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Carmean (1996) site index models for northwest Ontario

Source: R/si_carmean1996.R
si_carmean1996.Rd

Implementation of the northwest Ontario site-index equations documented in Carmean (1996) and the appendix equations transcribed from that report.

Usage

si_carmean1996(age, height = NULL, si = NULL, species)

Arguments

age

Numeric vector. Breast-height age (years), with `age > 0`.

height

Optional numeric vector. Total tree height (m). If provided, `si` is predicted.

si

Optional numeric vector. Site index (m, base age 50 years at breast-height age). If provided, `height` is predicted.

species

Character vector of species codes (e.g., `"PINU.BAN"`).

Value

A tibble with columns:

height

Predicted total tree height (m), returned when input `si` is provided.

si

Predicted site index (m), returned when input `height` is provided.

Details

Species coverage: PINU.BAN, PICE.MAR, PICE.GLA, ABIE.BAL, POPU.TRE, BETU.PAP, LARI.LAR.

Geographic use: northwest Ontario.

Age definition note: `age` is breast-height age (years).

Base-age note: site index is defined as total height (m) at 50 years breast-height age.

Forward/inverse consistency note: for PICE.MAR, ABIE.BAL, and BETU.PAP, the published site-index prediction equations used for `height -> si` are separate fitted equations from Appendix IV rather than exact algebraic inverses of the forward height-curve equations. As a result, predictions from `height -> si` may differ slightly from the input height even when `age = 50`.

Provide exactly one of `height` or `si`:

  • If `height` is provided, the function predicts `si`.

  • If `si` is provided, the function predicts `height`.

Inputs and outputs are metric (m). Some source equations were published in mixed unit form and are converted internally using the species-specific metadata stored in the internal parameter table.

References

Carmean, W. H. (1996). Site-quality evaluation, site-quality maintenance, and site-specific management for forest land in northwest Ontario. Ontario Ministry of Natural Resources, Northwest Science and Technology, Technical Report TR-105.

Examples

si_carmean1996(
  age = c(20, 40, 60),
  si = c(10, 14, 18),
  species = c("PINU.BAN", "PICE.MAR", "PICE.GLA")
)
#> # A tibble: 3 × 1
#>   height
#>    <dbl>
#> 1   5.29
#> 2  12.0 
#> 3  20.5 

si_carmean1996(
  age = c(20, 40, 60),
  height = c(6, 12, 19),
  species = c("PINU.BAN", "PICE.MAR", "PICE.GLA")
)
#> # A tibble: 3 × 1
#>      si
#>   <dbl>
#> 1  11.3
#> 2  14.0
#> 3  16.5