| treegrowth {datana} | R Documentation |
Diameter and height growth of Grand-fir sample trees.
Description
Diameter and height growth of 66 Grand-fir trees. Data derived from stem analysis sample trees collected by Dr Albert Stage (US Forest Service, Moscow, ID, USA.)
Usage
data(treegrowth)
Format
Contains seven column, as follows:
- tree.id
Tree number identificator. An unique number to each sample tree.
- forest
Forest type.
- habitat
Forest habitat type.
- tree.code
A composite tree code representing the following columns: tree.id-forest-habitat
- age
Age, in yr
- dbh
Diameter at breast-height, in cm.
- htot
Total height, in m.
Source
Originally, the data were provided by Dr Albert Stage (R.I.P) to Professor Andrew Robinson (University of Idaho, USA), whom used them to explain the fitting of statistical models. Dr Christian Salas-Eljatib was a former graduate student of Statistics of Prof Robinson at the Univ. of Idaho.
References
Stage, A. R., 1963. A mathematical approach to polymorphic site index curves for Grand fir. Forest Science 9 (2), 167–180.
Examples
head(treegrowth)
unique(treegrowth$tree.code)