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ENVIRONMENTAL SCIENCE

13e. ENVIRONMENTAL SCIENCE. CHAPTER 8: Sustaining Biodiversity: The Species Approach. Core Case Study: Polar Bears and Projected Climate Change. 20,000 – 25,000 polar bears in Arctic Hunt seals on winter sea ice

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ENVIRONMENTAL SCIENCE

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  1. 13e ENVIRONMENTALSCIENCE CHAPTER 8:Sustaining Biodiversity: The Species Approach

  2. Core Case Study: Polar Bears and Projected Climate Change • 20,000 – 25,000 polar bears in Arctic • Hunt seals on winter sea ice • Global warming is quickly reducing the amount of sea ice and how long it lasts in winter • Polar bears have less time to hunt and store fat for summer fasting • Projected 30-35% decline by 2050 • Potentially extinct from wild by 2100

  3. Fig. 8-1, p. 152

  4. 8-1 What Role Do Humans Play in the Premature Extinction of Species? • Concept 8-1 Species are becoming extinct 100 to 1,000 times faster than they were before modern humans arrived on earth, and by the end of this century, the extinction rate is expected be 10,000 times higher than the background rate.

  5. Human Activities and Extinction • Background extinction rate • Current rate is 100-1000 times background extinction • Rate likely to rise to 10,000 times • Is a mass extinction coming?

  6. Current Extinction Rate Estimates Are Conservative • Species and biodiversity decrease in next 50–100 years • Biodiversity hotspot rates higher than global average • Degrading, simplifying, and destroying diverse environments

  7. Fig. 8-2, p. 154

  8. Passenger pigeon Great auk Dodo Golden Toad Aepyornis (Madagascar) Fig. 8-2, p. 154

  9. Science Focus: Estimating Extinction Rates (1) • Three difficulties • Not easy to document – takes a long time • Only 2 million species of 8-100 million identified • Little is known about the 2 million species

  10. Science Focus: Estimating Extinction Rates (2) • Study records of post-human extinctions with previous extinctions from the fossil record • DNA copying mistakes • How habitat reduction increases extinction • Mathematical models • Inadequate data and models • Normal: 1 million to 10 million years • Humans have greatly accelerated this

  11. Ecological Smoke Alarms • Endangered species • Threatened species • The first to go: large, slow, tasty, or have valuable parts • Some behaviors make species prone to extinction

  12. Fig. 8-3, p. 156

  13. Kirkland’s warbler Grizzly bear Knowlton cactus African elephant Florida manatee Siberian tiger Utah prairie dog Golden lion tamarin Swallowtail butterfly Humpback chub Fig. 8-3, p. 156

  14. Fig. 8-3, p. 156

  15. Whooping crane Northern spotted owl Giant panda Black-footed ferret Blue whale Hawksbill sea turtle California condor Mountain gorilla Florida panther Black rhinoceros Fig. 8-3, p. 156

  16. Fig. 8-4, p. 157

  17. Examples Characteristic Blue whale, giant panda, rhinoceros Low reproductive rate Blue whale, giant panda, Everglades kite Specialized niche Elephant seal, desert pupfish Narrow distribution Bengal tiger, bald eagle, grizzly bear Feeds at high trophic level Blue whale, whooping crane, sea turtle Fixed migratory patterns African violet, some orchids Rare Snow leopard, tiger, elephant, rhinoceros, rare plants and birds Commercially valuable California condor, grizzly bear, Florida panther Large territories Fig. 8-4, p. 157

  18. Characteristic Examples Low reproductive rate Blue whale, giant panda, rhinoceros Blue whale, giant panda, Everglades kite Specialized niche Elephant seal, desert pupfish Narrow distribution Bengal tiger, bald eagle, grizzly bear Feeds at high trophic level Fixed migratory patterns Blue whale, whooping crane, sea turtle African violet, some orchids Rare Snow leopard, tiger, elephant, rhinoceros, rare plants and birds Commercially valuable California condor, grizzly bear, Florida panther Large territories Stepped Art Fig. 8-4, p. 157

  19. Fig. 8-5, p. 157

  20. Fish 34% (51% of freshwater species) Amphibians 32% Mammals 25% 20% Reptiles 14% Plants 12% Birds Fig. 8-5, p. 157

  21. Case Study: Extinction of the Passenger Pigeon • Audubon, 1813: 3 days for a flock to pass over • Extinct by 1900 • Good to eat • Feathers good for pillows • Bones good for fertilizer • Easy to kill

  22. 8-2 Why Should We Care about Preventing Species Extinction? • Concept 8-2 We should prevent the premature extinction of wild species because of the economic and ecological services they provide and because they have a right to exist regardless of their usefulness to us.

