land resources
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Chapter 18. Land Resources. Many ecosystem services provided by rural lands enable the majority of humans to live in urban environments. - PowerPoint PPT PresentationTRANSCRIPT
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