Session: The Wildland-Urban Interface

April 2, 10:15 AM

L. Annie Hermansen,
USDA Forest Service

Other papers from this session:

The Wildland-Urban Interface: Urban Influences on Forest Ecosystems

Policy in the Wildland-Urban Interface

This paper explores common definitions and characteristics of the wildland-urban interface, particularly from a natural resource planning and policy perspective. Factors that are driving the rapid change and expansion of the wildland-urban interface are also examined.

The Southern United States is experiencing unprecedented population growth, resulting in rapid land use change and profound effects on forest ecosystems. Such areas of rapid change are commonly referred to as the wildland-urban interface. The USDA Forest Service, Southern Center for Wildland-Urban Interface Research and Information (SCWUIRI) was established in 2002 in Gainesville, FL to address issues related to human influences on forest ecosystems in the Southern United States. Prior to the establishment of the Center, the Forest Service conducted an assessment of the factors driving change in the wildland-urban interface, as well as the consequences of such changes (Macie and Hermansen 2002). The assessment also identified key areas of research and information needed to address the challenges of the interface and serves as the foundation for the interdisciplinary program pursued at SCWUIRI. This paper contains information covered in the introduction to the session titled "The Wildland-Urban Interface", presented at the 2003 National APA Conference. For the rest of the presentation, please refer to the following two papers within this proceeding: "Urban Influences on Natural Resources" and "Policy in the Wildland-Urban Interface".

The wildland-urban interface has been variously defined, but perhaps the most common definitions are from spatial, fire, sociopolitical, and natural resource perspectives. There are four common spatial (or geographical) definitions. The first is the classic interface, which is characterized by areas of urban sprawl where development presses against public and private wildlands, such as commercial forestland or land under public ownership and management. The intermix refers to areas undergoing a transition from primarily agriculture and forest uses to urban land uses. These areas are characterized by a mixing of land uses in the same area. The isolated interface is made up of isolated structures surrounded by large areas of vegetation, typically summer and recreation homes, ranches, and farms. And finally, as cities grow together islands of undeveloped land are left, creating wildland-urban interface islands (Hermansen and Macie 2002).

From a sociopolitical perspective, the interface can be thought of as a place of interaction between different political forces and potentially competing interests (Vaux 1982). Particularly in the interface, where people are in close contact to natural resource management, public attitudes, values and perceptions shape the way that those resources can be managed and conserved.

The wildland-urban interface can also be defined as a zone where human-made infrastructure is located in or adjacent to areas prone to wildfire. From a community-level perspective the interface can be defined as the conditions that make a neighborhood or community vulnerable to a wildland fire disaster.

These last two definitions define the interface not so much as a place, but rather as a condition. The interface can be an environmental condition where a mix of fuel, weather, and topographical conditions make a community at risk of wildland fire. Or the interface can be viewed as a social condition in which there is potential for interaction, or confrontation, between different political forces, each of which has somewhat different perceptions and values regarding natural resources.

In our assessment of the wildland-urban interface, we defined the interface from a natural resource perspective. Our definition is an area or zone where increased human influence and land use conversion are changing natural resource goods, services, and their management (Hermansen and Macie 2002).

Some common characteristics of the interface are changes to disturbance regimes; changes to biodiversity; changes to hydrological systems; and alteration of the goods and services that nature provides. In the interface we see land use change, loss and alteration of natural areas, and deforestation and fragmentation of forests.

Floods, winds, and fire are natural disturbances, but urbanization is also a disturbance (anthropogenic). Urbanization affects disturbance regimes by altering the frequency, severity, and the types of disturbances seen in an area (Zipperer 2002). For example, wildfire suppression has threatened the existence of fire-dependent communities and species, and has led to large-scale fires (increased size and severity) that have been numerous in many parts of the country over the past decade.

Urbanization changes biodiversity by altering the composition of plant and animal species in both terrestrial and aquatic systems. For example, population densities of raccoons have increased dramatically in some parts of the South, causing problems because raccoons are carriers of rabies and a predator of ground-nesting animals. This increase of raccoons is a direct result of increased human development because this species can thrive in urbanizing areas where other species cannot (Zipperer 2002). Also, along a gradient from the rural areas to the city, species richness decreases for native plants and increases for non-native plants. Also along this same gradient, species richness decreases for amphibians, reptiles, mammals, and birds (Kowarik 1990).
Urbanization alters water flow in the interface, resulting in a change in hydrological systems. Changes include increased amount of impervious surfaces, decreased infiltration, increased surface runoff, and much more. Also urbanization drains wetlands, channelizes streams, and increases the amounts of sediments nutrients, and pesticides entering the aquatic system (Zipperer 2002).
Collectively all of these characteristics significantly affect forest health and modify the goods and services provided by forest ecosystems. Goods are those items with a monetary value, such as food, wood, decorative products, tourism and recreation. Services are valued economically but rarely are bought or sold, such as the beauty and inspiration provided by nature and the cleansing of air and water provided by forest ecosystems (Zipperer 2002).

Major factors influencing the rapid change and expansion of the interface in the South and across the country are population and demographic trends, economic and tax issues, and land use planning and policy issues.

We are living longer, migrating from one region of the U.S. to another (e.g. the Rocky Mountains, the South, and the Pacific Coast are gaining in population, whereas the North and Midwest are losing population), and immigrating from abroad. These trends are making us much more diverse as a country than at any other time in our history. For example, between 1990 and 2000, the South’s population increased by 13.9 percent. By 2020, the South’s population is projected to increase another 24 percent, reaching almost 114 million people (fig. 1) (Cordell and Macie 2002).

