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We have seen that resources can be managed or they can be over-exploited, depending on a number of factors related to economics, human behavior, and specific management practices. Proper resource management is also dependent on specific aspects of the type of land involved as well as the agency and the guidelines under which it operates. In this module, we will examine land management practices in rangelands and forests, with a focus on timber management practices and fire management. We will also examine trends in residential land use and the causes and consequences of urban sprawl.

Learning Objectives

After reading this module, you should be able to

Now that we have a basic picture of how public land is classified and of the relationship between public land use and management agencies in the United States, let’s turn to some of the specific issues involved in managing different types of public lands. Note that many of the management issues we discuss here apply to private lands as well.

Rangelands

Rangelands are dry, open grasslands primarily used for the grazing of cattle, which is the most common use of land in the United States. Rangelands are semiarid ecosystems and are therefore particularly susceptible to fires and other environmental disturbances. When humans overuse rangelands, those rangelands can easily lose biodiversity.

Like most human activities, livestock grazing has mixed environmental effects. One environmental benefit of grazing is that ungulates—hoofed animals such as cattle and sheep—can be raised on lands that are too dry to farm. In addition, grazing these animals uses less fossil fuel energy than raising them in feedlots. However, improperly managed livestock can damage stream banks and pollute surface waters. Grazing too many animals can quickly denude a region of vegetation (FIGURE 30.1), which leaves the land exposed to wind erosion and makes it difficult for soils to absorb and retain water when it rains.

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Many environmental scientists argue that rangeland ecosystems are too fragile for multiple uses. Certain environmental organizations have suggested that as much as 55 percent of U.S. rangeland soils are in poor or very poor condition, due in large part to overgrazing. However, the BLM, which manages most public rangelands in the United States, has maintained that the percentage of poor or very poor soils is not nearly that high. Reconciling this difference is a challenge because of the many factors that influence how soil condition is determined.

The Taylor Grazing Act of 1934 was passed to halt overgrazing. It converted federal rangelands from a commons into a permit-based grazing system. The goal of a permit-based system is to limit the number of animals grazing in a particular area and thereby avoid a tragedy of the commons situation. However, critics maintain that the low cost of the permits continues to encourage overgrazing. In 2009, the latest year for which data are available, the federal government spent seven times more money managing its rangelands than it received in permit fees. Thus, in effect, grazing is subsidized with federal funds.

The BLM focuses on mitigating the damage caused by grazing and considers “rangeland health” when it sets grazing guidelines. For example, state and regional rangeland managers are required to ensure healthy watersheds, maintain ecological processes such as nutrient cycles and energy flow, preserve water quality, maintain or restore habitats, and protect endangered species. However, because these managers are not given detailed guidance, and the BLM regulations do not require the involvement of environmental scientists, the managers have wide latitude to set their own guidelines and standards. As a result, BLM regulations are not consistently successful in preserving vulnerable rangeland ecosystems.

Forests

Forests are dominated by trees and other woody vegetation. Approximately 73 percent of the forests used for commercial timber operations in the United States are privately owned. Many national forests were originally established to ensure a steady and reliable source of timber, and commercial logging companies are currently allowed to harvest U.S. national forests, usually in exchange for a royalty that is a percentage of their revenues. The federal government typically spends more money managing the timber program and building and maintaining logging roads than it receives from these royalties, essentially subsidizing the timber program as it does grazing on rangelands.

Timber Harvest Practices

The two most common ways in which trees are harvested for timber production are clear-cutting and selective cutting, both of which are illustrated in FIGURE 30.2. Clear-cutting involves removing all, or almost all, the trees within an area (FIGURE 30.2a); it is the easiest harvesting method and, in most cases, the most economical. When a stand, or cluster, of trees has been clear-cut, foresters often replant or reseed the area. Often the entire area will be replanted at the same time, so all the resulting trees will be the same age. Because they are exposed to full sunlight, clear-cut tracts of land are ideal for fast-growing tree species that achieve their maximum growth rates with large amounts of direct sunlight. Because other species may not be so successful in these conditions, there can be an overall reduction in biodiversity. However, if a commercially valuable tree species constitutes only a small fraction of a stand of trees, it may not be economically efficient to clear-cut the entire stand. This is particularly true in many tropical forests, where economically valuable species constitute only a small percentage of the trees and are mixed in with many other less valuable species.

