ABSTRACT
Phosphorus concentration in the Earth’s crust is reported to be approximately 0.1%. Under natural conditions, weathering of minerals releases phosphorus into the environment. The phosphorus cycle is dynamic and involves interaction or exchange between biotic and abiotic pools. Phosphorus lacks a major gaseous component, so on any given landscape, phosphorus transfer is typically “downhill” from uplands to wetlands and then to the aquatic environment. The supply of phosphorus, a major macronutrient to land and water, is a major factor governing long-term ecosystem productivity and eutrophication. Phosphorus loads from uplands to many aquatic systems rapidly increased during the industrial and green revolution as a result of heavy fertilizer use and the demand to produce more food to meet the demand of the population explosion. In phosphorus-limited wetlands and aquatic systems, phosphorus availability is tightly controlled and cycled to maintain ecosystem stability.
