THROUGH-GROWTH 



Through-growth is defined as the proportion of the total ingrowth that will grow through 

 the 4-inch diameter class and into the 5-inch class, in the same growth period. It is assumed 

 that no trees will grow through to the 6-inch class. 



As with the mortality and conversion models, I modeled through-growth using the nonlinear 

 logistic function. Independent variables tried in this weighted, nonlinear analysis included 

 predicted basal area growth in the 4-inch diameter class, predicted total ingrowth, and time- 

 since-last-cutting. The finished models were selected after fitting and closely examining a 

 number of alternative models. The regression coefficients for these models are in table 17 

 and plots of the models in figures 6 and 7. 



Table 17. --Final through-growth equations 

 -X 



Through-growth = (1.0 + e ) 



where 



Through-growth = proportion of the total number of ingrowth trees that through grow into 

 the 5-inch diameter class 



-2.636336 + 28 . 73438*BJBAGl-4" - . 03419626*Ai *TINGRO 



or 



-2.490266 + 24.95862*BJBAG2-4" - . 03440381 *Ai *TINGRO 



BJBAGl-4" = predicted basal area growth of the 4-inch diameter class using the even- and 

 uneven-aged blackjack pine equation 



BJBAG2-4" = predicted basal area growth of the 4-inch diameter class using the uneven- 

 aged blackjack pine equation 



TINGRO = predicted total number of ingrowth trees 



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