  23. Value of Species • Instrumental value of biodiversity • Food crops • Genetic information • Medicine • Bioprospectors • Ecotourism • Do not know what we lose when species go extinct

  24. Fig. 8-6, p. 158

  25. Fig. 8-7, p. 158

  26. Rosy periwinkle Rauvolfia Pacific yew Neem tree Foxglove Cinchona Cathranthus roseus, Madagascar Hodgkin's disease, lymphocytic leukemia Taxus brevifolia, Pacific Northwest Ovarian cancer Rauvolfia sepentina, Southeast Asia Anxiety, high blood pressure Azadirachta indica, India Treatment of many diseases, insecticide, spermicide Digitalis purpurea, Europe Digitalis for heart failure Cinchona ledogeriana, South America Quinine for malaria treatment Fig. 8-7, p. 158

  27. Ethical Obligations • Intrinsic (existence) value • Stewardship viewpoint

  28. 8-3 How Do Humans AccelerateSpecies Extinction? • Concept 8-3 The greatest threats to any species are (in order) loss or degradation of its habitat, harmful invasive species, human population growth, pollution, climate change, and overexploitation.

  29. Fig. 8-8, p. 160

  30. Natural Capital Degradation Causes of Depletion and Premature Extinction of Wild Species Underlying Causes • Population growth • Rising resource use • Undervaluing natural capital • Poverty Direct Causes • Habitat loss • Habitat degradation and fragmentation • Introduction of nonnative species • Pollution • Climate change • Overfishing • Commercial hunting and poaching • Sale of exotic pets and decorative plants • Predator and pest control Fig. 8-8, p. 160

  31. Causes of Endangerment and Premature Extinction (HIPPCO) • Habitat destruction • Invasive species • Population growth • Pollution • Climate change • Overexploitation

  32. Habitat Loss • Deforestation of tropical areas greatest eliminator of species • Endemic species • Habitat fragmentation

  33. Fig. 8-9, p. 161

  34. Fig. 8-9, p. 161

  35. Indian Tiger Black Rhino Range 100 years ago Range in 1700 Range today Range today African Elephant Asian or Indian Elephant Former range Probable range 1600 Range today Range today Stepped Art Fig. 8-9, p. 161

  36. Case Study: Declining BirdSpecies (1) • Decline of ~70% of ~10,000 known species • 12% threatened with extinction • Birds around humans benefited, but forest species declined • Long-distance migrants – greatest decline

  37. Case Study: Declining BirdSpecies (2) • Reasons • Habitat loss • Habitat fragmentation • Climate change • Birds are environmental indicators • Perform economic and ecological services

  38. Species Introductions • Most beneficial – food crops, livestock, pest control • 500,000 alien invader species globally • 50,000 nonnative species in the U.S. • Some definitely not beneficial

  39. Fig. 8-10, p. 163

  40. Deliberately Introduced Species African honeybee (“Killer bee”) Salt cedar (Tamarisk) Purple loosestrife European starling Nutria Marine toad (Giant toad) European wild boar (Feral pig) Water hyacinth Hydrilla Japanese beetle Fig. 8-10, p. 163

  41. Fig. 8-10, p. 163

  42. Accidentally Introduced Species Eurasian ruffe Sea lamprey (attached to lake trout) Argentina fire ant Brown tree snake Common pigeon (Rock dove) Zebra mussel Gypsy moth larvae Formosan termite Asian long-horned beetle Asian tiger mosquito Fig. 8-10, p. 163

  43. Deliberately introduced species Purple loosestrife European starling African honeybee (“Killer bee”) Nutria Salt cedar (Tamarisk) Hydrilla Marine toad (Giant toad) Water hyacinth Japanese beetle European wild boar (Feral pig) Accidentally introduced species Sea lamprey (attached to lake trout) Argentina fire ant Common pigeon (Rock dove) Brown tree snake Eurasian ruffe Formosan termite Zebra mussel Asian long-horned beetle Asian tiger mosquito Gypsy moth larvae Stepped Art Fig. 8-10, p. 163

  44. Case Study: The Kudzu Vine • Kudzu introduced to control erosion • Prolific growth • Uses • Asians use powdered starch in beverages • Edible • Source of tree-free paper • Japanese kudzu farm in Alabama

  45. Fig. 8-11, p. 164

  46. Disruptions from AccidentallyIntroduced Species • Downside of global trade • Downside of traveling • Argentina fire ant • Burmese python • Zebra mussel

  47. Fig. 8-12, p. 165

  48. Prevention of Nonnative Species (1) • Identify characteristics of successful invaders • Detect and monitor invasions • Inspect imported goods • Identify harmful invasive species and ban transfer

  49. Prevention of Nonnative Species (2) • Ships discharge ballast waters at sea • Introduce natural control organisms of invaders

  50. Fig. 8-13, p. 165

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