Phosphorus Reservoirs Flashcards
The majority of phosphorus is
Locked up the crust as minerable rock, soils and sediments.
Differs from carbon, sulfur and nitrogen cycles because
Phosphorus has no atmospheric gas reservoir.
Mineral rock reservoir -
10’000 x 10^12 g P
Soil reservoir -
200’000 x 10^12 g P
Sediment reservoir -
4 x 10^9 x 10^12 g P
Ocean reservoir -
90’000 x 10^12 g P
The phosphorus reservoir has no significant flux of
Gas from the oceans.
Phosphorus rock content is small,
Organisms rely on rapid recycling for survival.
The flux of phosphorus between soil and biota is
Almost a closed system, however soil erosion allows particles to be transported away by moving water.
Phosphorus can be derived from
Weathering reactions and released and soluble phosphate.
Phosphate can be
Assimilated by organisms.
The decomp of organic matter
Returns phosphorus to water or soil.
In rivers, phosphorus is absorbed to iron and aluminium oxidies, these are carried as
Suspended particles and deposited as sediment on the continental shelf. The remainder enters the ocean as dissolved phosphate which is assimilable by marine organisms.
Of the dissolved phosphate in the oceans, assimilated by marine organisms, 90% is taken up by
Marine organisms, the remainder is lost through the water column, thus generating a concentration of phosphorus in the deep ocean, greater than at the surface.
