Related Utilities

The following are simple programs that are designed to do calculations related to the ORGANON growth model. Each program can be downloaded as a compressed file and can be expanded using WINZIP. The programs are executed from the DOS prompt by typing the name of the program followed by the 'Enter' key. Just follow the on-screen directions.


This program computes site index given heights and breast height ages for Douglas-fir and ponderosa pine or heights and total ages from seed for red alder using the curves build into the various versions of ORGANON (Bruce 1981, Hann and Scrivani 1987, King 1966, Weiskettel et al. 2009).

Download SICAL (189K 1/20/11)


This program is a more general version of SICAL and computes site index and top heights for 17 curves for 10 species in the Pacific Northwest. It will also draw a curve of the top height over age.

Download SICALC (104K 12/22/97)



This program uses the taper equations for Walters and Hann (1986) (which are used in SWO and NWO ORGANON) to compute upper stem diameters inside bark for conifers only given a tree's species number (see below), DBH, total height and crown ratio (requir ed).

The SWO and NWO taper equations are the same but use different breast height bark thickness equations. This program has not been updated to include the equations on the SMC or RAP versions of ORGANON. Species Number equivalents used in ORGANON:

Program ORGDIB (41K 12/11/97)


Species Code SWO NWO
------------------------- --------- -------- -------
White fir 015 X X
Grand fir 017 X X
Incense cedar 081 X  
Sugar pine 117 X  
Ponderosa pine 122 X  
Douglas-fir 202 X  
Western hemlock 263 X  
Bigleaf maple 312 X X
Pacific madrone 361 X X
Golden chinkapin 431 X  
Tanoak 631 X  
Canyon live oak 805 X  
Oregon white oak 815 X X
Calif. black oak 818 X  

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