Figure 4. Global phosphorus reservoirs, fluxes
and turnover times.
Major reservoirs are underlined, pool sizes and fluxes are given in Tg (1012 g) P and Tg P yr-1. Turnover times (reservoir divided by largest flux to or from reservoir ) are in parenthe
ses. To convert Tg P to moles P, multiply by 3.2 x 1010.
Note that the phosphorus cycle has no atmospheric component, and
is restricted to solid and liquid phases. The major sink is burial in marine sediments. Marine phosphorite deposits are mined and reintroduced to the cycle by man's activities. The
phosphorus biomass reservoirs are derived from the carbon cycle and C:P ratios.