Biodiversity. Chapter 10

Transcription

1 Biodiversity Chapter 10

2 Biodiversity Biodiversity = the number and variety of species in a given area. Unknown diversity = scientists do not know the actual diversity. Many remote areas are still unexplored. ~ 1.7 million known species Greater than 10 million estimated.

3 Species known and estimated Scientists believe that most of the undiscovered Species are insects and fungi.

4 Estimating numbers of species Scientists predict the number of species on earth by sampling. Mark-Recapture Count the # of organisms in a small area and then multiply by the area. Sampling

5 Ecosystem diversity Example: Rain Forest vs. a monoculture (one species) tree farm.

6 Benefits of Biodiversity 1. Ecosystem Stability - improves the chances of recovery after a natural disasters. - less chance of species extinction.

7 2. Medical Uses 40% of prescription drug were discovered from nature. Ex: Gastric Brooding Frog Able to shut down stomach acids- cure for ulcers Vanished within a few years of being discovered

8 3. Industrial Uses Wood (teak, mahogany) Fibers (bamboo, rattan, & raffia) Rainforest products Essential oils (used in perfumes, suntan lotion, cough drops, natural insect repellent, soaps ) Gums & resins (used in paint, perfume, fuel )

9 4. Agricultural Uses Most crops originated from areas of high biodiversity.

10 5.Species survival Ex: Florida Panther

11 Panther range has been reduced Small population size Gene pool is limited Inbreeding has cause infertility Extinction is inevitable.

12 6.Ethics, Aesthetics, & Recreation

13 A form of tourism that supports conservation in ecologically unique areas. Ecotourism Example: Galapagos Islands

14 Biodiversity At Risk. Endangered Species: likely to become extinct Threatened Species: Likely to become endangered

15 The Loneliest Animal Video

16 How humans cause extinction 1. Habitat Destruction and Fragmentation Leading cause of extinction Interior species decrease Edge species increase Increase predation and invasive species.

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18 2.Invasive Species Cane toads melaleuca trees fire ants Fire ants introduced From South America into Alabama Melaleuca taking over the Everglades from Australia

19 Human pest Damage crops

20 3.Harvesting, hunting & poaching Whales Sharks Elephants Black Rhino Rhino horn

21 4.Pollution Example: Beluga whale Belugas and pollution

22 Areas of Critical Biodiversity Hotspots = Places of high diversity or unique diversity. 1.Tropical Rain Forests 2.Coral Reefs 3.Islands Endemic Species = unique to one area.

23 Hot Spots

24 Saving Species 1.Save habitats/ecosystems Save 1 habitat = saving many species.

25 2.Save Keystone Species A species on which a large number of other species depends. Examples: Sea Otters

26 Sea otters and kelp

27 3.Captive Breeding Programs Breeding animals for later release Panda breeding Problems: few species, does the habitat still exist, inbreeding, false sense of security.

28 4.Zoos, Aquariums, Botanical Gardens Used for research, captive breeding, education, and saving the last of some species. Zoos and preserves

29 5.Germ banks (seeds, eggs, sperms, DNA) Millennium seed bank

30 6. Endangered Species Act USFWS must make a list of all endangered and threatened species. Endangered species cannot be caught, killed, harmed, sold, or traded. The government cannot carry out a project that will endanger any listed species. USFWS must make a recovery plan this typically involves setting aside land. Endangered beetle

31 7.Biodiversity Treaty Asks that wealthier countries give money to poor countries to save endangered species. Not signed by president George Bush Signed later by President Bill Clinton