TADAM-df, TADAM-p, and TADAM-s,  are growth models for British Columbia Coastal Douglas-fir , Interior lodgepole pine, and Interior white spruce  plantations, respectively. They are based on a stand-level dynamical system approximation to output from TASS (see TASS animations at the bottom of this page).

TADAM-df is documented, in FBMIS, Volume 1, and the other two models in this article (see also the errata). There is also some background and bits of info in an article by García here , and in this WESBOGY presentation . If you have a VRML viewer, try these 3-D graphs.

Currently there are two computer implementations of the models. One is an interactive simulator that runs on Palm PDAs, and compatibles. The other is an Excel add-in that makes growth and utility functions available in any spreadsheet. The dll used in the add-in can also be accessed from user-written programs under MS Windows, and the C source code for the functions is freely available upon request for use in other computer systems.

Potential users might like to try some laboratory exercises from UNBC's FSTY 405 course:  Laboratory 1 introduces the Palm version.  Laboratory 2 uses the Excel add-in.  Laboratory 9 shows how to use TADAM and Excel's Solver to find a "best" combination of initial density, rotation length, and timing and intensity of thinning.  Here is a spreadsheet built for this lab.

Updates history.


Palm (and PC's).  75 Kb.

These programs can also be run on a PC (MS Windows) using the Palm OS Simulator, see instructions. Or under Windows, Unix/Linux or Mac, with the Palm Emulator, which interfaces with the clipboard and is closer in appearance to the PDA, but is  somewhat more complex to set up (you might find some useful links here).

Excel add-in.  68 Kb.

The first version of the add-in was produced by Gyula Gulyas (Olympic Resource Management, presently with JS Thrower and Associates), using the TADAM DLLs (included in this file).  Demo spreadsheets are included.

MS Windows DLLs.  18 Kb.

TADAM's "engine" in a Windows dll:

Palm TADAM screen shots


From the Palm program HELP:

TADAM for Coastal Douglas-fir

TADAM (TASS Approximation by an Aggregated Dynamical Model) is a stand-level growth model fitted to output from TASS (http://www.for.gov.bc.ca/hre/gymodels/TASS/index.htm ) for planted stands of Coastal Douglas-fir. It only approximates the TASS-generated yield tables used in TIPSY, and includes very few of TIPSY’s numerous variables and options. On the other hand, it can simulate a wider range of thinning treatments, with arbitrary timings and intensities, and starting from any initial conditions in existing stands.


Help - Context help can be obtained by tapping the “i” icon on the top right of the pop-up forms.

Usage - After entering the initial conditions, the simulation is advanced through the Grow or Step buttons. You can Thin at any time. One level of Undo is available. The "Show detail" command (in the menu) displays more information on the current state. The hardware scroll buttons scroll one page at a time, the ones on screen scroll by lines. Use New to clear the screen and start a new simulation.

Menu - Accessed by tapping the round menu button at the bottom-left below the screen or, on newer models, also by tapping on the title line. The usual editing commands can be used to select and copy output to the clipboard. Output can be saved to the Memo Pad in various formats for exporting to spreadsheets, etc. Site index and volume info is available. Set the merchantability limit in Info>Preferences.

TASS animations

This animated GIF follows closely the model described in Mitchell's 1975 publication, although in two dimensions instead of three.  It simulates the canopy development between ages 0 and 100 years.  The stand is unthinned, with initial spacing averaging 2 m.

Here is a larger version, in QuickTime movie format.  You can advance (or recede) at your own rate by dragging the indicator in the time line, or single-step with the arrow keys.

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