Clear-cutting, especially on slopes, increases wind and water erosion, which causes the loss of soil and nutrients (FIGURE 30.3). Erosion also adds silt and sediment to nearby streams, which harms aquatic populations. In addition, the denuded slopes are prone to dangerous mudslides like the Stafford, California, mudslide described at the beginning of this chapter. Clear-cutting also increases the amount of sunlight that reaches rivers and streams, which raises water temperatures that can adversely affect certain aquatic species. Even the replanting process can have negative environmental consequences. Timber companies often use fire or herbicides to remove bushy vegetation before a clear-cut is replanted. These practices reduce soil quality, and herbicides may contaminate water that runs off into streams and rivers. Many environmental scientists identify clear-cutting as a cause of habitat alteration and destruction as well as forest fragmentation. These effects decrease biodiversity and sometimes lower the aesthetic value of the affected forest.

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Selective cutting (FIGURE 30.2b) removes single trees or a relatively small number of trees from the larger forest. This method creates many small openings in a stand where trees can reseed or young trees can be planted, so the regenerated stand contains trees of different ages. Because seedlings and young trees must grow next to larger, older trees, selective cutting produces optimum growth only among shade-tolerant tree species.

The environmental impact of selective cutting is less extensive than that of clear-cutting. However, many of the negative environmental impacts associated with logging remain the same. For example, whether a company uses clear-cutting or selective cutting, it will need to construct logging roads to carry equipment and workers into the area that will be harvested. These roads fragment the forest habitat, which affects species diversity, and compact the soil, which causes nutrient loss and reductions in water infiltration.

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A third approach to logging—ecologically sustainable forestry—removes trees from the forest in ways that do not unduly affect the viability of other, noncommercial tree species. This approach has a goal of maintaining both plants and animals in as close to a natural state as possible. Some loggers have even returned to using animals such as horses to pull logs in order to reduce soil compaction, although the costs of such methods make it difficult to compete economically with mechanized logging practices. (FIGURE 30.4)

Logging, Deforestation, and Reforestation

Approximately 30 percent of all commercial timber in the world is produced in the United States and Canada. Compared with South America and Africa, forest losses in these two major timber-producing countries have been relatively small over the last several decades. Still, timber production presents important ecological challenges in these two countries.

Throughout this chapter we have seen examples of the conflicts over land use created by competing interests and values. Perhaps nowhere is this conflict so clear as in the case of logging. For example, while timber production has always been a part of the mission of the United States Forest Service, maintaining biodiversity is an equally important goal. It would seem that we can’t have both.

All logging disrupts habitat and usually has an effect, either negative or positive, on plant and animal species. One such species is the marbled murrelet (Brachyramphus marmoratus). This bird spends most of its life along the coastal waters of the Pacific Northwest, but it nests in coastal redwood forests. With the intensive logging of these forests, the marbled murrelet has become endangered. The tree sit described at the beginning of this chapter brought this species, among others, to the public’s attention.

Logging often replaces complex forest ecosystems with tree plantations, which are large areas typically planted with a single rapidly growing tree species. These same-aged stands can be easily clear-cut for commercial purposes, such as pulp and wood, and then replanted. Because of this cycle of planting and harvesting, tree plantations never develop into mature, ecologically diverse forests. If too many planting and harvesting cycles occur, the soil may become depleted of important nutrients such as calcium.

Since 1982, federal regulations have required the USFS to provide appropriate habitat for plant and animal communities while at the same time meeting multiple-use goals. However, because these regulations fail to specify how biodiversity protection should be achieved or how the results should be quantified, the USFS has had to choose its own approach to biodiversity management. Critics charge that the USFS is not adequately protecting biodiversity and forest ecosystems, but the USFS maintains that it is doing the best it can at meeting many different objectives.

