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Environment: The Science Behind the Stories, 3e (Withgott)
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Chapter 7
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Environmental Systems and Ecosystem Ecology
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7.1
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Graph and Figure Interpretation Questions
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Use Figure 7.1 to answer the following questions.
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1)
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This graph helps to explain ______.
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A)
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why the open ocean is so productive
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B)
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why cultivated lands are a logical choice to replace rainforests
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C)
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why we need to be concerned with damage to rainforests and coral reefs
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D)
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why tundra has such high net primary productivity of biomass
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E)
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the importance of deserts
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Answer:
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C
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Diff: 2
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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2)
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Recall that areas with high net primary productivity not only produce high levels of biomass rapidly, they also take up large amounts of CO2 and give off large amounts of oxygen. What is the likely result of the increasing amounts of sediments and fertilizers in the major rivers emptying into oceans and affecting algal beds, reefs, swamps, and estuaries?
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A)
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Productivity in these areas will increase permanently, leading to more CO2 uptake and more oxygen released.
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B)
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Eutrophication, followed by hypoxia, is a likely result, ultimately leading to less CO2 uptake and less oxygen released.
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C)
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Eutrophication, followed by hypoxia, is a likely result, ultimately leading to more CO2 uptake and more oxygen released.
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D)
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Eutrophication, followed by hypoxia, is a likely result, ultimately leading to less CO2 uptake and more oxygen released.
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E)
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Fisheries will improve as the extra nutrients feed shellfish and fish.
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Answer:
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B
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Diff: 2
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Objective:
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7.3 Human impacts on systems and cycles
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3)
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Overall, it appears that biomes with more available freshwater ______.
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A)
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tend to have less productivity than those without much freshwater
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B)
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tend to have about the same productivity as those without much freshwater
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C)
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tend to have more productivity than those without much freshwater
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D)
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don't differentiate between freshwater as rainfall and freshwater as ice in glaciers
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E)
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No real conclusions can be drawn
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Answer:
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C
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Diff: 2
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Objective:
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7.2 Biogeochemical cycles
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7.2
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Matching Questions
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Match the following.
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1)
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A large ecological unit influenced by temperature, elevation, precipitation, and latitude
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A)
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ecosystem
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B)
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evaporation
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Diff: 1
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C)
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precipitation
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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D)
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lithosphere
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2)
1
Matter contained in living organisms
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E)
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biome
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Diff: 1
1
F)
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biosphere
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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G)
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hydrosphere
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3)
1
The solid earth beneath our feet
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H)
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sedimentary
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Diff: 1
1
I)
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biomass
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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J)
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atmosphere
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4)
1
Rocks that form as soils, minerals, and weathered rock particles are deposited, weighted down, and compressed over time
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K)
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metamorphic
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Diff: 1
1
Objective:
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7.4 Plate tectonics and rock cycles
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5)
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The process by which water moves from Earth's surface (such as in lakes or rivers) to the atmosphere
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Diff: 1
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Objective:
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7.2 Biogeochemical cycles
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6)
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Water returns from the clouds to Earth's surface as
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Diff: 1
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Objective:
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7.2 Biogeochemical cycles
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1)
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E
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2)
1
I
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3)
1
D
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4)
1
H
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5)
1
B
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6)
1
C
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7.3
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Short Answer Questions
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1)
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What three factors contribute to the "dead zone" in the waters off the Gulf of Mexico?
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Answer:
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Invention of synthetic ammonia; Midwestern farm practices; global nitrogen cycle thrown out of balance, uptake of dissolved oxygen by benthic bacteria, algal blooms
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Diff: 2
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Objective:
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7.3 Human impacts on systems and cycles
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2)
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Define the term emergent properties and give an example from a natural system.
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Answer:
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Emergent properties are characteristics that are not evident in the system's components (the whole is greater than the sum of its parts). The component parts of a tree (leaves, branches, roots, bole) do not lead to the whole tree's emergent properties as a source of shade for understory vegetation, a home for birds and insects, a rich resource filled with nectar and pollen during flowering season, and/or a source of food for many organisms in the form of fruits or nuts.
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Diff: 3
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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3)
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What determines which biome covers any particular portion of the planet?
