Environmental Problems, Their Causes, and Sustainability 1

parkways, trails, rivers, seashores, and lakeshores.Only camping, hiking, sport fishing, and boating cantake place in the national parks, but sport hunting,mining, and oil and gas drilling is allowed in NationalRecreation Areas.The most restricted public lands are 660 roadlessareas that make up the National Wilderness PreservationSystem. These areas lie within the other types of publiclands and are managed by agencies in charge of thoselands. Most of these areas are open only for recreationalactivities such as hiking, sport fishing, camping,and nonmotorized boating.How Should U.S. Public Lands Be Managed?An Ongoing ControversySince the 1800s there has been controversy overhow U.S. public lands should be used becauseof the valuable resources they contain.Federal public lands contain valuable oil, natural gas,coal, timber, and mineral resources. Since the 1800sthere has been controversy over how the resources onthese lands should be used and managed.Most conservation biologists and environmentaleconomists and many free-market economists believethe following four principles should govern use ofpublic land:■ Protecting biodiversity, wildlife habitats, and theecological functioning of public land ecosystemsshould be the primary goal.■ No one should receive government subsidies ortax breaks for using or extracting resources on publiclands—a user-pays approach.■ The American people deserve fair compensationfor extraction of any resources from their property.■ All users or extractors of resources on public landsshould be responsible for any environmental damagethey cause.Aldo Leopold’s land-use ethic (Section 2-5, p. 30) is thebasis for most of these guiding principles.There is strong and effective opposition to theseideas. Economists, developers, and resource extractorstend to view public lands in terms of their usefulnessin providing mineral, timber, and other resources andtheir ability to increase short-term economic growth.They have succeeded in blocking implementationof the four principles just listed. For example, in recentyears the government has given more than $1 billion ayear in subsidies to privately owned mining, logging,and grazing interests using U.S. public lands.Some developers and resource extractors go furtherand have mounted a campaign to get the U.S.Congress to pass laws that would■ Sell public lands or their resources to corporationsor individuals at less than fair market value.■ Slash federal funding for regulatory administrationof public lands.■ Cut all old-growth forests in the national forestsand replace them with tree plantations.■ Open all national parks, national wildlife refuges,and wilderness areas to oil drilling, mining, off-roadvehicles, and commercial development.■ Do away with the National Park Service andlaunch a 20-year construction program of private concessionsand theme parks run by private firms in theformer national parks.■ Continue mining on public lands under the provisionsof the 1872 Mining Law, which allows mininginterests to pay no royalties to taxpayers for hard-rockminerals they remove.■ Repeal the Endangered Species Act or modify it toallow economic factors to override protection of endangeredand threatened species.■ Redefine government-protected wetlands so thatabout half of them would no longer be protected.■ Prevent individuals or groups from legally challenginguses of public land for private financial gain.xHOW WOULD YOU VOTE? Should much more of the U.S.public lands (or government-owned lands in the countrywhere you live) be opened to extraction of timber, mineral,and energy resources? Cast your vote online at http://biology.brookscole.com/miller14.11-4 MANAGING AND SUSTAININGFORESTSWhat Are the Major Types of Forests? Old-Growth, Second-Growth, and TreePlantationsSome forests have not been disturbed by humanactivities for several hundred years, others havegrown back after being cut, and some consist ofplanted stands of a particular tree species.Forests with at least 10% tree cover occupy about 30%of the earth’s land surface (excluding Greenland andAntarctica). Figure 6-16 (p. 111) shows the distributionof the world’s boreal, temperate, and tropical forests.These forests provide many important ecological andeconomic services (Figure 11-7, p. 200).Forest managers and ecologists classify forestsinto three major types based on age and structure. Onetype is an old-growth forest: an uncut forest or regeneratedforest that has not been seriously disturbed byhuman activities or natural disasters for at least severalhundred years. Old-growth forests are storehousesof biodiversity because they provide ecologicalniches for a multitude of wildlife species (Figure 6-30,p. 122).http://biology.brookscole.com/miller14199