LobDyn is a whole-stand growth and yield model for loblolly pine in
Piedmont region of the USA. It is described in:
García, O., Burkhart, H.E., and Amateis, R.L. (2011). A biologically-consistent stand growth model for loblolly pine in the Piedmont physiographic region, USA. Forest Ecology and Management 262(11), 2035–2041. doi: 10.1016/j.foreco.2011.08.047. Preprint.
There are three computer implementations:
The spreadsheet version runs in Microsoft Excel, LibreOffice, and OpenOffice. Use the link above to download a zip archive containing the spreadsheet, a README text file, and pdf Help. To run, unzip somewhere, and execute LobDyn.xls. You may have to lower macro security to Medium, and allow Enable Macros when prompted. Once the spreadsheet opens, click on HELP at the top for instructions.
Here are two short video tutorials: Demo 1, Demo 2 (thanks to Wink).
The LobDyn spreadsheet is open-ended, in that you can use the standard tools to extend it with special-purpose entries, to produce graphs, or to customize it in other ways.
A very different implementation uses the boxes and arrows of System Dynamics. Here is an input file that can be loaded into the free version of Vensim. This can be useful for experimentation, and may help to better understand the structure of the model. The software can display graphs or tables for any of the variables, with inputs and parameters being changed through keyboard or graphical sliders in real-time.
Finally, there is also a set of R functions
An extended write-up with methodological details is available for download. The stand volume functions and other auxiliary relationships are documented here. LobDyn is similar to the Scube spruce model, see http://forestgrowth.unbc.ca/scube for more information. There are also some old work documents on top heights and site index. This conference presentation may help with the basic concepts.
Article on self-thinning, using LobDyn to illustrate relationships and theory.
NEW: Introduction to dynamical systems, with LobDyn as an example.
The software is open source (MIT license).
Please contact Oscar García (firstname.lastname@example.org) or Ralph Amateis (email@example.com) for any questions or comments.