17 Land Resources

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)

Land Use - United States

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

Deforestation Temporary 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 ~ 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 1 st 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  1 0 source of world’s industrial wood & wood fiber  Harvested (Extensively) by clearcut loggingare  Evergreen trees( spruce, fir, cedar, and hemlock) Biome - climatically and geographically defined as contiguous areas with similar climatic conditions

Rangeland lands Land 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

Wetlands Lands 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)  1 0 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

Conservation and Land Resources © 2012 John Wiley & Sons, Inc. All rights reserved.