Deck 53: Ecosystems and Global Ecology

Question 1

You own 300 acres of patchy temperate forest. Which one of the following actions would increase the net primary productivity of the area the most?

A) relocating all the deer found in the area
B) planting 500 new trees
C) introducing 100 rabbits into the area
D) adding fertilizer to the entire area

Answer 1

B

Question 2

Which of the following consume other living organisms?

A) primary producers
B) herbivores
C) carnivores
D) decomposers
E) Both B and C

Answer 2

E

Question 3

Why are changes in the global carbon cycle important?
I. Burning reduces available carbon for primary producers and, therefore, primary consumers.
II. Deforestation and suburbanization reduce an area's net primary productivity.
III. Increasing atmospheric concentrations of carbon dioxide could alter Earth's climate.
IV. By using fossil fuels, we are destroying a nonrenewable resource.

A) only II, III, and IV
B) only II and IV
C) only I, II, III, and IV
D) only I, II, and IV
E) only I and III

Answer 3

only I, II, III, and IV

Question 4

Why is energy lost when herbivores eat primary producers?

A) Digestion takes place so rapidly that very little energy is absorbed.
B) Most primary producers contain no usable energy for herbivores.
C) Primary producers have energy stored in indigestible substances.
D) Primary producers cannot produce once eaten.

Question 5

What is the leading hypothesis as to why terrestrial productivity is higher in equatorial climates?

A) Productivity increases with water availability.
B) Productivity increases with available sunlight.
C) Hypothesis is most likely a combination of the other answers.
D) Productivity increases with temperature.

Question 6

When primary producers expend energy to build new tissue, this is

A) net primary productivity.
B) the amount of energy available to consumers.
C) maintenance costs.
D) Both A and B
E) Both B and C

Question 7

If the flow of energy in an arctic ecosystem goes through a simple food chain, perhaps involving humans, starting from phytoplankton to zooplankton to fish to seals to polar bears, then which of the following could be true?

A) Seal populations are larger than fish populations.
B) Fish can potentially provide more food for humans than seal meat.
C) Polar bears can provide more food for humans than seals can.
D) The total biomass of the fish is lower than that of the seals.
E) Seal meat probably contains the lowest concentrations of fat- soluble toxins.

Question 8

Detritus can be consumed by which of the following primary decomposers?

A) bacteria
B) fungi
C) earthworms
D) archaea
E) all of the above

Question 9

Figure 53.5
After looking at the figure above, what can be said about productivity in this ecosystem?

A) Between 10 and 20% of the energy is lost at the next highest trophic level.
B) Nothing can be said based on this information.
C) Productivity increases with each trophic level.
D) Between 80 and 90% of the energy is lost at the next highest trophic level.

Question 10

Figure 53.3
Which category in the figure above makes available the highest productivity per square meter?

A) tropical wet forest
B) open ocean
C) algal beds and reefs
D) wetlands

Question 11

Which statement best describes what ultimately happens to the chemical energy that is NOT converted to new biomass in the process of energy transfer between trophic levels in an ecosystem?

A) It is undigested and winds up in the feces and is not passed on to higher trophic levels.
B) It is eliminated as feces or is dissipated into space as heat, consistent with the second law of thermodynamics.
C) Heat produced by cellular respiration is used by heterotrophs for thermoregulation.
D) It is recycled by decomposers to smaller and smaller forms until it finally breaks down to form soil.
E) It is used by organisms to maintain their life processes through the reactions of cellular respiration.

Question 12

Which of the following is a consequence of biomagnification?

A) The biomass of producers in an ecosystem is generally higher than the biomass of primary consumers.
B) Toxic chemicals in the environment pose greater risk to top- level predators than to primary consumers.
C) The amount of biomass in the producer level of an ecosystem decreases if the producer turnover time increases.
D) Populations of top- level predators are generally smaller than populations of primary consumers.
E) Only a small portion of the energy captured by producers is transferred to consumers.

Question 13

At the Hubbard Brook Experimental Forest in New Hampshire, how did large amounts of energy leave the decomposer food web?

