forest: Stand density of mixed nothofagus forest plots

In smbdata: Data from "Statistical Methods in Biology"

Stand density of mixed nothofagus forest plots

Description

A survey was conducted on 41 plots of pure or mixed Nothofagus forest located at the foot of the Andes. Each plot was classified into one of three stand types based on the dominant tree species: Coigue (type 1, 13 plots), Rauli (type 2, 9 plots), or Roble (type 3, 19 plots). For each plot, stand density (number of trees per hectare, SD) and mean quadratic diameter (in cm, QD) were recorded. The primary aim of the study was to model how stand density relates to quadratic diameter and to compare this relationship across the three forest stand types.

Usage

forest

Format

A data frame with 4 variables: DPlot, Type, SD, QD.

DPlot

Factor. Unique identifier for each forest plot.

Type

Factor. Forest stand type classified by dominant Nothofagus species in the plot: "Coigue", "Rauli", or "Roble".

SD

Integer. Stand density, recorded as the number of trees per hectare in each plot.

QD

Numeric. Mean quadratic diameter (in centimeters) of trees in the plot.

Source

Welham, S. J., Gezan, S. A., Clark, S. J., and Mead, A. (2015) Statistical Methods in Biology: Design and analysis of experiments and regression

Dra. Alicia Ortega Z., Universidad Austral de Chile

Examples

lm(log(SD) ~ log(QD) * Type, data = forest)

smbdata documentation built on Jan. 20, 2026, 5:06 p.m.