Land Use Change

Tue, 11/08/2011 - 08:00 -- cadoughe

Since humans arrived in this region, they have disturbed the land - sometimes lightly, other times severely. Human impacts have included the utilization of natural resources, the introduction of exotic plants and disease, extirpation/extinction of species, and urban development. These impacts raise concern because their long-term consequences are often unknown. Also, the human process of disturbance is often much greater in magnitude than typical natural disturbances.

Land conversion is a significant threat to biodiversity in Western North Carolina. As the landscape becomes more developed, areas that were once forest or other natural systems are cleared for houses and infrastructure. With habitats removed and natural systems fundamentally altered, many native plants and animals cannot survive. These plant and animal species must move to other suitable areas - which may or may not exist nearby.

Historical Perspective

Land use 1976

Land use changes have increased in the past 10 years. The map on the facing page, constructed in 1976 from satellite imagery, shows four primary land use categories: developed, undeveloped, water, and protected. Developed land is defined as land that has large amounts of paved (impervious) surfaces. This includes major roads, subdivisions, towns, and shopping areas. Undeveloped land includes forests and farms with minor roads and farm buildings. Protected land is owned or managed by entities that strive to limit the amount of land use conversion, such as national and state forests and parks and land conservancies.

By comparing past and present land use, assumptions can be made about future land use trends. If these trends are inconsistent with our desired future condition, we can attempt to identify and implement alternate outcomes that sustain natural systems while still providing services for a growing population.

The 1976 land use map of Western North Carolina is not very different from one created 50 years before. There are a few urban centers, connected by interstates, and large regions of connected green space. The map shows initial pressure from development along secondary roads, but only 1 percent of the land is truly developed.

Current Picture

Land use 2006

In the late 1970’s, Western North Carolina experienced change in land use patterns. The completion of Interstate 40 through the region, a strong domestic economy, and a desire to travel reopened Western North Carolina to tourism and to seasonal home markets. In addition, low energy costs allowed residents to commute long distances to work, making it easy to live in rural areas and work in urban centers. Land values, in most of Western North Carolina, were inexpensive compared to the rest of the country. These factors, coupled with an ideal mountain climate compared to the surrounding southeastern U.S., gained the attention of a national audience.

The 2006 land use map for Buncombe, Henderson, Madison, and Transylvania counties shows some astonishing changes over the previous 30 years. Not only was there a rapid conversion of land from rural to developed, but now each individual occupied more land. Per capita land consumption, which can be thought of as a “human footprint,” increased from 0.06 acres per person in 1976 to 0.22 acres per person in 2006. While only 1 percent of the land was developed in 1976, 7.1 percent of the land was developed by 2006. This is a land use conversion rate of over six acres per day!

Few natural systems can withstand this rapid rate of change, and Western North Carolina is no different. While many new residents to the region settled on old farms and in valleys, there has also been a move 'up the mountain'. In the pursuit of better views and perceived quality of life, many new homes are built on land that had been forested for generations. This trend displaces wildlife and exposes the forest to a wide range of threats.

Fortunately, many forward-looking individuals and groups recognize the need to protect important natural systems. In the period 1976 -2006, the 7 percent increase in development in these four counties was matched by a 7 percent increase in protected lands.

Possible Future

Land use 2030

As the region’s population grows (a 22.7 percent increase is projected from 2010-2030), the rate at which rural land is converted to urban use will increase. The map (facing page) projects land use change by 2030 for four counties. The projection is based on a statistical model that incorporates factors such as distance to roads, attraction of employment centers, percent slope, and 'pressure' exerted by previously developed areas. A separate factor is the millions of acres of national and state forest and park lands that annually attract well over 10 million visitors to the region. It is likely some small percentage of these visitors will relocate to the area. It is hard to know whether the high rate of development that occurred during the previous 30 years will continue; however, we present here one possible future scenario. Based on this model, an additional 47,500 acres will be developed in the four counties at a conversion rate of almost 6 acres per day. This increase is equivalent to about 6 percent of the region’s current private, undeveloped land.

Continued development leads to several challenges, including the amount municipal governments must spend to provide services to residents, increasing erosion of steep slopes, more frequent flooding, and more fires (studies show that 96 percent of all fires are caused by human activity). In addition, as demand for recreation grows, use patterns will creep toward the center of the mountain ranges, disturbing vulnerable habitat.

Although land conversion is one of the biggest threats to Western North Carolina’s forests, it is also one over which humans have direct control. There are effective ways to mitigate the negative impacts of land conversion, including:

* the preservation and restoration of critical habitat so that species may adapt and survive,

* the control of invasive species through chemical and mechanical treatment,

* the management of lands around water bodies (which are among the most sensitive areas likely to experience environmental stress with increased human activity), and

* reduction of the risk of wildfire by creating residential landscapes that, by design, reduce the spread of fire.

As land is converted from undeveloped to developed, the economics, politics, infrastructure, and quality of life of the region also change. New partnerships and constituencies are needed to help communities, developers, and property owners make informed decisions. Mechanisms that enable and encourage cooperative and cross-boundary management are also necessary.