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UNIT V
Chapter 6Human Impacton Ecosystems
Unit V: EcologyChapter 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 undesirablefactor, 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/Invasive 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 Act- designed 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 Agency- created 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 16Chapter 16Human ImpactHuman ImpactOn EcosystemsOn 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.
