SoilR (version 1.1-23)

bacwaveModel: Implementation of the microbial model Bacwave (bacterial waves)

Description

This function implements the microbial model Bacwave (bacterial waves), a two-pool model with a bacterial and a substrate pool. It is a special case of the general nonlinear model.

Usage

bacwaveModel(t, umax = 0.063, ks = 3, theta = 0.23, Dmax = 0.26,  kd = 14.5, kr = 0.4, Y = 0.44, ival = c(S0 = 0.5, X0 = 1.5),  BGF = 0.15, ExuM = 8, ExuT = 0.8)

Arguments

t

vector of times (in hours) to calculate a solution.

umax

a scalar representing the maximal relative growth rate of bacteria (hr-1)

ks

a scalar representing the substrate constant for growth (ug C /ml soil solution)

theta

a scalar representing soil water content (ml solution/cm3 soil)

Dmax

a scalar representing the maximal relative death rate of bacteria (hr-1)

kd

a scalar representing the substrate constant for death of bacteria (ug C/ml soil solution)

kr

a scalar representing the fraction of death biomass recycling to substrate (unitless)

Y

a scalar representing the yield coefficient for bacteria (ug C/ugC)

ival

a vector of length 2 with the initial values for the substrate and the bacterial pools (ug C/cm3)

BGF

a scalar representing the constant background flux of substrate (ug C/cm3 soil/hr)

ExuM

a scalar representing the maximal exudation rate (ug C/(hr cm3 soil))

ExuT

a scalar representing the time constant for exudation, responsible for duration of exudation (1/hr).

Value

Details

This implementation containts default parameters presented in Zelenev et al. (2000). It produces nonlinear damped oscillations in the form of a stable focus.

References

Zelenev, V.V., A.H.C. van Bruggen, A.M. Semenov. 2000. ``BACWAVE,'' a spatial-temporal model for traveling waves of bacterial populations in response to a moving carbon source in soil. Microbail Ecology 40: 260-272.

Examples

  
hours=seq(0,800,0.1)

#Run the model with default parameter values
bcmodel=bacwaveModel(t=hours)
Cpools=getC(bcmodel)

#Time solution
matplot(hours,Cpools,type="l",ylab="Concentrations",xlab="Hours",lty=1,ylim=c(0,max(Cpools)*1.2))
legend("topleft",c("Substrate", "Microbial biomass"),lty=1,col=c(1,2),bty="n")

#State-space diagram
plot(Cpools[,2],Cpools[,1],type="l",ylab="Substrate",xlab="Microbial biomass")

#Microbial biomass over time
plot(hours,Cpools[,2],type="l",col=2,xlab="Hours",ylab="Microbial biomass")