marelac (version 2.1.11)

redfield: Redfield Ratio Calculator

Description

Estimate elemental composition of biomass (or media) according to the Redfield ratio.

Usage

redfield(q, species, method = c("mol", "mass"), 
         ratio = c(C=106, H=263, O=110, N=16, P=1))

Value

A data frame with the estimated ratio of the main elements.

Arguments

q

amount of substance of that element (in mol or mass units),

species

The element that is given ("C", "H", "O", "N", "P"),

method

measurement unit ("mol" or "mass"),

ratio

average elemental composition.

Details

The average elemental composition of marine plankton (Redfield ratio) is traditionally assumed to be \(\mathrm {C_{106}H_{263}O_{110}N_{16}P_{1}}\) (Redfield 1934, 1963, Richards 1965). Note that while the C:N:P ratio is widely agreed there is still discussion about the average of O and H, e.g. \(\mathrm{C_{106}H_{180}O_{45}N_{16}P_{1}}\) (Stumm, 1964).

Note also that there are, of course, large differences depending on species and physiological state.

References

Redfield AC, 1934. On the proportions of organic derivations in sea water and their relation to the composition of plankton. In: James Johnstone Memorial Volume. (ed. R.J. Daniel). University Press of Liverpool, 177-192.

Redfield, AC, Ketchum, BH and Richards FA, 1963. The influence of organisms on the composition of seawater. In: Hill, MN, Editor, The Sea vol. 2, Interscience, New York (1963), pp.26-77.

Richards FA, 1965. Anoxic basins and fjords. In: Riley JP, Skirrow D. (Eds.), Chemical Oceanography, vol. 1. Academic Press, New York, 611-645. (cited in Hedges et al, 2002).

Stumm W, 1964. Discussion (Methods for the removal of phosphorus and nitrogen from sewage plant effluents by G. A. Rohlich). In Eckenfelder, WW (ed.), Advances in water pollution research. Proc. 1st Int. Conf. London 1962, volume 2, pp. 216-229. Pergamon.

Vollenweider RA, 1985. Elemental and biochemical composition of plankton biomass: some comments and explorations. Arch. Hydrobiol. 105, 11-29.

Anderson LA, 1995. On the hydrogen and oxygen content of marine plankton. Deep-Sea Res. 42, 1675-1680.

Hedges JI., Baldock JA, Gelinas Y, Lee C, Peterson ML and Wakeham SG, 2002. The biochemical and elemental compositions of marine plankton: A NMR perspective. Marine Chemistry 78, 47-63.

See Also

AtomicWeight, molvol, molweight

Examples

## Redfield ratio
redfield(1, "P")
## returns the molar Redfield ratio, rescaled to nitrogen
redfield(1, "N")
## how many mass units are related to 2 mass units (e.g. mg) P
redfield(2, "P", "mass")
redfield(c(1, 2, 3), "N", "mass")

## mass percentage of elements
x <- redfield(1, "P", "mass")
x / sum(x)

## with alternative elemental composition (Stumm, 1964)
x <- redfield(1, "P", "mass", 
              ratio = c(C = 106, H = 180, O = 45, N = 16, P = 1))
x / sum(x)

## rule of thumb for fresh mass (in mg) formed by 1 microgram P
redfield(1, "P", "mass")$C * 2 * 10 / 1000
sum(redfield(1, "P", "mass",
  ratio = c(C = 106, H = 180, O = 45, N = 16, P = 1))) * 10 / 1000