SoilR (version 1.0-3)

TwopParallelModel14: Implementation of a two-pool C14 model with parallel structure

Description

This function creates a model for two independent (parallel) pools. It is a wrapper for the more general function GeneralModel_14 that can handle an arbitrary number of pools.

Usage

TwopParallelModel14(t, ks, C0, In, gam, xi = 1, FcAtm, lambda = -0.0001209681, 
    lag = 0, solver = deSolve.lsoda.wrapper, pass = FALSE)

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 C14

ks

A vector of length 2 containing the decomposition rates for the 2 pools.

C0

A vector of length 2 containing the initial amount of carbon for the 2 pools.

In

A scalar or a data.frame object specifying the amount of litter inputs by time.

gam

A scalar representing the partitioning coefficient, i.e. the proportion from the total amount of inputs that goes to pool 1.

xi

A scalar or a data.frame specifying the external (environmental and/or edaphic) effects on decomposition rates.

FcAtm

A Data Frame object consisting of a function describing the fraction of C_14 in per mille. The first column will be assumed to contain the times.

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 scalar representing a time lag for radiocarbon to enter the system.

solver

A function that solves the system of ODEs. This can be euler or ode 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

Value

• A Model Object that can be further queried

See Also

TwopSeriesModel14, TwopFeedbackModel14

Examples

data(C14Atm_NH)
#Fc=TimeMap.from.Dataframe(C14Atm_NH)
years=seq(1901,2009,by=0.5)
LitterInput=700 

Ex=TwopParallelModel14(t=years,ks=c(k1=1/2.8, k2=1/35),C0=c(200,5000), In=LitterInput, gam=0.7,FcAtm=C14Atm_NH,lag=2)
R14m=getTotalReleaseFluxC14CRatio(Ex)
C14m=getTotalC14CRatio(Ex)
C14t=getSoilC14Fraction(Ex)

par(mfrow=c(2,1))
plot(C14Atm_NH,type="l",xlab="Year",ylab="Delta 14C (per mil)",xlim=c(1940,2010)) 
lines(years, C14t[,1], col=4)
lines(years, C14t[,2],col=4,lwd=2)
legend("topright",c("Delta 14C Atmosphere", "Delta 14C pool 1", "Delta 14C pool 2"),lty=c(1,1,1),col=c(1,4,4),lwd=c(1,1,2),bty="n")

plot(C14Atm_NH,type="l",xlab="Year",ylab="Delta 14C (per mil)",xlim=c(1940,2010)) 
lines(years,C14m,col=4)
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")
par(mfrow=c(1,1))