Fire Management

In many ecosystems, fire is a natural process that is important for nutrient cycling and regeneration. As discussed briefly in Chapter 3, when fires periodically move through an ecosystem, they liberate nutrients tied up in dead biomass. In addition, areas where vegetation is killed by fire provide openings for early-successional species.

Humans have followed a variety of management policies with respect to fire. For many years, managers of forest ecosystems, including the USFS, worked to suppress fires. This strategy led to the accumulation of large quantities of dead biomass on the forest floor, which built up until a large fire became inevitable. One method for reducing the accumulation of dead biomass is a prescribed burn, in which a fire is deliberately set under controlled conditions. Prescribed burns help reduce the risk of uncontrolled natural fires as well as providing some of the other benefits of fire. More recently, forest managers have allowed certain fires that have occurred naturally to burn. This policy appears to have been accepted in many parts of the United States, as long as human life and property are not threatened.

Probably the best-known forest fires in the United States are those that occurred in Yellowstone National Park in the summer of 1988, the driest year on record at the park where a combination of human activity and lightning set off multiple fires (FIGURE 30.5). Over 25,000 people participated in fighting the fires. While this effort saved human lives and property, the firefighters had little impact on the fires. When the fires were out, more than one-third of Yellowstone National Park had burned. Initially, many people were outraged that the NPS and others had “allowed” the park to burn. However, within a few years, it became clear that the fires had created new, nutrient-rich habitat for early-successional plant species that attracted elk and other herbivores. Ultimately, researchers and forest managers concluded that the Yellowstone fires of 1988 provided many benefits to the Yellowstone ecosystem. Today, a typical visitor viewing a portion of the park that burned in 1988 probably wouldn’t even know that there had been a major fire 25 years earlier.

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National Parks

As we have already noted, many national parks were established to preserve scenic views and unusual landforms. Today, national parks are managed for scientific, educational, aesthetic, and recreational use. Since Yellowstone National Park was founded in 1872, 57 additional national parks have been established in the United States. Today the NPS manages a total of 400 national parks and other areas, such as historical parks and national monuments, and the list continues to grow.

The Goals of National Park Management

Management of national parks, like that of national forests, is based on the multiple-use principle. Unlike national forests, U.S. national parks were set aside specifically to protect ecosystems. In establishing Yellowstone National Park, Congress mandated the Department of the Interior to regulate the park in a manner consistent with the preservation of timber resources, mineral resources, and “natural curiosities.” However, it did not require a management process based on ecological principles.

It was not until the 1960s that ecology became a focus of national park management. In 1963, an advisory board on wildlife management presented the Leopold Report to Secretary of the Interior Stewart Udall. This report established the guiding principles of national park management that are followed today. It proposed that the primary purpose of NPS should be to maintain the parks in the same biotic condition in which they were first found by European settlers. To this end, the authors believed that NPS should focus its efforts on conservation and on protection of wildlife species and their habitats. The report claimed that human activity had severely affected normal ecological processes in the parks and that active intervention was required to achieve the goal of a return to a more “natural” state.

Today, NPS applies knowledge gained from environmental science to maintain biodiversity and ecosystem function in all national parks. As we saw in the example of the Yellowstone fires, NPS policies continue to be controversial. Each national park adapts U.S. policy to its specific needs. In parks with high levels of endemic biodiversity, for example, management focuses on conserving endemic species. The Channel Islands National Park off the coast of southern California, for instance, is an important breeding ground for many seabirds, including a pelican species rarely found elsewhere in the western United States. Because of this, the Channel Islands National Park is managed primarily to conserve its biodiversity. Other national parks balance biodiversity protection with recreational use.

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National Parks and Human Activities

Reducing the impact of human activities both outside and inside park borders is the primary challenge of most national parks throughout the world. Air and water pollution from distant sources can reduce biodiversity, recreational value, and economic opportunities. Ongoing development adjacent to park boundaries can be particularly problematic. In many locations, national parks have become islands of biodiversity amid increasing human development, but even the protected status of the parks cannot defend them completely from invasive species and other problems, such as pollution. These external threats require large-scale evaluation, planning, and management that extend beyond the borders of individual parks.

