ES 7.2 LESSON

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Environmental Science, 1e
SUSTAINING YOUR WORLD
G. TYLER MILLER | SCOTT E. SPOOLMAN

7

Saving Species and Ecosystem

Services

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• HIPPCO:

– Habitat destruction, degradation, and fragmentation (greatest

threat to species)

– Invasive (nonnative species)

– Population growth and increasing use of resources

– Pollution

– Climate change

– Overexploitation

7.2 What Role Do Humans Play in the Loss of Ecosystem
Services?

Multiple Select

Which THREE of these are the greatest threat to species?

• habitat destruction

• habitat degradation

• pollution

• climate change

• habitat fragmentation

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• Many human activities destroy or degrade habitat for wild

species.

– Agriculture, industrial development, aquaculture, oil and gas

exploration, deforestation, water diversion

• Tropical rain forests have suffered the greatest habitat loss.
• Island species especially vulnerable, as they have nowhere

to go (Hawaiian islands)

Loss of Habitat Is the Greatest Threat to Species

Multiple Select

Which THREE of these are human activities that destroy or degrade habitats?

• agriculture

• oil and gas exploration

• volcanic activity

• deforestation

• habitat restoration

Multiple Choice

Why are island species especially vulnerable?

• there is less biodiversity on islands

• they have nowhere to escape to

• their resources are more limited

• they tend to be smaller and weaker

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• Habitat islands: formed by habitat fragmentation—occur

when intact habitats are divided into smaller patches by
roads, logging, crop fields, and urbanization

– Isolates populations of species

• Makes them more vulnerable to predators, disease, hazardous natural

events

• Makes it more difficult to migrate, find mates, colonize areas, find food

Habitat Fragmentation

Multiple Select

Which THREE of these are problems caused by habitat fragmentation?

• makes species more vulnerable to predators

• makes is easier for prey to hide from predators

• makes it more difficult to find mates

• makes it more difficult to find food

• makes it more difficult for producers to make food

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Impacts of Habitat Loss

Multiple Select

Which THREE species have suffered habitat loss due to habitat destruction and fragmentation?

• Siberian tiger

• African elephant

• Nine-banded armadillo

• Black Rhino

• Burmese pythons

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• Invasive species harm ecosystems.

– Prey on/parasitize/outcompete native species

• 42% U.S. endangered species due to invasive species

– Transmit new disease

– Alter structure or function of environment

– Spread rapidly due to few predators, other limits

– Threaten human health/economies

– Introduced intentionally or accidentally (ballast water, produce,

packaging, luggage, exotic pets)

Invasive Species Disrupt Ecosystems

Multiple Choice

Why do invasive species tend to spread so rapidly?

• they alter the structure or function of the environment

• they have few predators

• they transmit new diseases

• 42% of US endangered species are because of invasive species

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• Asian carp (escaped from fish ponds/wastewater treatment

plants)

• Kudzu vine (deliberately planted, grew out of control in
many areas including South Carolina)
• Red imported fire ant (brought in with cargo from South

America, now biting South Carolinians every summer)

• Burmese python (pets released/escaped)
• Zebra mussels (ballast tanks of ocean-going ships)

Examples of Invasive Species

Multiple Select

Which TWO of these invasive species have spread in South Carolina?

• Asian carp

• Kudzu vine

• Red fire ants

• Burmese pythons

• Zebra mussels

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Deliberately and Accidentally Introduced Species

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• Once nonnative species become established it is almost

impossible to remove them, so preventing their introduction is
best approach

– Research natural predators, parasites, bacteria, viruses that could

be used to control invaders

– Develop better ways to track/predict spread of invasive species

– International ban on transfer of nonnative species

– Educate the public

Prevention Is the Best Way to Reduce Threats From
Invasive Species

Multiple Choice

Why is prevention the best way to reduce the threat of invasive species?

• removing them could further upset the native ecosystem

• once established, invasive species are nearly impossible to remove

• invasive species can be removed, but it is very expensive so the cost would be too high

• invasive species eventually become good food sources for local native species

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• Human population now stands at 7.3 billion, predicted to

reach 9.8 billion

– Exponential growth of the human footprint leads to more

resource use, more extinctions

• Agricultural chemicals

– Pesticide/fertilizer use has increased significantly

– Wash into waterways, pollute soil/groundwater

– DDT example of pesticide impact on food chain

• Biomagnification/bioaccumulation in birds of prey

Threats from Human Population Growth and Pollution

Multiple Choice

Why is human population growth such a problem?

• It is logistical growth

• it is exponential growth

• it has recently reached carrying capacity

• it leads to less resource use and less extinctions

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Human Population Growth

Multiple Choice

What does the graph indicate?

• As the human population rises then number of extinctions rise

• As the human population rises then number of extinctions falls

• As the human population falls then number of extinctions falls

• As the human population falls then number of extinctions rise

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• Atmospheric warming is a serious threat.

– Increased burning of fossil fuels, deforestation, agriculture all

contribute to excess carbon dioxide and methane in atmosphere.

– Projected climate change could drive one-quarter to one-half of

terrestrial animals and plants to extinction by end of the century.

• Melting polar ice/glaciers, rise in sea levels, ocean acidification, more

extreme weather, habitat loss

• Hardest hit: species with limited ranges/low tolerance for temperature

changes

Greenhouse Gas Emissions

Multiple Select

Which TWO describe species that are the hardest hit by atmospheric warming?

• those with a broad range of habitats

• those with limited ranges

• those with low tolerance for temperature change

• those that are generalist species

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• Overharvesting

– Bushmeat trade

• Exotic Pet Trade

– More than 260 bird species threatened as result, along with

various species of amphibians, reptiles, tropical fish, plants

• Illegal Trade

– Black market prices make poaching worth risk (gorillas, tigers,

giant pandas, rhinos, elephants)

Loss of Species Due to Overexploitation

Multiple Select

Which of these are examples of overexploitation?

• pet trade

• black market sales of endangered species

• overharvesting

• accidental release of invasive species