Biological Studies. Biodiversity maintains a healthy biosphere and provides direct and indirect...

Chapter 5: Biodiversity & ConservationBiological Studies

Biodiversity maintains a healthy biosphere and provides direct and indirect value to humans.

5.1 Biodiversity

Biodiversity• The variety of life in an area

• determined by the number of different species in that area

• Increases health and stability of biosphere

• Extinction – when the last member of a species dies• Extinction causes a decrease in biodiversity, which

decreases the health of the biosphere

• Levels of Biodiversity:• Genetic• Species• Ecosystem

Levels of Biodiversity• Genetic Diversity - variety of genes or

inheritable characteristics present in a population• increases the chances that some species will survive

during changing environmental conditions

• Species Diversity – number of different species and the abundance of each species in a biological community• Not evenly distributed over biosphere• Increases closer to the equator

• Ecosystem Diversity – variety of ecosystems present in the biosphere

Importance of Biodiversity• A healthy biosphere provides services to humans

and other organisms on Earth• Healthy ecosystems provide protection against

floods and drought, detoxify and decompose wastes, and regulate climates

BIODIVERSITY

http://www.pbs.org/wnet/nature/episodes/the-loneliest-animals/web-exclusive-video-the-importance-of-biodiversity/4942/

Some human activities reduce biodiversity in ecosystems. This could have serious long-term effects on the biosphere.

5.2 Threats to Biodiversity

Extinction• Background Extinction – process of becoming

extinct• Scientists worried about the rate of extinction

• Mass Extinction – an event in which a large percentage of all living species becomes extinct in a relatively short period of time• DINOSAURS!

Threats to Biodiversity• Current high rate of extinction

due to activity of one species – Homo sapiens

• Humans are changing the conditions on earth faster than new traits to can develop to cope with the new changes

• Evolving species do not have the natural resources they need

• Threats include:• Overexploitation• Habitat Loss• Pollution• Introduced Species

Threats• Overexploitation - excessive

use of species that have economic value• Rhinoceros – hunted and killed

for their horns

• Habitat Loss• Destroyed: clearing a natural

rain forest• Disrupted: decline of one

species in the food web disrupts other species (overfishing)

• Fragmented: separation of an ecosystem into smaller parts, cannot cross human barriers to get resources or reproduce, changes abiotic conditions

http://www.nytimes.com/interactive/2011/10/01/science/earth/forests.html?_r=0

Increasing human population has lead to:

Needing more space to live

Loss of habitat

Loss of species

Loss of biodiversity

http://world.time.com/timelapse/

Pollution• Changes the composition of

air, soil, and water• Biological magnification:

increasing concentration of toxic substances in organisms as the trophic levels increase

• Acid Precipitation: burning fossil fuels creates sulfur and nitrogen compounds that react with other substances in the air to form sulfuric and nitric acid• Removes calcium, potassium,

and other nutrients from the soil, deprives plants

Introduced Species• Nonnative species that are either intentionally or

unintentionally introduced to a new habitat• Often reproduce in large numbers because there

are no predators, become invasive• Responsible for 40% of extinctions since 1750

Alligator Snapping Turtle

People are using many approaches to slow the rate of extinctions and to preserve biodiversity

5.3 Conserving Biodiversity

Natural Resources• The biosphere supplies basic

needs for 7 billion humans • The growth in population is not

evenly distributed, nor is the consumption of natural resources

Natural Resources

Renewable• Resources that are

replaced by natural processes faster than they are consumed• Solar energy• Clean air• Clean water

Nonrenewable• Found on Earth in

limited amounts or that are replaced by natural processes over LONG periods of time• Fossil fuels• A species if it becomes

extinctSustainable Use – using resources at a rate in which they can be replaced or recycled while preserving the long-term environmental health of the biosphere

GOING GREEN

http://channel.nationalgeographic.com/channel/videos/human-footprint/

Conserving Biodiversity

Protecting• Hot Spots• Corridors

Restoring• The larger the effected

area, the longer it takes to recover

• Bioremediation – the use of living organisms, such as prokaryotes, fungi, or plants, to detoxify a polluted area

• Biological augmentation – adding natural predators to a degraded ecosystem

1. A2. B3. C4. D

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Which factor is most responsible for the lack of plants in polar regions?

