Sapwood area and depth, and bark allometric models

Source: R/data.R

Returns allometric models for 14 species from several North-American sites. The models relate independent (i.e. outcomes) parameters sapwood area and depth, as well as bark thickness to diameter at breast height (DBH, 1.3 \(m\)). A detailed description on model development and assessment is provided in Pappas et al. (2021; in prep.). The data used for these models is found in allometry.data.

allometry.models

Format

Provides a list (one item for each allometric parameter) with model data.frames/tibbles nested by species. Relevant parameters can be extracted either by unnesting (tidyr::unnest()), or by selecting a single nested item, e.g., allometric.models$Saparea_cm2$fit[[1]].

Each data.frame/tibble has four columns

Species

Assessed species (character)

data

data used to fit model; single-species subset of allometry.data (list column)

fit

nls or lm model fit (list column)

model_parameters

Convenient summary of models as produced by broom::tidy() (list column)

Details

OLS models (y ~ x) are used for relationships between DBH (dependent) and sapwood / bark thickness; A non-linear LS model (y ~ a * x ^ b ) is used for the relationship between DBH (dependent) and sapwood area.

  • Abies balsamea

  • Acer rubrum

  • Acer saccharum

  • Betula alleghaniensis

  • Betula papyrifera

  • Fagus grandifolia

  • Fraxinus nigra

  • Picea glauca

  • Picea mariana

  • Picea rubens

  • Pinus banksiana

  • Populus tremuloides

  • Quercus rubra

  • Thuja occidentalis