Exam 22: Biogeochemical Cycles

Nearly all of the phosphorus in terrestrial ecosystems comes from the ________ of calcium phosphate minerals.

Which of the following nutrients is most closely linked to the energy cycle in ecosystems?

Biological nitrogen fixation is accomplished by symbiotic ________ living in mutualistic association with plants.

Carbon cycles more quickly through cold and dry ecosystems than it does through warm and wet ecosystems.

The sulfur biogeochemical cycle is a sedimentary cycle with essentially no gaseous cycle.

Most aerobic autotrophs produce and consume oxygen in order to live.

Which of the following represents a loss of nutrients from an aquatic ecosystem?

Large quantities of nutrients are bound tightly in ________ structure; they are not readily available until released by the activities of decomposers.

Atmospheric sulfur dioxide returns to Earth in rain as weak sulfuric acid.

One way that sulfur enters the atmosphere is through volcanic activity.

Oxygen is taken up by plants during photosynthesis.

According to the figure,when is atmospheric CO₂ the highest?

Nutrients deposited on leaves as dust and materials leached from leaves through insect action are most often transported to the forest floor by

Flowing-water aquatic systems (streams and rivers)contain high levels of organic matter so are rarely dependent on inputs from terrestrial systems.

The process of nitrification produces a form of nitrogen that is easily lost from soil through leaching.

Which region contains the largest amount of the global carbon pool?

Lightning converts N₂ to a nitrogen form that enters soil and can be readily assimilated by plants.

Humans have altered the nitrogen cycle by burning fossil fuels.

Which region contains the largest amount of the global nitrogen pool?

Which area has the highest nitrogen deposition?