ForestElementsR (version 2.0.1)

si_to_mai_age: Convert a Standard Site Index Into an MAI(age) Site Index

Description

A useful way of site indexing is to give the site index of a stand in terms of a mean annual increment (mai) at a given age, typically 100 years. This function converts a standard site index into such an mai site index. See si_to_mai_max for an alternative mai based site indexing method.

Usage

si_to_mai_age(si, mai_variable, age, ytable)

Value

The requested mai value corresponding to the given standard site index at the given age

Arguments

si

Standard site index to be converted, must correspond to the site index nomenclature of the yield table to be used (param ytable, see below).

mai_variable

Character, name of the mai_variable to be used. Must be one if the mai variables listed in the fe_yield_table object provided with the parameter ytable.

age

The stand age (years) for which the mai site index is to be defined, typically 100 years.

ytable

An object of class fe_yield_table

See Also

Other yield table functions: fe_yield_table(), plot.fe_yield_table(), si_to_mai_max(), site_index(), stocking_level(), yield_tables_for_species, ytable_age_slice(), ytable_lookup(), ytable_max_slice()

Examples

 age <- 100
 mai_var <- "mai_m3_ha_yr" # mai in volume over bark before harvest

 si_to_mai_age(2.3, mai_var, age, fe_ytable_larch_schober_moderate_1946)
 si_to_mai_age(0.7, mai_var, age, fe_ytable_larch_schober_moderate_1946)
 si_to_mai_age(2.3, mai_var, age, fe_ytable_beech_wiedemann_moderate_1931)
 si_to_mai_age(0.7, mai_var, age, fe_ytable_beech_wiedemann_moderate_1931)

 mai_var <- "red_mai_m3_ha_yr" # mai in vol. under bark minus harvest losses
 si_to_mai_age(2.3, mai_var, age, fe_ytable_larch_schober_moderate_1946)
 si_to_mai_age(0.7, mai_var, age, fe_ytable_larch_schober_moderate_1946)
 si_to_mai_age(2.3, mai_var, age, fe_ytable_beech_wiedemann_moderate_1931)
 si_to_mai_age(0.7, mai_var, age, fe_ytable_beech_wiedemann_moderate_1931)