A) Energy was lost through incomplete decomposition.
B) Detritus was sublimated by increased solar radiation.
C) Large numbers of decomposers emigrated from the area.
D) Detritus was washed away into streams during heavy rain.

Question 14

What is the main reason for using food webs instead of food chains in analyzing ecosystems?

A) Most organisms eat more than one type of food.
B) Most organisms feed at several trophic levels.
C) The decomposition cycle needs to be shown.
D) Answers A and B both apply.
E) All of the above answers apply.

Question 15

Figure 53.3
Which terrestrial category in the figure above has the highest economic impact on Earth's ecosystem?

A) tropical seasonal forest
B) tropical wet forest
C) rock, sand, and ice
D) bogs

Question 16

Figure 53.4
After looking at the experiment in the figure above, what can be said about productivity in marine ecosystems?

A) Marine organisms break down iron for energy and thus for productivity.
B) Nothing can be said based on this information.
C) Productivity increases when chlorophyll a is added.
D) Iron can be a limiting nutrient in productivity.

Question 17

Figure 53.3
Which habitat type in the figure above covers the largest area on Earth?

A) tropical wet forest
B) open ocean
C) algal beds and reefs
D) wetlands

Question 18

How are the components in the figure above linked by the flow of energy?

A) A
B) B
C) C
D) D

Question 19

Figure 53.3
In the figure above, how is net primary productivity represented?

A) organized by biome
B) organized by region
C) organized by geography
D) randomly organized

Question 20

Figure 53.3
Which habitat type in the figure above makes available the most new tissue to consumers?

A) tropical wet forest
B) open ocean
C) algal beds and reefs
D) wetlands

Question 21

Figure 53.7
Considering the global water cycle depicted in the figure above, where does one find the largest amount of water changing phases?

A) evaporation and precipitation over the oceans
B) movement of water vapor from ocean to land
C) groundwater runoff to oceans
D) evaporation/transpiration and precipitation over land

Question 22

Use the following information when answering the corresponding questions).
Abstract:
Increased radiative forcing is an inevitable part of global climate change, yet little is known of its potential effects on the energ in natural ecosystems. To simulate the conditions of global warming, we exposed peat monoliths depth, 0.6 cm; surface area, from a bog and fen in northern Minnesota, USA, to three infrared IR) loading ambient, +45, and +90 W m^{- 2}) and three
water table - 16, - 20, and - 29 cm in bog and - 1, - 10 and - 18 cm in fen) treatments, each replicated in three mesocosm plots.
Net radiation Rn) and soil energy fluxes at the top, bottom, and sides of the mesocosms were measured in 1999, five years after the treatments had begun. Soil heat flux G) increased proportionately with IR loading, comprising about 3%- 8% of Rn. In the fen, the effect of IR loading on G was modulated by water table depth, whereas in the bog, it was not. Energy dissipation from the mesocosms occurred mainly via vertical exchange with air, as well as the deeper soil layers through the bottom of the mesocosms, whereas lateral fluxes were 10- to 20- fold smaller and independent of IR loading and water table depth. The exchange with deeper soil layers was sensitive to water table depth, in contrast to G, which responded primarily to IR loading. The qualitative responses in the bog and fen were similar, but the fen displayed wider seasonal variations and greater extremes in soil energy fluxes. The differences of G in the bog and fen are attributed to differences in the reflectance in the long waveband as a function of vegetation type, whereas the differences in soil heat storage may also depend on different soil properties and different water table depth at comparable treatments. These data suggest that the
ecosystem- dependent controls over soil energy fluxes may provide an important constraint on biotic response to climate change. Copyright © 2004 Springer- Verlag A. Noormets et al. 2004. The effects of infrared loading and water table on soil energy fluxes in northern peatlands. Ecosystems 7:573- 582.)
The Noormets et al. study 2004) shows that there was an ecosystem- specific control over soil energy fluxes, and this constrained the biotic response to climate change. How do you think radiative heat would affect the water table in a wetland versus a temperate forest?

