Which of the following statements is correct about biogeochemical cycling?
A) The phosphorus cycle involves the recycling of atmospheric phosphorus.
B) The phosphorus cycle involves the weathering of rocks.
C) The carbon cycle is a localized cycle that primarily involves the burning of fossil fuels.
D) The carbon cycle has maintained a constant atmospheric concentration of CO2 for the past
million years.
E) The nitrogen cycle involves movement of diatomic nitrogen between the biotic and abiotic
components of the ecosystem.

The phosphorus cycle involves the weathering of rocks.

Why do logged tropical rain forest soils typically have nutrient-poor soils?
A) Tropical bedrock contains little phosphorous.
B) Logging results in soil temperatures that are lethal to nitrogen-fixing bacteria.
C) Most of the nutrients in the ecosystem are removed in the harvested timber.
D) The cation exchange capacity of the soil is reversed as a result of logging.
E) Nutrients evaporate easily into the atmosphere in the post-logged

Most of the nutrients in the ecosystem are removed in the harvested timber.

What is the first step in ecosystem restoration?
A) to restore the physical structure
B) to restore native species that have been extirpated due to disturbance
C) to remove competitive invasive species
D) to identify the limiting factors of the producers
E) to remove toxic pollutants

to restore the physical structure

What is the goal of restoration ecology?
A) to replace a ruined ecosystem with a more suitable ecosystem for that area
B) to speed up the restoration of a degraded ecosystem
C) to completely restore a disturbed ecosystem to its former undisturbed state
D) to prevent further degradation by protecting an area with park status
E) to manage competition between species in human-altered ecosystems

to speed up the restoration of a degraded ecosystem

Which of the following relies upon existing biodiversity for the decontamination of polluted
ecosystems?
A) Some types of bacteria naturally convert toxins to less hazardous forms.
B) Sawdust from lumber mills can be used to soak up chemicals that have saturated natural
ecosystems.
C) Species in contaminated areas may evolve into forms that can survive in contaminated soils.
D) After centuries of agricultural production, soils depleted of nitrogen can be replenished by
promoting the growth of nitrogen-fixing organisms.

Some types of bacteria naturally convert toxins to less hazardous forms.

Which of the following would be considered an example of bioremediation?
A) using a bulldozer to reshape the land around an abandoned strip mine to change erosion
patterns
B) dredging a river bottom to remove contaminated sediments
C) reconfiguring the channel of a river to increase the flow of water down a river
D) raising chromium-accumulating plants to extract chromium from contaminated soil
E) selectively harvesting younger trees in a forest to leave older trees for woodpecker nesting
habitat

raising chromium-accumulating plants to extract chromium from contaminated soil

To selectively remove soil toxins from regions affected by Hurricane Katrina, some residents
have raised sunflowers and other plants in their yards. Then, the mature plants are pulled up and
safely stored with other contaminated wastes. This is an example of
A) biological augmentation.
B) reducing primary production.
C) lowering production efficiency.
D) bioremediation.
E) arresting nutrient cycling.

bioremediation

Corn production in many states of the Midwest is limited by nitrogen levels in the soil. Some
farmers reduce the need to apply expensive anhydrous ammonia to their fields by rotating corn
crops with nitrogen-fixing soybean crops. Using soybeans to add nitrogen to soils is an example
of
A) biological augmentation.
B) the biomass pyramid.
C) promoting leaching efficiency.
D) bioremediation.
E) trophic efficiency.

biological augmentation.