BioCro 0.93

Simulates canopy assimilation

Usage

CanA(lai, doy, hr, solar, temp, rh, windspeed, lat = 40, nlayers = 8, kd = 0.1, StomataWS = 1, chi.l = 1, heightFactor = 3, photoControl = list(), lnControl = list(), units = c("kg/m2/hr", "Mg/ha/hr"))

Arguments

lai
leaf area index.
doy
day of the year, (1--365).
hr
hour of the day, (0--23).
solar
solar radiation (micro mol m-2 s-1).
temp
temperature (Celsius).
rh
relative humidity (0--1).
windspeed
wind speed (m s-1).
lat
latitude.
nlayers
number of layers in the simulation of the canopy (max allowed is 50).
kd
Ligth extinction coefficient for diffuse light.
StomataWS
coefficient controlling the effect of water stress on stomatal conductance and assimilation.
heightFactor
Height Factor. Divide LAI by this number to get the height of a crop.
photoControl
list that sets the photosynthesis parameters. See BioGro.
lnControl
list that sets the leaf nitrogen parameters. LeafN: Initial value of leaf nitrogen (g m-2). kpLN: coefficient of decrease in leaf nitrogen during the growing season. The equation is LN = iLeafN * exp(-kLN * TTc). lnFun: controls whether there is a decline in leaf nitrogen with the depth of the canopy. 'none' means no decline, 'linear' means a linear decline controlled by the following two parameters. lnb0: Intercept of the linear decline of leaf nitrogen in the depth of the canopy. lnb1: Slope of the linear decline of leaf nitrogen in the depth of the canopy. The equation is 'vmax = leafN_lay * lnb1 + lnb0'.
units
Whether to return units in kg/m2/hr or Mg/ha/hr. This is typically run at hourly intervals, that is why the hr is kept, but it could be used with data at finer timesteps and then convert the results.

Value

list

returns a list with several elements

CanopyAssim: hourly canopy assimilation (kg/m2 per hour) or canopy assimilation (Mg/ha per hour)

CanopyTrans: hourly canopy transpiration (kg/m2 per hour) or canopy transpiration (Mg/ha per hour)

CanopyCond: hourly canopy conductance (units ?)

TranEpen: hourly canopy transpiration according to Penman (kg m^{-2} per hour) or canopy transpiration according to Penman (Mg ha^{-1} per hour)

TranEpen: hourly canopy transpiration according to Priestly (kg/m2 per hour) canopy transpiration according to Priestly (Mg/ha per hour)

LayMat: hourly by Layer matrix containing details of the calculations by layer (each layer is a row). col1: Direct Irradiance col2: Diffuse Irradiance col3: Leaf area in the sun col4: Leaf area in the shade col5: Transpiration of leaf area in the sun col6: Transpiration of leaf area in the shade col7: Assimilation of leaf area in the sun col8: Assimilation of leaf area in the shade col9: Difference in temperature between the leaf and the air (i.e. TLeaf - TAir) for leaves in sun. col10: Difference in temperature between the leaf and the air (i.e. TLeaf - TAir) for leaves in shade. col11: Stomatal conductance for leaves in the sun col12: Stomatal conductance for leaves in the shade col13: Nitrogen concentration in the leaf (g m^-2) col14: Vmax value as depending on leaf nitrogen

Description

It represents an integration of the photosynthesis function c4photo, canopy evapo/transpiration and the multilayer canopy model sunML.

Examples

## <strong>Not run</strong>: 
# data(doy124)
# tmp <- numeric(24)
# 
# for(i in 1:24){
#    lai <- doy124[i,1]
#    doy <- doy124[i,3]
#    hr  <- doy124[i,4]
#  solar <- doy124[i,5]
#   temp <- doy124[i,6]
#     rh <- doy124[i,7]
#     ws <- doy124[i,8]
# 
#   tmp[i] <- CanA(lai,doy,hr,solar,temp,rh,ws)$CanopyAssim
# 
# }
# 
# plot(c(0:23),tmp,
#             type='l',lwd=2,
#             xlab='Hour',
#             ylab=expression(paste('Canopy assimilation (kg  ',
#             m^-2,' ',h^-1,')')))
# 
# ## <strong>End(Not run)</strong>