bigleaf (version 0.7.0)

intercellular.CO2: Bulk Intercellular CO2 Concentration

Description

Bulk canopy intercellular CO2 concentration (Ci) calculated based on Fick's law given surface conductance (Gs), gross primary productivity (GPP) and atmospheric CO2 concentration (Ca).

Usage

intercellular.CO2(data, Ca = "Ca", GPP = "GPP", Gs = "Gs_mol",
  Rleaf = NULL, missing.Rleaf.as.NA = FALSE,
  constants = bigleaf.constants())

Arguments

data

Data.Frame or matrix with all required columns

Ca

Atmospheric or surface CO2 concentration (umol mol-1)

GPP

Gross primary productivity (umol CO2 m-2 s-1)

Gs

Surface conductance to water vapor (mol m-2 s-1)

Rleaf

Ecosystem respiration stemming from leaves (umol CO2 m-2 s-1); defaults to 0

missing.Rleaf.as.NA

if Rleaf is provided, should missing values be treated as NA (TRUE) or set to 0 (FALSE, the default)?

constants

DwDc - Ratio of the molecular diffusivities for water vapor and CO2 (-)

Value

Ci -

Bulk canopy intercellular CO2 concentration (umol mol-1)

Details

Bulk intercellular CO2 concentration (Ci) is given by:

$$Ci = Ca - (GPP - Rleaf)/(Gs/1.6)$$

where Gs/1.6 (mol m-2 s-1) represents the surface conductance to CO2. Note that Gs is required in mol m-2 s-1 for water vapor. Gs is converted to its value for CO2 internally. Ca can either be atmospheric CO2 concentration (as measured), or surface CO2 concentration as calculated from surface.CO2.

References

Kosugi Y. et al., 2013: Determination of the gas exchange phenology in an evergreen coniferous forest from 7 years of eddy covariance flux data using an extended big-leaf analysis. Ecol Res 28, 373-385.

Keenan T., Sabate S., Gracia C., 2010: The importance of mesophyll conductance in regulating forest ecosystem productivity during drought periods. Global Change Biology 16, 1019-1034.

Examples

# NOT RUN {
# calculate bulk canopy Ci of a productive ecosystem
intercellular.CO2(Ca=400,GPP=40,Gs=0.7)
 
# note the sign convention for NEE

# }