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Answer:
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A variety of abiotic factors, including temperature, precipitation, atmospheric circulation, and soil characteristics, exert the greatest influence on biomes, with temperature and precipitation having the largest effects.
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Diff: 2
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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4)
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Briefly explain the concept of plate tectonics and why it is important for the study of geography
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Answer:
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Plate tectonics make up the processes that move continental plates, underlie earthquakes and volcanoes, create mountain ranges, and shape shorelines. They determine much of the geography of Earth's surface.
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Diff: 2
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Objective:
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7.4 Plate tectonics and rock cycles
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5)
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What are the anthropogenic sources of phosphorus, and why are they a problem?
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Answer:
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The major anthropogenic source of phosphorus is effluent from sewage treatments, which tends to be phosphate rich. Fertilizers also provide large amounts of anthropogenic phosphorus, and many detergents play a part as well. Introduction of phosphates from all of these sources into surface waters causes eutrophication and algal growth, leading to murkier waters and changes in the structure and function of ecosystems.
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Diff: 2
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Objective:
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7.3 Human impacts on systems and cycles
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6)
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What is the net effect of human activity on Earth's carbon reservoirs?
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Answer:
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Humans have changed the rates of flux for carbon and are shifting carbon from the lithosphere, as a source, into the atmosphere, as a sink. Most of the carbon is entering the atmosphere in the form of carbon dioxide.
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Diff: 2
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Objective:
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7.3 Human impacts on systems and cycles
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7)
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How and for what is GIS software used?
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Answer:
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GIS (geographic information system) software is used by landscape ecologists to analyze and visualize how geographic elements of a landscape are arrayed spatially. The elements can be arranged as layers to form a composite map, useful for mapping niches of various species and establishing management strategies for any landscape, natural or urban.
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Diff: 2
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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8)
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The extremely low dissolved oxygen concentrations in the "dead zone" represent a condition called ______.
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Answer:
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hypoxia
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Diff: 1
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Objective:
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7.3 Human impacts on systems and cycles
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9)
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The process of nutrient enrichment, subsequent increased production of organic matter, and eventual ecosystem degradation is known as ______.
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Answer:
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eutrophication
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Diff: 1
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Objective:
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7.2 Biogeochemical cycles
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10)
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The term ______describes all of the interacting organisms and the abiotic factors that occur in a particular place at the same time.
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Answer:
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ecosystem
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Diff: 1
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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11)
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Earth's surface consists of a lightweight thin ______of rock floating atop a malleable ______.
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Answer:
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crust; mantle
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Diff: 1
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Objective:
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7.4 Plate tectonics and rock cycles
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12)
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Substances move though the environment in cycles called nutrient cycles or ______cycles.
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Answer:
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biogeochemical
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Diff: 1
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Objective:
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7.2 Biogeochemical cycles
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13)
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In the process of ______, autotrophs such as green algae and plants use the sun's energy, water, and carbon dioxide from the air to produce new biomass.
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Answer:
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photosynthesis
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Diff: 1
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Objective:
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7.2 Biogeochemical cycles
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7.4
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Multiple-Choice Questions
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1)
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Any network of relationships among a group of components, which interact with and influence one another through exchange of matter and/or information, is referred to as ______.
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A)
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an interchange
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B)
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a system
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C)
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an ecosystem
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D)
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an environmental collaboration
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E)
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hierarchy
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Answer:
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B
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Diff: 1
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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2)
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A system receiving inputs and producing outputs without undergoing any changes in size or function is said to be in ______.
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A)
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static control
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B)
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environmental balance
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C)
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harmonic resonance
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D)
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normal balance
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E)
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dynamic equilibrium
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Answer:
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E
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Diff: 1
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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3)
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Cattle on an open range, in some areas, may compact fragile soils while grazing. This can damage plant roots, leading to fewer, smaller plants, which may in turn cause cattle to graze more and work harder to obtain food. This is an example of a ______.
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A)
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positive feedback loop
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B)
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negative feedback loop
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C)
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homeostatic system
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D)
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dynamic equilibrium
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E)
1
food web
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Answer:
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A
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Diff: 2
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Objective:
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7.3 Human impacts on systems and cycles
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4)
1
The eutrophication that has taken place in the Gulf of Mexico and other locations appears to be due to ______.
