UNIT V
Chapter 6
Human Impact
on Ecosystems
Unit V: Ecology
Chapter 16: Human Impact on Ecosystems
I. Human Population Growth and Natural
Resources (16.1)
A. Earth’s human population continues to
grow
1. Earth’s Carrying Capacity
a. Thomas Malthus
(late 1700’s)- studied
human population
growth and said was
growing faster than
Earth’s resources
b. Modern scientists use his observations and
predictions when describing ecosystem’s carrying
capacity
c. Current human population is about 6 billion.
d. Not sure what the limit (carrying capacity) is for
size of human population.
2. Technology and Human Population
a. Humans have modified their environment
through agriculture, transportation, medical
advances, sanitation,etc. This increased the
carrying capacity
b. Technologies have allowed Earth to support far
more people than Malthus could have imagined.
B. The growing human population exerts pressure
on Earth’s natural resources
1. nonrenewable resources- they
are used faster than they are
formed (e.g. oil, natural gas, coal)
2. renewable resources- resources that cannot be
used up or can replenish themselves over time
(e.g. wind energy, solar, lumber, etc.)
a. As human population continues to grow,
management of renewable and
nonrenewable resources will play important
role
b. Today, the U.S. uses
more resources and
generates more waste than
any other country (1 ton of
waste per person per year)
C. Effective management of Earth’s resources will
help meet the needs of the future
1. Effects both current and future generations
2. Ecological footprint- The amount of land
necessary to produce and maintain enough
food and water, shelter, energy and waste
a. Varies from country to country (smaller in
developing countries)
b. Developing countries like China and India have
smaller footprint per individual, but many more
people
II. Air Quality (16.2)
A. Pollutants accumulate in the air
1. Pollution- describes any undesirable
factor, or pollutant, that is added to the
air, water, or soil
a. Effect can be immediate or delayed
b. Effects may add up over time and disrupt
functions of ecosystems
2. Smog and Ozone
a. Smog- type of air pollution caused by
interaction of sunlight with pollutants
produced by fossil fuel emissions
b. Particulates- microscopic bits of dust, metal,
and unburned fuel (1-10 microns in size) that are
produced by many different industrial processes
c. Ozone- produced by reactions of nitrogen oxide
and oxygen forming ozone (O3)
1). ozone harmful to organisms
2). Also forms
important protective
layer in atmosphere
to protect against
ultraviolet rays
found in sunlight
d. Acid Rain- chemicals from fossil fuel emissions
can lead to formation of acid rain that can affect
many environments
B. Air pollution is changing Earth’s biosphere
1. Scientists have been studying the periodic
changes in Earths temperature and
relationship to carbon dioxide levels
2. Greenhouse effect- greenhouse gasses act like
insulator to slow loss of heat through atmosphere
a. Include: water vapor, carbon dioxide,
methane
b. Absorb infrared radiation trying to
escape into space from Earth’s surface
3. Global warming- the trend of increasing global
temperatures
a. Changes are normal part of Earth’s climate
cycle
b. Human impact may be speeding up
production of greenhouse gasses and global
warming
c. Predict temperature increase of 1.4 - 5.8°C by
the year 2100. Could dramatically effect Earth’s
biosphere
III. Water Quality (16.3)
A. Water pollution affects ecosystems
1. Chemical contaminants, raw
sewage, trash, etc. end up in rivers,
lakes, and aquifers all over the world
2. Indicator species- a species that can provide a
sign, or indication, of the quality of the ecosystems
environmental conditions
B. Biomagnification causes accumulation of
toxins in the food chain
1. biomagnification- as pollutant
moves up the food chain, it’s
concentration increases
2. Many pesticides dramatically
effect top level consumers
(predators)
IV. Threats to Biodiversity (16.4)
A. Preserving biodiversity is important to the
future of the biosphere
1. The loss of habitat
and growing
pollution problems
are affecting
animaland plant
population around the
world
2. The loss of biodiversity has a long term effects
on stability of ecosystems
B. Loss of habitat eliminates species
1. As human population grows and expands
into new areas, they displace large numbers
