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GEOG 4400: Resource Use

GEOG 4400: Resource Use. Lecture 7 Biota. “Any fool can destroy trees. They cannot defend themselves or run away.” John Muir.  The World’s Forests. Where How much. Where. How much Change. Change. Deforestation. 10.1 billion acres of forest in the world (31% of land cover)

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GEOG 4400: Resource Use

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  1. GEOG 4400: Resource Use Lecture 7 Biota

  2. “Any fool can destroy trees. They cannot defend themselves or run away.” John Muir

  3.  The World’s Forests • Where • How much

  4. Where • How much • Change

  5. Change

  6. Deforestation • 10.1 billion acres of forest in the world (31% of land cover) • 50% of tropical forests cleared (2/3 in SE Asia) • 40-50 million acres per year • 150 acres per minute • Football field per second

  7. Deforestation • agriculture • local needs • export crops • wood supply • fuelwood

  8. Causes of Deforestation • Poverty • Fuelwood crisis

  9. Causes of change • Population growth • Capitalism • Inappropriate technology • Inappropriate government policies • Forest concessions • Underpricing • Removal of indigenous population • Ecological collapse • Tragedy of the commons

  10. Forest resources • Hardwood • Coffee • Spices • Nuts • Cacao (chocolate) • Latex • Dye • Medicines • Agriculture (rice, wheat, corn) • 50-90% of all biological diversity is in forests • Potential loss of 5-15% of world’s species from 1990-2000 • 50-150 species per day

  11. Uses of forest products • Traditional • Industrial • Services

  12. Types of harvest • Shelterwood • Selective • Clear-cutting • Biomass harvesting

  13. Effects of harvesting • Roads (340,000 miles = 10x interstate highway system) • Compaction from heavy equipment • Erosion • Nutrient removal • Water regime alteration • Stream conversion

  14. Trends in forestry • Industrial wood supply • Plantations • Global trade • Fuelwood • Services

  15. Other problems: • Greenhouse effect

  16. Forest structure • Fire • Good: release nutrients, remove old sick trees, allow light, burn off fuel • Bad: consume biomass, increase in runoff, sedimentation • Fire frequency- return interval • Types: ground, surface, crown, firestorm • Disease: fusiform rust, dwarf mistletoe, root diseases • Insects: spruce budworm, gypsy moth, pine beetle

  17. Reforestation • Causes of change • Population growth • Capitalism • Inappropriate technology • Inappropriate government policies • Forest concessions • Underpricing • Removal of indigenous population • Ecological collapse • Tragedy of the commons

  18. Reforestation • Natural regeneration/ seed tree • Artificial seeding • Seedling plantings • Plantation conversion (forest??)

  19. Sustained Yield • Harvesting of a species at a rate equal to its reproduction or maturation

  20. Multiple Use Sustained Yield Act of 1960 • recognize other uses of national forests • balanced management approach • timber • watershed maintenance • wildlife habitat • recreation

  21. National Forest Management Act of 1976 • limited size of clearcuts • protect riparian areas • regulation of rate of harvest • wilderness reviews (RARE studies)

  22. Debt for Nature swaps

  23. Wildlife

  24. Extinction

  25. Genetic Material

  26. Exotic Invasions

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