GaudinskiModel14: Implementation of a the six-pool C14 model proposed by Gaudinski et al. 2000

Description

This function creates a model as described in Gaudinski et al. 2000. It is a wrapper for the more general functions GeneralModel_14 that can handle an arbitrary number of pools.

Usage

GaudinskiModel14(
  t,
  ks = c(kr = 1/1.5, koi = 1/1.5, koeal = 1/4, koeah = 1/80, kA1 = 1/3, kA2 = 1/75, kM =
    1/110),
  C0 = c(FR0 = 390, C10 = 220, C20 = 390, C30 = 1370, C40 = 90, C50 = 1800, C60 = 560),
  F0_Delta14C = rep(0, 7),
  LI = 150,
  RI = 255,
  xi = 1,
  inputFc,
  lambda = -0.0001209681,
  lag = 0,
  solver = deSolve.lsoda.wrapper,
  pass = FALSE
)

Value

A Model Object that can be further queried

Arguments

t: A vector containing the points in time where the solution is sought. It must be specified within the same period for which the Delta 14 C of the atmosphere is provided. The default period in the provided dataset C14Atm_NH is 1900-2010.
ks: A vector of length 7 containing the decomposition rates for the 6 soil pools plus the fine-root pool.
C0: A vector of length 7 containing the initial amount of carbon for the 6 pools plus the fine-root pool.
F0_Delta14C: A vector of length 7 containing the initial amount of the radiocarbon fraction for the 7 pools as Delta14C values in per mil.
LI: A scalar or a data.frame object specifying the amount of litter inputs by time.
RI: A scalar or a data.frame object specifying the amount of root inputs by time.
xi: A scalar or a data.frame specifying the external (environmental and/or edaphic) effects on decomposition rates.
inputFc: A Data Frame object containing values of atmospheric Delta14C per time. First column must be time values, second column must be Delta14C values in per mil.
lambda: Radioactive decay constant. By default lambda=-0.0001209681 y^-1 . This has the side effect that all your time related data are treated as if the time unit was year.
lag: A positive integer representing a time lag for radiocarbon to enter the system.
solver: A function that solves the system of ODEs. An alternative to the default is euler or any other user provided function with the same interface.
pass: if TRUE Forces the constructor to create the model even if it is invalid

References

Gaudinski JB, Trumbore SE, Davidson EA, Zheng S (2000) Soil carbon cycling in a temperate forest: radiocarbon-based estimates of residence times, sequestration rates and partitioning fluxes. Biogeochemistry 51: 33-69

Examples

Run this code

years=seq(1901,2010,by=0.5)

Ex=GaudinskiModel14(
t=years,
ks=c(kr=1/3, koi=1/1.5, koeal=1/4, koeah=1/80, kA1=1/3, kA2=1/75, kM=1/110),
inputFc=C14Atm_NH
)
R14m=getF14R(Ex)
C14m=getF14C(Ex)

plot(
C14Atm_NH,
type="l",
xlab="Year",
ylab=expression(paste(Delta^14,"C (per mille)")),
xlim=c(1940,2010)
) 
lines(years,C14m,col=4)
points(HarvardForest14CO2[1:11,1],HarvardForest14CO2[1:11,2],pch=19,cex=0.5)
points(HarvardForest14CO2[12:173,1],HarvardForest14CO2[12:173,2],pch=19,col=2,cex=0.5)
points(HarvardForest14CO2[158,1],HarvardForest14CO2[158,2],pch=19,cex=0.5)
lines(years,R14m,col=2)
legend(
"topright",
c("Delta 14C Atmosphere",
"Delta 14C SOM", 
"Delta 14C Respired"
),
lty=c(1,1,1), 
col=c(1,4,2),
bty="n"
)
## We now show how to bypass soilR s parameter sanity check if nacessary 
## (e.g in for parameter estimation ) in functions
## which might call it with unreasonable parameters
years=seq(1800,2010,by=0.5)
Ex=GaudinskiModel14(
t=years,
ks=c(kr=1/3,koi=1/1.5,koeal=1/4,koeah=1/80,kA1=1/3,kA2=1/75,kM=1/110),
inputFc=C14Atm_NH,
pass=TRUE
)