of wildlife
2. Habitat fragmentation- when barrier forms that
prevents an organism from accessing its entire
home range
a. Growing problem (urban sprawl)
b. Beginning to address problems
C. Introduced species can disrupt stable
relationships in ecosystem
1. Introduced species- any organism that
was brought to an ecosystem as the result of
human activities
a. Can have detrimental effect on native species
b. Can out-compete native species and drive them
out
2. Economic damage- can
have major impact on humans
as well as ecosystems
V. Conservation (16.5)
A. Sustainable development manages
resources for present and future generations
1. Sustainable development- a
practice in which natural resources are
used and managed in a way that meets
current needs without hurting future
generations
a. Covers wide range of
resource management
b. Has changed way we
harvest natural resources
B. Conservation practices focus on a few species
but benefit entire ecosystems
1. Endangered Species Actdesigned to protect individual
species by establishing
protection for organism and
its environment
2. Often called Umbrella species (listed species),
because its protection also protect wide range of
other species
3. As result, entire ecosystems can benefit from
efforts to save a single species
B. Protecting Earth’s resources helps protect our
future
1. Global warming, pollution, and
loss of biodiversity are only a few
of the direct threats to our planet
2. Protecting Natural resources
a. Environmental Protection Agencycreated as part of National Environmental
Policy Act in 1970
b. Led to development of policies and
regulations to protect environment across
U.S.
1). Clean Air Act, Clean Water Act, Endangered
Species Act have major impact on environment
2). Has greatly increased public awareness
c. Formation of National Parks to preserve large
areas of wilderness has protected ecosystems
3. A sustainable Earth- humans represent an
integral part of Earth’s ecosystems
a. We have ability to control how fast our
population grows, through controlling birth
rates
b. We can develop technology to produce
more food and produce less waste
c. We have ability to change our practices
and take action to protect and maintain
ecosystems
Chapter 16
Human Impact
On Ecosystems
In the very distant past, most people
a.
lived in small groups.
b.
lived in permanent settlements.
c.
did not gather plants.
d.
did not hunt animals.
In the very distant past, most people
a.
lived in small groups.
b.
lived in permanent settlements.
c.
did not gather plants.
d.
did not hunt animals.
The arrival of Europeans in the Hawaiian Islands
changed the islands by introducing
a.
ranching.
b.
predators.
c.
disease.
d.
all of the above
The arrival of Europeans in the Hawaiian Islands
changed the islands by introducing
a.
ranching.
b.
predators.
c.
disease.
d.
all of the above
Early hunters and gatherers in North America are
responsible for
a.
natural plant and animal populations.
b.
a major extinction event of large animals.
c.
producing new varieties of crops.
d.
inventing technology such as manufactured
tools.
Early hunters and gatherers in North America are
responsible for
a.
natural plant and animal populations.
b.
a major extinction event of large animals.
c.
producing new varieties of crops.
d.
inventing technology such as manufactured
tools.
Which has become the most important source for
environmental change on Earth?
a.
climate
b.
energy
c.
human activity
d.
conservation biology
Which has become the most important source for
environmental change on Earth?
a.
climate
b.
energy
c.
human activity
d.
conservation biology
Land is a resource that provides
a.
space for cities and suburbs.
b.
raw materials for industry.
c.
soil for growing crops.
d.
all of the above
Land is a resource that provides
a.
space for cities and suburbs.
b.
raw materials for industry.
c.
soil for growing crops.
d.
all of the above
An old-growth forest is
a.
a renewable resource.
b.
a nonrenewable resource.
c.
a microclimate.
d.
poor in biodiversity.
An old-growth forest is
a.
a renewable resource.
b.
a nonrenewable resource.
c.
a microclimate.
d.
poor in biodiversity.
Why are fossil fuels nonrenewable?
a.
They require hundreds of millions of years to
form.
b.
Their ecosystems change forever when they
are burned.
c.
They are converted to carbon dioxide when
they are burned.
d.
They exist in a very small supply.