National parks are also victims of their popularity. Although the park system was established in part to make areas of great beauty accessible to people, human overuse can harm the very environment that attracts visitors. For example, all-terrain vehicles (ATVs) are a major cause of air and noise pollution in national parks, as well as a direct cause of habitat destruction (FIGURE 30.6). Today, many parks strictly limit or even ban the use of ATVs. Still, park managers grapple with how best to determine appropriate limits on human activity. In many cases, there is no easy answer to the trade off between short-term recreational uses and long term protection of biodiversity.

Wildlife Refuges and Wilderness Areas

National wildlife refuges are the only federal public lands managed for the primary purpose of protecting wildlife. The Fish and Wildlife Service manages more than 450 national wildlife refuges and 28 waterfowl production areas on 34.4 million hectares (85 million acres) of publicly owned land.

National wilderness areas are set aside with the intent of preserving large tracts of intact ecosystems or landscapes. Sometimes only a portion of an ecosystem is included. Wilderness areas are created from other public lands, usually national forests or rangelands, and are managed by the same federal agency that managed them prior to their designation as wilderness areas.

These areas allow only limited human use and are designated as roadless. Although logging, road building, and mining are banned in national wilderness areas, roads that existed before the designation sometimes remain in use, and activities such as mining that were previously permitted on the land are allowed to continue. More than 38.5 million hectares (95 million acres) of federal land, 60 percent of which is in Alaska, are classified as wilderness.

Federal Regulation of Land Use

Government regulation can influence the use of private as well as public lands. The 1969 National Environmental Policy Act (NEPA) mandates an environmental assessment of all projects involving federal money or federal permits. Along with other major laws of the 1960s and 1970s, such as the Clean Air Act, the Clean Water Act, and the Endangered Species Act, NEPA creates an environmental regulatory process designed to ensure protection of the nation’s resources.

Before a project can begin, NEPA rules require the project’s developers to file an environmental impact statement. An environmental impact statement (EIS) typically outlines the scope and purpose of the project, describes the environmental context, suggests alternative approaches to the project, and analyzes the environmental impact of each alternative. NEPA does not require that developers proceed in the way that will have the least environmental impact. However, in some situations, NEPA rules may stipulate that building permits or government funds be withheld until the developer submits an environmental mitigation plan stating how it will address the project’s environmental impact. In addition, preparation of the EIS sometimes uncovers the presence of endangered species in the area under consideration. When this occurs, managers must apply the protection measures of the Endangered Species Act, a 1973 law designed to protect species from extinction.

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Members of the public are entitled to comment on the environmental assessment and decision makers are required to respond. And, although developers are not obligated to act in accordance with public wishes, in practice public concern often improves the project’s outcome. For this reason, attending informational sessions and providing input is a good way for concerned citizens to learn more about local land use decisions and to help reduce the environmental impact of land development.

Roughly a century ago, large numbers of people in the United States began to move from rural areas to large cities. The last 50 years have seen an increased movement from those cities to the surrounding areas, which has resulted in the growth of two classes of communities: suburban and exurban. Suburban areas surround metropolitan centers and have low population densities compared with urban areas. Exurban areas are similar to suburban areas, but are not connected to any central city or densely populated area. Since 1950, more than 90 percent of the population growth in metropolitan areas has occurred in suburbs, and two out of three people now live in suburban or exurban communities.

The U.S. census bureau currently categorizes a population as urban if the area contains more than 2,500 people. FIGURE 30.7 shows U.S. urban and rural populations between 1910 and 2012. The rural population in the United States has been roughly the same since 1910, and a century later it makes up less than a fifth of the total U.S. population. Although this population shift has brought with it a new set of environmental problems associated with urban sprawl, attempts to find creative solutions have been increasingly successful.

Causes and Consequences of Urban Sprawl

If you have ever been to a strip mall, you are familiar with the phenomenon known as urban sprawl—urbanized areas that spread into rural areas and remove clear boundaries between the two. The landscape in these areas is characterized by clusters of housing, retail shops, and office parks, which are separated by miles of road. Large feeder roads and parking lots that separate “big box” and other retail stores from the road discourage pedestrian traffic.