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A)
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global warming from human use of fossil fuels
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B)
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pesticide use along the waterways
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C)
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heavy metals dumped in the sewage
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D)
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weather alone, because it is only obvious in the summer
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E)
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excess nutrients from fertilizers
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Answer:
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E
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Diff: 2
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Objective:
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7.3 Human impacts on systems and cycles
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5)
1
The physical, abiotic components of our planet can be divided into the ______.
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A)
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geosphere and atmosphere
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B)
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lithosphere, hydrosphere, and atmosphere
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C)
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lithosphere, biosphere, and atmosphere
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D)
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lithosphere, hydrosphere, biosphere, and atmosphere
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E)
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centrosphere, geosphere, biosphere, and abiosphere
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Answer:
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B
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Diff: 2
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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6)
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A natural ecosystem, undamaged by human activity, is ______.
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A)
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a closed system of organic materials and energy; everything is recycled
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B)
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an open system of organic materials and energy
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C)
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an open system of organic and inorganic materials and energy
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D)
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a closed system of organic and inorganic materials and energy; everything is recycled
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E)
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an open system of inorganic materials and energy
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Answer:
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C
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Diff: 2
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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7)
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The swamplands of extreme southern Louisiana, which contain elements of both the forests and the coast, could be called ______.
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A)
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a superbiome
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B)
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an ecotone
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C)
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a dead zone
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D)
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a closed ecosystem
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E)
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an abiotic system
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Answer:
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B
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Diff: 2
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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8)
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A small section of prairie grasses, over a year, produces enough biomass to feed insects, mice, rabbits, birds, deer, antelope, and a host of decomposers. The amount of food potentially available to the herbivores is the ______.
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A)
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net primary production
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B)
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gross primary production
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C)
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secondary production
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D)
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productivity
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E)
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food chain
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Answer:
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A
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Diff: 2
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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9)
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The rate at which biomass becomes available to consumers is termed ______.
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A)
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gross primary production
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B)
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ecosystem productivity
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C)
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grossulosity factor
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D)
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net density
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E)
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net primary productivity
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Answer:
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E
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Diff: 2
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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10)
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The biosphere consists of the ______.
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A)
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water, saltwater, and freshwater in surface bodies and the atmosphere
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B)
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solid earth beneath our feet
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C)
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sum of all the planet's living organisms and the abiotic portions of the environment
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D)
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air surrounding our planet
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E)
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abiotic portions of the environment
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Answer:
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C
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Diff: 1
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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11)
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Ecotones are the ______.
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A)
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sounds that animal communities make in ecosystems
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B)
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interactive behaviors leading to communication
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C)
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areas between territories of organisms
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D)
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studies of specific biomes by ecologists
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E)
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transitional zones between ecosystems
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Answer:
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E
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Diff: 1
1
Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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12)
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Examining areas from the landscape scale, termed landscape ecology, is useful because ______.
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A)
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humans have not yet caused alterations to landscapes
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B)
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the dynamics of animals result in localized problems
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C)
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the role of ecosystems is often overstated
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D)
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multiple ecosystems may exist in a single area with many transitional zones
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E)
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it helps to define the entire closed system
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Answer:
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D
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Diff: 2
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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13)
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Macronutrients ______.
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A)
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are large molecules necessary for making macromolecules
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B)
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are required in large amounts for organisms to survive
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C)
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are the only nutrients that can be tracked in nutrient cycles
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D)
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can only be taken up by plants from rock cycles
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E)
1
are what large predators eat
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Answer:
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B
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Diff: 1
1
Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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14)
1
Experiments done in coastal regions of oceans throughout the world have demonstrated that ______.
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A)
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the same few micronutrients limit growth everywhere
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B)
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only one micronutrient, nitrogen, limits growth everywhere
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C)
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only one micronutrient, phosphorus, limits growth everywhere
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D)
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different micronutrients appear to limit growth in different places
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E)
1
the only micronutrient that is important is carbon
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Answer:
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A
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Diff: 2
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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15)
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Plants conduct photosynthesis, making glucose and other carbohydrates. To do this they need ______.
