52. Ecosystems

In general, the biomass in an ecosystem will be greatest at the trophic level comprising __________.

What is the main abiotic reservoir for elements, such as calcium and phosphorus, involved in local biogeochemical cycles?

In ecosystems, organisms at the highest trophic levels usually contain less collective biomass than the organisms at lower trophic levels because __________.

Which of the following statements is correct?

The global water cycle supports a net flow of atmospheric water vapor __________.

Local conditions such as heavy rainfall or the removal of plants may limit the amount of nitrogen, phosphorus, or calcium available to a particular ecosystem, but the amount of carbon available to the system is seldom a problem. Why?

By which process is carbon dioxide released from plants back to the atmosphere?

Which of the following is a key part of the carbon cycle?

Bacteria are especially important in making __________ available to plants.

The direct product of nitrogen fixation is __________.

Which of the following is true of the nitrogen cycle?

The phosphorus cycle lacks a(n) __________ component.

Which of the following organisms is incorrectly paired with its trophic level?a. cyanobacterium—primary producerb. grasshopper—primary consumerc. zooplankton—primary producerd. fungus—detritivore

What is the main global reservoir of nitrogen?

Add labels to the figure that follows, which illustrates the interacting factors in a declining population that contribute to the extinction vortex.