Flux-gradient method

fg_flux() implements different approaches to the flux-gradient method (FGM). It takes a valid input dataset from cfp_dat() and calculates for each layer defined in cfp_layers_map().

Usage

fg_flux(x, ...)

# S3 method for class 'cfp_dat'
fg_flux(x, ...)

# S3 method for class 'cfp_fgres'
fg_flux(x, ...)

# S3 method for class 'cfp_fgmod'
fg_flux(x, ...)

Arguments

x

A cfp_dat object with all the necessary input datasets.

...

Arguments passed on to cfp_fgmod

gases

(character) A character vector defining the gases for which fluxes shall be calculated.

modes

(character) A character vector specifying mode(s) for dcdz calculation. Can be "LL","LS","EF".

LL

local linear approach: within each layer a linear model is evaluated of concentration over the depth.

LS

linear spline approach: A linear spline is fitted over the complete profile with nodes at the layer intersections.

EF

exponential fit approach: An exponential function of form y=a+b*x^c is fit of concentration against depth. Using the first derivative of that function the concentration gradient is evaluated for each layer.

DA

exponential fit approach: An exponential function of form y=a+b*(1-exp(-a*x)) is fit of concentration against depth. Using the first derivative of that function the concentration gradient is evaluated for each layer. From Davidson (2006).

param

(character) A vector containing the the parameters of soilphys, for which means should be calculated, must contain "c_air" and "DS", more parameters may help interpretation.

funs

(character) A vector defining the type of mean to be used for each parameter in param. One of "arith" or "harm".

Value

A cfp_fgres model result.

Details

The model result contains the original data, but adds the dataset FLUX, which contains the calculated flux rates. You can use functions efflux and production to calculate different elements or access the raw result with model_result$FLUX.

References

DAVIDSON, E. A., SAVAGE, K. E., TRUMBORE, S. E., & BORKEN, W. (2006). Vertical partitioning of CO2 production within a temperate forest soil. In Global Change Biology (Vol. 12, Issue 6, pp. 944–956). Wiley. https://doi.org/10.1111/j.1365-2486.2005.01142.x

See also

Other flux models: pro_flux()

Examples

fg_flux(ConFluxPro::base_dat)
#> 
#> validating datasets
#> id_cols: site, Date, gas
#> 24 unique profiles
#> 
#> A cfp_fgres fg_flux model result. 
#> mean R2 achieved:  0.956653 
#> number of failed fits:  0 
#> 
#> A cfp_fgmod fg_flux model. 
#> gases: CO2  
#> modes:  LL  
#> param:  c_air DS  
#> funs:  arith harm  
#> 
#> A cfp_dat object to be used as input in ConFluxPro models. 
#> id_cols: site Date gas 
#> number of profiles:  24 
#> number of groups:  2 
#>