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Alternatives for Coastal Development: One Site, Three Scenarios
Clearing Costs Indicator Information
In the ScenariosWhen land is slated for development, it is often cleared of existing vegetation. Land clearing is a costly venture that can have unintended consequences on the surrounding area. Each scenario cleared and preserved differing amounts of vegetation. Conventional designs tend to clear the land of more existing vegetation than other design types. However, building practices vary by region and developer. The conventional scenario cleared a total of 401 acres of vegetation, which made the clearing cost high at $801,940. The new urbanist scenario clustered development into three distinct regions and preserved a large tract of centrally located land. As a result, each cluster has a relatively high number of dwelling units per acre. In the clustered regions, almost all of the vegetation was cleared. These cleared areas are equivalent to 165 acres, with an associated clearing cost of $329,420, or roughly half the cost of clearing in the conventional scenario. The conservation scenario had the lowest clearing costs of all at $290,980 because it was designed to preserve the scenic beauty, natural resources, and habitat found on the site. Specifically, this design avoided development in wetlands, preserved tree canopy, and ensured that preserved areas were connected to maintain wildlife habitat and biodiversity. For details on how clearing costs are calculated for each scenario, refer to the Indicator Methods section. Why Minimize Land Clearing?Trees and forested areas provide many benefits to communities. Some of the obvious benefits trees provide are shade, glare reduction, privacy, and an aesthetically pleasing background (International Society of Arboriculture 2003). Trees also provide many unseen benefits that are often overlooked when land is developed. Clearing existing vegetation is not only costly, but it also can have unintended consequences on the surrounding area. Some of these unintended consequences are habitat fragmentation, decreased air and water quality, increased stormwater runoff and erosion, increased energy consumption, and lower property values. Trees and Habitat Fragmentation An often overlooked benefit provided by trees and forested land is habitat. According to the U.S. Fish and Wildlife Service, "habitat is a combination of environmental factors that provides food, water, cover and space that a living thing needs to survive and reproduce. . . Destruction, degradation, and fragmentation of habitat is the driving force behind today's decline in species and biodiversity. Impacts to habitat can be caused directly by such activities as the clearing of forests to grow crops or build homes, or indirectly, for example, by the introduction of invasive species or increased pollution run-off from yards and fields" (2003). Specifically, habitat fragmentation is the reduction of habitat into smaller, disconnected patches. Living things have a hard time surviving because food becomes scarce, wildlife populations are genetically isolated, and migration between habitat patches leaves wildlife vulnerable to predators (Meffe and Carroll 1997). This visualization demonstrates how development can fragment habitat (Project NAUTILUS 2003). Trees and Their Effects on Air and Water Quality Although trees and forested areas may not look busy, they are constantly working to filter pollutants from the air and water. To breathe, trees remove carbon dioxide from the air and release oxygen. During this process, trees remove other air pollutants; ozone, carbon monoxide, and sulfur dioxide (ISA 2003). Trees, such as other living things, require water. Whereas animals simply drink water, trees do much more: absorb, filter, and reduce water flow and velocity. Trees, forested areas, and other existing vegetation are nature's way of reducing stormwater runoff, reducing erosion, and filtering pollution from water (Mitchell, 2001, Keating, 2003, ISA, 2003). By absorbing water, trees decrease the water flow and velocity, which reduces erosion. At the same time, trees absorb and use as food substances that pollute water bodies such as nitrates, phosphorous, and potassium. A study published by American Forests on the City of Garland, Texas, reported "that current tree cover was saving the city $5.3 million a year, a figure that included residential energy savings, runoff reduction, and air pollution removal" (Keating 2003). Trees and Energy Savings Everyone knows trees provide a shady refuge on a hot day. Few people realize that trees and tree canopy provide energy saving benefits as well. The International Society of Arboriculture (ISA) explains that deciduous trees planted on home's southern and western sides can reduce air conditioning bills by 10 to 15 percent. On the flip side, heating costs are reduced when trees are used as wind breaks (2003). Trees and Property Values Another benefit of trees that is often overlooked is that they increase property values. ISA estimates that "property values of landscaped homes are 5–20% higher than those of non landscaped homes." ISA reports that, "street trees also improve the curb appeal of a neighborhood, increasing real estate values by 5–20%" (2003). A University of Georgia study looked at how trees and parks could enhance property values. Part of the study focused on discovering if property values increased after a tree protection ordinance was adopted by Fulton County. The ordinance was designed to save mature trees and thereby conserve established tree canopy. The study concluded that "the protection of mature trees exerts a significant upward influence on house sale prices" (Nelson, Dorfman, and Fowler 2002).
