Exam 57: Ecosystems

Refer to the figure. Using this generalized diagram of a nutrient (biogeochemical) cycle, explain the importance of detritus and detritivores in the movement of nutrients through the system.Include the concepts of pools and fluxes.

Which of these is not a factor that must be considered when determining the value of an ecosystem service?

Briefly contrast the flow of energy and the cycling of nutrients through an ecosystem.

Carbon dioxide has shown a continual increase since measurements began about 1960.Why are scientists concerned about this rise?

As atmospheric CO₂ levels rise, much of the excess CO₂ is absorbed at the ocean surface and enters the ocean ecosystem.What major effect is this absorbed gas having on the oceans?

Atmospheric sulfur participates in world climate by helping to form clouds, which decrease incoming solar radiation.Which sulfur compound is most associated with cloud formation?

Refer to the graph. In the key, "elevated" refers to the addition of CO₂ above ambient levels, and "fertilized" refers to the addition of nitrogen fertilizer to the soil.Based on these data, can one conclude that nitrogen fertilizer enhances the effect of increased CO₂ on NPP in the forest?

A farmer is growing corn, which requires high levels of nitrogen.Corn does not have root nodules with nitrogen-fixing bacteria and therefore cannot produce its own nitrogen.What will most likely happen to the soil's nitrogen content if corn is grown in the same place year after year?

Which of these ecosystem services could be considered an example of a cultural service?

Which statement best describes a key difference between movement of energy and movement of nutrients through an ecosystem?

A company is manufacturing artificial fertilizers.They are carrying out the process of _______, which is a major process in the nitrogen cycle.

A student calculates the amount of plant biomass produced by a field during one season.He defines this as the gross primary production of the field.Is this correct, and why or why not?

Net primary production (NPP) equals gross primary production (GPP) minus _______.

Without microbes (primarily bacteria), what would most likely happen to the world's natural nitrogen cycle?

The wolves in Yellowstone National Park exert _______ control on energy flow in the ecosystem.

Cities in China are greatly increasing the burning of coal in power plants and the use of automobiles.This is resulting in massive levels of air pollution.Which substances, produced during the burning of coal and oil, are likely causing much of China's air pollution?

Which of these situations does not involve an ecosystem service trade-off?

Steller sea lion populations in Alaska declined after the 1970s, and survivors were smaller and had lower birth rates.Earlier populations had fed mostly on herring, a fish rich in fat.When herring declined, they fed mostly on cod and haddock, which are larger but lower in fat.This suggests that sea lion population changes can be directly linked to

Refer to the graph, showing changes in atmospheric CO₂ concentrations in the Northern Hemisphere from 1960 to 2015. The data indicate that the overall CO₂ concentration is _______, with yearly fluctuations due to _______.

For most of human history, we have received many ecosystem services free and have taken them for granted.These include clean air, clean water, pollination, and flood control by wetlands.Compared with a century ago, these types of ecosystem services seem to be