Development and Nature: Enhancing Ecosystems Where We Build
The Real Goods Solar Living Center in Hopland, California covers 12 acres (4.9 ha) with carefully restored wetlands, oak-savanna habitat, organic gardens, and edible landscaping. Where once there were flash-flood-prone gullies almost devoid of soil, today visitors to the demonstration center can listen to songbirds as they walk along the paths or sit under the shade of an artistically sculpted canopy of gray poplar trees—one of seven “living structures” on the site that will grow and change over time. Visiting here, it’s hard to imagine that, just nine years ago, this was the site of a California Department of Transportation dump. Decades of misuse had scarred the site and turned the stream running through it into an erosion-prone channel that leached hazardous chemicals into nearby surface waters. As part of the development of the Solar Living Center, this brownfield was transformed from an eyesore into a vibrant, blossoming habitat that helps support biodiversity in Northern California’s Central Plain—and helps visitors understand the ecosystems around them.
This article takes a look at how development (and redevelopment) can be a driver for
improving ecosystems, rather than destroying them. For environmentalists accustomed to fighting development, this is a fairly radical concept. But for those knowledgeable about the potential (and need) for ecological restoration, it may not sound so strange after all. Restoring ecosystems and celebrating nature around our developed properties is one of the most important ways that we can “green” our buildings. Realize, however, that efforts to strengthen our connection to nature have some built-in conflicts that may need to be addressed.
How We Encourage Ecosystem Protection
Excluding Alaska, there are approximately 1.9 billion acres (770 million ha) of land area in the United States, 77% of which are privately owned. Every five years, the Natural Resources Conservation Service (NRCS) of the U.S. Department of Agriculture publishes the National Resources Inventory (NRI), with estimates of how this land is being used (cropland, forestland, etc.), including how much land is developed. (As defined by NRCS, “developed” land includes residential, industrial, commercial, and institutional land; construction sites; railroad yards; airports; urban and rural roadways; and so forth.)
For 1997 (based on newly revised figures), the NRI estimate of developed land came to 98 million acres (39.7 million ha)—an area almost as large as California. Since 1982, the year these land-use estimates were first published, the area of developed land has increased by 34%. In some parts of the country, the increase in development during this 15-year period has been far more dramatic: 48% in New Mexico, 67% in Georgia, and 55% in New Hampshire, for example. In most areas, this increase in developed land area is far more rapid than the increase in population—because our urban centers are sprawling out at lower density.
A number of tactics have historically been used to protect land in the U.S. On public lands (national forests, Bureau of Land Management [BLM] property, state forests, etc.), protection has been effected by converting those lands into wilderness or roadless areas; by creating parks, monuments, or wildlife refuges; or by more carefully regulating how resources are extracted from that land (e.g., forest management practices, grazing regulations, and mining restrictions).
With undeveloped private land, one protection strategy has been to acquire that land and permanently protect it—either as publicly owned parks and wildlife refuges, or as private preserves, such as those established by The Nature Conservancy. Rather than purchasing lands outright, a public or private entity can acquire the
development rights on that land. This is a widely used practice of state and regional
land trusts, many of which focus primarily on preservation of farmland. (The Vermont Land Trust, one of the oldest statewide land trusts in the country, has protected 372,000 acres (150,000 ha) since its founding in 1977—more than 6% of the state’s total area—but it actually owns almost none of this land; rather it acquires, by gift or purchase, perpetual conservation easements that restrict development of the land.)
Another approach for protecting or improving wildlife habitat on private land has been to encourage landowners to voluntarily improve their land management. The USDA Conservation Reserve Program, for example, pays farmers to keep some of their cropland unplanted—leaving it as native prairie, woodland, or wetland. Other government programs encourage farmers to plant hedgerows between planted fields, or to establish buffer strips along waterways. Environmentally concerned consumers encourage responsible management of farmland and forests by choosing certified organic foods or third-party-certified wood products. (See
developed land, or land that is destined for development? The strategy of keeping land undeveloped is simply not viable in all situations. And most developed land—the acres of turf surrounding corporate office buildings, for example—is far from being productive wildlife habitat. Can we do better? Absolutely.
