AP Environmental Science Fall Semester Review

Wolves were reintroduced into Yellowstone National Park in 1995. In addition to tracking changes in the wolf population, scientists were interested in how the wolves would affect other parts of the Yellowstone ecosystem. In particular, they were interested in changes to the population of elk, the wolves’ primary prey. The graph below shows the population size of the wolf and elk populations over time.

Which of the following is a potential disadvantage of reintroducing wolves to Yellowstone?

• The wolves are causing a trophic cascade that could further increase the number of beavers and tree species such as willows and aspens.

• Wolves leaving the park may prey on livestock in grazing land outside the park.

• Wolves are extremely fast breeders and may become an invasive species if they get outside the park.

• The ecosystem could collapse because wolves were never in Yellowstone before 1995.

The underlying subsoil of this biome is permafrost, which prevents both water draining through and deep-rooted plants from growing. Additionally, there is very little precipitation per year.

• Temperate grassland

• Taiga

• Tropical rainforest

• Tundra

Which of the following is the zone of a pond or lake in which rooted, emergent plants such as cattails and rushes are located?

• Benthic

• Limnetic

• Littoral

• Profundal

• Riparian

Based on the diagram above, which process most directly results in the storage of carbon as coal and oil over millions of years?

In the nitrogen cycle illustrated above, nitrification occurs in which of the following steps?

• Step 1

• Step 2

• Step 3

• Step 4

Which of the following diagrams correctly illustrates the nitrogen cycle?

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The diagram shows the amount of phosphorus measured in teragrams (1 teragram = 1 x 10¹² grams), in the various reservoirs of the phosphorus cycle.

According to the diagram, the movement of phosphorus between biological organisms and soil is in a steady state in an undisturbed system. Which of the following best explains the reason for this steady movement?

• Phosphorus is taken up by plants during photosynthesis to create carbohydrates.

• A decrease in buffer zones prevents phosphorus runoff in waterways.

• There is a rapid influx of phosphorus from the weathering of rocks.

• Readily available organic phosphorus in the soil is assimilated by plants.

The diagrams above show an area that was once a pasture that has since undergone changes to the vegetation over time. Which of the following changes in the hydrologic cycle is most likely to occur as a result of the change in vegetation in the area?

• Increased infiltration

• Increased runoff

• Decreased transpiration

• Decreased precipitation

The net primary production of a pine forest on a lava flow on Mount Fuji is about 175,000 kcal/m²/yr, and the plant respiration is estimated to be 115,000 kcal/m²/yr.

What is the total amount of energy (in kcal/m²/yr) transferred during photosynthesis for this ecosystem?

Which of the following best explains why terrestrial trophic pyramids usually do not have levels higher than tertiary consumers?

• Tertiary consumers are the largest organisms in an ecosystem and require the most space to survive.

• Plants can only perform photosynthesis during the day, so tertiary consumers cannot get enough energy from consuming plants.

• A large proportion of energy is lost as heat as it is transferred up the pyramid, so there is not enough energy available to support another level.

• Tertiary consumers are often indicator species and are the first to be affected by environmental disturbances.