ForestElementsR (version 2.0.1)

height_crown_base_silva: Estimate a tree's height to crown base

Description

This function can be used to estimate a tree's height to crown base, given its stem diameter at breast height, its height and its species. This is the height to crown base function implemented in the forest growth simulator SILVA pretzsch_single_2002ForestElementsR. Height to crown base in this context is defined as the height where the lowest living branch of the tree's primary crown branches of the stem.

Usage

height_crown_base_silva(species_id, dbh_cm, height_m)

Value

An estimate of the tree's height to crown base in m.

Arguments

species_id

Vector of species id's following the tum_wwk_short species coding. Ideally, these species_id's are provided as a fe_species_tum_wwk_short object. If they are provided as another fe_species object, height_crown_base_silva will make an attempt to convert them. If this is not possible, 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 not defined in the tum_wwk_short coding), an error is thrown and the function terminates.

dbh_cm

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

height_m

Vector of tree height values in m

References

Examples

# Estimate the height to crown base of a Scots pine with a stem diameter
# at breast height of 45.2 cm and a total height of 29.2 m:
height_crown_base_silva(
  species_id = "3",     # will be internally converted to tum_wwk_short
  dbh_cm = 45.2,
  height_m = 29.2
) # 20.9 m (rounded)

# Height to crown base estimate for a European beech with
# the same height and diameter:
height_crown_base_silva(
  species_id = "5",     # will be internally converted to tum_wwk_short
  dbh_cm = 45.2,
  height_m = 29.2
) # 15.0 m (rounded)

# Run on vectors
spec <- mm_forest_1_fe_stand_spatial$trees$species_id
h <- mm_forest_1_fe_stand_spatial$trees$height_m
d <- mm_forest_1_fe_stand_spatial$trees$dbh_cm
height_crown_base_silva(spec, d, h)