Each time you breathe out, you return carbon to the air in the form of carbon dioxide. One less noticeable cycle is the nitrogen cycle . The nitrogen cycle is one cycle that is entirely dependent on microorganisms. Measuring Efficiency Ecosystems that have been around for awhile develop extremely efficient processes. Very little energy and nutrients are wasted.
Scientists believe they can determine the health of an ecosystem by measuring efficiency.
Click on the Forest Nutrition activity above to learn how researchers are measuring efficiency in Olympic's forests.