Urban sprawl has had a dramatic environmental impact. Dependence on the automobile causes suburban residents to drive more than twice as much as people who live in cities. Between 1950 and 2000, the number of vehicle miles traveled per person in U.S. suburban areas tripled. Because suburban house lots tend to be significantly larger than their urban counterparts, suburban communities also use more than twice as much land per person as urban communities. Urban sprawl tends to occur at the edge of a city, often replacing farmland and increasing the distance between farms and consumers. In its most recent survey, the U.S. Department of Agriculture estimated that between 1982 and 2007, U.S. farmland was being converted to residential uses at a rate of 405,000 ha (1 million acres) per year. There are four main causes of urban sprawl in the United States: automobiles and highway construction, living costs, urban blight, and government policies.

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Automobiles and Highway Construction

Before automobiles and highway systems existed, transportation into and out of cities was difficult: Horses were slow, roads were bad, and trolley services rarely went far beyond the city limits. In those days, if you wanted to take advantage of the many amenities of city life, such as job opportunities, cultural institutions, shopping, and social activities, you had to live within a few miles of the city center.

The advent of the automobile, and the subsequent development of the interstate highway system in the 1950s and 1960s, changed everything. Today we think nothing of working in the city during the day and commuting home to the suburbs at night. And if you live in the suburbs but want to get into the city on a Saturday night for dinner, a concert, or a movie, that’s no problem either. With rapid, comfortable transportation between urban and suburban areas, it became possible to work or play in the city and then return to a large home in a quiet neighborhood. For the first time in history, people could enjoy the best of both worlds.

Living Costs

Land in the suburbs, because it is readily available, is relatively inexpensive when compared with land in the city. For the cost of a tiny one-bedroom condominium in a desirable section of a city, you may be able to purchase a five-bedroom house with a big yard in the suburbs. In addition, because suburban governments often provide fewer public services than cities, tax rates in the suburbs are likely to be lower. For these reasons, moving to the suburbs allows some people to enjoy a higher standard of living than they could afford in the city.

Although single-family homes in the suburbs are likely to be less expensive than desirable housing in the city, they are still out of reach for many people. And because single-family homes are usually the only housing option available in the suburbs, those with lower incomes are excluded. Most suburban communities have little, if any, low-income or “affordable” housing. Furthermore, in many suburban locations, it is difficult to commute to the city without a car, which compounds the difficulties for lower-income individuals. Even when public transportation is available, commuting costs can be high.

Urban Blight

We have seen that urban sprawl encourages population shifts to the suburbs. As people leave the city, city revenue from sources such as property, sales, and service taxes begins to shrink. However, the cost of maintaining urban services, including public transportation, police and fire protection, and social services, does not decrease. Faced with declining tax receipts, cities are forced to reduce services, raise tax rates, or both. As services decline, crime rates may increase, either because police resources are stretched thin or because conditions for lower-income residents decline even further. Infrastructure also deteriorates, leading to a decline in the quality of the built environment. These problems, combined with higher taxes, have made cities less attractive places to live in previous decades, and those who can afford to move away have often been likely to do so.

In addition, as the population shifts to the suburbs, jobs and services follow. Suburbanization has spawned suburban office parks, which have led to an increase in suburb-to-suburb commuting. Commuting patterns develop around cities rather than into and out of them, and these new traffic patterns make it more difficult to provide public transportation to the spreading region. As wealthy and middle-income people leave cities, urban retail stores lose customers and are forced to close, giving people even fewer reasons to go to the city to shop. This further decreases the customer base for the remaining stores. This cascade of effects leads to the positive feedback loop shown in FIGURE 30.8. This loop creates urban blight—the degradation of the built and social environments of the city that often accompanies and accelerates migration to the suburbs.

