Ecology Cycles

Phosphorus Cycle, Carbon Cycle, & Nitrogen Cycle

The Phosphorus Cycle

The Phosphorus Cycle - the movement of phosphorus from the environment to organisms and then back to the environment

  • this cycle is slow and does not usually occur in the atmosphere because phosphorus rarely occurs as a gas


Phosphorus - an element that is part of many molecules that make up the cells of living organisms.

The Carbon Cycle

The Carbon Cycle - a process by which carbon is cycled between the atmosphere, land, water, and organisms.


Carbon -

  • enters a long-term cycle
  • may be converted in carbonates

The Nitrogen Cycle

The Nitrogen Cycle - a process in which nitrogen is cycled between the atmosphere, bacteria, and other organisms.


Nitrogen-Fixing Bacteria - a few species of bacteria that are the only organisms that can fix atmospheric nitrogen into chemical compounds.