Protecting Ecosystems at the Land-Use Planning Level
Arguably, the most important strategy for protecting or enhancing ecosystems and wildlife habitat is to enact municipal plans and land-use regulations that encourage or mandate protection of open space. Town plans or municipal master plans generally provide a framework for how land may be developed.
Municipal zoning bylaws put teeth into those plans by enacting actual regulations. A zoning bylaw may include such components as agricultural overlay zones, wildlife corridor overlay zones, riparian buffers along streams and rivers, and sliding-scale zoning. (With sliding-scale zoning, larger areas of contiguous open space are likely to remain after subdivision of large land parcels, because both the minimum and maximum size of a new lot are specified. Instead of the more standard 10-acre [4 ha] zoning, for example, in which a 100-acre [40 ha] parcel could be divided into ten equal-size lots, sliding-scale zoning might specify a maximum of ten lots but with the subdivided lots being 2 to 5 acres [0.8 to 2 ha] in size, so that one 55-acre [22 ha] lot would remain after full build-out, and the subdivided lots would be more likely to be clustered.)
Finally, we can encourage more responsible development patterns through voluntary programs. Austin, Texas already has an incentive program that does this (see article, page 6). More broadly, the U.S. Green Building Council is considering a new LEED rating program for development-scale projects that would reward clustering of buildings and protection of open space.
Even though we have a long way to go in cleaning up our development and industrial processes in the U.S., we are doing a far better job, on many fronts, than was the case over most of the last 150 years. Past land-use practices and industrial activities have left hundreds of thousands of severely contaminated sites throughout the country (see
Vol. 8, No. 3). The U.S. General Accounting Office estimates that there are more than 450,000 brownfield sites in the U.S., affecting almost every community in the country. These areas not only fail to support healthy ecosystems, but many of them actually pose risk to surrounding ecosystems and people. From an environmental standpoint, brownfield sites can be ideal for development because (1) they reduce pressure on pristine “greenfield” sites, and (2) they can be cleaned up and ecologically restored as part of the development process.
Unfortunately, brownfield sites are not alone in needing ecological restoration. Even many of our so-called “greenfield” sites that have never been developed are ecologically damaged. Dr. Eville Gorham, in the book
Placing Nature (see listings on page 15), points out that in the eastern U.S. nonnative plants account for 20% of all flora. Invasive animal and plant species, from zebra mussels to kudzu, are wreaking havoc in ecosystems throughout the U.S. (see page 2 for more on the dire situation in Hawaii). And our agricultural land is far from ecologically pristine. There are 377 million acres (153 million ha) of land planted with crops in the U.S. (not including rangeland and pastureland). Much of this cropland has been dosed with high levels of pesticides, herbicides, and fertilizers for decades. (The soil in some old New England apple orchards has such high levels of lead and arsenic that it would almost qualify as hazardous waste if removed.)
Fortunately, tremendous advances have been made in the area of toxics remediation and ecosystem restoration over the past few decades. Innovative new practices are dramatically increasing our ability to restore land.
Bioremediation is the use of bacteria and other microbes to break down and detoxify pollutants.
Phytoremediation is the use of plants that selectively absorb certain contaminants, such as heavy metals, to clean up toxic sites (the plants are harvested and either disposed of in a hazardous waste site or incinerated under controlled conditions to recover heavy metals).
Bioengineering is the use of carefully designed plantings to stabilize slopes or control erosion.
Fire management can often be used to eliminate invasive plant species while boosting native vegetation.
Ecological restoration specialists make use of a wide range of practices and tools to remove contaminants, to control invasive species, and to restore ecosystems to what they might have been like prior to European settlement. The Society for Ecological Restoration is a very active, growing organization that has been providing a forum for the evolving science of ecological restoration since 1988. An important component of such efforts is the establishment of native plantings. The table on page 13 provides a sampling of native seed and plant suppliers around the country.
