Deck 39: Biomes

Question 1

In an article in Nature magazine, Sean Nee wrote: "Earth's real biodiversity is invisible, whether we like it or not." What does that statement mean?

Answer 1

One interpretation is that bacteria and other microscopic organisms are extremely diverse, although that diversity is difficult to measure. Moreover, these microbes ultimately control the processes that support all life on Earth.

Question 2

Give an example of an environmental problem that can immediately reduce biodiversity and one that has a delayed effect.

Answer 2

An environmental problem that can immediately reduce biodiversity is changing a river's path, which can cause stream bank erosion and choke out downstream communities. An environmental problem that has a delayed effect is global climate change; CO₂ released into the air has caused the average global temperature to rise gradually.

Question 3

What are major sources of industrial smog, photochemical smog, and acid deposition?

Answer 3

Major sources of industrial smog include power plants, factories, and households that burn coal and oil. Photochemical smog comes from emissions from vehicles. Coal-burning power plants are major sources of acid deposition.

Question 4

Which human activities promote habitat destruction?

Question 5

Several polar bears were discovered that have reproductive organs of both sexes. These bears also have high concentrations of PCBs in their blood, but researchers do not know whether exposure to PCBs is related to the disturbed sexual development. Given that many heavily polluted ecosystems are tainted with several types of pollutants, how could you link exposure to one chemical to a specific biological effect?

Question 6

What effects do smog, acid deposition, particulates, and the thinning ozone layer have on life?

Question 7

How can too much of a nutrient alter an aquatic ecosystem?

Question 8

In the southeastern United States, several species of freshwater mussels are extinct or threatened because of habitat destruction. In the past, they were also harvested for the button trade. How would a population ecologist (see chapter 36) approach the problem of species recovery for these animals?

Question 9

Why is CO₂ accumulating in Earth's atmosphere?

Question 10

How does the Gulf of Mexico's "dead zone" demonstrate the connections among the world's ecosystems?

Question 11

Your friend reads an article about scientists who are collecting DNA from endangered species. She says, "I don't know why we spend so much money to save these species when we can just sequence their DNA." Given what you know about the importance of biodiversity, how would you respond?

Question 12

Describe how and why Earth's climate changed during the past century.

Question 13

Visit the waterfootprint.org website to see how much water is required to produce various foods and beverages. Do you think it is important for an individual to choose products with a low water footprint? Why or why not?

Question 14

Use the Internet to search for examples of conflicts involving the Endangered Species Act and the rights of private property owners. If you owned land that housed an endangered species, what would you be willing to sacrifice to save the species? What information would you need before answering this question?

Question 15

How does global climate change threaten biodiversity?

Question 16

How does the combustion of fossil fuels influence such different phenomena as acid deposition and global climate change?

Question 17

The red-cockaded woodpecker is an example of an "umbrella species" because conserving this bird's habitat will also protect many other species. Can you think of other species in your area that might qualify as umbrella species?

Question 18

What features characterize an invasive species?

Question 19

Particulate air pollution damages animal respiratory tracts. How might dust-covered leaves harm a plant?

Question 20

Use the Internet to learn about so-called "biodiversity hot spots." Choose one to investigate in detail. Why is the area you chose a hot spot? What are the main threats to biodiversity in the area? What efforts are being made to preserve the area?

Question 21

How do invasive species disrupt ecosystems?

Question 22

In what ways is the greenhouse effect both beneficial and detrimental?

Question 23

Refer back to section 11.6, which describes the bottleneck effect. With this information in mind, why might recovery be difficult for species, such as cheetahs, that are nearly extinct?

Question 24

List examples of species declines caused by overexploitation.

Question 25

Cite biological evidence of global climate change.

Question 26

What is the value of diversity to humans and to ecosystems as a whole?

Question 27

What is the relationship between human population growth and conservation biology?

Question 28

Explain the logic behind planting trees as a way to reduce global climate change.

Question 29

Describe the three types of biodiversity.

Question 30

List and describe seven tools that conservation biologists use to preserve biodiversity.
1. Set aside protected habitat. 2. Reverse habitat destruction. 3. Captive breeding and reintroduction to help increase population numbers. 4. Manage harvests, reducing the numbers of organisms taken in a year. 5. Predator control. 6. Biotechnology, perhaps to clone extinct or endangered organisms or to identify undiluted gene pools in the wild. 7. Develop ecotourism and other economic incentives for preservation.
3. How can scientists, governments, and ordinary citizens work together for conservation?.

Question 31

Select a biome from chapter 38, and list three ways that an earlier spring and later fall resulting from global climate change might affect biodiversity in that biome.

Question 32

Differentiate among extinct, endangered, and vulnerable species.

Question 33

Summarize the evidence that climate change is a factor in the extinction of harlequin frogs.

Question 34

What are examples of pollutants in air and in water? Which of these pollutants eventually reach land?

Question 35

Why are invasive species harmful?

Question 36

What is conservation biology?

Question 37

Other than climate change, what is an alternative hypothesis that could explain that extinction of harlequin frogs? How would you test your hypothesis?

Question 38

List the main threats to biodiversity worldwide.

Question 39

One approach to combat invasive species is to kill the invaders. In Hawaii, officials shoot feral cats, goats, and pigs. In Australia, the government added chlorine and copper to a bay to kill zebra mussels, killing everything living in the water. Do you think that this is an effective approach? Suggest an alternative.

Question 40

Which human activities account for most of the loss of terrestrial habitat?

Question 41

How does human population growth contribute to each of the main factors causing species extinctions?

Question 42

Which of the strategies described in sectioN₃9.5 are being used in the Everglades restoration project?

Question 43

How do dams and channelization alter river ecosystems?

Question 44

Describe the relationships among the three levels of biodiversity. Why is each level important?

Question 45

Name three ways you can alter your lifestyle in a way that promotes conservation practices.

Question 46

Why is damage to estuaries especially devastating?

Question 47

Give examples of government actions that threaten biodiversity and examples of government actions that preserve biodiversity.

Question 48

Search the Internet for information on the Convention on Biological Diversity and on the international agreement called CITES. How does each approach tackle the biodiversity crisis on a global scale?

Question 49

How do toxic chemicals, nutrients, sediments, and heat affect aquatic ecosystems?