17 Land Resources. Land Use – World Wide One of the best ways to protect endangered & threated species restore natural areas World wide humans use.

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

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

Conservation and Land Resources

© 2012 John Wiley & Sons, Inc. All rights reserved.