Redfield stoichiometry, importance

Nitrification can also be an important sink for oxygen in aquatic environments, is released through the aerobic oxidation of organic matter and nitrification according to the classic Redfield stoichiometry (Redfield et ah, 1963) ... 

Shifts in the stoichiometry of regenerated nutrients in sediments from the expected Redfield ratio has been suggested as an important factor controlling the metabolism of shallow estuaries. 

Figure 16.20 Nitrogen-to-phosphorus (N P) ratios at Station ALOHA. (A) Depth profiles of N P forinorganic (NO3 P04 ) and total (TDN TDP) pools showing fundamentally different depth trends relative to the 16N 1P Redfield ratio, which is shown as a vertical dashed line in each plot. The elevated N P (>16) for the total dissolved pool, especially in the upper 100 m of the water column, indicates an excess of N relative to the P requirements for biomass production, if all DON and DOP are biologically available.The middle plot shows the depth dependence for the stoichiometric relationships if the DON and DOP pools are corrected for residual deep water concentrations (DON = 2.23 pM and DOP = 0.04 pM, respectively) to remove the contribution of the recalcitrant pools. After this correction, the near-surface N P appears to converge near the Redfield ratio with a broader envelope of values near the surface. This stoichiometry of the DOM pool may be an important factor in the selection for, or against, N2 fixing microorganisms. From Karl et al. (2001a).

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