age_h_gnfi3 {ForestElementsR} | R Documentation |
Inverse Tree Height Growth Model of the 3rd German National Forest Inventory (2012)
Description
Inverse tree height growth model of the third German National Forest Inventory of 2012 (Riedel et al. 2017). Allows to estimate a tree's age at any height if its height is known at a given age.
Usage
age_h_gnfi3(species_id, h_m, h_m_known, age_yr_known)
Arguments
species_id |
Vector of species id's preferably following the
ger_nfi_2012 species coding. Ideally, these species_id's are provided as
a |
h_m |
Single numeric value or vector of tree heights (m) for which the age is to be estimated |
h_m_known |
Vector of known height (m) values at age
|
age_yr_known |
Vector of ages (years) for which the height
|
Details
Originally, the function was parameterized for species and species groups
corresponding to the national forest inventory's species coding
(fe_species_ger_nfi_2012
). We have attributed in addition these
the original parameters also to the species codings
fe_species_tum_wwk_short
, and
fe_species_bavrn_state_short
. When called with a given species
coding, the function will try to use the "nearest" of these three
alternatives. Fallback option is the attempt to use
fe_species_tum_wwk_short
.
Value
A single age value or vector of age values corresponding to
h_m
References
Riedel T, Hennig P, Kroiher F, Polley H, Schmitz F, F. S (2017). Die dritte Bundeswaldinventur (BWI 2012). Inventur- und Auswertungsmethoden. Thuenen Institut fuer Waldoekosysteme.
See Also
Other growth functions:
age_d_gnfi3()
,
d_age_gnfi3()
,
h_age_gnfi3()
Examples
# A European beech has a height of 25.2 m at age 75. Estimate
# its age at height 26.8 m
age_h_gnfi3(100, 26.8, 25.2, 75) # 100 is ger_nfi_2012 code for E. beech
# Do the same backward in time, age at height 21.7 m
age_h_gnfi3(100, 21.7, 25.2, 75)
# Apply for more than one tree, different species, same age
h_known <- c(23.1, 16.2, 35.2, 19.3, 21.8)
h_age <- c(25.5, 18.2, 38.0, 21.6, 24.2)
species <- as_fe_species_tum_wwk_short(c(3, 3, 3, 6, 6))
age_h_gnfi3(
species, h_m = h_age, h_m_known = h_known, age_yr_known = 60
)