Author: David Max MA DPhil (2017-11-08)
Growth of native black poplar trees analysed using R
This study reports on survival and growth of native black poplar trees (Populus nigra betulifolia) planted at Hillside House.
Summary
- Sixteen male native black poplars Populus nigra betulifolia (clone 25) were planted in a strip approximately 60 metres by 12.
- Two female native black poplars (clone 32) are also planted in the same strip.
- Trees are planted in mounds to prevent waterlogging of the roots.
- Nearest-neighbour gaps are set at 8 metres.
- Planting in mounds increased annual growth by 0.38 metres (38 cm).
- Over four years, annual growth of trees in mounds averages 1.00 metres per year (n = 15 trees).
Details
An account of planting methods can be found on the Hillside House website.
An A4 pdf file is available for reading on devices with wider screens.
Growth of the surviving trees has been analysed using the free stats package R...
Detailed analysis of native black poplar growth at Hillside House using R (pdf file, A4 pagesize)
Data and R script files for download
R files to run this problem are available for download as either tar or zip archives.
- poplars.tar (for Unix, Linux etc; tar is also available for Windows)
- poplars.zip (for Windows)
Click one of the links and your browser should ask you what you want to do with the selected archive file.
First, save the file into a working directory (i.e. folder, in Windows-speak) of your choice.
The tar archive file can be unpacked using the shell command...
tar -xf poplars.tar.
On Windows the zip archive file can be unpacked by right clicking on the file and choosing "Extract all".
To run the R script, you will need a working installation of R on Linux/Unix or Windows. (The tests here were done using R 3.4.0).
Unpack the archive into your chosen working directory. Start an R session, navigate to the chosen working directory, then run the main job control file TEST.POPLARS7.R, using the R command...
source('TEST.POPLARS7.R').