SoilR (version 1.0-0)

TwopSeriesModel: Implementation of a two pool model with series structure

Description

This function creates a model for two pools connected in series. It is a wrapper for the more general function GeneralModel.

Usage

TwopSeriesModel(t, ks, a21, C0, In, xi = 1, solver = deSolve.lsoda.wrapper)

Arguments

t

A vector containing the points in time where the solution is sought.

ks

A vector of length 2 with the values of the decomposition rate for pools 1 and 2.

a21

A scalar with the value of the transfer rate from pool 1 to pool 2.

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.

xi

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

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.

Value

• A Model Object that can be further queried

See Also

TwopParallelModel,TwopFeedbackModel

Examples

t_start=0 
t_end=10 
tn=50
timestep=(t_end-t_start)/tn 
t=seq(t_start,t_end,timestep) 
ks=c(k1=0.8,k2=0.4)
a21=0.5
C0=c(C10=100,C20=150)
In = 30

Temp=rnorm(t,15,1)
TempEffect=data.frame(t,fT.Daycent1(Temp))

Ex1=TwopSeriesModel(t,ks,a21,C0,In,xi=TempEffect)
Ct=getC(Ex1)
Rt=getReleaseFlux(Ex1)

plot(t,rowSums(Ct),type="l",ylab="Carbon stocks (arbitrary units)",xlab="Time (arbitrary units)",lwd=2,ylim=c(0,sum(Ct[1,]))) 
lines(t,Ct[,1],col=2)
lines(t,Ct[,2],col=4) 
legend("bottomright",c("Total C","C in pool 1", "C in pool 2"),lty=c(1,1,1),col=c(1,2,4),lwd=c(2,1,1),bty="n")

plot(t,rowSums(Rt),type="l",ylab="Carbon released (arbitrary units)",xlab="Time (arbitrary units)",lwd=2,ylim=c(0,sum(Rt[1,]))) 
lines(t,Rt[,1],col=2)
lines(t,Rt[,2],col=4) 
legend("topright",c("Total C release","C release from pool 1", "C release from pool 2"),lty=c(1,1,1),col=c(1,2,4),lwd=c(2,1,1),bty="n")

Inr=data.frame(t,Random.inputs=rnorm(length(t),30,5))
plot(Inr)

Ex2=TwopSeriesModel(t,ks,a21,C0,In=Inr,xi=fT.Q10(15))
Ctr=getC(Ex2)
Rtr=getReleaseFlux(Ex2)

plot(t,rowSums(Ctr),type="l",ylab="Carbon stocks (arbitrary units)",xlab="Time (arbitrary units)",lwd=2,ylim=c(0,sum(Ctr[1,]))) 
lines(t,Ctr[,1],col=2)
lines(t,Ctr[,2],col=4) 
legend("topright",c("Total C","C in pool 1", "C in pool 2"),lty=c(1,1,1),col=c(1,2,4),lwd=c(2,1,1),bty="n")

plot(t,rowSums(Rtr),type="l",ylab="Carbon released (arbitrary units)",xlab="Time (arbitrary units)",lwd=2,ylim=c(0,sum(Rtr[1,]))) 
lines(t,Rtr[,1],col=2)
lines(t,Rtr[,2],col=4) 
legend("topright",c("Total C release","C release from pool 1", "C release from pool 2"),lty=c(1,1,1),col=c(1,2,4),lwd=c(2,1,1),bty="n")