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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 frogBroads 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?

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 lossIf there are 5 million species - 25,000

species/yearIf there are 20 million species – 100,000

species/yearIf 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

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

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

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.