Pollution

BIOGEOCHEMICAL CYCLES
• Description of the movement of chemical substances
(nutrients and pollutants) through the environment.
• Usually represented as a flow chart showing material
transfer between different reservoirs (“spheres”).
• If all components of a cycle are identified and the rates of
material transfer quantified, the term budget is used.
• Cycles of water soluble substances are closely linked to
the water (hydrologic) cycle.
• Important biogeochemical cycles: oxygen, carbon,
sulfur, nitrogen, phosphorus.
• Can set up biogeochemical cycle for any element (e.g.
heavy metals).