Human Impact on Biodiversity

What is biodiversity?

• The number of different organisms in an ecosystem

What is diff between endangered and extinct ?

• Endangered:• Population is very low, and

problem that caused the low pop is not going away (habitat destruction, fragmentation, pollution, etc)

• Extinct: • Gone….forever….not coming back

Ivory billed woodpecker• Thought last one died 60

years ago• In Cuba, bird was hung

outside door to prevent witches from entering the house

• 1920’s- found a breeding pair in Fl-

• Shot them for specimens• One observed by Cornell

ornithologist in 2002 in Arkansas… she said, “I almost fell out of my canoe when I saw it”

So… Cornell University scientists

• Quietly bought up 120,000 acres of swampland

• they did not want birders to stampede the area, killing the bird with kindness

With good reason• In economically struggling east

Arkansas, the speculation of a possible return of the Ivory-bill has served as a great source of economic exploitation, with tourist spending up 30%, primarily in and around the city of Brinkley, Arkansas. A woodpecker "festival", a woodpecker hairstyle (a sort of mohawk with red, white, and black dye), and an "Ivory-bill Burger" have been featured locally

Reasons species should be preserved

• #1. future medical uses

• For example: digitalis for heart problems comes from the foxglove plant

• Rosy periwinkle treats childhood leukemia

# 2. (to preserve)

• Use in agriculture• The more of a variety of species, the

better able to resist disease, parasites, and environmental changes

#3. (to preserve)

• Maintain stable ecosystems• Species need shelter, food, niche of

disappearing organism• Wetlands are drained for farm fields• But.. They are reservoirs of water for times of

drought, and purify water (roots soak up toxins from pesticides), reduce effects of erosion,

• Can ultimately change climate ( increased wind)

• (How wetlands work on next slide)

http://geoscape.nrcan.gc.ca/h2o/bowen/images/wetlands_e.jpg

# 4. (to preserve)

• We appreciate the beauty (aesthetics)

# 5. (to preserve)

• Ethics- species have a right to exist, even if humans do not appreciate them (who are we to ……)

#6 (add it)

• Future source of genetic material for reasons we may not know yet

4 reasons to NOT want to preserve biodiversity

• # 1. • Costs money• Close to $10 million to buy up

the swamps of Arkansas, and they have not even proved the Ivory billed woodpecker is really there

#2. ( to not preserve)

• Loss of jobs• In Arkansas, no logging, no

draining wetlands for farmlands• Farmers and loggers are not in

the quickstops, or restaurants, etc.

#3 (to NOT preserve)

• Ignorance and apathy• Don’t know, don’t care

#4 (to NOT preserve)

• Not convenient• Plastic water and soda bottles,

(PLASTIC EVERYTHING!!) • Try to go one day without using

plastic

Renewable vs. non-renewable

• Renewable – can get more• Examples: • Wind, sun, hydro (water)• Nonrenewable- cannot get more• Examples:• Fossil fuels (coal, oil, gas)

Exponential vs. linear growth

Biomagnification

• Increasing concentration as you go up a food chain

Decrease biodiversity due to invasive species

• Zebra mussels, purple loosestrife

• Caused by:• Increased global traffic

• Ballast water in ships• Who cares?• Takes over native species

habitat and niche

To “fix” invasive species problem

• Clean ballast water before discharging

• education

Decrease biodiversity due to habitat

destruction• Cut down forests for homes or

farmland• Caused by (same as above)• Activities to “fix”:• Parklands, careful cutting of

trees to leave some

Why do we care?

• See back, # ?

Decrease biodiversity due to desertification

• Cut rainforests, soil dries up and blows away

• Caused by: cutting all the trees• “Fix”:• Plant trees, • Plant grasses, • No till farming

Amazon desertification/deforesta

tion

Decrease biodiversity due to soil runoff

Causes: same as aboveCaused by: same as above“Fix”: don’t clearcut, same as

above

Why do we care about soil runoff,

desertification, habitat destruction?

• Increased extinction rates, no soil, no food for us either

Global Warming• Increased CO2 blanket, increases

temp• Caused by• Burning fossil fuels• Help “fix” with• Ride a bus or bike• Recycle plastic bottles (etc)• Clean up smoke stacks• Why do we care?- changing

climate, flooding, migration routes changing

Ozone depletion

• Example: hole in protective layer• Caused by• Use of CFC’s and aerosols, destroying

ozone layer• Fix:• Stop use of CFC and aerosols• Why do we care?• Increased cancers, cataracts,

mutations of DNA

Air pollution, acid rain

• Caused by• Industrial pollution• Fix: cleaner coal, use renewable

energy (solar, wind), decrease amt of “stuff” we use

• Why do we care?• Changes pH of lakes, killing

algae, fish starve