What Can I Do?Many things can be done to preserve tree canopy. By taking actions like those listed below, homeowners will reap the benefits directly in lower energy bills, increased property values, and wildlife viewing in their own yards. Homeowners can
Local governments can play a significant role in preserving existing vegetation and trees. In fact, as evidenced in the previous section, it is in taxpayers' best interests for local governments to preserve trees and existing vegetation. Once the decision is made to preserve existing vegetation and trees, local governments can
The resources and references below provide information that can help communities take the next step. References and ResourcesAmerican Forests Web site provides a free geographic information system-based tool, CITYgreen, that helps local communities analyze, understand, and calculate the value of trees in urban environments. Other resources include community success stories focusing on dollars saved through on stormwater management, air quality improvement, and energy conservation. The mission of American Forests, a nonprofit citizens' conservation organization founded in 1875, is to have healthy forest ecosystems for every community. The Web site for the Green Building Program of the City of Austin, Texas, provides guidelines, primers, ordinances, and resources from Austin's four different green building programs: residential, commercial, multifamily, and municipal. Clarke, George Aponte and Nancy Stoner. 2001. "Stormwater Strategies: The Economic Advantage." Stormwater: The Journal for Water Quality Professionals. January/February 2001. The green infrastructure Web site of the Conservation Fund and the U.S. Department of Agriculture's Forest Service provides a strategic approach to conservation that addresses the ecological, social and economic impacts of sprawl and the accelerated consumption and fragmentation of open land. The Environmental Protection Agency also provides information on green building and reducing the urban heat island effect. The Georgia Community GreenSpace Program works with communities to promote green space, tree preservation, and provides funds for related projects. This program also provides links to existing green space planning tools, including impact fees, transfer of development rights, conservation, and farmland protection. The Green Affordable Housing Coalition (GAHC) provides numerous resources on green building programs, including a list of cities and counties with green programs, tools, financing, fact sheets, and cases studies. The GAHC is a coalition of San Francisco Bay Area public-sector and private-sector professionals committed to incorporating green building practices into the design, construction, operation, and maintenance of affordable housing through education and outreach. The International Society of Arboriculture (ISA) Web site provides guidelines for planning, developing, and evaluating tree ordinances. ISA, founded in 1924, serves the tree care industry as a scientific and educational organization. Keating, Janis. 2002. "Trees: the Oldest New Thing in Stormwater Treatment?" Stormwater: The Journal for Water Quality Professionals. March/April 2002. The Lawrence Berkeley National Laboratory Heat Islands Web site provides resources designed to help reduce heat islands. Resources include studies looking at the benefits of vegetation, estimating energy cost savings from adopting mitigation measures, and many other resources that take a holistic look at reducing environmental impacts of development. Meffe, Gary K and C. Ronald Carroll. 1997. Principles of Conservation Biology. 2nded. Mitchell, Martha S. 2001. "Green Solutions: Planting Trees for Healthy Watersheds." Erosion Control. July/August 2001. Nelson, Nanette, Dorfman, Jeffery Dr., and Laurie Fowler. 2002. "The Potential for Community Forests to Be Self-Financing: An Hedonic Analysis of the Enhancement Value of Georgia's Trees." The University of Georgia, Institute of Ecology, Office of Public Service and Outreach. November 2002. The North Carolina Department of Environment and Natural Resources Web site provides an example of how to encourage conservation through its tax credit incentive program. The program assists land owners, both private and corporate, in protecting the environment and the quality of life when land provides specific public benefits. Towson University Department of Geography and Environmental Planning provides resources on habitat fragmentation, including a glossary of relevant terms. U.S. Fish and Wildlife Service. 2003. Habitat portal. Department of Interior. The Southern Research Station of the U.S. Department of Agriculture's Forest Service provides more in-depth information about factors affecting habitat on its Web site, Southern Forest Resource Assessment: General and Technical Reports. |
![[photograph of Angel Oak located on John's Island, SC]](images/angelOak.jpg)
Builders and developers can help preserve tree canopy by cutting trees selectively during the planning phase and protecting trees during construction. ISA provides tips on how to avoid damaging trees during construction. Economic benefits will accrue to builders in the form of increased sale value and decreased cost of sewer lines and stormwater mitigation measures (Keating 2003).