CHAPTER 23 Test Your Knowledge
DRIVING QUESTION 1
What are ecosystems, and how are ecosystems being affected by climate change?
By answering the questions below and studying Infographics 23.1, 23.2, 23.3, and 23.6 and Up Close: Biomes, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
Which of the following are parts of an ecosystem?
a. the plant life present in a given area
b. the animals living in a given area
c. the amount of annual rainfall in a given area
d. the soil chemistry in a given area
e. none of the above
f. all of the above
List several examples of species discussed in this chapter that have changed their geographic distributions or the timing of events in their life cycle as a result of global climate change.
In identifying a biome, for which of the characteristics below would it be most important to have data? (Select all that apply.)
a. monthly rainfall
b. temperatures throughout the year
c. plant life
d. animal life
e. size of the human population in the area
Which biome is characterized principally by evergreen trees?
Look at Up Close: Biomes. Where in North and South America do you find temperate forest? Tropical forest?
If global warming causes Arctic sea ice to melt, what will be the effect on sea levels in a low-lying region like Miami? If large parts of the Antarctic polar ice cap should melt, what would be the effect on sea level?
USE IT
Although trees may not be able to walk away from increasingly warm regions, evolutionary adaptations may allow trees to survive in warmer regions. Discuss each of the adaptations listed below and decide if it is likely to be helpful or harmful in a warming environment. (Think about water—water is taken up by the roots of plants, and lost through pores in the leaves; CO2 levels—CO2 is taken up by plants through pores in leaves, then used by leaves for photosynthesis; and the movement of other species, for example insects, in response to global warming.)
a. having smaller leaves
b. having a larger number of pores on each leaf
c. having thicker and waxier bark
What is a possible risk for humans if insects that carry pathogenic bacteria or viruses expand their range northward?
DRIVING QUESTION 2
What is the greenhouse effect, and what does it have to do with global warming?
By answering the questions below and studying Infographics 23.4, 23.5, 23.7, 23.8, and 23.11, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
Which greenhouse gas is emitted every time you breathe out?
a. oxygen
b. carbon dioxide
c. methane
d. nitrogen
e. water vapor
Which of the following organisms contributes to reducing atmospheric CO2 levels?
a. maple trees
b. most algae
c. polar bears
d. pear thrips
e. a and b
f. a, b, and d
Could we live in the absence of the greenhouse effect? Explain your answer.
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USE IT
Explain how each of the following contributes to an elevation of levels of greenhouse gases.
a. large-scale slash-and-burn agriculture
b. driving gasoline-fueled cars
c. producing cattle for beef and dairy products
d. rice production
DRIVING QUESTION 3
How do carbon and other chemicals cycle through ecosystems?
By answering the questions below and studying Infographic 23.9 and Up Close: Chemical Cycles, you should be able to generate an answer for the broader Driving Question above.
Fill in the blanks in the image below.
KNOW IT
Decomposers ________________ CO2 by the process of ________________.
a. emit; photosynthesis
b. take up; photosynthesis
c. emit; cellular respiration
d. take up; cellular respiration
e. store; cellular respiration
Atmospheric nitrogen is in the form of
a. N2.
b. proteins.
c. ammonium (NH4+).
d. nitrates (NO32).
e. any of the above
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MINI CASE
For more than 30 years, a system of lakes in northwestern Ontario, Canada, called the Experimental Lakes, has been used to study the impacts of various pollutants in order better to understand how to maintain healthy freshwater ecosystems. A challenge in many aquatic ecosystems is eutrophication—nutrient enrichment that leads to overgrowth of algae. When the algae die, the decomposers use so much oxygen as they feast on the dead algae that other organisms in the ecosystem cannot survive. Eutrophication led to loss of many fish from Lake Ontario in the 1960s and 1970s. In one of the Experimental Lakes, two basins of the lake were separated by a plastic sheet. The basin shown at the bottom of the photo below received nitrogen, phosphorus, and carbon. The basin shown at the top of the photo received only carbon and nitrogen. The green scum covering the water surface is algae.
a. What nutrient is most important in the eutrophication process?
b. What are human-derived sources of this nutrient?
c. Do some online research to see what measures were taken in Ontario to prevent eutrophication.
DRIVING QUESTION 4
How are scientists able to compare present-day levels of atmospheric carbon dioxide to past levels, and why would they want to?
By answering the questions below and studying Infographics 23.5, 23.9, 23.10, and 23.11, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
Fossil fuels are most immediately derived from
a. organic molecules.
b. CO2.
c. methane.
d. melting ice caps.
e. photosynthesis.
Name at least two human activities that increase CO2 levels in the atmosphere and two natural processes that contribute CO2 to the atmosphere.
USE IT
How is ice useful in the measurement of atmospheric levels of CO2?
Describe the evidence that increasing levels of greenhouse gases are responsible for global climate change. What if someone suggested to you that global climate change is due to increased intensity of solar radiation (i.e., the amount of sunlight reaching Earth)? What kind of evidence would you ask this person to provide to support this hypothesis?
Which of the following data would you use to determine the levels of atmospheric CO2 in 1750? Justify your choice, including an explanation of why the other alternatives would not be as effective.
a. historical weather records of daily temperatures
b. archives of the Manua Loa Observatory (to examine records from 1750)
c. tree-ring analysis (to look for evidence of extreme fires)
d. ice cores from ice formed in 1750
BRING IT HOME
Visit an online carbon footprint or carbon emissions calculator (for example, http://www.epa.gov/climatechange/ghgemissions/ind-calculator.html) and calculate your total carbon emissions.
a. What is your largest source of emissions?
b. What steps can you take to decrease your carbon emissions?
c. Explain how drying your laundry on a clothesline rather than in the dryer can decrease your carbon emissions.
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INTERPRETING DATA
A 2010 study compared the amount of CO2 emitted when locally grown broccoli was delivered to Virginia Tech University with the amount emitted when broccoli grown in California was delivered to Virginia Tech. The California broccoli was delivered in shipments containing 768 lbs of broccoli, in a tractor-trailer that traveled 2,786 miles. Tractor-trailer fuel efficiency is 5 miles per gallon, and 20 lbs of CO2 are released per gallon of fuel burned. The local broccoli was delivered in shipments of 587 lbs of broccoli in a cargo van that traveled 19.1 miles. Cargo van fuel efficiency is 16 miles per gallon, and 20 lbs of CO2 are released per gallon of fuel burned.
a. Complete the table below to determine the CO2 emissions associated with delivering 1 lb of local and 1 lb of nonlocal broccoli.
b. Is locally sourced fresh broccoli a year-round option at Virginia Tech?
c. Do some online research to determine approximately what proportion of CO2 emissions are associated with food delivery vs. food production.
SOURCE: Schultz, J. and Clark, S. (2010) Foodprint Comparison of Local vs Nonlocal Produce.
http://www.blacksburgfarmersmarket.com/docs/Schultz_Foodprint_Comparison_of_Local_vs_Nonlocal.pdf (accessed 5/4/2013)