1. Land Use

2. Land Use • 29% of the earth is land • 29% forests and woodlands • 27% range and pastures • 11% cropland • 33% tundra, marsh, desert, urban areas, bare rock, ice or snow

3. Forest Use • More than ½ converted to cropland, pasture, settlements, and wasteland • Ecological roles? • Used for: • ~25% of world’s forests are actively managed for wood production.

4. Forest Management • Harvesting methods • Selective cutting • Seed tree cutting • Strip cutting • Clear cutting

5. Urbanization & Urban growth • Urban area-contains more than 1000 people per square mile • Urban growth due to: • natural increase - births • immigration • Trends of urban growth: • ~75% of people in developed countries live in urban areas • Increase of 2% to 45% of people in urban areas since 1950 • By 2050 about 66% of the world’s people will be living in urban areas.

6. Urbanization & Urban growth • The number of large cities is mushrooming • megacities and megalopolis • Today, more than 400 cities have over 1 mil. or more people. • 19 megacities with over 10 mil. people i.e. Tokyo (35.7 mil), Mexico City (18 mil), New York (19 mil).

7. Urbanization & Urban Growth • Developing countries-most will be urban growth • Poverty is becoming increasingly urbanized • slums, squatter settlements and shantytowns • at least 1 billion people live in crowed slums of inner cities. • No access to water, sewer, electricity, education etc. 100 mil people are homeless & sleep on the streets • Case study - Mexico City

8. Mexico City • Tied for 2nd largest city with 19 million people (1 in 5 Mexicans) • severe air pollution (over 4 million cars) within a valley that causes an estimated 100,000 premature deaths/year • high unemployment rate, close to 50% • high crime rate • Over 1/3 (6 million) of its residents live in slums (barrios) without running water, sewer (but running sewage), or electricity • high infection rates i.e. salmonella, hepatitis

9. Urban Resources & Environmental Problems • 50% of people living in 5% of land – cities – consume 75% of the world’s resources • Urban areas depend upon imports

10. Urban Resource and Environmental Problems • Destruction of plant life - what is $ value? • Cities produce little of own food • Urban heat island effect --> dust dome • Water supply and flooding problems • High pollution exposure

12. Urban Resource & Environmental Problems • Excessive noise exposure  health effects • Hearing loss, hypertension, muscle tension, migraines, headaches, higher cholesterol levels, gastric ulcers, irritability, insomnia, psychological disorders, aggression

13. Benefits of urbanization • recycling more economically feasible • decreased birth rates reduces environmental pressures • population concentration impacts biodiversity less

14. United States Urbanization • Migration to large central cities • Migration from cities to suburbs • Migration from north & east to south & west • Urban sprawl,growth of low-density development on the edge of cities. • Main causes: • Automobiles and highway construction • Living costs • Urban blight (positive feedback) • Government policies • Highway Trust Fund

15. Impacts of Urban Sprawl Fig. 25-8 p. 666

16. Impacts of Urban Sprawl

17. Drive alone 80% Other 4% Public transit 5% Car pool 11% Motor vehicle concentration • Ground transportation: individual (cars, etc) and mass (buses and rail)

18. Pros and Cons of Mass transit • 3% mass transit use in U.S. to 47% in Japan • Rapid rail, suburban trains and trolley - efficient at high population density • High speed rail lines – replace planes, buses and private cars; but require large government subsidies • Bus systems more flexible than rail systems

19. Alternatives to Urban Land Use? • Smart Growth-efficient use of land resources and existing urban infrastructure • Using zoning laws to prevent sprawl, direct growth in certain areas • Mixed land uses • Create a range of housing opportunities and choices • Create walkable neighborhoods • Encourage community and stakeholder collaboration in development decisions • Take advantage of compact building design • Foster distinctive, attractive communities with a strong sense of place • Preserve open space, farmland, natural beauty, and critical environmental areas • Provide a variety of transportation choices • Strengthen and direct development toward existing communities • Make development decisions predictable, fair, cost effective (no cookie cutters)