v_red_harvest_ubark: Reduce a Given standing Volume Over Bark to Harvested Volume Under Bark
Description
Many tree volume functions (like v_gri) calculate wood volumes
defined as standing and over bark. Practictioners often prefer to work with
volumes where the harvest losses and the bark volume have been substracted.
Given an over bark standing volume, this function uses species specific
reduction factors in order to obtain harvested volume under bark. The
reduction factors are taken from
hilfstafeln_bavaria_1990ForestElementsR; they relate to the
species coding fe_species_tum_wwk_short or, alternatively
fe_species_bavrn_state_short.
Usage
v_red_harvest_ubark(species_id, v_orig_m3)
Value
A vector of the reduced volumes defined as harveest
Arguments
species_id
Vector of species id's. Ideally, these species_id's are
provided as a fe_species_tum_wwk_short or a
fe_species_bavrn_state_short object. If they are provided as
another fe_species object, v_red_harvest_ubark will make an
attempt to convert them into fe_species_tum_wwk_short. The
exception is the coding fe_species_bavrn_state which will be
converted into fe_species_bavrn_state_short. If all
conversion attempts fail, the function will terminate with an error. The
species id's can also be provided as numeric values (double or
integer) or character. These will be internally converted to
fe_species_tum_wwk_short. If this fails (i.e. the user
provided species codes are not defined in the tum_wwk_short coding), an
error is thrown and the function terminates.
v_orig_m3
Vector of wood volumes (m³) defined as standing over bark.
If species_id and v_orig_m3 do not have the same length, an
attempt is made to recyle them according to the tibble rules.
# Take all species groups of tum_wwk_short and a standing volume of 1 m³# over bark species_id <- fe_species_tum_wwk_short(1:10)
v_red_harvest_ubark(species_id, 1)