Cycling of Phosphorus

The dissolved P tmnover rates varied significantly in different marine environments, and the residence time of TDP increased from 3 4 d in the coastal 

The rates in which the nutrient is fixed by phytoplankton and transferred upward in the food web to zooplankton can largely determine the productivity of fish in the marine system. Traditionally, studies of nutrient flux rates have been conducted using incubation experiments with artificial C or N isotope tracer and the transfer of activity over time into the various size classes of phytoplankton and zooplankton examined. The difficulty with such types of research is that they involve significant perturbations to the system of interest. For example, samples are first separated from the ecosystem before incubation. Bottle incubations will, at best, miss sporadic bloom events and provide rate estimates that are only valid for discrete depths and time. Recently, naturally produced and have been used to investigate directly the uptake rates 

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In smaller shallow lakes, where the internal re-cycling of phosphorus can be... 

Stumm, W. (1973). The acceleration of the hydrogeo-chemical cycling of phosphorus. Water Res. 7,131-144. 

Withers PJA, Jarvie HP (2008) Delivery and cycling of phosphorus in rivers a review. Sci Total Environ 400 379-395... 

The cycling of phosphorus in marine sediments is quite different from that of nitrogen in that its remineralized form, HPO , is readily sequestered in several mineral phases, namely carbonate fluoroapatite (CFA) and iron-rich clays and oxyhydroxides. 

Griffith, E.J. Modem mankind s influence on the natural cycles of phosphorus. In Phosphorus and the Environment Ciha Poundation, New Series, 57, 1978. 

The continental cycle of phosphorus is determined by ten fluxes (Figure 4.1) closed by a single component Ps indicating the phosphorus supplies on land in soil-vegetation formations and in animals. The supplies of phosphorus in soils are replenished due to fluxes Hf (l = 2,4,5,8,9,10). The loss of phosphorus from the soil is determined by fluxes Hj ( / = 3,6,7,11). As the detailing of surface reservoirs of phosphorus and consideration of more ingenious effects in the interaction between these reservoirs gets more complicated, so the classification of the surface fluxes of... 

Krapivin V.F. (2000d). Simulation model of biogeochemical cycle of phosphorus in the biosphere. Problems of Environment and Natural Resources, 10, 26 - 30 [in Russian]. 

The microbial cycling of phosphorus does not alter its oxidation state. Most phosphorus transformations mediated by microorganisms can be viewed as inorganic to organic phosphate transfers or as transfers of phosphate from insoluble, immobilized forms to soluble or mobile compounds. Various microorganisms have evolved transport systems for the regulated acquisition of phosphate from the environment. 

Benitez-Nelson, C. R. (2000). The biogeochemical cycling of phosphorus in marine systems. Earth-Sci. Rev. 51, 109-135. 

The transfer of phosphorus from the terrestrial biomass to soil as dead organic matter has been estimated to be 136.4 TgP y 133.3 Tg P y is derived from plants and 3.1 Tg P y from animal material (Pierrou, 1976). The uptake of phosphorus by plemts from soil was calculated by Bazilevich (1974) to be 178TgPy while Stumm (1973) estimated it to be 236.8 Tg P y including that of the freshwater ecosystems. The terrestrial biota has been calculated to absorb 0.065 Tg P y from aquatic ecosystems and 0.063 Tg P y from industrially made foodstuffs and pharmaceutical products (Pierrou, 1976). An important aspect on which quantitative data are not yet available is the bacterial cycling of phosphorus within soils. This internal cycle helps in making phosphorus available for plants. 

The biogeochemical cycle of phosphorus is shown in more detail in Figure 30. 

Characterize the global biogeochemical cycle of phosphorus. Note the similarity and differences with natural biogeochemical cycles of carbon and nitrogen. 

Suzumura, M., Miyajima, T., Hata, H., Umezuwa, Y., Kayanne, H. and Koike, I. (2002) Cycling of phosphorus maintains the production of microphytobenthic communities in carbonate sediments of a coral reef. Limnology and Oceanography, 47, 771-781. 

Vadstein, O. (1994) The role of heterotrophic, planktonic bacteria in the cycling of phosphorus in lakes phosphorus requirements, competitive ability and food web interactions. PhD thesis, University of Trondheim (cited by Gismervik etal., 1996). 

E.M. Frossard, M. Brossard, M.J. Hedley and A. Metherell, Reactions controlling the cycling of phosphorus in soils. In H. Tiessen (ed.), Phosphorus in the global environment transfers, cycles and management. J. Wiley and Sons, New York, 1995, p. 107. 

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