ForestElementsR (version 2.0.1)

standing_area_gnfi3: Estimate the Standing Area of Single Trees

Description

An implementation of the standing area estimation of the third German National Forest Inventory bwi3_methods_2017ForestElementsR. Its main intended use is the calculation of virtual species areas in mixed stands. According to bwi3_methods_2017ForestElementsR, it is recommended only to include the main stand in such calculations, neither understorey, nor any layers above the main stand.

Usage

standing_area_gnfi3(species_id, dbh_cm)

Value

A vector of the estimated standing areas in m²

Arguments

species_id

Vector of species id's preferably following the ger_nfi_2012 species coding. Ideally, these species_id's are provided as a fe_species_ger_nfi_2012 object. See Details for how other species codings are handled.

dbh_cm

Vector of tree dbh values in cm (dbh = stem diameter at breast height, i.e. 1.3 m)

Details

Originally, the function was parameterized for species and species groups corresponding to the national forest inventory's species coding (fe_species_ger_nfi_2012). We have attributed in addition these the original parameters also to the species codings fe_species_tum_wwk_short, and fe_species_bavrn_state_short. When called with a given species coding, the function will try to use the "nearest" of these three alternatives. Fallback option is the attempt to use fe_species_tum_wwk_short.

Examples

  # Three spruces, two pines, two beech
  species_id <- fe_species_ger_nfi_2012(c(10, 10, 10, 20, 20, 100, 100))
  dbh_cm     <- c(10.1, 27.4, 31.4, 35.5, 39.8, 45.2, 47.2)

  standing_area_gnfi3(species_id, dbh_cm)