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A)
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water from the soil
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B)
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water from the humid atmosphere and carbon dioxide from the soil
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C)
1
water from the soil and carbon dioxide from the soil
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D)
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carbon dioxide from the atmosphere
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E)
1
water from the soil and carbon dioxide from the atmosphere
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Answer:
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E
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Diff: 2
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Objective:
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7.2 Biogeochemical cycles
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16)
1
The largest pools of carbon in the carbon cycle are ______.
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A)
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freshwater systems and oceans
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B)
1
plants and animals
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C)
1
sedimentary rock and fossil fuels
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D)
1
atmosphere
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E)
1
hydrosphere
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Answer:
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C
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Diff: 2
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Objective:
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7.2 Biogeochemical cycles
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17)
1
The origin of all phosphorus in biological tissues is ______.
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A)
1
volcanic activities
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B)
1
atmospheric phosphorus gas
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C)
1
phosphorus weathered from rock
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D)
1
phosphorus dissolved in the ocean and taken up by shellfish
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E)
1
phosphorus in animal bones
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Answer:
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C
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Diff: 2
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Objective:
1
7.2 Biogeochemical cycles
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18)
1
The origin of all nitrogen in biological tissues is ______.
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A)
1
earthquake activities
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B)
1
atmospheric N2 gas
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C)
1
nitrogen weathered from rock
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D)
1
lightning
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E)
1
volcanoes
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Answer:
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B
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Diff: 2
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Objective:
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7.2 Biogeochemical cycles
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19)
1
Nitrogen fixation is a process that makes nitrogen available to plants by ______.
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A)
1
photosynthesis
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B)
1
volcanic eruptions
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C)
1
parasitic bacteria
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D)
1
dissolving in freshwater and in the ocean
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E)
1
mutualistic and free‑living bacteria
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Answer:
1
E
1
Diff: 2
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Objective:
1
7.2 Biogeochemical cycles
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20)
1
Humans have dramatically altered the rate of nitrogen fixation into forms usable by autotrophs ______.
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A)
1
due to the burning of fossil fuels to meet our energy needs
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B)
1
because of the erosion of farmlands through poor agricultural practices
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C)
1
as we produce synthetic fertilizers and apply them to crops, lawns, and parks
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D)
1
by using antibiotics to reduce the numbers of denitrifying bacteria
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E)
1
by selectively removing leguminous plants
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Answer:
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C
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Diff: 3
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Objective:
1
7.3 Human impacts on systems and cycles
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21)
1
The freshwater we depend on for our survival accounts for ______.
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A)
1
two-thirds of all water on Earth
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B)
1
one-third of all water on Earth
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C)
1
10% of all water on Earth
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D)
1
3% of all water on Earth
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E)
1
less than 1% of all water on Earth
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Answer:
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D
1
Diff: 2
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Objective:
1
7.2 Biogeochemical cycles
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22)
1
Aquifers are ______.
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A)
1
natural ponds and lakes
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B)
1
recharge lakes at water quality facilities
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C)
1
underground water reservoirs
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D)
1
the result of transpiration
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E)
1
oceans
1
Answer:
1
C
1
Diff: 2
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Objective:
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7.2 Biogeochemical cycles
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23)
1
By damming rivers and using methods such as flood irrigation, we are ______.
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A)
1
increasing evaporation
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B)
1
increasing the water table
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C)
1
decreasing the water table
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D)
1
decreasing transpiration
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E)
1
increasing transportation
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Answer:
1
A
1
Diff: 3
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Objective:
1
7.3 Human impacts on systems and cycles
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24)
1
Rock that has undergone heat or pressure that causes it to change form is called ______.
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A)
1
conglomerate
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B)
1
igneous
1
C)
1
sedimentary
1
D)
1
metamorphic
1
E)
1
deformative
1
Answer:
1
D
1
Diff: 1
1
Objective:
1
7.4 Plate tectonics and rock cycles
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25)
1
The process of subduction ______.
