Phosphorus cycle organisms

Koenings, J. P., and F. F. Hooper. 1976. The influence of colloidal organic matter on iron and iron-phosphorus cycling in an acid bog lake. Limnology and Oceanography 21 684-696. 

Benitez-Nelson, C. R., O Neill, L., Kolowith, L. C., Pellechia, P. J., and Thunell, R. C. (2004). Phosphonates and particulate organic phosphorus cycling in an anoxic marine basin. Limnol. Oceanogr. 49,1593-1604. 

Potential processes that may be called upon to explain the large discrepancy between excess N2 and NOs deficits within the SNM are (1) sedimentary denitrification, (2) anammox, (3) metal (Fe, Mn)-catalyzed denitrification, and (4) non-Redfieldian organic matter mineralization (Codispoti et al., 2001 Devol et al., 2006a,b). The first of these possibilities requires a decoupling between nitrogen and phosphorus cycles (e.g. possible greater burial of phosphorus in continental margin sediments). The less likely additional requirement is that the maximal inputs from the sediments should occur at the same depth as the water column peak of N02. In other words, the exact coincidence of the extrema in NOs , N02, ... 

Clark L. L., Ingall E. D., and Benner R. (1999) Marine organic phosphorus cycling novel insights from nuclear magnetic resonance. Am. J. Sci. 299, 124-131. 

Very little detail is known about the nitrogen and phosphorus cycles. Dissolved orthophosphate is taken up in plant growth and returned eventually after serving in cell fluids and tissues. It appears to be released primarily in the form of organophosphorus compounds, and at certain seasons of the year more than half the phosphorus in the water is described as "dissolved organic phosphorus. Yet as of a year or so ago... 

Phosphorus is usually found in biological systems as the phosphate ion, which transits rapidly through plants and animals, but moves much more slowly through the soil and the oceans, making the phosphorus cycle overall one of the slowest biogeochemical cycles. The major mineral with an important phosphorus content is apatite [Ca5(P04)30H], but this is not a major source, and many organisms rely on soil-derived phosphorus released from dead organic matter for their phosphoms requirements. 

These ectoenzymes play a significant part in phosphorus cycling in natural waters. In lakes and oceans, phosphorus is partitioned among particulate and dissolved inorganic and organic fractions and is rapidly transformed from one fraction to another. Estimates of the size of the labile dissolved organic phosphorus pool in waters off the coast of Hawaii (0.01-0.2 /rg at P L 1), and its rapid turnover (0.008-0.04 h 1), presumably facilitated by extracellular phosphatases, are comparable with those of PO4- (Smith et al., 1985) and indicate the importance of ectoenzymes in the major nutrient cycles. 

In section 7.4.2.1 the theoretical significance of phosphate adsorption onto iron oxides was illustrated. Numerous studies on natural sediments suggest that iron oxides control phosphate pore water and solid phase concentrations, as well as the overall sedimentary phosphate cycle (Krom and Berner 1980 Froelich et al. 1982 Sundby et al. 1992 Jensen et al. 1995 Slomp et al. 1996a,b). A generalized representation of the sedimentary phosphorus cycle is shown in Fig. 6.11. Apart from the Fe-bound P, organic P and authigenic carbonate fluorapatite are the principal carriers of solid phase P. HPO/ is the predominant dissolved P species under sea water conditions (Kester and Pytkowicz 1967). 

Enzymatic hydrolysis of organic phosphorus is an essential step in the biogeo-chemical phosphorus cycle, including the phosphorus nutrition of plants and microorganisms (see Oberson and Joner, Chapter 7 Richardson et al., Chapter 8 Heath, Chapter 9, this volume) and the transfer of organic phosphorus from soils to water bodies (see Turner, Chapter 12, this volume). It also plays a role in gene fluxes in the environment by its effect on the residual extracellular DNA in soil, and in the degradation of... 

Microorganisms constitute a large pool of phosphorus in the soil and mediate several key processes in the biogeochemical phosphorus cycle. Microbial uptake of phosphorus and its subsequent release and redistribution strongly affect the availability of phosphorus to plants in natural and managed ecosystems, especially when the latter receive organic amendments (Walbridge,... 

Salas, A.M., Elliott, E.T., Westfall, D.C., Cole, C.V. and Six, j. (2003) The role of particulate organic matter in phosphorus cycling. Soil Science Society of America Journal 57, 1 81 -1 89. 

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