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HUMAN IMPACT on the BIOSPHERE Chapter 6-3 BIODIVERSITY

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Presentation on theme: "HUMAN IMPACT on the BIOSPHERE Chapter 6-3 BIODIVERSITY"— Presentation transcript:

1 HUMAN IMPACT on the BIOSPHERE Chapter 6-3 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 THREATS TO BIODIVERSITY _______________________ ____________
HABITAT DESTRUCTION Deforestation Fragmentation pollution Invasive species Poaching & over hunting

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

5 BIODIVERSITY THREAT Tropical rainforests are disappearing
Tropical rainforests are disappearing at a rate of about 80 acres per minute.

6 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%.

7 BIODIVERSITY THREAT Nearly half of the world's species of plants, animals and microorganisms will be destroyed or severely threatened over the next quarter century due to ____________________________ rainforest deforestation.

8 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

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

10 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

11 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.

12 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.

13 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 including _______________________ and into Canada. SOUTH DAKOTA

14 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

15 EXAMPLES OF INVASIVE SPECIES
LEAFY SPURGE __________________ is native to Europe and Asia and first appeared in Massachusetts in 1827. Across _____________ and much of the Great Plains, leafy spurge is one of the most threatening invasive plants, ____________ out native grassland and damaging ___________________. South Dakota crowding grazing land

16 EXAMPLES OF INVASIVE SPECIES
302,000 acres in South Dakota are infested with LEAFY SPURGE. According to the U.S. Department of Agriculture, leafy spurge infestations in the Dakotas, Montana and Wyoming alone cost agricultural producers and taxpayers at least $144 million annually in production losses, control expenses and other impacts to the economy .

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

18 _____ 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

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

20 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

21 → → 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

22 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

23 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”

24 told of DDT’s harmful effects.
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

25 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

26 CONSERVING BIODIVERSITY
Wise management of natural resources = __________________ Protecting endangered species requires detailed information about ecological _________________ We can’t protect a species without understanding how it ____________ with the _________________. conservation relationships interacts ecosystem

27 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

28 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

29 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


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