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Land Use – World Wide
One of the best ways to protect endangered & threated species restore natural areas
World wide humans use ~3% of the total land
area for cities ~38% for agriculture
~29% available / potential for human development
Land Use - United States
55% of US land is privately owned 3% by Native American tribes 35% of US land is owned by the fed government 7% by local & state
Management of public & private land Economic factors largely control land use “Wide-use movement”
Believe the primary purpose of fed land is to enhance economic growth
“Environmental movement” Believe fed lands are a legacy of the U.S. citizens (preserve)
Wilderness Parks & Wildlife Refuges
Wilderness protected area of land in which no human development
is permitted (no permanent living) Wilderness Act (1964)
Set aside federally owned land Areas to remain natural and
unchanged for the future gen. to enjoy
Given the highest protection of any public land
Managed by NPS, USFS, FWS, &BLM
National Park System (NPS)
Created in 1916 Currently includes 58 parks Primary goal
Teach people about the natural environment, management of natural resources and history of a site
Yosemite National Park
National Park System
Threats to U.S. Parks Crime & Vandalism Traffic jams Pollution of the soil, water and air Resource violations, litter (Cutting of gov. funding)
Natural Regulation Policy to let nature take it course No culling wildlife (elk) or suppressing wildfire
National Wildlife Refuges System
1903, Theodore Roosevelt Most extensive network of lands & waters committed to
wildlife habitat in the world 535 refuges nationwide
Represent all major ecosystems found in US
Mission To preserve lands and waters for the conservation of
fishes, wildlife and plants of the US
Forests
Role in Hydrologic Cycle Local & Regional ppt.
Regulate global biogeochemical cycles
Forest Topics Forest Management Deforestation Forest Trends in the US Trends in Tropical Forests Boreal Forests
Forest Management
Traditional Forest Management Managed for timber production Low diversity- monoculture
Ecological Sustainable Forest Management Environmentally balanced Diverse trees Prevent soil erosion Preserve watersheds Wildlife corridors- unlogged / undeveloped areas
Provide escape routes, migration routes & more territories of increased biodiversity
Harvesting Trees US, Canada, Russia, Brazil, and China currently produce more than half of the worlds timber.
50% of harvested wood goes to make fuelwood charcoal
Harvesting trees Selective cutting Shelterwood cutting Seed tree cutting Clearcutting
NONE of these methods are currently used
DeforestationTemporary or permanent clearance of large expanses of forest for agriculture or other use
World forests shrank 32 million acres annually
from 2000–2010 Causes
Fire Expansion of agriculture Construction of roads Tree harvest Insect and disease Production of hydroelectric
power
Results of Deforestation Decreased soil fertility Uncontrolled soil erosion Increased sedimentation of
waterways Formation of deserts Extinction of species Global climate changes
Forest Trends in US
US has 155 national forests Most temperature forest are
steady or expanding
Returning stands lack biodiversity of original forests
More than 50% of US forest are privately owned Forest Legacy Program (1990)
Helps private land owners protect forestlands from development
Conservation easement Legal agreements that protect privately
owned land forests from development for a number of years
Concervation Tongass National Park
Largest national forest in the US (17 million acres)
One of world’s few temperate rainforests
Prime logging area
Roadless area conservation Politics rule – Lots of flip flopping over the years Fighting to conserve
Tropical rainforests & tropical dry forests
Tropical rainforests Occur in warm moist climates (> 200cm of ppt. annually)
Central & south America, Africa, & Southeast Asia Tropical Dry forests
Less ppt. than rain forests (prolonged dry seasons) India, Kenya, Zimbabwe, Egypt & Brazil
Disappearing Tropical Rain Forests
Remaining tropical rain forests are being cleared and burned at a rate unprecedented in human history
Immediate causes Population growth Subsistence agriculture
maintaining or supporting oneself at a minimum level
Commercial logging Cattle ranching
Other causes Mining Hydroelectric power
Human Settlement in a Brazilian Tropical Rain Forest
Disappearing Tropical Dry Forests
Slash-and-burn agriculture Practiced by ~200-500 million subsistence farmers agricultural technique that involves cutting and burning
of trees and plants to make farm land
Primarily destroyed for fuel wood Used for heating and cooking 1st crop yield is generally high Soil productivity declines rapidly if it is done over and over
Led to fuel crisis in many countries & large scale errosion Increase in waterborne diseases cooking water is not boiled
Boreal Forests (Taiga)
World’s largest biome Alaska, Canada, Scandinavia, & Northern Russia
10 source of world’s industrial wood & wood fiber Harvested (Extensively) by clearcut logging are
Evergreen trees( spruce, fir, cedar, and hemlock)
Biome - climatically and geographically defined as contiguous areas with similar climatic conditions
Rangeland landsLand that is not intensively managed and is used for grazing livestock
Degradation & Deforestation Animals exceed land’s carrying capacity (K)
Max # of animals that the land can sustain over an indefinite period without degradation
When the K exceeds Overgrazing leaves ground barren
Land degradation Natural or human-induced
process that decreases future ability of land to support crops or livestock
Desertification Degradation of once fertile land into nonproductive desert
Rangeland Trends in US
Make up 30% of total US land area Mostly in the western states
1/3 publicly owned & 2/3 privately owned
Pressure from developers to subdivide
Public rangeland managed by: Taylor Grazing Act (1934) Federal Land Policy and Management Act (1976)
Conditions of public rangeland are slowly improving
Agricultural Land
US has 300 million acres of prime farmland Suburban sprawl
Parking lots Housing
developments Shopping malls
WetlandsLands that are usually covered with water for at least part of the year
Characteristic soils, and water-tolerant vegetation Transitional lands between aquatic & terrestrial
Benefits Habitat for migratory waterfowl and wildlife Recharge groundwater Reduce damage from flooding Improve water quality Produce many commercially important products
Human Threats to Wetlands
Drained for agriculture or mosquito control
Dredging for navigation Construction of dams, dykes or seawalls Filling in for solid waste disposal Road building Mining for gravel, fossil fuels, etc.
Shrinking 24,300 acres per year since 1985
Protection of Wetlands
Clean Water Act (1972) 10 federal law in the US governing water pollution No clear definition of wetland
Emergency Wetlands Resource Act (1986) allocated funds from the LWCF for the purchase of
wetlands by the Sec. of Interior Instituted a National Wetlands Priority Conservation Plan
Opponents of wetland protection Say that it infringes on use of privately-owned land
Coastlines
Coastal wetlands Provide food and habitat for many aquatic animals Historically regarded as wasteland
Few laws protect shoreline along bays & sounds
Many coastal areas overdeveloped 3.8 billion people live within 150km of coastline 6.0 billion people will likely live there by 2025
United States 14 of 20 largest US cities along coast 19 of 20 most densely populated countries along coasts
Conservation and Land Resources
Four criteria of importance of conservation:
Areas lost or degraded since European colonization
Number of present ecosystem of a type
Estimate of the likelihood that a given ecosystem will lose significant area or be degraded in next 10 years
Number of threatened & endangered species living in the ecosystem