est_params: Calibrate new allometric equations

In forestgeo/allodb: Tree Biomass Estimation at Extra-Tropical Forest Plots

Calibrate new allometric equations

Description

This function calibrates new allometric equations from sampling previous ones. New allometric equations are calibrated for each species and location by resampling the original compiled equations; equations with a larger sample size, and/or higher taxonomic rank, and climatic similarity with the species and location in question are given a higher weight in this process.

Usage

est_params(
  genus,
  coords,
  species = NULL,
  new_eqtable = NULL,
  wna = 0.1,
  w95 = 500,
  nres = 10000
)

Arguments

genus	a character vector, containing the genus (e.g. "Quercus") of each tree.
coords	a numeric vector of length 2 with longitude and latitude (if all trees were measured in the same location) or a matrix with 2 numerical columns giving the coordinates of each tree.
species	a character vector (same length as genus), containing the species (e.g. "rubra") of each tree. Default is NULL, when no species identification is available.
new_eqtable	Optional. An equation table created with the new_equations() function. Default is the compiled allodb equation table.
wna	a numeric vector, this parameter is used in the weight_allom() function to determine the dbh-related and sample-size related weights attributed to equations without a specified dbh range or sample size, respectively. Default is 0.1.
w95	a numeric vector, this parameter is used in the weight_allom() function to determine the value at which the sample-size-related weight reaches 95% of its maximum value (max=1). Default is 500.
nres	number of resampled values. Default is "1e4".

Value

An object of class "data.frame" of fitted coefficients (columns) of the non-linear least-square regression:

AGB = a * dbh ^ b + e, \space \mathit{with} \space e ~ N(0, sigma^2)

See Also

weight_allom(), new_equations().

Examples

# calibrate new allometries for all Lauraceae species
lauraceae <- subset(scbi_stem1, Family == "Lauraceae")
est_params(
  genus = lauraceae$genus,
  species = lauraceae$species,
  coords = c(-78.2, 38.9)
)

forestgeo/allodb documentation built on March 5, 2025, 2:21 a.m.