1. Global Change and a Sustainable Future Chapter 18

2. Mass Extinction Biodiversity a. instrumental and intrinsic value Extinctions a. “last member of the species dies” b. 5 major - 50,000 species extinctions/yr (0.5%) c. now experiencing the 6 th - human cause

3. Global Declines in Genetic Diversity Wild Organisms a. prone to inbreeding depression - produces impaired offspring b. natural causes v. human causes

4. Crops and Livestock a. producers have started concentrating on breeds that are most productive resulting in lower genetic variation b. forces breeds to become endangered

5. Global Decline in Species Diversity Status of species a. Data deficient – no reliable data to assess b. extinct – no longer exist since 1500 c. threatened – high risk of extinction d. near-threatened – very likely to become threatened e. least concern – very widespread species

6. Since 1500 a. birds - 10,000 existed, 133 extinct, 21% threatened b. mammals - 5,500 existed, 79 extinct, 25% threatened c. amphibians - 6,200 existed, 39 extinct, 49% threatened

7. Causes of Declining Biodiversity Habitat Loss a. greatest cause of decline ex) northern spotted owl - old growth forests

8. Alien Species a. native species – native to the land b. alien/exotic species - species living outside of their normal range - introduced accidentally or intentionally c. invasive species - no natural enemies - 2 most common in North America * Kudzu vine * Zebra Mussel - act as predators, pathogens, competitors to native species

9. Overharvesting a. removed faster than population can replace themselves – can cause extinction b. Dodo bird, sloths, mammoths c. poaching d. regulations - state and federal restrict hunting/fishing of game animals to particular times of the year and limit the number that can be harvested

10. Pollution a. pesticides, heavy metals, oil spills, endocrine disruptors (reproduction), release of nutrients (N and P), thermal pollution (cooling of power plants) Climate Change a. changes in patterns of temperature and precipitation in different regions of the world and how it will affect the organisms

11. Conserving Biodiversity Two general approaches a. single species approach b. ecosystem approach

12. Single Species Approach a. focuses on one species at a time b. approach 1. encourage population rebound - improving living conditions - providing additional habitat - reducing contaminants - captive breeding (California Condor)

13. c. legislation 1. Marine Mammal Protection Act - prohibits killing of all marine mammals in the US and prohibits the import/export of an marine mammal body parts - exceptions can only be made through: * US Fish and Wildlife Service * National Marine Fisheries

14. 2. Endangered Species Act (1973) - authorizes US Fish and Wildlife service to determine which species can be listed as threatened/endangered - prohibits the harming of the listed species as well as trade of species - authorizes govnt to purchase habitat for species - listed species * 201 invertebrate * 795 plants * 381 vertebrate

15. 3. Convention of Biological Diversity - international treaty - 3 objectives * conserve biodiversity * sustainably use biodiversity * equitably share the benefits that arise from commercial use of genetic resources

16. Ecosystem Approach a. preserves particular regions (biodiversity hotspots) – national parks, marine reserves b. Factors to consider 1. size and shape of protected area 2. connectedness to other protected areas 3. recognize how to incorporate conservation while seeing the need for sustainable habitat use for human needs

17. c. Island Biogeography applied to protected areas 1. distance between areas - further apart, harder for species to travel among them 2. metapopulations 3. edge habitat - where two different communities come together