Why are fossil fuels nonrenewable?
a.
They require hundreds of millions of years
to form.
b.
Their ecosystems change forever when they
are burned.
c.
They are converted to carbon dioxide when
they are burned.
d.
They exist in a very small supply.
The wearing away of surface soil by water and wind
is known as
a.
deforestation.
b.
desertification.
c.
overgrazing.
d.
soil erosion.
The wearing away of surface soil by water and wind
is known as
a.
deforestation.
b.
desertification.
c.
overgrazing.
d.
soil erosion.
Which is a way to limit deforestation?
a.
use more wood products
b.
plant and harvest trees on tree farms
c.
increase carbon dioxide levels
d.
fertilize the soil
Which is a way to limit deforestation?
a.
use more wood products
b.
plant and harvest trees on tree farms
c.
increase carbon dioxide levels
d.
fertilize the soil
The sulfur and nitrogen compounds in smog
combine with water to form
a.
ozone.
b.
ammonia.
c.
acid rain.
d.
chlorofluorocarbons.
When erosion and other factors cause soil to lose its
ability to hold water and other nutrients and to
support plant life, it is called
a.
desertification.
b.
depletion.
c.
deforestation.
d.
monoculture.
When erosion and other factors cause soil to lose its
ability to hold water and other nutrients and to
support plant life, it is called
a.
desertification.
b.
depletion.
c.
deforestation.
d.
monoculture.
Using renewable resources while ensuring that they
are not depleted is a practice called
a.
sustainable use.
b.
monoculture.
c.
biological magnification.
d.
renewable resource.
Using renewable resources while ensuring that they
are not depleted is a practice called
a.
sustainable use.
b.
monoculture.
c.
biological magnification.
d.
renewable resource.
An example of a sustainable-use practice is the use
of beneficial insects like ladybugs to
a.
harm natural resources.
b.
pollinate plants.
c.
control unwanted pests.
d.
eat unwanted plants.
An example of a sustainable-use practice is the use
of beneficial insects like ladybugs to
a.
harm natural resources.
b.
pollinate plants.
c.
control unwanted pests.
d.
eat unwanted plants.
The number of different species in the biosphere is
called
a.
biodiversity.
b.
ecosystem diversity.
c.
genetic diversity.
d.
species diversity.
The number of different species in the biosphere is
called
a.
biodiversity.
b.
ecosystem diversity.
c.
genetic diversity.
d.
species diversity.
Biodiversity is important to human society because it
a.
is a natural resource.
b.
provides food and goods.
c.
provides medicines.
d.
all of the above
Biodiversity is important to human society because it
a.
is a natural resource.
b.
provides food and goods.
c.
provides medicines.
d.
all of the above
The sum total of the genetically-based variety of
living organisms in the biosphere is called
a.
species diversity.
b.
sustainable use.
c.
biodiversity.
d.
conservation biology.
The sum total of the genetically-based variety of
living organisms in the biosphere is called
a.
species diversity.
b.
sustainable use.
c.
biodiversity.
d.
conservation biology.
What is meant by “a library of genetic information” in
reference to biodiversity?
a.
The biodiversity of plants and animals is
interesting to read about.
b.
Biodiversity contains genetic information upon
which humans can draw for future use.
c.
Species provide humans with many useful
products to enhance our lives.
d.
We have much to admire in the many forms of
life that surround us.
What is meant by “a library of genetic information” in
reference to biodiversity?
a.
The biodiversity of plants and animals is
interesting to read about.
b.
Biodiversity contains genetic information
upon which humans can draw for future use.
c.
Species provide humans with many useful
products to enhance our lives.
d.
We have much to admire in the many forms of
life that surround us.
Human well-being is tied to biodiversity because
a.
humans love to look at beautiful things.
b.
humans are part of the food webs and energy
cycles that a great variety of organisms share.
c.
less biodiversity makes humans vulnerable to
extinction.
d.
humans need a wide variety of animal species
for hunting and wildlife products.
