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BIODIVERSITY the variety of life on Earth!
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Benefits of Biodiversity
Clean air Food to eat Clean water Medicines Raw materials Recreational purposes
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THREATS TO BIODIVERSITY
H -Habitat loss I -Introduced species P –Pollution P –Population Growth O –Over-consumption
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BIODIVERSITY THREAT habitat destruction
Development of natural areas for cities or agriculture results in ____________________ habitat destruction
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BIODIVERSITY THREAT Tropical rainforests are disappearing
Tropical rainforests are disappearing at a rate of about 80 acres per minute.
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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%.
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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.
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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
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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
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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.
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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.
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BIODIVERSITY THREAT pollutants The addition of ________________
= harmful materials that can enter the biosphere through land, water or air can also threaten biodiversity.
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_____ 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
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drained into rivers and streams at LOW concentrations.
When DDT was sprayed, it drained into rivers and streams at LOW concentrations.
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______________________. food chain tissues doesn’t degrade
DDT in the environment gets into organisms through the ___________, is stored in __________, and ______________________. food chain tissues doesn’t degrade
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→ → 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 → →
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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”
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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
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WHAT DOES IT MEAN? REMEMBER! Everything is connected.
BIODIVERSITY is a measure of the health of an ecosystem. Image from: Pearson Education Inc, publishing as Pearson Prentice Hall ©2006
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CONSERVING BIODIVERSITY
Wise management of natural resources = __________________ Protecting endangered species requires detailed information about __________________________ We can’t protect a species without understanding how it ____________ with the _________________. conservation ecological relationships interacts ecosystem
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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
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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
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WHAT CAN BE DONE? 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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