land resources

Land Resources

Chapter 18

Many ecosystem services provided by rural lands enable the majority of humans to live in urban environments.

Examples: wildlife habitat, flood and erosion control, groundwater recharge, breakdown of pollutants, recycle wastes, maintain biological diversity, protect endangered and threatened species, recreation, education, aesthetic value, help us recover from stresses of urban life

Land Use

World Land Use 38% of the world’s land area is for agriculture

29% of land surface is for natural ecosystems

Land Use

Land Use in the US

Private

Tribes

Federal Gov.

State Gov.

Land Use

Federally managed land

Note: predominance of federal lands in the western states and Alaska

Land Use

Administration of Federal Lands

BLM

USFS

USFWS

NPS

Other

U.S. Department of the Interior: Bureau of Land Management, Fish and Wildlife Services, National Park Service

U.S. Department of Agriculture: U.S. Forest Service

Land UsePollution, population issues, preservation of our biological resources, mineral and energy

requirements and production of food are all tied to land use.

Managing Public and Private Land – largely controlled by economic factors

Public Planning of Land Use

• Development planning should be comprehensive

• Consider housing, businesses, agricultural, undeveloped, etc.

• Zoning regulations

Land Use

Management of Federal Lands

Wise-Use Movement vs. Environmental Movement

Managing Public and Private Land

Wise-Use:The government has too many regulations protecting the environment and property owners should have more flexibility to use natural resources

Environmental:Views federal lands as a legacy of U.S. citizens

Wilderness, Parks, and Wildlife Refuges

Wilderness

Land completely set aside; no development permitted (no roads)

Wilderness Act of 1964:Set aside lands that retain its primeval character. National Parks, National Forests, National Wildlife Refuges-These areas are given the highest protection of any lands-more than ½ of the lands in the National Wilderness Preservation System lie in Alaska

Wilderness, Parks, and Wildlife Refuges

National Parks ( 1872-Yellowstone)

Land set aside for recreation and preservation

(limited development permitted, such as roads)

NPS created in 1916-Land and Water Conservation Fund Act of 1965Provided funds for purchase of new lands

Wilderness, Parks, and Wildlife Refuges

National Parks

Most popular

Wilderness, Parks, and Wildlife Refuges

National Parks

Threats to US ParksDuring peak season use, the same problems plaguing urban areas are found in popular national parks: crime, vandalism, litter, traffic jams, pollution of soil, water and air-imbalance of wildlife populations ( elk in Yellowstone)-pollution from out of park boundaries-ecologists have found that when environmental stressors occur, several small “island” populations are more likely to become threatened than single large population in a sizable range

Wilderness, Parks, and Wildlife Refuges

National Parks

Natural RegulationLetting nature take its courseFires not controlled (unless buildings threatened)Animals not culled (except invasive)

Wilderness, Parks, and Wildlife Refuges

National Parks

A Representative National Park in AfricaWorld Wildlife Fund, Cameroon government, and other agencies managing Korup National Park

Wilderness, Parks, and Wildlife Refuges

Wildlife Refuges

• Lands managed for conservation of fish, wildlife, and plants

• Recreation (including hunting and fishing) are permitted if such activities do not impede conservation efforts

Forests

Role of forests in the hydrologic cycle:

Forests

Forest Management

Traditional forest management vs.Ecologically sustainable forest management

Typical tree plantation•Monoculture•Heavy use of pesticides• Very low biological

diversity

Forests

Forest Management

Harvesting Trees

Clearcutting

Forests

Forest Management

Harvesting Trees

Selective cutting Shelterwood cutting

Forests

Forest Management

Harvesting Trees

Seed tree cutting

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Forests

Deforestation

• World forests shrinking by 22 million acres each year

• Many causes (drought, agricultural expansion, construction, tree harvest, etc.)

• Results in soil infertility, warmer climates, disrupted hydrologic cycle

Forests

Forest Trends in the USForest Legacy Program in 1990 Farm Bill assists . . .

Forests

Forest Trends in the US

US National ForestsManaged for multiple uses (hunting, mining, recreation, timber harvesting, etc.)

ForestsForest Trends in the US

US National Forests

Case-in-Point: Tongass National Forest

Forests

Trends in Tropical Forests

Forests

Why Are Tropical Forests Disappearing?

Forests

Why Are Tropical Forests Disappearing?

•Subsistence Agriculture•Commercial Logging•Cattle Ranching and Agriculture for Export

ForestsWhy Are Tropical Dry Forests Disappearing?

Forests

Boreal Forests and Deforestation

Rangelands and Agricultural Lands

Rangelands

Rangelands and Agricultural Lands

Rangeland Degradation and Desertification

• Many rangelands consistently overgrazed

• Overgrazing coupled with extended droughts = desertification

• Worldwide desertification rate = 1,374 mi2 per year

Rangelands and Agricultural Lands

Rangeland Trends in the US

Rangelands comprise 30% of land in US

1/3rd public, 2/3rd private

Issues Involving Public Rangelands

Grazing permit fees

Wild horses and burros

Rangelands and Agricultural Lands

Agricultural Lands

US has 300 million acres of prime farmland

Main problem: suburban spread onto agricultural land

Wetlands and Coastal Areas

Wetlands

Wetlands and Coastal Areas

Human activities that threaten wetlands:

• Draining for agriculture or mosquito control

• Dredging for navigation

• Channelization

• Construction of dams, sea walls, dykes

• Filling in for solid waste disposal, roads, residential / industrial development

• Conversion to aquaculture

Wetlands and Coastal Areas

US legislation has attempted to maintain a “no net loss” of wetlands

Reconstructed wetland in San Diego

Wetlands and Coastal Areas

Coastlines

Severely degraded or destroyed in US by filling and draining

Residential and industrial development common

Resulting problems:

Wetlands and Coastal Areas

Coastlines

Coastal Demographics• In US, 19 of 20 most densely populated

areas along coast.

• Worldwide, coastal management plans rarely integrate land and offshore water concerns

• Results in overdevelopment and pollution

Wetlands and Coastal Areas

Coastlines

National Marine Sanctuaries• US has 12

• Managed for multiple uses, including conservation, recreation, education, etc.

• Commercial fishing permitted, though there are “no take” zones

Conservation of Land Resources

Most endangered ecosystems in the US