Human well-being is tied to biodiversity because
a.
humans love to look at beautiful things.
b.
humans are part of the food webs and
energy cycles that a great variety of organisms
share.
c.
less biodiversity makes humans vulnerable to
extinction.
d.
humans need a wide variety of animal species
for hunting and wildlife products.
An endangered species is
a.
a diseased animal.
b.
a dangerous predator.
c.
a group of organisms near extinction.
d.
all organisms at the top of a food chain.
An endangered species is
a.
a diseased animal.
b.
a dangerous predator.
c.
a group of organisms near extinction.
d.
all organisms at the top of a food chain.
DDT was used to
a.
fertilize soil.
b.
kill insects.
c.
form ozone.
d.
feed animals.
DDT was used to
a.
fertilize soil.
b.
kill insects.
c.
form ozone.
d.
feed animals.
One property that makes DDT hazardous over the
long run is that DDT is
a.
an insecticide.
b.
a perfect pesticide.
c.
nonbiodegradable.
d.
deadly to herbivores.
One property that makes DDT hazardous over the
long run is that DDT is
a.
an insecticide.
b.
a perfect pesticide.
c.
nonbiodegradable.
d.
deadly to herbivores.
The first, and perhaps the best known, case of
biological magnification involved the pesticide
a.
CFC.
b.
UV.
c.
CITES.
d.
DDT.
The first, and perhaps the best known, case of
biological magnification involved the pesticide
a.
CFC.
b.
UV.
c.
CITES.
d.
DDT.
One of the greatest threats today to biological
diversity is
a.
old-growth forests.
b.
ozone depletion.
c.
habitat destruction.
d.
monoculture.
One of the greatest threats today to biological
diversity is
a.
old-growth forests.
b.
ozone depletion.
c.
habitat destruction.
d.
monoculture.
As DDT moves up the trophic levels in food chains,
or food webs, its concentration
a.
stays the same.
b.
increases.
c.
decreases.
d.
is eliminated.
As DDT moves up the trophic levels in food chains,
or food webs, its concentration
a.
stays the same.
b.
increases.
c.
decreases.
d.
is eliminated.
A major factor that negatively affects biodiversity is
a.
biological magnification.
b.
habitat fragmentation.
c.
the green revolution.
d.
nonrenewable energy.
A major factor that negatively affects biodiversity is
a.
biological magnification.
b.
habitat fragmentation.
c.
the green revolution.
d.
nonrenewable energy.
One of the goals of conservation biology is to
a.
enforce environmental laws.
b.
protect habitats.
c.
manage natural resources.
d.
all of the above
One of the goals of conservation biology is to
a.
enforce environmental laws.
b.
protect habitats.
c.
manage natural resources.
d.
all of the above
An ecological “hot spot” is an area where
a.
habitats and species are healthy.
b.
hunting is encouraged.
c.
habitats and species are in the most danger of
extinction.
d.
species diversity is too high.
An ecological “hot spot” is an area where
a.
habitats and species are healthy.
b.
hunting is encouraged.
c.
habitats and species are in the most danger
of extinction.
d.
species diversity is too high.
An increase in Earth’s average temperature from the
buildup of carbon dioxide and other gases in the
atmosphere is called
a.
the greenhouse effect.
b.
ozone depletion.
c.
global warming.
d.
particulate dispersal.
An increase in Earth’s average temperature from the
buildup of carbon dioxide and other gases in the
atmosphere is called
a.
the greenhouse effect.
b.
ozone depletion.
c.
global warming.
d.
particulate dispersal.
Some scientists think that global warming is
a.
a natural variation in climate.
b.
difficult to predict.
c.
melting the polar ice caps.
d.
all of the above
Some scientists think that global warming is
a.
a natural variation in climate.
b.
difficult to predict.
c.
melting the polar ice caps.
d.
all of the above
The major cause of ozone depletion is
a.
nitric acid.
b.
sulfuric acid.
c.
chlorofluorocarbons.
d.
ultraviolet light.
The major cause of ozone depletion is
a.
nitric acid.
b.
sulfuric acid.
c.
chlorofluorocarbons.
d.
ultraviolet light.