A) Both areas would absorb similar amounts of radiative heat and therefore affect the water table equally.
B) The wetland would likely absorb less heat than the temperate forest and therefore not significantly change water table depth.
C) The wetland would likely absorb more heat than the temperate forest and significantly change water table depth.
D) The temperate forest would likely absorb more heat than the wetland and significantly change water table depth.

Question 23

Regarding soil and organic matter in humus, which of the following statements is true?

A) Completely decayed soil organic matter is called humus.
B) Soil organic matter is completely decayed.
C) Eventually, the nutrients in soil organic matter are converted to organic form.
D) Humus is composed of inorganic nutrients, and organic matter is composed only of organic matter.

Question 24

Which of the following could be a cause of eutrophication?

A) removing a limiting resource from an aquatic ecosystem
B) adding a large amount of a limiting resource to a terrestrial ecosystem
C) removing a limiting resource from a terrestrial ecosystem
D) adding a large amount of a limiting resource to an aquatic ecosystem

Question 25

Which of the following human activities is impacting the water cycle the least?

A) increases in irrigated agriculture
B) increase in asphalt and concrete surfaces
C) conversion of grasslands and forests into agricultural fields
D) increased processing of salt water to freshwater

Question 26

Considering the global carbon cycle, where are humans having a large impact?

A) terrestrial ecosystems
B) oceans
C) atmosphere
D) beneath the surface of the Earth
E) Both A and C

Question 27

Considering the global carbon cycle, where is the largest reservoir of carbon?

A) beneath the surface of the Earth
B) terrestrial ecosystems
C) atmosphere
D) oceans

Question 28

Considering the current scientific literature on global warming, which statement best summarizes the most recent findings?

A) The Intergovernmental Panel on Climate Change concluded that carbon dioxide is the sole cause of global warming.
B) The Intergovernmental Panel on Climate Change concluded that current evidence suggests no link between human activity and climate change.
C) The Intergovernmental Panel on Climate Change concluded that the evidence for global warming is unequivocal and that it is very likely due to human- induced changes in greenhouse gases.
D) The Intergovernmental Panel on Climate Change concluded that current evidence suggests that most of the warming over the past 50 years is attributable to human activities.

Question 29

Why are changes in the global carbon cycle important?

A) Carbon is the chief source of food, and burning it reduces available food for primary consumers.
B) Carbon dioxide is a greenhouse gas, and increasing atmospheric concentrations could alter Earth's climate.
C) Carbon can be recycled only a limited number of times.
D) Global carbon availability is directly related to the water cycle.

Question 30

Figure 53.9
Upon looking at the figure above, what can be concluded?

A) Residents of industrialized countries use more energy per person.
B) Residents in colder climates use more energy per person.
C) Residents of more populated countries use more energy per person.
D) English- speaking countries tend to use more energy per person.

Question 31

Figure 53.9
Based on the figure above, and given the populations of the following countries, which country uses the most oil overall?

A) United Kingdom population = 60 million)
B) China population = 1.32 billion)
C) Russia population = 142 million)
D) United States population = 300 million)
E) Canada population = 33 million)

Question 32

Which of the following most often controls the rate of nutrient cycling in ecosystems?

A) rate of decomposition of detritus
B) primary productivity
C) secondary productivity
D) Both B and C

Question 33

How much nitrogen is fixed from human processes?

A) It is about half that fixed by natural means.
B) It is equal to the amount fixed by natural means.
C) It is about double that fixed by natural means.
D) We cannot calculate this value.

Question 34

Based on the experiment in the figure above, all of the following are plausible reasons for the result EXCEPT that

A) plant roots that held soil particles in place are no longer there.
B) nutrients are attached to small particles of sand or clay that leave the watershed.
C) nutrients evaporate now that vegetation is absent.
D) nutrients dissolve in the water running through the watershed.

Question 35

Figure 53.8
Considering the global nitrogen cycle, how are humans altering this cycle?