In other regions, the North is projected to increase by 8 percent, the Pacific Coast by 24 percent, the Rocky Mountains by almost 29 percent, and the Conterminous States by 17 percent. The South is projected to dominate in the coming years in terms of the overall U.S. population. To bring this even closer to home, Denver’s population is projected to increase by 47% by 2020 (Cordell and Overdest 2001).

With population growth, we see a corresponding increase in urban sprawl. Growth is occurring mostly to already burgeoning metropolitan areas (e.g. Houston, Atlanta, Miami) and former rural areas and forests are being converted at unprecedented rates to wildland-urban interface zones (fig. 2) (Cordell and Macie 2002).

As our population ages and becomes more ethnically and culturally diverse, public attitudes, perceptions, and values undergo a change. Public attitudes impact natural resources by influencing how they will be used. Research has shown that different age and ethnic groups differ in how each use and value forests and other natural resources.

An economic issue of concern in the interface is that land development generates less revenue than municipal governments spend to provide services to the area. Numerous studies have shown that municipalities spend between 15 to 80 cents in services for every dollar of tax revenue generated by farms and forests, and between 15 and 47 cents for every dollar of revenue generated by commercial development. In contrast, residential development costs range from $1.04 to $1.55 per dollar of revenue collected (Esseks et al. 1999). But these values do not even include the non-monetary values provided to municipal governments by forests. For example, the trees lost to development in the Puget Sound region since 1973 would have reduced storage requirements by 1.2 billion cubic feet – the equivalent of a $2.4 billion stormwater management system (Smith 1999).

A major land use planning issue in the interface is that of multiple, overlapping jurisdictions. Current land-use policies have been unable to prevent the overlap of multiple Federal, State, and local jurisdictions over land use. As a result, various levels of government are making land-use decision independently of each other. Often these decisions are made without any common understanding of what long-range growth management goals each government level wants to achieve and no common approach for addressing environmental issues across jurisdictional boundaries (Kundell et al. 2002).

Higher population densities in the interface increase potential for neighbors to directly affect one another’s quality of life. As a result, by most accounts, with urbanization we tend to see an increase in regulation of forest and land management practices (Hull and Stewart 2002)

Conclusion

The wildland-urban interface is an area of increased human influence and land use conversion. Population and demographic trends, economic and tax issues, and land use planning and policy issues all play a part in influencing change in the wildland-urban interface. These factors are important to understand, as are the consequences of human influences on forest ecosystems, in order to establish and ecological framework for planning and policy in the wildland-urban interface.

Literature Cited

Cordell, H.K., E.A. Macie, 2002. Population and demographic trends, In Human influences on forest ecosystems: The southern wildland-urban interface assessment, E. Macie, L.A. Hermansen (eds.), Asheville, North Carolina, U.S. Department of Agriculture, Forest Service, Southern Research Station, General Technical Report SRS-55, pp. 11-35.

Cordell, H.K., C. Overdest, 2001. Footprints on the land: an assessment of demographic trends and the future of natural resources in the United States, Sagamore Publishing, Champaign, IL, 314 pp.

Esseks J.D., H.E. Schmidt, K.L. Sullivan, 1999. Fiscal costs and public safety risks of low-density residential development on farmland: findings from three diverse locations on the urban fringe of the Chicago metro area, American Farmland Trust, Center for Agriculture in the Environment, DeKalb, IL, 100 pp.

Hermansen, L.A., E.A. Macie, 2002. Introduction. In Human Influences on Forest Ecosystems: The Southern Wildland-Urban Interface Assessment, E. Macie, L.A. Hermansen (eds.), Asheville, North Carolina, U.S. Department of Agriculture, Forest Service, Southern Research Station, General Technical Report SRS-55, pp. 1-7.

Kowarik, I., 1990. Some responses of flora and vegetation to urbanization in central Europe, In Urban Ecology: Plants and Plant Communities in Urban Environments, Sukopp, H., (ed.), SPB Academic Publishers, The Hague, pp. 45.

Kundell, J.E., M. Myszewski, T.A. DeMeo, 2002. Zipperer, W., 2002. Land use planning and policy issues. In Human Influences on Forest Ecosystems: The Southern Wildland-Urban Interface Assessment, E. Macie, L.A. Hermansen (eds.), Asheville, North Carolina, U.S. Department of Agriculture, Forest Service, Southern Research Station, General Technical Report SRS-55, pp. 53-69.

Macie, E.A., and L.A. Hermansen, 2002. Human influences on forest ecosystems: The southern wildland-urban interface assessment, Asheville, North Carolina, U.S. Department of Agriculture, Forest Service, Southern Research Station, General Technical Report SRS-55.

Smith, D., 1999. The case for greener cities. American Forests, 105(3), pp. 18-22.

Vaux, H.J., 1982. Forestry’s hotseat: the urban/forest interface. American Forests, 88(5), pp. 36-46.

Woods and Poole Economics, Inc., 1997. 1997 complete economic and demographic data source (CEDDS) [CD-ROM], Woods and Poole Economics, Washington, DC.

Zipperer, W., 2002. Urban influences on forest ecosystems. In Human Influences on Forest Ecosystems: The Southern Wildland-Urban Interface Assessment, E. Macie, L.A. Hermansen (eds.), Asheville, North Carolina, U.S. Department of Agriculture, Forest Service, Southern Research Station, General Technical Report SRS-55, pp. 73-91.

Author and Copyright Information

Contact:

L. Annie Hermansen
USDA Forest Service
Southern Center for Wildland Urban Interface Research and Information
408 W. University
Suite 306
Gainesville, FL 32601
(352) 376-3271
ahermansen@fs.fed.us