280 likes | 365 Views
Chapter 11. Biodiversity Unit. Just the facts. About 82% of temperate deciduous forests have been cleared, broken apart and dominated worldwide US – 95% of virgin forests logged US - 98% of tallgrass prairie is gone US - 85% of California’s redwood forest destroyed
E N D
Chapter 11 Biodiversity Unit
Just the facts • About 82% of temperate deciduous forests have been cleared, broken apart and dominated worldwide • US – 95% of virgin forests logged • US - 98% of tallgrass prairie is gone • US - 85% of California’s redwood forest destroyed • US -99% of California’s grassland is gone.
Can you place a value on that? • Instrumental value: based on usefulness to humans • Use values: goods, services, economy, fun, medicines, etc. • Nonuse values: aesthetic value, bequest value (people will pay to protect it), • Is simple existence reason enough for protecting something?
Notice anything???? Arctic Circle Arctic Circle 60° EUROPE NORTH AMERICA ASIA 30°N Tropic of Cancer Atlantic Ocean AFRICA Pacific Ocean Pacific Ocean 0° 150° 120° 90° 30°W 0° 60°E 90° 150° SOUTH AMERICA Indian Ocean Tropic of Capricorn AUSTRALIA 30°S Antarctic Circle 60° ANTARCTICA Critical and endangered Threatened Stable or intact Projected Status of Biodiversity 1998–2018
The Species Approach The Ecosystem Approach Same problem,two approaches Goal Goal Protect populations of species in their natural habitats Protect species from premature extinction Strategies Strategy • Identify endangered species • Protect their critical habitats Preserve sufficient areas of habitats in different biomes and aquatic systems Government and Laws – often in response to a problem. Reactive Organizations – often to prevent problem from occurring. Proactive Tactics Tactics • Protect habitat areas through private purchase or government action • Eliminate or reduce populations of alien species from protected areas • Manage protected areas to sustain native species • Restore degraded ecosystems • Legally protect endangered species • Manage habitat • Propagate endangered species in captivity • Reintroduce species into suitable habitats
Public Lands National parks and preserves National forests (and Xs) National wildlife refuges
Even aged-management Weak trees removed Seedlings planted Clear cut 25 15 10 30 Years of growth 5
Explain selective cutting: Older trees are cut and removed. This prevents overcrowding and allows natural regeneration Selective Cutting
Explain shelterwood cutting: Using multiple cutting to take down most mature trees. Allows for more sunlight to reach lower levels. Cut 2 Cut 1 Shelterwood Cutting
Explain seed-tree cutting: Nearly all mature and middle trees are removed. Seed trees are left to regenerate area Seed-Tree Cutting
Uncut Cut Cut Cut Uncut 1 year ago 3–5 years ago 6–10 years ago Strip Cutting Explain strip cutting: Clear cut in strips, allow time to regenerate
Trade-Offs Clear-Cutting Forests Advantages Disadvantages Reduces biodiversity Disrupts ecosystem processes Destroys and fragments some wildlife habitats Leaves moderate to large openings Increases soil erosion Increases sediment water pollution and flooding when done on steep slopes Eliminates most recreational value for several decades Higher timber yields Maximum economic return in shortest time Can reforest with genetically improved fast- growing trees Short time to establish new stand of trees Needs less skill and planning Best way to harvest tree plantations Good for tree species needing full or moderate sunlight for growth Clear Cutting
Natural Capital Degradation Deforestation • Decreased soil fertility from erosion • Runoff of eroded soil into aquatic systems • Premature extinction of species with • specialized niches • Loss of habitat for migratory species such as • birds and butterflies • Regional climate change from extensive clearing • Releases CO2 into atmosphere from burning • and tree decay • Accelerates flooding Consequences
Solutions Solutions Sustainable Forestry • Grow more timber on long rotations • Rely more on selective cutting and strip cutting • No clear-cutting, seed-tree, or shelterwood cutting • on steeply sloped land • No fragmentation of remaining large blocks of forest • Sharply reduce road building into uncut forest areas • Leave most standing dead trees and fallen timber for • wildlife habitat and nutrient recycling • Certify timber grown by sustainable methods • Include ecological services of trees and forests in • estimating economic value
Certify Forests?? • Independent companies certify that logging is completed in a sustainable manner, deadwood is left, soils are undamaged. • Mitusbishi (one of the world’s largest forestry companies) has all operations certified by a third party. • Home Depot, Lowes, Andersen have agreed to sell only wood certified as sustainably grown
Surface fire Surface fires burn the organic litter and “clean” the forest floor. Nutrients are returned to soil. Occasional surface fires are beneficial and can prevent crown fires.
II. The Living World (10-15%) • 1. Ecosystem Structure (edge effects) • 4. Natural Ecosystem Change (ecological succession) Video clip of syllabus points.
Top Causes of Tropical Rain Deforestation • Population growth (room/food for people) • Poverty (try to produce own food) • Environmentally harmful government subsidies (some give titles to people who clear the land • Debts owed to developed countries (try to make money off TRF to pay back) debt-for-nature-swap • Don’t recognize ecological value of forests
TRF products Rauvolfia Rauvolfia sepentina, Southeast Asia Tranquilizer, high blood pressure medication
Foxglove Digitalis purpurea, Europe Digitalis for heart failure TRF products
Pacific yew Taxus brevifolia, Pacific Northwest Ovarian cancer TRF products
Cinchona Cinchona ledogeriana, South America Quinine for malaria treatment TRF products
Rosy periwinkle Cathranthus roseus, Madagascar Hodgkin's disease, lymphocytic leukemia TRF products
Neem tree Azadirachta indica, India Treatment of many diseases, insecticide, spermicide TRF products Read page 213 “The Incredible Neem Tree” Is it worth planting more of these???
Biosphere Reserve Core area Buffer zone 1 Buffer zone 2 Tourism and education center Human settlements Research station
What Can You Do? Sustaining Terrestrial Biodiversity • Plant trees and take care of them. • Recycle paper and buy recycled paper products. • Buy wood and wood products made from trees that • have been grown sustainably. • Help rehabilitate or restore a degraded area of • forest or grassland near your home. • When building a home, save all the trees and as much • natural vegetation and soil as possible. • Landscape your yard with a diversity of plants natural • to the area instead of having a monoculture lawn.