5.1 Vanishing Species
• Biodiversity– Increases as you move toward the equator.
• Tropical rainforest, coral reef, large tropical lakes
– Larger areas (islands) have more biodiversity (more habitats)
– # of Species depends on the # of habitats.
www.cspo.org/gck/images/Biodiversity%202.jpg
5.1 Vanishing Species
• Importance of Biodiversity– Living things are interdependent
• Loss of one species may have large effects on other species in the area.
– Loss of habitat, food source, niche, protection, etc.
– Provides Stability• Stop spread of disease
– Humans Count on it• Hybrid food, medicine, other products
5.1 Vanishing Species• Loss of Biodiversity - Extinction
– Background extinction: natural amount• 1-10 sp/year (based on 10 million sp)
– Current rate• 100-10,000 sp/year
– Causes• Human pop. growth, • habitat loss, • land exploitation
5.1 Vanishing Species• Extinct
– Eastern Cougar (2011)
– Carribean Monk Seal (1952)
• Endangered– California Condor– Sea Turtles– Tiger– Alligator Snapping
Turtle– W. Lowland Gorilla
• Threatened
-African elephants
-Bald Eagle
5.1 Vanishing Species• Threats
– **Habitat Loss** • Farm land, firewood, development
– Habitat Fragmentation• Decreases biodiversity, geo./genetic isolation, LF
– Edge effect• Roads, field, water, etc.
www.adb.org/.../img/biodiversity.gif
5.1 Vanishing Species• Threats cont’.
– Habitat Degradation1. Air – burning fossil fuels, volcanoes, fires
– Acid precipitation takes nutrients out of soil, damages tissues, changes pH (range of tolerance)
2. Water pollution – fertilizers, animal waste, detergents, trash– Causes Algal blooms = take O2 away
3. Land pollution- trash, pesticides, chemicals– Biological magnification
Threats Cont’
• Exotic Species (non-native)-– Not native to an area:
• Disrupt ecosystems, communities, etc
• Population explodes due to lack of predators– Use up resources
• Zebra Mussel– Introduced to Great Lakes in ballast water of ships
– Blocking food chains
» Eat algea
» Disturb fish reproduction
» Disturb nutrient flow
5.2 Conservation of Biodiversity• Conservation – to protect biodiversity
– Legal: US Endangered Species Act (1973)• Endangered and threatened sp. protected
– Preserving Habitat: National Parks • 1872 – Yellowstone Nat. park
– Habitat Corridors: protected areas for migration
5.2 Conservation of Biodiversity– Sustainable Use: use resources, but
maintain ecosystem– Reintroduction programs: breeding
endangered species, then release them back to their habitat
• California Condor
– Captivity: keeping of animals by humans• Can be the only place to find species• Animals cannot be reintroduced
– Giant Tortoise– Barbary Lion