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A)
1
causes the formation of deep ocean trenches
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B)
1
occurs when denser ocean crusts slide beneath lighter continental crusts
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C)
1
is caused by volcanoes
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D)
1
occurs when plates pull apart
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E)
1
is responsible for hurricanes
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Answer:
1
B
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Diff: 3
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Objective:
1
7.4 Plate tectonics and rock cycles
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26)
1
Human beings have dramatically altered the flux rate of nitrogen from ______.
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A)
1
the atmosphere to various pools on the earth's surface
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B)
1
from soils to the atmosphere
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C)
1
proteins to inorganic ions in soils
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D)
1
oceans to soils
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E)
1
producers to consumers through increased wildfires
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Answer:
1
A
1
Diff: 2
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Objective:
1
7.2 Biogeochemical cycles
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7.5
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True/False Questions
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1)
1
Ecosystems that convert solar energy to biomass rapidly are said to have low primary productivity.
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Answer:
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FALSE
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Diff: 1
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Objective:
1
7.1 Systems, ecosystems, biotic, and abiotic factors
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2)
1
Biogeochemical cycles are one example of a positive feedback loop.
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Answer:
1
FALSE
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Diff: 2
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Objective:
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7.1 Systems, ecosystems, biotic, and abiotic factors
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3)
1
Excess carbon dioxide in the atmosphere is most easily taken up by a) producers in photosynthesis and by b) the ocean and many of its organisms.
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Answer:
1
TRUE
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Diff: 3
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Objective:
1
7.2 Biogeochemical cycles
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4)
1
Most ecosystems are limited by nitrogen as phosphorus is weathered from rock at relatively high rates.
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Answer:
1
FALSE
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Diff: 1
1
Objective:
1
7.2 Biogeochemical cycles
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5)
1
Producers and primary consumers can take up phosphorus dissolved in water; higher-level consumers must obtain phosphorus from organisms below them in the food web.
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Answer:
1
TRUE
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Diff: 3
1
Objective:
1
7.2 Biogeochemical cycles
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6)
1
All landmasses were once joined together in a supercontinent called Pangaea.
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Answer:
1
TRUE
1
Diff: 1
1
Objective:
1
7.4 Plate tectonics and rock cycles
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7)
1
Human beings have tremendously accelerated the flux rate of carbon from the earth to the atmosphere by burning fossil fuels.
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Answer:
1
TRUE
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Diff: 1
1
Objective:
1
7.2 Biogeochemical cycles
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8)
1
Denitrifying bacteria convert atmospheric nitrogen gas directly to nitrate ions
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Answer:
1
FALSE
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Diff: 1
1
Objective:
1
7.2 Biogeochemical cycles
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7.6
1
Essay Questions
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1)
1
Compare and contrast positive and negative feedback loops. Give an example of each and how common each is in natural systems.
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Answer:
1
A system's output can serve as input to that same system, a circular process described as a feedback loop. In a negative feedback loop, output pushing the system in one direction acts as input that moves the system in another direction. The output and input essentially neutralize one another, stabilizing the system. An example would be the regulation of our body temperature. Negative feedback loops are relatively common in nature. In a positive feedback loop, inputs don't stabilize a system but drive them further toward one extreme or another. An example of this process in natural systems is erosion. These are relatively rare in nature but are common in natural systems altered by human actions.
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Diff: 2
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Objective:
1
7.1 Systems, ecosystems, biotic, and abiotic factors
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2)
1
Differentiate between an open and a closed system. If possible, give a specific and somewhat detailed example of each. Do both exist in nature? Why or why not?
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Answer:
1
A closed system is one that is isolated and self-contained. It is hypothetical and allows scientists to grapple with complex systems. An open system is one that exchanges energy, matter, and information with another system. The Mississippi River is an open system that interacts with all aquatic systems, terrestrial systems, and atmospheric systems from its origin to the Gulf of Mexico. It is affected by all sources of pollution, fertilizer, temperature change, and other human impacts that can access its waters. Closed systems do not exist in nature. Even a system as closed as a desktop computer becomes an open system when plugged into the wall socket that is in contact with the electricity that runs through an entire local community. Matter may recycle through a system, but energy must be constantly input from an external source, such as the sun.