crown_diameter_silva {ForestElementsR} | R Documentation |
Estimate a tree's crown diameter
Description
This function can be used for estimating a tree's crown diameter, given its
species, its stem diameter at breast height, and its total height. This is
the crown diameter function which is implemented in the forest growth
simulator SILVA (Pretzsch et al. 2002). The crown
diameter in this context is defined as the average diameter of the crown at
its greatest lateral extension. The crown diameter equations are
available for exactly the species (groups) defined in the coding
tum_wwk_short. If they are called with another species coding supported by
the package ForestElementsR, crown_diameter_silva
will attempt to
convert them accordingly.
Usage
crown_diameter_silva(species_id, dbh_cm, height_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
|
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 |
Value
An estimate of the tree's diameter of the crown at its greatest lateral extension in m.
References
Pretzsch H, Biber P, Dursky J (2002). “The single tree-based stand simulator SILVA: construction, application and evaluation.” Forest Ecology and Management, 162(1), 3–21. ISSN 0378-1127, doi:10.1016/S0378-1127(02)00047-6.
Examples
# Estimate the crown diameter of a Scots pine with a stem diameter
# at breast height of 45.2 cm and a total height of 29.2 m:
crown_diameter_silva(
species_id = "3", # will be internally converted to tum_wwk_short
dbh_cm = 45.2,
height_m = 29.2
) # 6.1 m (rounded)
# Crown diameter estimate for a European beech with
# the same height and diameter:
crown_diameter_silva(
species_id = "5", # will be internally converted to tum_wwk_short
dbh_cm = 45.2,
height_m = 29.2
) # 9.6 m (rounded)
# Run vectorized
spec <- mm_forest_1_fe_stand_spatial$trees$species_id
d <- mm_forest_1_fe_stand_spatial$trees$dbh_cm
h <- mm_forest_1_fe_stand_spatial$trees$height_m
crown_diameter_silva(spec, d, h)