UNIT V

Chapter 6Human Impacton Ecosystems

Unit V: EcologyChapter 16: Human Impact on EcosystemsI. Human Population Growth and Natural Resources (16.1)A. Earths human population continues to grow1. Earths Carrying Capacitya. Thomas Malthus (late 1700s)- studied human population growth and said was growing faster than Earths resources

b. Modern scientists use his observations and predictions when describing ecosystems 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 Populationa. 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 Earths natural resources1. 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 roleb. 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 Earths resources will help meet the needs of the future1. Effects both current and future generations2. 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 air1. Pollution- describes any undesirablefactor, or pollutant, that is added to the air, water, or soil

a. Effect can be immediate or delayedb. Effects may add up over time and disrupt functions of ecosystems

2. Smog and Ozonea. 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 organisms2). 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 Earths biosphere1. 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 atmospherea. Include: water vapor, carbon dioxide, methaneb. Absorb infrared radiation trying to escape into space from Earths surface

3. Global warming- the trend of increasing global temperaturesa. Changes are normal part of Earths climate cycleb. Human impact may be speeding up production of greenhouse gasses and global warming

c. Predict temperature increase of 1.4 - 5.8C by the year 2100. Could dramatically effect Earths biosphere

III. Water Quality (16.3)A. Water pollution affects ecosystems1. 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 chain1. biomagnification- as pollutant moves up the food chain, its concentration increases2. Many pesticides dramatically effect top level consumers (predators)

IV. Threats to Biodiversity (16.4)A. Preserving biodiversity is important to the future of the biosphere1. 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 species1. 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 rangea. Growing problem (urban sprawl)b. Beginning to address problems

C. Introduced species can disrupt stable relationships in ecosystem1. Introduced species- any organism that was brought to an ecosystem as the result of human activities

a. Can have detrimental effect on native speciesb. 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 generations1. Sustainable development- a practice in which natural resources are used and managed in a way that meets current needs without hurting future generationsa. Covers wide range of resource managementb. 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 species3. As result, entire ecosystems can benefit from efforts to save a single species

B. Protecting Earths resources helps protect our future1. Global warming, pollution, and loss of biodiversity are only a few of the direct threats to our planet

2. Protecting Natural resourcesa. Environmental Protection Agency- created as part of National Environmental Policy Act in 1970b. 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 environment2). 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 Earths ecosystemsa. We have ability to control how fast our population grows, through controlling birth ratesb. We can develop technology to produce more food and produce less wastec. We have ability to change our practices and take action to protect and maintain ecosystems

Chapter 16Human ImpactOn Ecosystems

In the very distant past, most peoplea.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 peoplea.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 introducinga.ranching.b.predators.c.disease.d.all of the above

The arrival of Europeans in the Hawaiian Islands changed the islands by introducinga.ranching.b.predators.c.disease.d.all of the above

Early hunters and gatherers in North America are responsible fora.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 fora.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.climateb.energyc.human activityd.conservation biology

Which has become the most important source for environmental change on Earth?a.climateb.energyc.human activityd.conservation biology

Land is a resource that providesa.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 providesa.space for cities and suburbs.b.raw materials for industry.c.soil for growing crops.d.all of the above

An old-growth forest isa.a renewable resource.b.a nonrenewable resource.c.a microclimate.d.poor in biodiversity.

An old-growth forest isa.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 asa.deforestation.b.desertification.c.overgrazing.d.soil erosion.

The wearing away of surface soil by water and wind is known asa.deforestation.b.desertification.c.overgrazing.d.soil erosion.

Which is a way to limit deforestation?a.use more wood productsb.plant and harvest trees on tree farmsc.increase carbon dioxide levelsd.fertilize the soil

Which is a way to limit deforestation?a.use more wood productsb.plant and harvest trees on tree farmsc.increase carbon dioxide levelsd.fertilize the soil

The sulfur and nitrogen compounds in smog combine with water to forma.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 calleda.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 calleda.desertification.b.depletion.c.deforestation.d.monoculture.

Using renewable resources while ensuring that they are not depleted is a practice calleda.sustainable use.b.monoculture.c.biological magnification.d.renewable resource.

Using renewable resources while ensuring that they are not depleted is a practice calleda.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 toa.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 toa.harm natural resources.b.pollinate plants.c.control unwanted pests.d.eat unwanted plants.

The number of different species in the biosphere is calleda.biodiversity.b.ecosystem diversity.c.genetic diversity.d.species diversity.

The number of different species in the biosphere is calleda.biodiversity.b.ecosystem diversity.c.genetic diversity.d.species diversity.

Biodiversity is important to human society because ita.is a natural resource.b.provides food and goods.c.provides medicines.d.all of the above

Biodiversity is important to human society because ita.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 calleda.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 calleda.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 becausea.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 becausea.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 isa.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 isa.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 toa.fertilize soil.b.kill insects.c.form ozone.d.feed animals.

DDT was used toa.fertilize soil.b.kill insects.c.form ozone.d.feed animals.

One property that makes DDT hazardous over the long run is that DDT isa.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 isa.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 pesticidea.CFC.b.UV.c.CITES.d.DDT.

The first, and perhaps the best known, case of biological magnification involved the pesticidea.CFC.b.UV.c.CITES.d.DDT.

One of the greatest threats today to biological diversity isa.old-growth forests.b.ozone depletion.c.habitat destruction.d.monoculture.

One of the greatest threats today to biological diversity isa.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 concentrationa.stays the same.b.increases.c.decreases.d.is eliminated.

As DDT moves up the trophic levels in food chains, or food webs, its concentrationa.stays the same.b.increases.c.decreases.d.is eliminated.

A major factor that negatively affects biodiversity isa.biological magnification.b.habitat fragmentation.c.the green revolution.d.nonrenewable energy.

A major factor that negatively affects biodiversity isa.biological magnification.b.habitat fragmentation.c.the green revolution.d.nonrenewable energy.

One of the goals of conservation biology is toa.enforce environmental laws.b.protect habitats.c.manage natural resources.d.all of the above

One of the goals of conservation biology is toa.enforce environmental laws.b.protect habitats.c.manage natural resources.d.all of the above

An ecological hot spot is an area wherea.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 wherea.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 Earths average temperature from the buildup of carbon dioxide and other gases in the atmosphere is calleda.the greenhouse effect.b.ozone depletion.c.global warming.d.particulate dispersal.

An increase in Earths average temperature from the buildup of carbon dioxide and other gases in the atmosphere is calleda.the greenhouse effect.b.ozone depletion.c.global warming.d.particulate dispersal.

Some scientists think that global warming isa.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 isa.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 isa.nitric acid.b.sulfuric acid.c.chlorofluorocarbons.d.ultraviolet light.

The major cause of ozone depletion isa.nitric acid.b.sulfuric acid.c.chlorofluorocarbons.d.ultraviolet light.