# Ilex opaca

Aquifoliaceae. 4 equations apply. Each output lists them most specific first: fitted on this species, on a variety of it, pooled fits that included it, then its genus and family. Within each step, equations the authors advised against go last, then those read from compilations; more trees come first. The order shows how specific the evidence is, not which equation predicts best.

Wood density 0.55 g/cm³, estimated from 30 samples in 4 studies by the [Global Wood Density Database v.2](https://doi.org/10.5281/zenodo.16919509) (Fischer et al. 2026, https://doi.org/10.1111/nph.70860; CC BY 4.0).

## Aboveground biomass

1. Westfall et al. 2024 (this species): Fitted on this species; 13 trees; DBH 2.54–18.8 cm; Read from the original paper.
   - [NSVB American holly, species-level (all ecodivisions): total aboveground biomass (without foliage), Schumacher-Hall model (Eq. 1)](https://treeallometry.org/equations/westfall-2024-ilex-opaca-agb/), Westfall et al. 2024: Ilex opaca, United States; inputs DBH + Height; DBH 2.54–18.8 cm; 13 trees.

## Branch biomass

1. Westfall et al. 2024 (this species): Fitted on this species; 13 trees; DBH 2.54–18.8 cm; Read from the original paper.
   - [NSVB American holly, species-level (all ecodivisions): branch biomass (wood and bark), Schumacher-Hall model (Eq. 1)](https://treeallometry.org/equations/westfall-2024-ilex-opaca-branch/), Westfall et al. 2024: Ilex opaca, United States; inputs DBH + Height; DBH 2.54–18.8 cm; 13 trees.

## Foliage biomass

1. Westfall et al. 2024 (this species): Fitted on this species; 13 trees; DBH 2.54–18.8 cm; Read from the original paper.
   - [NSVB American holly, species-level (all ecodivisions): foliage biomass, Schumacher-Hall model (Eq. 1)](https://treeallometry.org/equations/westfall-2024-ilex-opaca-foliage/), Westfall et al. 2024: Ilex opaca, United States; inputs DBH + Height; DBH 2.54–18.8 cm; 13 trees.

## Stem volume

1. Westfall et al. 2024 (this species): Fitted on this species; 91 trees; DBH 2.54–41.4 cm; Read from the original paper.
   - [NSVB American holly, species-level (all ecodivisions): total stem wood volume (inside bark), Schumacher-Hall model (Eq. 1)](https://treeallometry.org/equations/westfall-2024-ilex-opaca-volume/), Westfall et al. 2024: Ilex opaca, United States; inputs DBH + Height; DBH 2.54–41.4 cm; 91 trees.