trees {spuRs}

von Guttenberg Norway spruce tree measurement data

Description

These are a subset of the von Guttenberg data, a set of measurements on Norway spruce (Picea abies [L.] Karst) in several different locations and site categories.

Usage

data(trees)

Format

A data frame with 1200 observations on the following 3 variables.

ID

A factor identifying the tree by location, site, and tree number.

Age

The age at which the tree was measured.

Vol

The bole volume of the tree, in cubic dm.

Source

These data were kindly provided by Professor Boris Zeide, University of Arkanasa, Monticello, AK, USA, and are further documented in Zeide (1993).

References

A.R. von Guttenberg. 1915. Growth and yield of spruce in Hochgebirge. Franz Deuticke, Wien. (In German)

B. Zeide, 1993. Analysis of growth equations. Forest Science 39 594–616.

Examples

data(trees)