Plankton stoichiometry

Inasmuch as the RKR model is a generalization, specific exceptions should be expected. The most important exceptions relate to growth conditions that can affect the stoichiometry of nutrient incorporation into plankton biomass. During respiration, the... 

Characklis, W.G., W.C. Lee, and S. Okabe (1990), Kinetics and stoichiometry of planktonic and biofilm (sessile) sulfate-reducing bacteria, report of Inst. Biological and Chemical Process Analysis, Montana State University, Bozeman, MT. 

This equation describes the ratios with which inorganic nutrients dissolved in seawater are converted by photosynthesis into the biomass of "average marine plankton" and oxygen gas 02. The opposite of this reaction is respiration, or the remineralization process by which organic matter is enzymatically oxidized back to inorganic nutrients and water. The atomic ratios (stoichiometry) of this reaction were established by... 

An estimate of the amoimt of organic matter respired since a water mass was last at the sea surfece can be inferred from its AOU and the stoichiometry given in Eq. 8.4. The respiration of 1 mol of POM comprised of average detrital plankton biomass requires the oxidation of 106 mol organic carbon. As per Eq. 8.6, this requires 106 mol O2 ... 

Deviations from the stoichiometry given in Eq. 8.4 have been observed. They are the result of several phenomena, such as variability in the elemental composition of plankton. Furthermore, not all of the POM that is respired is plankton. Other types of... 

Gismervik, I. (1997). Imphcations of zooplankton stoichiometry on distribution of N and P among planktonic size fractions. J. Plankton Res. 19(3), 343—356. 

Waive, J., and Larsson, U. (1999). Carbon, nitrogen and phosphoms stoichiometry of crustacean zooplankton in the Baltic Sea Implications for nutrient cychng.J. Plankton Res. 21(12), 2309—2321. Weatherby, J. H. (1929). Excretion of nitrogenous substances in protozoa. Physiol. Zool. 2, 375—394. Webb, K. L., and Johannes, R. E. (1967). Studies of the release of dissolved free amino acids hy marine zooplankton. Limnol. Oceanogr. 12, 376—382. 

Twining, B. S., Baines, S. B., and Fisher, N. S. (2004). Element stoichiometries of individual plankton cells collected during the Southern Ocean Iron Experiment (sofex). Limnol. Oceanogr. 49, 2115-2128. 

Table 10.6 gives data on the stoichiometry of plankton. The information in Table 10.6b may not be tme Redfield ratios. 

Clearly, there remain a range of possible stoichiometries and this mean value will probably continue to be revised. Based on the plankton study of Hedges et al (2002) and the analysis of Anderson (1995), formulas in the range C106-120H170-180O35-45N14-18P. which require an O2/C quotient of 1.42-1.46, appear to be realistic. 

Measurements of the essential trace metals in some eukaryotic marine plankton grown in culture resulted in a Redfield-like stoichiometry for the essential trace metals (Morel et al., 2003) ... 

This stoichiometry cannot he taken very seriously at this point as it is variable from species to species, and it is sure to evolve as more data become available. None the less, it clearly demonstrates the order of magnitude of the concentration of trace metals necessary for plankton growth. Iron and manganese have concentrations ten times higher than the other trace metals, but still 100 times lower than the macronufrient phosphorus. 

Comparative studies of the relation between primary productivity and benthic mineralization processes (Jahnke et al. 1990 Rowe et al. 1994 Hensen et al. 2000) show, however, that these empirical formulations are restricted to a limited, regional use (cf Section 12.3). A further important factor in this regard is the reaction stoichiometry of organic matter degradation, since it determines the proportional release of CO, NO and PO. Based on planktonic decomposition studies. 

Plankton production involves the formation of hard parts (biogenic calcium carbonate and biogenic opal) in addition to soft material. The stoichiometry varies around ... 

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