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Activity: Should we drill in the Artic National Wildlife Refuge? pretty picture

Comparison of ANWR to Continental US

Map

Pictures Muskoxen Snow geese Predators Porcupine caribou Vegetation Oil

Oil consumption

A Country’s wealth Material Cultural Biological

The value of biodiversity Intrinsic value –American spend $18.2 billion to watch wildlife (vs. 5.8 billion on movie tickets and $5.9 billion on professional sporting events) Economic value –Wildlife tourism generates $30 billion worldwide each year Male lion living to 7 years old in Kenya - $500,000 Elephant living to 60 years old in Kenya - $1 million Coral reefs off Florida – $1.6 billion/year

What do tropical forests provide? The economics! 50-90% of world’s species ½ world’s supply of –Hardwood –Food products like coffee, tea, cocoa, spices, nuts, fruits, natural rubber, resins, dyes, oils. coffee bananas

Medicines Active ingredients for 25% of all prescription drugs are derived from plants, most of which are in tropical forest. Drugs with active ingredients from these plants generate $100 billion/year worldwide ($15.5 billion/ year in US) 70% of plant derived cancer-fighting drugs

Example: rosy periwinkle From Madagascar childhood leukemia and Hodgkin's disease.

Drugs from frog skins Painkiller hundreds of times more potent than morphine New class of powerful and versatile antibiotics Cancer-detecting hormone And less than 5% of all frogs have been investigated.

Examples African clawed frog. Antimicrobial compound that disinfects everything it touches Gastric brooding frog Broads in young in its stomach. Applications to treating stomach ailments?

Sustainable use of rainforests Sustainable harvesting of these food products over 50 years would produce –2 times as much $ as timber production –3 times as much $ as conversion to cattle ranching.

Why is tropical deforestation going on?

Related to population growth, poverty, government policies Road-building –Increases accessibility Clearing –Farming –Cattle ranching Mining and drilling for oil Logging – wood and firewood Increased susceptibility to fires

Species extinctions To survive and be successul, populations must have: –Critical population density –Minimum viable population size Background extinctions –A certain level of species extinction is normal. –Populations that do not survive environmental changes will go extinct.

Extinctions in the horse lineage

Past extinctions in the fossil record Mass extinctions –Many, many species become extinct simultaneously Causes –Climate change –Volcanic eruptions –Disease –Extraterrestrial impacts

Some of the biggest extinctions Over what time periods? 225 million years ago >90% of all species 65 million years ago 50% of all species

Fig/ mass extinctions

Lessons from the fossil record Extinctions are irreversible –Usually followed by a period of adaptive radiation – diversity of life increased, –but different species evolved. Recovery time may be > 10 million years

Current extinctions 20% by 2022, 50% by 2042 Loss of species due to human impacts –Difficult to determine how many, which ones

Estimates using small-scale field data Annual loss of tropical forest habitat 1.8% = 0.5% species loss If there are 5 million species - 25,000 species/year If there are 20 million species – 100,000 species/year If there are 100 million species – 500,000 species/year.

Threats to biodiversity

1.Habitat loss Deforestation – tropical and temperate Wetland loss Coral reef destruction

Example: Deforestation in Brazil

2.Habitat fragmentation Often accompanies habitat loss Division of formerly continuous landscape into smaller, often isolated pieces Edge effects –Invasion by exotics –Hotter, drier, windier conditions –Proximity to humans Smaller area –Large carnivores need large areas

3.Exotic species Introduced, non-native species Out-compete/exclude native species Often, no predators in new environment

Example: Purple loosestrife Replaces cattails, willows, horsetails, other plants Eliminates food and cover for ducks, geese, muskrats, mink, bog turtle, sandhill cranes, others Manual control unsuccessful. Now trying biological control with introduced beetles

4.Hunting

Decreases population size Can remove top predator or keystone species

Example: Northern right whale Hunted because –Easy to find –Slow –Lots of oil Hunting reduced population by 97% to 600 individuals Protected in 1949, now threatened by habitat degradation

5.Environmental degradation

Air pollution Water pollution Noise and light pollution Climate change –Warming, precipitation Land degradation –Erosion from deforestation, poor farming practices –Removes nutrient-rich top-soil –Dumps sediment into rivers and lakes

Example: Sea turtles Come on shore to lay eggs. Disturbed by bright lights, tend to choose darker beaches. Hatchlings are confused by lights, head in the wrong direction.