sunML: Sunlit shaded multi-layer model

In BioCro: Simulation of Biomass Crops

Description

Simulates the light microenvironment in the canopy based on the sunlit-shade model and the multiple layers.

Usage

sunML(Idir,Idiff,LAI=8,nlayers=8,cos.theta=0.5,kd=0.7,chi.l=1,heightf=3,
  maxIdir = 2235, maxIdiff = 119)

Arguments

Idir	direct light (quantum flux), (micro mol /m2/s).
Idiff	indirect light (diffuse), (micro mol /m2/s).
LAI	leaf area index, default 8.
nlayers	number of layers in which the canopy is partitioned, default 8.
cos.theta	cosine of theta, solar zenith angle.
kd	extinction coefficient for diffuse light.
chi.l	The ratio of horizontal:vertical projected area of leaves in the canopy segment.
heightf	height factor. simple empirical relationship between LAI and height of a canopy.
maxIdir	Maximum direct irradiance
maxIdiff	Maximum diffuse irradiance

Value

a data.frame structure with components

row number equal to the number of layers.

layIdir	direct solar radiation.
layIdiff	difusse solar radiation.
layItotal	total solar radiation.
layFsun	proportion of the leaf area in each layer which is in direct light.
layFshade	proportion of the leaf area in each layer which is in indirect light.
layHeight	layer height.

Examples

res2 <- sunML(1500,200,3,10)

xyplot(layFsun + layFshade ~ c(1:10), data=res2,
       ylab="LAI",
       xlab="layer",
       type="l",lwd=2,col=c("blue","green"),
       lty=c(1,2),
       key=list(text=list(c("Direct","Diffuse")),lty=c(1,2),
                cex=1.2,lwd=2,lines=TRUE,x=0.7,y=0.5,
                col=c("blue","green")))

BioCro documentation built on May 2, 2019, 6:15 p.m.