Fostering Love and Respect for Nature
The term “biophilia” was coined by Harvard scientist E. O. Wilson to describe an evolutionary basis for our appreciation of nature. Professor Steve Kellert of the Yale School of Forestry and co-editor with Wilson of
The Biophilia Hypothesis, describes biophilia as “a complex of weak biological tendencies to affiliate with natural, especially living, process and diversity.” In a chapter of
Reshaping the Built Environment, Kellert outlines nine human values of nature and proposes that “when we impoverish and degrade environmental health and integrity, we inevitably diminish our material, emotional, and intellectual potential and capacity.”
Pioneering environmental activist David Brower, who passed away last November, was making practical use of biophilia ideas long before Wilson coined the term. Helping people appreciate nature was a key part of Brower’s success in fighting dams and other environmental destruction when he served as executive director of the Sierra Club in the 1950s and ’60s. During this period, Brower began publishing picture books of the places the Club wanted to protect—a tactic that resulted in a tremendous upwelling of public support for these natural areas.
By bringing nature closer to the places where we work and live, we may not only increase our well-being but also improve long-term prospects for protection of natural areas. If a worker processing insurance forms can glance out the window now and then and watch a bobolink fly over a stand of tall-grass prairie in full bloom, his appreciation for nature may increase along with his desire to protect it. If a child on a school playground can listen to wood frogs or watch salamanders in a shallow pond, she may grow up with a greater reverence for the wild. If so, then our efforts to protect and restore ecosystems around our buildings can have benefits on three levels: the direct benefits realized by wildlife and ecosystems; the “biophilia” benefits realized by the individuals directly affected; and the long-term benefits of building a constituency for nature.
In bringing people closer to nature, we must be aware that humans and nature do not always mix well. Conflicts may arise. On the one hand, we want the people for whom we are designing buildings to be able to appreciate nature—after all, this may inspire them to work harder to protect imperiled ecosystems. But on the other hand, putting people in close proximity to nature can negatively affect those very natural features being celebrated. In
Placing Nature, contributor William Romme writes about the ironic contradiction of people building homes in the remarkably scenic La Plata County of southwestern Colorado. Those homeowners want to be able to appreciate nature, but in the process they are detracting from everybody’s ability to appreciate those places, and they are interfering with critically important wildlife corridors for elk and mule deer. How do we achieve the balance of bringing people closer to nature but not harming nature in the process? Indeed, that is one of the leading challenges of green design.
In striving to improve wildlife habitat as a part of the development process, win-win solutions abound. Measures that support healthy ecosystems around our buildings usually also deal more responsibly with stormwater, introduce fewer chemicals and fertilizers into surface waters or groundwater, minimize introduction of exotic invasive plants, and conserve precious water supplies. Such win-win environmental solutions may also be
economic solutions, reducing operating costs (energy, landscape management, etc.) and increasing the value of properties.
Conflicts occasionally arise in restoring ecosystems and improving wildlife habitat—few people would want cougars stalking deer around their children’s schoolyards, for example, or lush stands of poison ivy in a neighborhood park; and maintaining dense vegetation around homes in certain seasonally arid regions poses an unacceptable fire risk. In most cases, however, ecosystem restoration and the goal of bringing people into closer contact with nature will provide strong net benefits.
The checklist on page 14 offers a starting point for enhancing ecosystems and wildlife habitat around our built environment. Much additional information is available in the books listed below.
– Alex Wilson
For more information:
Placing Nature: Culture and Landscape Ecology, edited by Joan Iverson Nassauer (Island Press, Washington, D.C., 1997)
“Ecological Challenge, Human Values of Nature, and Sustainability in the Built Environment” by Stephen R. Kellert, in
Reshaping the Built Environment, edited by Charles J. Kibert (Island Press, Washington, D.C., 1999)
Sustainable Landscape Construction: A Guide to Green Building Outdoors by J. William Thompson and Kim Sorvig (Island Press, Washington, D.C., 2000)
The Native Plant Primer by Carole Ottesen (Harmony Books, New York, 1995)
Stokes Bird Gardening Book: The Complete Guide to Creating a Bird-Friendly Habitat in Your Backyard by Donald and Lillian Stokes (Little Brown & Co., Boston, 1998)
The Bird Garden: A Comprehensive Guide to Attracting Birds to Your Backyard Throughout the Year by Stephen W. Kress (Dorling Kindersley Ltd., London, 1995)