52. Ecosystems

Based on the law of conservation of energy, ecosystem ecologists can make which of the following assertions?

Most of the sunlight that reaches Earth __________.

A study of metabolic rates in a terrestrial community showed that the energy released by respiration exceeded the energy captured in photosynthesis. Which of the following situations is most likely?

What are the major factors that control primary production in terrestrial ecosystems?

What frequently causes eutrophication in lakes?

What is the amount of chemical energy in a consumer's food that is converted to its own new biomass over a period of time called?

In the transition from each trophic level of the food chain to the next trophic level, there is about a __________.

Which of the following best describes the base of a pyramid of net production?

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?