GCubeR (version 0.1.3)

dagnelie_vc22_1: Single-entry Dagnelie volume (tarif 1)

Description

Computes the standing volume \(v_{c,22}\) (in cubic metres per tree) using Dagnelie's single-entry tarif-1 equations. The volume is derived from the stem circumference at 1.30 m (c130, in cm) and the tree species, using species-specific polynomial coefficients stored in the reference table dan1.

Usage

dagnelie_vc22_1(data, output = NULL)

Value

A data.frame identical to the input data but augmented with:

• species-specific coefficients and validity ranges,

• dagnelie_vc22_1: the computed Dagnelie tarif-1 volume (m\(^3\) per tree).

Arguments

data

A data.frame containing at least:

• c130: stem circumference at 1.30 m (cm),

• species_code: tree species code.

output

Optional file path where the resulting data frame should be exported as a CSV. If NULL (default), no file is written. Export is handled by the utility function export_output() and failures trigger warnings without interrupting execution.

Supported species

The following species codes are supported by dagnelie_vc22_1:

• "QUERCUS_SP"

• "QUERCUS_ROBUR"

• "QUERCUS_PETRAEA"

• "QUERCUS_PUBESCENS"

• "QUERCUS_RUBRA"

• "FAGUS_SYLVATICA"

• "ACER_PSEUDOPLATANUS"

• "FRAXINUS_EXCELSIOR"

• "ULMUS_SP"

• "PRUNUS_AVIUM"

• "BETULA_SP"

• "ALNUS_GLUTINOSA"

• "PICEA_ABIES"

• "PSEUDOTSUGA_MENZIESII"

• "LARIX_SP"

• "PINUS_SYLVESTRIS"

• "CRATAEGUS_SP"

• "PRUNUS_SP"

• "CARPINUS_SP"

• "CASTANEA_SATIVA"

• "CORYLUS_AVELLANA"

• "MALUS_SP"

• "PYRUS_SP"

• "SORBUS_ARIA"

• "SAMBUCUS_SP"

• "RHAMNUS_FRANGULA"

• "PRUNUS_CERASUS"

• "ALNUS_INCANA"

• "POPULUSxCANADENSIS"

• "POPULUS_TREMULA"

• "PINUS_NIGRA"

• "PINUS_LARICIO"

• "TAXUS_BACCATA"

• "ACER_PLATANOIDES"

• "ACER_CAMPESTRE"

• "SORBUS_AUCUPARIA"

• "JUNGLANS_SP"

• "TILLIA_SP"

• "PICEA_SITCHENSIS"

• "ABIES_ALBA"

• "TSUGA_CANADENSIS"

• "ABIES_GRANDIS"

• "CUPRESSUS_SP"

• "THUJA_PLICATA"

• "AESCULUS_HIPPOCASTANUM"

• "ROBINIA_PSEUDOACACIA"

• "SALIX_SP"

Details

The tarif-1 volume is calculated as: $$ v_{c,22} = coeff\_a + coeff\_b \cdot c130 + coeff\_c \cdot c130^2 + coeff\_d \cdot c130^3 $$ where \(a\), \(b\), \(c\), and \(d\) are species-specific coefficients.

The function performs the following steps:

• checks that the input data frame contains the required variables c130 and species_code,

• validates that c130 is numeric,

• verifies that all species are available in the dan1 reference table and issues a warning otherwise,

• merges the input with dan1 to retrieve coefficients and species-specific validity ranges (min_c130, max_c130),

• warns when c130 values fall outside the recommended range,

• computes tarif-1 volume and returns the augmented data frame.

If one or more species codes are not found in dan1, the function issues a warning and returns NA-values for missing coefficients and volumes. Trees with c130 values outside the recommended species-specific range produce a warning but still receive a computed volume.

See Also

dan1 for species-specific coefficients.

Examples

df <- data.frame(
  c130         = c(145, 156, 234, 233),
  species_code = c("PINUS_SYLVESTRIS", "QUERCUS_RUBRA",
                   "QUERCUS_SP", "FAGUS_SYLVATICA")
)
dagnelie_vc22_1(df)