Biogeochemical Cycles

1. On this planet, there are a limited amount of nutrients essential to life.
2. These elements and chemicals are recycled within the natural environment.
3. In natural systems there is no waste - organisms have adapted to convert and utilize materials for their use.
4. A shortage of an element can be a limiting factor for an organism :
   1. A plant may not reach its optimum size if there is insufficient nitrogen in the soil.
   2. This can lead to lowering of reproductive capacity.
5. Each chemical cycles by a variety of paths. The chemical properties of the chemical helps determine the paths :
   1. Gaseous forms of chemicals (carbon, nitrogen, etc) are more mobile and participate in global interactions.
   2. Other chemicals are less mobile (phosphorus, calcium, etc) and they move on more local scales.
6. There are four main reservoirs for nutrients:
   1. Available nutrients in organic materials.
   2. Unavailable nutrients in organic materials.
   3. Available nutrients in inorganic materials.
   4. Unavailable nutrients in inorganic materials.
7. The paths taken by elements in the cycling process can be generalized as shown in the diagram.