Chapter 38

1. 0 Chapter 38 Conservation Biology

2. Myanmar tiger photographed by a remote “camera trap” • Saving the Tiger • Tigers once roamed across Asia • The arrival of humans brought competition for food, and also hunters • Tiger trophies, claws and bones are worth a lot of money • Poor people in the region are invading tiger habitat to make ends meet

3. Conservation efforts • providing protection for tigers so their populations can increase • The efforts to save tigers • Reflect a worldwide struggle to preserve biodiversity, the diversity of living things

4. Tiger populations have declined from over 100,00 to fewer than 5,000 in the wild • We are now presiding over a biodiversity crisis • A rapid decrease in Earth’s great variety of organisms • Conservation biology • Is a goal-driven science that seeks to counter the biodiversity crisis

5. THE BIODIVERSITY CRISIS: AN OVERVIEW • 38.1 Human activities threaten Earth’s biodiversity • Biodiversity includes • Genetic diversity, within and between populations • Species diversity • Ecosystem diversity

6. We are experiencing a mass extinction • Named 1.8 million species • 10-200 million species exist on Earth • Current global extinction rate is 1,000 times higher than any time in the past 100,000 years. • Over half of the current plant and animal species will be extinct by the end on the 21st century

7. We are experiencing a mass extinction • About 12% of the 9,946 known bird species and 24% of the 4,763 known mammalian species are threatened with extinction • About 20% of the known freshwater fishes in the world have either become extinct in recent history or are threatened with extinction • Of the 20,000 known plant species in the US, 200 have become extinct since we started keeping records and 730 species are endangered or threatened

8. Human activities effect • Important ecosystem processes: • Trophic structure • Energy flow • Chemical cycling • Natural disturbances

9. WHY SHOULD WE CARE?

10. 38.2 Biodiversity is vital to human welfare • Intrinsic Value • Biophilia • Moral beliefs • Food • Fiber • Medicines (25%) • ecosystem services (O2, fertile soil) • 33 TRILLION USD vs 18 TRILLION global GNP

11. 38.3 Habitat destruction, introduced species, and overexploitation are the major threats to biodiversity • Human Alteration of Habitat: • Poses single greatest threat to biodiversity • Agriculture • Mining • Urban development • Forestry • Environmental pollution

12. Introduced Species • Can disrupt communities by competing with or preying on native species • Ex) Kudzo EX) Lake Victoria’s Nile Perch • Hitchhiking seeds or insects, escaped exotic pets, species transported as unknown “cargo”, agriculture or ornamentation • 50,000 in US costing over 130 BILLION in damages and control efforts

13. Overexploitation of wildlife by harvesting • Has threatened various animal and plant species • Rates of harvesting exceed the ability of the populations to rebound • Commercial Harvest • Poaching • Sport Hunting • Illegal trade • Whales, tigers, American bison, Galapagos tortoises, and numerous fishes (NA bluefin tuna)

14. Herring gull eggs 124 ppm Lake trout 4.83 ppm Concentration of PCBs Smelt 1.04 ppm Zooplankton 0.123 ppm Phytoplankton 0.025 ppm • 38.4 Pollution of the environment compounds our impact on other species • Effects of pollution include • Acid rain • ozone depletion • eutrophication • dead zones • Chemical pesticides • Are concentrated by biological magnification

15. 38.5 Rapid global warming could alter the entire biosphere • Burning of fossil fuels • Is increasing the amount of CO2 and other greenhouse gases in the air • The increase of these gases in the atmosphere • May lead to global warming • EXTRA CREDIT: Watch An Inconvenient Truth • Write an essay about it: 2pgs double spaced • 20 points!

16. 1.05 390 0.90 380 0.75 370 Temperature 0.60 360 0.45 350 Temperature variation (°C) 0.30 CO2 concentration (ppm) 340 0.15 330 CO2 0 320 –0.15 310 –0.30 300 –0.45 1970 1975 1990 1995 2000 2005 1960 1965 1980 1985 Year

17. Human activities and natural processes add CO2 to the atmosphere, increasing the effect. Photosynthesis removes CO2 from the atmosphere, decreasing the effect. Global warming: CO2 lets sunlight through but retains the heat radiated from Earth. CO2 CO2 in the atmosphere CO2 CO2

18. Global warming may • Change climate patterns, melt polar ice caps, flood coastal regions • Increase the rate of species loss

19. 38.6 Two ways to study endangered populations are: • The small-population approach • The declining-population approach • Habitat degradation • Often fragments populations, causing their numbers to decline • WHY?

20. The small-population approach • Identifies the minimum viable population size and focuses on preserving genetic variation • Extinction Vortex • Loss of genetic variation • How small is too small? • Population Viability Analyses • DEPENDS!

21. The declining-population approach • Diagnoses and treats the causes of a population’s decline • Proactive Strategy • Confirm species is in decline • Study natural history • Develop hypotheses for all possible causes for decline • Test most likely first • Apply results to management strategies

22. 38.7 Identifying critical habitat factors can guide conservation efforts • Preserving critical habitat • May help endangered species recover • Conflicts may arise • Between habitat preservation and resource use by humans

23. Example: red-cockaded woodpecker • NEEDS: • mature pine forests • Dominated by long-leaf pines • Low growth around trees • Destruction of forests • fire management in what is left

24. Management Strategies: • Protection of long-leaf pine forest • Use of controlled burns • Created nest cavities in unoccupied areas for dispersal into new areas • Single-Species Management • Can negatively effect other species • Ex) Migratory birds • Tested managed vs. non-managed habitats and compared bird species • Managed areas had enhanced populations of ALL bird species not just the woodpecker • Near extinction to a sustainable population