vol_assortment {woodValuationDE}

Relative volume share of different assortments

Description

The function estimates the share of different assortments. It is expressed in relation to the salable volume, i.e., the sum of pulp wood, saw log, and fuel wood assortments. The function is based on the assortment tables from Offer and Staupendahl (2018) and its derivation is similar to the approach described in Fuchs et al. (2023) for the salable and skidded volume. The underlying assortment tables are based on data from HessenForst, the public forest service of the Federal State of Hesse in Germany. For further details see the woodValuationDE README.

Usage

vol_assortment(
  diameter.q,
  species,
  assortment,
  value.level = 2,
  logging.method = "combined",
  species.code.type = "en",
  method = "fuchs.orig"
)

Arguments

diameter.q

Quadratic mean of the diameter at breast height (dbh) of the harvested trees [cm].

species

Tree species, using an available species.code.type. For a list with the available species and codes call get_species_codes.

assortment

wood assortment whose share is sought, currently implemented: "saw.logs"

value.level

Stand quality expressed as an integer of 1:3, with 1 for an extraordinarily high stand quality with high shares of wood suitable for high-valued usages such as furniture, 2 for a moderate quality, and 3 for a low quality (e.g., trees with thick branches). The value.levels refer to the applied assortment tables of Offer and Staupendahl (2018).

logging.method

Logging method, with "manually" for motor-manual logging using a chain saw, "harvester" for logging with highly mechanized forest harvesters, or "combined" for a combination of the previous methods dependent on the mean diameter.

species.code.type

Type of code in which species is given. "en" for English species names or "nds" for numeric species codes used in Lower Saxony, Germany. For a list with the available species and codes call get_species_codes.

method

argument that is currently not used, but offers the possibility to implement alternative parameters and functions in the future.

Value

A vector with relative shares of the respective assortment's wood volume.

References

Fuchs, Jasper M.; Husmann, Kai; v. Bodelschwingh, Hilmar; Koster, Roman; Staupendahl, Kai; Offer, Armin; Moehring, Bernhard, Paul, Carola (2023): woodValuationDE: A consistent framework for calculating stumpage values in Germany (technical note). Allgemeine Forst- und Jagdzeitung 193 (1/2), p. 16-29. doi: 10.23765/afjz0002090

Offer, Armin; Staupendahl, Kai (2018): Holzwerbungskosten- und Bestandessortentafeln (Wood Harvest Cost and Assortment Tables). Kassel: HessenForst (publisher).

Examples

# saw log volume per cubic meter salable volume
share.saw.logs <- vol_assortment(40,
                                 "beech",
                                 "saw.logs")
share.saw.logs

# fuel wood per cubic meter salable volume
share.fuel.wood <- (vol_salable(40,
                                "beech") -
                      vol_skidded(40,
                                  "beech")) /
  vol_salable(40,
              "beech")
share.fuel.wood

# pulp wood per cubic meter salable volume
share.pulp.wood <- 1 - share.saw.logs - share.fuel.wood

# saw log volume per cubic meter volume over bark
vol_assortment(40,
               "beech",
               "saw.logs") *
  vol_salable(40,
              "beech")