1. HUMAN IMPACT on the BIOSPHERE Part 3 BIODIVERSITY

2. BIODIVERSITY The sum of the genetically based
variety of all the organisms in the
biosphere = ___________________
Biodiversity gives __________ to the
ecosystems that we are so dependent
on, enhances their ____________, and
provides an important source of new
_____, ________, and other _________.
BIODIVERSITY
stability
productivity
medicine
food
products

3. BIODIVERSITY THREAT habitat destruction
Development of natural areas for cities or
agriculture results in ____________________
habitat destruction

4.
BIODIVERSITY THREAT
Changes in Brazilian rainforest over 30 years
The tropical rainforests once covered more than 14% of the earth's total land surface,
but now cover less than 6%.

5. BIODIVERSITY THREAT Habitat fragmentation
Splitting a habitat into smaller disconnected pieces = _____________________
It results in small “islands”
of natural area isolated
from each other by crop
land, pasture, pavement,
or even barren land.
Habitat fragmentation

6. BIODIVERSITY THREAT Habitat fragmentation brings wildlife in
more frequent contact with humans.
When it comes
down to
“us or them” . . .
“they” usually lose.

7. BIODIVERSITY THREAT INVASIVE SPECIES PREDATORS INCREASE
One of most important threats to
biodiversity come from apparently
harmless plants or animals that
humans transport into new habitats =
_____________________
New habitats don’t have ____________
and parasites that control the population
in their native habitats, so invasive species
populations _____________ rapidly.
INVASIVE SPECIES
PREDATORS
INCREASE

8. EXAMPLES OF INVASIVE SPECIES
24 rabbits turned loose for
hunting in 1859 in Australia,
reproduced at such a rapid rate they have taken over
the continent.
Within 10 years they had
multiplied so rapidly, 2 million
rabbits a year could be shot or trapped without any noticeable effect on population.

9. EXAMPLES OF INVASIVE SPECIES
They are believed to be
responsible for the
_______________ of 1/8 of
the mammal species,
unknown numbers of plant
species, as well as serious
________________ problems.
It is still a major problem and rabbit diseases have been purposely introduced to try to control the population.
extinction
soil erosion.

10. EXAMPLES OF INVASIVE SPECIES
Zebra mussels
_________________ are native to the Caspian Sea region of Asia. They are believed to have been transported to the Great Lakes in the ballast water from a ship.
They were first discovered in 1988, and have since spread rapidly to all of the Great Lakes
and waterways in many
States and into Canada.

11. PROBLEMS CAUSED BY ZEBRA MUSSELS
Clog power plant and public water intakes and pipes, costing taxpayers millions of dollars · Damage boat engines · Blanket shorelines with their sharp shells and foul smell · Consume available food for
native species and smother
native mussels · Threaten water-based
recreational activities

12. EXAMPLES OF INVASIVE SPECIES
Kudzu
There's so much of this fast-growing vine in the Southeastern U.S., you might think it was a native plant. Actually, it took a lot of hard work to help kudzu spread so widely. Now that it covers over seven million acres of the deep South, there are a lot of people working hard to get rid of it! But kudzu is used in ways which might surprise you...

13. BIODIVERSITY THREAT pollutants The addition of ________________
= harmful materials that can enter the biosphere through land, water or air can also threaten biodiversity.

14. _____ was first modern insecticide
Example:
_____ was first modern insecticide
It was cheap, stayed active for long time, and kills many different insects
Used to control agriculture pests
and disease carrying
_______________
DDT
MOSQUITOES

15. drained into rivers and streams at LOW concentrations.
When DDT was sprayed, it
drained into rivers and
streams at LOW
concentrations.

16. doesn’t ______________. food chain tissues degrade
DDT in the environment gets into organisms through the ___________, is stored in __________, and
doesn’t ______________.
food chain
tissues
degrade

17. → → BIOLOGICAL MAGNIFICATION ______________________________
= the ____________ of a harmful substance
____________as it passes to organisms at
_______________levels in food chain or web.
concentration
increases
higher trophic
Plants pick up
DDT from water
& store it
Herbivores eat
plants and store some DDT
Carnivores eat
herbivores and store more DDT → →

18. Figure 6-16 Biological Magnification of DDT
Section 6-3
Magnification of
DDT Concentration
Fish-Eating Birds
10,000,000
Large
Fish
1,000,000
100,000
Small Fish
10,000
Zooplankton
1000
Producers
Water 1

19. The wide spread use of DDT threatened many species… especially fish eating birds like osprey, brown pelican, and
bald eagles.
DDT causes birds to lay
eggs with ___________
shells so eggs would
break when sat on.
American Bald Eagle was declared
endangered in It has since been
reclassified as _____________________
fragile
“threatened”

20. _______________ published the book,_____________ which
In 1962, American biologist
_______________ published the book,_____________ which
told of DDT’s harmful effects.
The book led to a large public outcry and eventually resulted in DDT being _________ in the United States in the 1970’s
The book was one of the important events in the birth of the _________________________.
Rachel Carson
Silent Spring
banned
environmental movement

21. WHAT DOES IT MEAN? REMEMBER! Everything is connected.
BIODIVERSITY is a measure
of the __________ of an ecosystem.
_______ DIVERSITY = BETTER
HEALTH
MORE
Image from: Pearson Education Inc, publishing as Pearson Prentice Hall ©2006

22. CONSERVING BIODIVERSITY
Examples of efforts to keep a species from becoming extinct:
___________________
(raised and protected in zoos until population is stable, then returned to wild
Captive breeding

23. CONSERVING BIODIVERSITY
Today
conservation
efforts focus on
protecting entire
ecosystems not
just individual
species
______________ =
are places that are
MOST endangered
HOT SPOTS
Image from: Pearson Education Inc publishing as Pearson Prentice Hall© 2006

24. WHAT CAN BE DONE? Urban planning so there is less “ Sprawl”
Set aside land for parks/preserves
Research to understand species/ecosystem interactions
Concentration of $
on HOT SPOTS to
maximize results for
$ spent