PROGRAM ORGANIZATION 

 AND LOGIC SEQUENCES 



The growth prognosis program is organized as an interrelated set of subroutines 

 executed under the control of a very brief main program. The first few subroutines 

 serve to read in the control information, to set up the sampling probabilities for the 

 trees and plots (NOTRE, see Appendix 111), to fill in missing data (CRATET) , and to 

 calibrate the various growth projection functions (DGCALP) . Once this initial house- 

 keeping has been accomplished, the program proceeds to cycle through the projection 

 intervals. The first major subroutine called within the projection cycle is TREGRO. 

 The purpose of this subroutine is to monitor the growth of individual tree records, to 

 bring in the aspects of random variation in diameter growth rates and to deplete the 

 stand through the expected mortality and harvest. To accomplish this task four lower 

 level subroutines are utilized: DGF calculates the diameter increments for each tree 

 record; MORTS decreases the number of trees per acre represented by each tree record 

 for its expected mortality; HTGF calculates height increment and crown changes; and CUTS 

 contains the logic for selecting trees to be harvested for the management regime pro- 

 posed for the stand. The next major subroutine to be called is STAND, a subroutine that 

 summarizes the total stand attributes implied by the new tree records. This summary 

 includes the number of trees per acre and their distribution by tree d.b.h., the volume 

 characteristics of the total stand as summarized by the primary units of volume in 

 cubic feet, surface area of the boles in square feet, and the accumulated total tree 

 height. In addition, the total cubic foot volume representing the accretion on the ini- 

 tial tree population and the total cubic foot volume represented by the mortality are 

 also summarized and their distributions shown by percentile of the diameter distribu- 

 tion. Also at this point in the computation cycle, predictions of stand growth expressed 

 by growth projection formulae for the stand as a whole would be applied. However, at 



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