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Land Use Change

Forest lands have been the largest source of land for development in recent years. The most significant trend affecting forests is the conversion to residential, commercial, industrial, and infrastructure uses. Although forestry, agriculture, grazing, and developed uses all compete for a fixed amount of land, forests have been most affected. One million acres of forests have been lost to development annually from 1992 to 1997. Another 26 million acres could be lost by 2030 (Alig and Plantinga 2004). This trend increasingly will affect our ability to provide adequate ecological protection, ecosystem services, and other open space benefits in future years.

Another important trend in the United States has been the population shift and rapid development in the outlying fringe of metropolitan areas and in rural areas with attractive recreational and aesthetic amenities, especially forests. These areas are referred to as the Wildland-Urban Interface (WUI). The expansion of the WUI in recent decades has important implications for forest management and impacts. For example, WUI expansion has increased the likelihood that wildfires will threaten structures and people.

At WWETAC, we consider land use change a potential threat because loss of wildlands to development and WUI expansion in the West raises several concerns. For example, how does development affect our ability as a Nation to produce sufficient timber and other forest commodities? How does development affect the many ecological, water resource, recreation, and scenic values we also desire from forests as open space? Regarding open space benefits, there is concern about loss of fish and wildlife habitat owing to forest fragmentation and changes in forest structure that may accompany development, concern about the adverse effects that development can have on water quality and the timing of supply, and concern about loss of access to forest lands for recreation and aesthetic enjoyment. Does parcelization—the breaking up of large forest parcels into smaller parcels for development—reduce the economic feasibility of commercial forest management, because several small parcels can be more costly to manage than few large parcels? If commercial forestry becomes less profitable, it is feared forest landowners will have yet another reason to sell land for development.

These concerns are all important. As a Nation, we typically have assumed a public interest in maintaining sufficient national supplies of timber and other ecosystem services that wildlands provide. Ecosystem services are the multiple benefits provided by ecosystems to humans—they have ecological and societal importance. Ecosystem services are the outputs of functioning ecosystems that benefit people, including material goods such as food, fuel and fiber, fresh water, fish and wildlife, recreational resources, and scenery, among others. We all benefit from them in some way even though a large share comes from private lands.

 

Threat Interactions

Land use change interacts with all the other threats that we study. For example, in dry-land fire-prone forests, there also are concerns about the risks wildfires pose for homes located in forest settings. As wildlands are developed, native plants may be replaced by exotic species. Some of these species maybe become invasive. Developed areas often provide ample habitat for invasive plants and can promote the establishment and spread of invasive plants. Roads are a special area of concern and threat. Activity associated with a change in land use can also cause direct damage or stress to resident native vegetation. Under such damaging or stressful conditions, this vegetation often becomes more susceptible to attack by native and exotic pests and pathogens, which can reduce vigor and may eventually result in death.

Another important threat interaction with land-use change involves climate change. People and development affect climate and climate affects people. For example, increased development is linked to increased greenhouse gas emissions. Converting forest land to housing or other types of development can also reduce the amount of carbon that the ecosystem will store. Climate change may also shape land use changes in the future, as people migrate away from areas prone to extensive droughts and to areas with better water supplies or optimal climates.

 

WWETAC Projects

• Evaluating forest and range land development in the Western United States
• Mapping forest composition and structure in the Pacific Coast States with gradient nearest neighbor imputation (GNN)
• Interaction of private and public forest fire risk management decisions
• A national early warning system for environmental threats
• National environmental threat assessment maps (NETAM)
• Wildland Environmental Threat Assessment GeoService
• Literature synthesis of potential components of an adaptive capacity self-assessment tool for WUI communities
• Assessment review of remote sensing technologies for threat detection
• Adaptive Co-management of riparian resources on private and public land in the US west: An inventory of challenges and opportunities

Alig, R.J.; Plantinga, A. 2004. Future forestland area: impacts from population growth and other factors that affect land values. Journal of Forestry. 102(8): 19-24.