in a politically acceptable manner are far from evident.⁶ The underlying basis for such policies is, however, clear: We must regulate, or “zone,” the uses of landscapes (and seascapes) for specific purposes far more rigorously and effectively than has hitherto been possible. We do, of course, practice such zoning regularly in our cities; in addition, we pass open-space and greenbelt legislation and set aside land for national and state forests, parks, wildlife refuges, and wilderness areas. On the other hand, current political trends in many parts of the world are strongly opposed to the philosophy behind such zoning policies, which are taken to interfere with individual property rights, and they will be very difficult to expand until the need becomes much more apparent. That it is likely to do so within the coming century seems obvious to many ecosystem and landscape ecologists.

Figure 1. The influence of human populations, operating through their agricultural and industrial activities, on ecosystems and landscapes. (Copyright New Zealand Ecological Society. Reproduced with permission from Vitousek et al.)

In a prescient article published more than a quarter-century ago, Eugene Odum, the doyen of American ecology in the years after World War II, offered a useful approach to land-use regulation by proposing a four-compartment model of the landscape divided into urban-industrial, productive, protective, and compromise ecosystems, the last type being responsible for both productive and protective functions.⁷ He argued for a model in which towns and cities occupying a given amount of space would require for their sustenance a certain amount of land to trap solar energy for food production. They would also require a certain amount of protective landscape, such as national parks and wilderness areas, to provide those basic services of air and water purification, soil formation, temperature control, and protection of biological diversity that nature provides to us at no cost. To be effective, Odum’s global categories would of course require refinement and division into subcategories on both regional and local scales to take into account different sorts and areas of croplands, forests, grasslands, wetlands, and other ecosystems.

Let us focus on the importance of productive and protective ecosystems and the value of the services they provide. As a crude indication of what the costs of those services might be were it to become necessary for us to pay for them, consider the case of Biosphere 2 (earth being Biosphere 1). Biosphere 2, conceived as an ecotechnological model for exploring and colonizing space, is a futuristic “greenhouse” of glass and steel engineered to be a self-sustaining landscape without exchange of materials (including atmospheric gases) with the outside world. It did, however, require substantial inputs of fossil-fuel energy costing about a million dollars a year to drive a variety of engineering systems that enhanced the life support provided by the almost 4,000 species of plants and animals inhabiting individual tropical rain forest, marsh, desert, savanna, stream, and agricultural ecosystems. The cost of building and maintaining the closed system that was designed (but failed) to support eight “Biospherians” on three acres of totally enclosed land through two years of operation was about $150 million, or almost $19 million per person.⁸ With costs such as these, can we really afford to overpopulate and tox-ify the planet at the same time that we severely decimate the rich array of millions of species engaged in providing our (and their) life support free of charge?

It is worth pointing out here that the inhabitants of Biosphere 2 made great efforts to recycle wastes effectively and efficiently and to avoid wherever possible the use of toxic chemicals. Unfortunately, this is not the case in our agricultural and urban-industrial systems where much of the waste is discharged to the air and water to pollute and degrade adjacent and even far distant ecosystems. Moreover, toxic chemicals are in widespread use, and many are discharged to the environment. Both wastes and toxins are treated as “externalities” in economic terms, uncounted in the balance sheet of credits and debits and left for others to pay now or in the future. Fortunately, a new breed of ecological economists is teaching us not only the true costs of these and other externalities but...

Table of contents

• About Island Press
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Acknowledgments
• INTRODUCTION - Culture and Landscape Ecology: Insights for Action
• PART I - Urgent Realities
• PART II - The Culture of Nature
• PART III - Landscape Ecology in Place
• CONCLUSION - Action across Boundaries
• Index
• Island Press Board of Directors