A. heavy grazing by

herbivores

B. little precipitation

C. no soil for plants to

take root

D. not enough sunlight

Biodiversity and ConservationChapter 5

Chapter Diagnostic Questions

1. A2. B3. C4. D

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What form of pollution is caused by extensive algae growth in waterways?

A. acid precipitation

B. eutrophication

C. biological

magnification

D. edge effects

1. A2. B3. C4. D

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Which is not a renewable resource?

A. solar energy

B. fossil fuels

C. agricultural plants

D. clean water

1. A2. B3. C4. D

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Which has indirect economic value?

A. ecosystems that decompose wastes

B. organisms that provide food and shelter

C. plants that contain medicinal substances

D. species that have desirable genetic traits

5.1 Formative Questions

1. A2. B



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It is likely that some of the world’s unidentified species will have economic value.

A. true

B. false

1. A2. B3. C



When does the aesthetic value of an ecosystem

become most apparent?A. when scientists begin

to

study the ecosystem

B. when the ecosystem

has been destroyed

C. when the ecosystem is

given economic value

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1. A2. B3. C4. D


A. background extinction

B. mass extinction

C. natural extinction

D. progressive extinction

Which describes the current rate of species

disappearance?

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1. A2. B3. C4. D


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A. deserts

B. grasslands

C. tropical forests

D. temperate forests

Where are most extinctions likely to occur

in the near future?


1. A2. B3. C4. D


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A. habitat loss

B. eutrophication

C. overexploitation

D. nonnative predators

What is the primary factor that has endangered

the North American bison and the white rhinoceros?


1. A2. B3. C4. D


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A. habitat loss

B. human predators

C. transported diseases

D. background extermination

What is the number one cause of species extinction today?


1. A2. B3. C4. D


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A. agricultural plants

B. clean water

C. forest timber

D. mineral deposits

Which resource is nonrenewable?


1. A2. B3. C4. D


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A. farming

B. logging

C. oil drilling

D. commercial fishing

For which human activity is sustainable use not possible?


1. A2. B3. C4. D


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Which is an example of bioremediation?

A. replanting trees in an area affected by acid rain

B. using microorganisms to detoxify an oil spill

C. enacting a law that protects endangered amphibians

D. introducing natural predators to control a crop pest


1. A2. B3. C4. D


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Look at the figure. Name the process that is occurring with the increasing concentration of DDT.

A. pollution

B. extinction

C. biological

magnification

D. habitat

fragmentation

Chapter Assessment Questions

1. A2. B3. C4. D


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Use the graph to determine the approximate recovery time for a volcanic eruption.

A. 1–10 years

B. 10–100 years

C. 100–1000 years

D. 1000 years ormore


Biodiversity and Conservation

Explain how killer whales adapted to their environment when their primary food

source began to disappear.

Answer: Killer whales started to prey onsea otters instead of sea lionsand harbor seals.

Chapter 5


1. A2. B3. C4. D


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A. ecosystem diversity

B. genetic diversity

C. social diversity

D. species diversity

Which type of biodiversity increases as you move geographically from the polar regions to the equator?

Standardized Test Practice

1. A2. B3. C4. D


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A. It increases the number of organisms that have useful genes.

B. It increases the ability of a species to adapt to environmental changes.

C. It produces a variety of species within a biological community.

D. It randomly distributes members of a species throughout an ecosystem.

How does genetic diversity increase a species’ chance of survival?

1. A2. B3. C4. D


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If a toxic substance enters this food web, which animals will have the highest concentration of the toxic substance in their tissues?

A. fishes

B. killer whales

C. sea otters

D. sea urchins

1. A2. B3. C4. D


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A. acid rain

B. fertilizers

C. PCBs

D. pesticides

What type of substances causes eutrophication of aquatic ecosystems?

1. A2. B3. C4. D


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Which factor has the greatest impact on a country’s rate of natural resource consumption?

A. land area

B. population

C. industrialization

D. availability of

resources

1. A2. B3. C4. D


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Which event has the greatest potential to cause irreversible damage to biodiversity?

A. oil spill

B. urbanization

C. industrial pollution

D. modern agriculture

Biological Studies. Biodiversity maintains a healthy biosphere and provides direct and indirect...

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