Historically, urban blight has contributed to racial segregation. In the 1950s and 1960s, when migration to the suburbs began in earnest, those leaving the cities for the suburbs were predominantly middle- or upper-income Caucasians. This so-called “white flight” resulted in highly concentrated minority populations in city centers and almost entirely white populations in the suburbs. Over time, the disparity of opportunity increased because tax revenues in suburban communities often allowed for better schools. In a number of U.S. cities, some of this segregation has begun to decline as Caucasians return to the cities and more minorities, after having accumulated wealth, move out to the suburbs. In addition, many young professionals are making the decision to work and live in cities. Nevertheless, racial disparities remain.

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Government Policies

Urban sprawl has also been enhanced by federal and local laws and policies, including the Highway Trust Fund, zoning laws, and subsidized mortgages.

The Highway Trust Fund, begun by the Highway Revenue Act of 1956 and funded by a federal gasoline tax, pays for the construction and maintenance of roads and highways. We have already seen that highways allow people to live farther from where they work. FIGURE 30.9 shows the resulting positive feedback loop. More highways mean more driving and more gasoline purchases, which lead to more gasoline tax receipts that pay for more roads, and so on. As people move farther away from their jobs, traffic congestion increases, and roads are expanded. But the new, even larger roads encourage even more people to live farther away from work. This cycle exemplifies a phenomenon known as induced demand, in which an increase in the supply of a good causes demand to grow.

Governments may use zoning to address issues of traffic congestion, urban sprawl, and urban blight. Zoning is a planning tool developed in the 1920s and used to separate industry and business from residential neighborhoods, thereby creating quieter, safer communities. Governments that use zoning can classify land areas into “zones” in which certain land uses are restricted. For instance, zoning ordinances might prohibit developers from building a factory or a strip mall in a residential area or a multi-dwelling apartment building in a single-home neighborhood. Nearly all metropolitan governments across the United States have adopted zoning.

Zoning often regulates much more than land use. The number of parking spaces a building must have, how far from the street a building must be placed, or even the size and location of a home’s driveway are among the development features that zoning may stipulate. Zoning laws have been helpful in addressing issues of safety and sometimes in minimizing environmental damage caused by new construction. One negative aspect of zoning, however, is that it generally prohibits suburban neighborhoods from developing a traditional “Main Street” with shops, apartments, houses, and businesses clustered together. Many communities are now attempting to incorporate multi-use zoning, which allows retail and high-density residential development to coexist in the same area. However, most zoning in the United States continues to promote automobile-dependent development.

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The federal government has also played a large part in encouraging the growth of suburbs through the Federal Housing Administration (FHA). Congress established the FHA during the Great Depression of the 1930s, in part to jump-start the economy by creating more demand for new housing. Through the FHA, people could apply for federally subsidized mortgages that offered low interest rates, which allowed many people who otherwise could not afford a house to purchase one. However, the FHA financed mortgages only for homes in financially “low risk” areas that were almost always the newly built, low-density suburbs. At the end of World War II, the GI Bill extended generous credit terms to war veterans, and the suburban housing boom continued. Suburbs became even more attractive as cars became more affordable and mass-produced housing allowed developers to sell suburban homes at affordable prices.

Smart Growth

People are beginning to recognize and address the problems of urban sprawl. One approach, smart growth, focuses on strategies that encourage the development of sustainable, healthy communities. The Environmental Protection Agency lists 10 basic principles of smart growth:

Of course, no individual new development or neighborhood plan is likely to incorporate all of these ideals, but as a guide to thinking about how to build communities, the smart growth concept has been quite successful.

Smart growth can have important environmental benefits. For example, compact development reduces the amount of impervious surface, reducing runoff and flooding downstream. A 2000 study found that smart growth in New Jersey would reduce water pollution by 40 percent compared with the more common, dispersed growth pattern. By mixing uses and providing transportation options, smart growth also reduces fossil fuel consumption. A 2005 study in Seattle found that residents of neighborhoods incorporating just a few of the techniques to make non-auto travel more convenient traveled 26 percent fewer vehicle miles than residents of more dispersed, less-connected neighborhoods. A 2012 San Francisco State University study found that similar smart growth practices led to a 20 percent reduction in miles traveled in 18 urban areas across the United States.