Lecture 6 - 1201

Lecture 6 - 1201 - Managing Forest Land Managing Forest...

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Unformatted text preview: Managing Forest Land Managing Forest Land 32% of earth’s surface is forest, 30% in USA Old growth forests most ecologically diverse Secondary Forests­ follow disturbance Tree plantations­managed with uniform species of same age Management Management How often trees harvested­ Depends on use Short Rotation Cycles­ pulp for paper, fuelwood 6­10 years in tropical forests, 20­30 years temperate forests Longer Rotation cycles required for higher quality wood Management Management Even Aged Management­same age and size­ plantations Uneven Aged Management­ Maintain variety of sizes, selective cutting­ foster biodiversity, long term sustainability, multiple uses Harvesting Techniques Harvesting Techniques Build a Logging Road­ opens access­ disqualifies land for protection as wilderness Clear cutting­ remove all trees Selective cutting­cut older trees singly Shelterwood cutting­ remove older trees in 2­3 cuttings over 10 years Seed­tree cutting­ leave a few trees to reseed Clear cutting Clear cut forest in Oregon Shelterwood cut forest Seed tree cut forest Seed tree cut forest Tropical Forests Tropical Forests 6% of world land area, 47% of forest cover 30% of species in Brazil tropical rain forest Half area has been cleared since 1950 Population growth, poverty, govt. policies encourage deforestation Tropical Forests Tropical Forests Commercial Logging­ clear cutting Unsustainable farming Cash crops Mining Fuelwood­15% of fuel supply Amazon Rainforest cleared For Agriculture Satellite Image of forest destruction in Bolivia for soybean cultivation Solutions Solutions Alternative fuels Sustainable Agroforestry/Multilayered cultivation Strip cutting of forests with long regeneration cycles Promote utilitarian uses of the forests Long Rotations Selective cutting Strip cutting Minimize fragmentation Reduce road building Leave dead trees/fallen timber for habitats US Forests­Maintaining US Forests­Maintaining Diversity Designing Nature Preserves Designing Nature Preserves Ecosystems are rarely stable Moderate disturbance leads to greatest diversity Prevention Strategy­ Reduce future loss by preserving species rich areas internationally or Emergency action­ Identify “hot spots”­ diverse areas in danger of habitat loss­ 1500 plant specices, lost 70% of vegetation Biodiversity Hotspots Biodiversity Hotspots Shape­ Circular is ideal­ interior is buffered; depends on available land Size­ one large vs several small Heterogeneity allows for movement and managing disturbance Corridors between reserves Buffer zones­ allow some resource extraction Management Goals Management Goals Maintain native ecosystem Sustain native species while controlling invasive species Sustain ecological processes­ succession, natural cycles, etc. Maintain evolutionary potential of species and ecosystem Allow sustainable human use of resources in ways that do not harm long­term sustainability Adaptive Ecological Management­ Integrate ecological, social and economic principles to maintain and restore, while supporting community and local economies Ecological Restoration Ecological Restoration Restoration or replacement? Identifying causes of damage­ Pollution, overgrazing, invasive species Mimic nature wherever possible Recreate niches that have been lost Rely on pioneer species, succession Remove non­native species ...
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  • Fall '08
  • SILVA,T.
  • Harvesting Techniques Harvesting Techniques, Ecological Restoration Ecological Restoration, Forests Tropical Forests
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