Exam 21: Movement of Elements in Ecosystems

Describe the path of nitrogen as it moves from the atmosphere to the soil, plants, animals, and back to the atmosphere. Describe each process and the location and the form of nitrogen (including chemical formula) at each step.

In the Hubbard Brook Experimental Forest, researchers found a 90 percent reduction in nitrates leaving the watershed over a 5-year period. To what did they attribute the majority of this reduction?

Why is the phosphorus cycle described as less complicated than the nitrogen cycle?

Which of the following is NOT a critical phosphorus-containing structure for organisms?

When terrestrial ecosystems are paved over, for example to construct a parking lot, how is the hydrologic cycle affected?

Nitrogen fixation in the soil is carried out by

In the study of leaf decomposition in a stream in Germany using leaf litter enclosed in either fine- or large-mesh bags, researchers found that decomposition was strongly affected by

Current atmospheric carbon dioxide levels are approximately

Decomposition is more rapid in _____ forests because of _____.

In aquatic ecosystems, most nutrients regenerate in

The chemical process NH₄⁺ → NO₂⁻ → NO₃⁻, is known as

Topic the breakdown of organic matter Level: medium Leaf litter with a _____ lignin composition should _____ k.

The leaf decomposition in a tropical forest

Weathering is important to the input of

Marine dead zones are formed when rivers that empty into oceans carry excess phosphorus and nitrate runoff. These dead zones are caused by

The carbon cycle in ecosystems mostly follows the same paths as the movement of

What are the six types of transformations in the carbon cycle?

How does phosphorus lead to eutrophication of aquatic ecosystems?

In waterlogged conditions, anaerobic metabolism of carbon compounds can cause the production of the greenhouse gas

Where does phosphorus originate in the phosphorus cycle?