The Global Phosphorus Cycle

Phosphorus is an essential nutrient for all life-forms. It is a key player in fundamental biochemical reactions involving genetic material (DNA and RNA) and energy transfer (ATP) and in structural support of organisms provided by membranes (phospholipids) and bone (the biomineral hydroxyapatite). Photosynthetic organisms utilize dissolved phosphorus, carbon, and other essential nutrients to build their tissues using energy from the sun. Biological productivity is contingent upon the availability of phosphorus to these simple organisms that constitute the base of the food web in both terrestrial and aquatic systems. It begins with a brief overview of the various components of the global phosphorus cycle. Estimates of the mass of important phosphorus reservoirs, transport rates (fluxes) between reservoirs. Following the overview, various aspects of the global phosphorus cycle are examined in more depth, including a discussion of the most pressing research questions currently being posed and research efforts presently underway to address these questions.