hgrdfir {datana} | R Documentation |
Tree height growth of Douglas-fir sample trees in the Northwest of the United States
Description
Data contains 148 observations on the height growth of dominant trees of Pseudotsguga mensiezzi in the Northwest of the United States.
Usage
data(hgrdfir)
Format
The data frame contains seven variables as follows:
- natfor.id
Code identifier.
- plot.code
Plot number identification
- tree.code
Tree number identification.
- dbh
Diameter at breast height at sampling, in in.
- toth
Total height at sa,pling, in ft.
- age
Age of tree, yr.
- height
Height at a given age, in ft.
Source
The data were provided by Dr Christian Salas.
References
- Monserud RA. 1984. Height growth and site index curves for Inland Douglas-fir based on stem analysis data and forest habitat type. Forest Science 30(4):943-965.
- Salas C, Stage AR, and Robinson AP. 2008. Modeling effects of overstory density and competing vegetation on tree height growth. Forest Science 54(1):107-122. doi:10.1093/forestscience/54.1.107
Examples
data(hgrdfir)
head(hgrdfir)
unique(hgrdfir$tree.code)
table(hgrdfir$plot.code,hgrdfir$tree.code)
tapply(hgrdfir$dbh, hgrdfir$tree.code, mean)
tapply(hgrdfir$dbh, hgrdfir$tree.code, mean) #dbh of each sample tree
tapply(hgrdfir$toth, hgrdfir$tree.code, mean) #toth of each sample tree