Chapter 10:Biodiversity/Forests/Forest Management
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Transcript of Chapter 10:Biodiversity/Forests/Forest Management
Chapter 10: Sustaining Terrestrial Biodiversity
The Ecosystem ApproachCase Study: The Reintroduction of the Gray Wolf to Yellowstone
Why Should We Care About Biodiversity? Intrinsic Value Instrumental Value
Use Value: For the usefulness in terms of economic and ecological services.
Nonuse Value: existence, aesthetics, bequest for future generations.
Figure 10-3Figure 10-3
Types of Forests Old-growth forest: uncut or
regenerated forest that has not been seriously disturbed for several hundred years. 22% of world’s forest. Hosts many species with
specialized niches.
Figure 10-5Figure 10-5
Types of Forests
Second-growth forest: a stand of trees resulting from natural secondary succession.
Tree plantation: planted stands of a particular tree species.
Figure 10-6Figure 10-6
Animation: Hubbard Brook Experiment
PLAYANIMATION
Forest Benefits1. Influence local climates:
cooler and moister due to transpiration
2. Global biogeochemical cycles: provide a sink for CO2
3. Release O2
4. Roots hold soil: reduce erosion
5. Watershed protection: absorb, hold and slowly release water, controlling floods
6. Provide habitat for many organisms
Tropical Deforestation Agriculture Logging Mining Hydroelectric power development
Tropical Deforestation: Causes
Fig. 11-18 p. 212
Reducing Tropical Deforestation
Refer to Fig. 11-19 p. 213
Reducing poverty and population growth
Reduce illegal cutting
Debt-for-nature swaps
Sustainable tropical agriculture
Encourage protection of large tracts
Amazon Rainforest
Satellite image of deforestation in the Amazon region, taken from the Brazilian state of Para on July 15, 1986.
http://www.bsrsi.msu.edu/rfrc/index.html
Boreal Deforestation Alaska, Canada, Scandinavia, North Russia 11% of earth’s land area – world’s largest biome Frequently clear cut Primary source of industrial wood and wood
fiber Annual loss twice the Amazonian rainforest of
Brazil
Temperate Forests Have been holding steady or increasing in recent
years Biodiversity lower than in virgin forests Reasons include:
Secondary succession of abandoned farms Commercial planting Government protection
Results of Deforestation1. Threatens native people and cultures2. Decreased soil fertility3. Soil erosion4. Increased sedimentation in streams5. Formation of deserts in dry areas6. Unregulated water – droughts and floods7. Species extinction8. Migrating species affected9. Regional and global climate change10. Increased CO2 in atmosphere
Selective Cutting The hard maple forest is
managed under a selection system. Individual trees are harvested from stands on a 28 year cycle. Specific trees are retained in these stands for biodiversity and wildlife habitat purposes.
Selective Cutting
Clear cutting
Clear cutting
Ten year old clear cut – Tongass National Forest, AlaskaUS FS photo 1979
Western Red cedar stump, Washington USFS photo
Logging debris in creek, Umpqua National Forest, Oregon USFS photo
Planting after clear cut – Jack Pine
Tree Plantation – one species and even aged stand
Shelterwood Cutting
Shelterwood Cutting – Lake Superior
Strip Cutting Forestry in Idaho
Types and Effects of Forest Fires
Depending on their intensity, fires can benefit or harm forests. Burn away flammable ground material. Release valuable mineral nutrients.
Figure 10-13Figure 10-13
Kenya’s Green Belt Movement:Individuals Matter
Wangari Maathai founded the Green Belt Movement.
The main goal is to organize poor women to plant (for fuelwood) and protect millions of trees.
In 2004, awarded Nobel peace prize.
Figure 10-10AFigure 10-10A
The Green Belt Movement Wangari Maathai
talks about the Billion Tree Campaign Earth Focus: Wangari Maathai