Verified answer

Lightning fixation is not considered a cycle. It is only a part of the nitrogen cycle: which is the an example of biogeochemical cycle.

List of biogeochemical cycles:

1. Water cycle

2. Carbon Cycle

3. Nitrogen Cycle

4. Phosphorus cycle

Site with pictures: http://www.colorado.edu/GeolSci/courses/GEOL1070/c...

Sulfur Cycle: http://homepages.nyu.edu/~pet205/sulfur.html

Oxygen Cycle: http://en.wikipedia.org/wiki/Oxygen_cycle

example of most important responsible for sulphur oxidation and sulphur reduction