A) nitrogen lost to the atmosphere
B) industrial nitrogen fixation
C) reduction of nitrogen fixation by bacteria
D) reduction of nitrogen available to terrestrial ecosystems

Question 36

Use the following graph and information to answer the question below.
Flycatcher birds that migrate from Africa to Europe feed their nestlings a diet that is almost exclusively moth cat The graph shows the mean dates of arrival, bird hatching, and peak caterpillar season for the years 1980 and 200

What is the shift in the peak of caterpillar season most likely due to?

A) acid precipitation in Europe
B) earlier migration returns of flycatchers
C) an innate change in the biological clock of the caterpillars
D) pesticide use
E) global warming

Question 37

Which of the following is not a source of human- fixed nitrogen?

A) irrigation agriculture
B) industrially produced fertilizers
C) combustion of fossil fuels
D) cultivation of soybeans

Question 38

Figure 53.6
After looking at the experiment in the figure above, what can be said about nutrient export in ecosystems?

A) Nutrient export is not affected by any form of cutting.
B) Nutrient export is typically 10 times higher in a clear- cut watershed.
C) Nutrient export is typically 10 times lower in a clear- cut watershed.
D) Nutrient export is typically 10 times higher in an uncut watershed.

Question 39

What do researchers typically focus on when they study a particular biogeochemical cycle?

A) the nature and size of the reservoirs
B) the rate of element movement between reservoirs
C) interaction of the current cycle with other cycles
D) Both A and B
E) Both B and C

Question 40

Figure 53.8
Considering the global nitrogen cycle depicted in the figure above, what is the limiting portion of the cycle for plants?

A) nitrogen lost to the atmosphere
B) nitrogen fixation by bacteria
C) internal nitrogen cycling in the oceans
D) industrial nitrogen fixation

Question 41

Use the following information when answering the corresponding questions).
Abstract:
Increased radiative forcing is an inevitable part of global climate change, yet little is known of its potential effects on the energ in natural ecosystems. To simulate the conditions of global warming, we exposed peat monoliths depth, 0.6 cm; surface area, from a bog and fen in northern Minnesota, USA, to three infrared IR) loading ambient, +45, and +90 W m^{- 2}) and three
water table - 16, - 20, and - 29 cm in bog and - 1, - 10 and - 18 cm in fen) treatments, each replicated in three mesocosm plots.
Net radiation Rn) and soil energy fluxes at the top, bottom, and sides of the mesocosms were measured in 1999, five years after the treatments had begun. Soil heat flux G) increased proportionately with IR loading, comprising about 3%- 8% of Rn. In the fen, the effect of IR loading on G was modulated by water table depth, whereas in the bog, it was not. Energy dissipation from the mesocosms occurred mainly via vertical exchange with air, as well as the deeper soil layers through the bottom of the mesocosms, whereas lateral fluxes were 10- to 20- fold smaller and independent of IR loading and water table depth. The exchange with deeper soil layers was sensitive to water table depth, in contrast to G, which responded primarily to IR loading. The qualitative responses in the bog and fen were similar, but the fen displayed wider seasonal variations and greater extremes in soil energy fluxes. The differences of G in the bog and fen are attributed to differences in the reflectance in the long waveband as a function of vegetation type, whereas the differences in soil heat storage may also depend on different soil properties and different water table depth at comparable treatments. These data suggest that the
ecosystem- dependent controls over soil energy fluxes may provide an important constraint on biotic response to climate change. Copyright © 2004 Springer- Verlag A. Noormets et al. 2004. The effects of infrared loading and water table on soil energy fluxes in northern peatlands. Ecosystems 7:573- 582.)
Once heat is transferred to the soil, where does it go afterward Noormets et al. 2004)?

A) The heat is emitted back to the atmosphere, transferred to other soil layers, and stored in the soil.
B) The heat stored in the soil.
C) The heat is both emitted back to the atmosphere and transferred to other soil layers.
D) The heat is transferred to other soil layers.
E) The heat is emitted back to the atmosphere.