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Biodiversity Notes

Biodiversity Notes. Pg. 191 - 219. Humans Impacting Terrestrial Biodiversity. Population increases Individual resource use is increasing. Biodiversity Values. Intrinsic value = ethical value Instrumental value = usefulness Use value = economical and ecological services

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Biodiversity Notes

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  1. Biodiversity Notes Pg. 191 - 219

  2. Humans Impacting Terrestrial Biodiversity • Population increases • Individual resource use is increasing

  3. Biodiversity Values • Intrinsic value = ethical value • Instrumental value = usefulness • Use value = economical and ecological services • Nonuse value = asthetics, existence, bequest for future generations

  4. Types of Forests • Old -growth forests • Uncut or regenerated • Has not been disturbed by humans or natural disasters for at least several hundred years

  5. Types of Forests • Second-growth forests • Results from secondary succession

  6. Types of Forests • Tree Plantations • All the same age and same species of tree • They are cut and cleared as soon as they become valuable • Benefits • If planted on most of deforested and degraded land, could be enough wood for future needs • Reduce soil erosion • Slow global warming by removing CO2

  7. Encouraging Trends in Forests • Total area of temperate forests has increased a little • Increased tree cover from regrowth of forests • Might not continue because… • Population increasing • Economic growth • Increased resource consumption

  8. Forests in Haiti • Only 2% of land is now covered by forests • Now soil erodes and its harder to grow crops

  9. Reducing Unsustainable Harvesting • Plant small plantations of fast growing fuelwood trees • Burn wood more efficiently • Can burn dried roots of gourds and squash

  10. Logging Roads • More erosion and sediment runoff • Habitat fragmentation • Biodiversity loss • Expose forests to invasive species • Farmers, miners, ranchers, hunters now have access to forest • Disqualify land for protection as wilderness

  11. Harvesting Trees • Selective cutting • Intermediate-aged or mature trees are cut down individually or in small groups • Clear cutting • Removing all the trees • Strip cutting • Clearing a strip of trees • Wait for it to start regenerating • Then clear another strip

  12. Forest Fires • Surface fires • Burn away undergrowth and leaf litter • Spare most mature trees and wildlife • Can help prevent more severe fires by removing flammable material • Release nutrients • Stimulate germination of certain seeds

  13. Forest Fires • Crown fires • Burn whole trees • Often jump from treetop to treetop • Usually occur if a surface fire has not occurred in several decades • Kill most vegetation and wildlife • Increase soil erosion

  14. Forest Fires • Ground fires • Surface fire goes underground • Burns decayed leaves or peat

  15. Reducing Harm from Fires • Set small, contained surface fires to clear out flammable material • Release goats to eat underbrush • Allow fires on public land to burn • Protect houses by thinning a zone around them

  16. Good Act or Bad Act? • 2003 Healthy Forests Restoration Act • If company clears smaller trees and flammable underbrush • Then they can cut down 71% of the medium/large trees • But removing large trees encourages growth of small fireprone trees • The reminants left behind are flammable

  17. Logging • Pros

  18. Tropical Forests and Extinction • Lots of specialists, and not many generalists

  19. Governments and Tropical Deforestation • They encourage the poor to colonize there by giving them title to land they clear

  20. Saving Tropical Forests • Teach settlers there how to use land sustainably • Debt-for-nature swaps • Harvest trees more gently • Reforest and rehabilitate degraded forests

  21. Grasslands • Services • Soil formation • Erosion control • Nutrient cycling • Storing atmospheric carbon • Gene pools for crops

  22. Overgrazing • When too many animals graze for too long and exceed the carrying capacity • Effects • Reduces grass cover • Increases soil erosion • Increases invasion of plants that cattle won’t eat

  23. Managing Rangelands • Control the number of grazing animals • Rotational grazing • Fencing off areas where cattle like to graze the most (near streams or rivers, called riparian zones) • Provide supplemental feeding • Putting water holes and tanks in strategic places • Supress growth of unwanted invader plants • Replanting barren areas

  24. US National Parks • Stresses • Popularity • Visitors still want all their modern conviences at the parks • Spending more time/money on law enforcement • Invasive species get introduced • Just islands of biodiversity

  25. Megadiversity • Brazil • Indonesia • Columbia

  26. Repairing Ecosystems • Restoration: • Return to original condition • Rehabilitation: • Make it functional again, but not fully restore it • Replacement: • Putting on ecosystem where another one was • Ex: replacing forest with tree farm • Creating artificial ecosystems

  27. What can you do? • Adopt a forest • Plant trees and take care of them • Recycle paper, buy recycle products • Buy sustainable wood and wood products • Choose wood subsititutes • Restore degraded forest/grassland • Landscape yard with native plants • Live in town to reduce suburban sprawl

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