[yueying (OP)]

what the difference between the carbon and nitrogen cycle?

do it have anything to do with the life cycle [decoposing, etc.]?

and do it concerns the whole ecosystem of how it is operated?

_{<Mod Edit - formatted the subject as a question - please do this to help keep the forum tidy and easy to navigate - thanks>]/sub]}

[yor_on]

Have you goggled?
http://earthobservatory.nasa.gov/Features/CarbonCycle/
Or are you up for a test?
" the carbon cycle deals with the exhange of carbon between organisms. The nitrogen cycle starts with nitrogen being fixed by nitrogen-fixing bacteria, or fungi. nitrogen can also be condensed in the air by lightning."