Phase 4 . --Weights were then developed and used in a weighted, nonlinear regression 

 program to determine the following, final weighted nonlinear model: 



Total ingrowth = doS(BACLi)^l (1 . 0+BACL2)'^2g(d3BA^'^ + dsAjBA^^ 



where 



do = 0.48630258 = -3 . 9772 1395E-06 



di = 0.65949418 di+ = 2.7667388 



d3 = -0.49280582 d^ = -1 . 33299951E-06 



where 



S = Minor's (1964) site index 



BA = total stand basal area per acre in square feet 



BACLj = basal area per acre in the 4- through 6-inch diameter classes 

 BACL2 - basal area per acre in the 7 -inch diameter classes. 



The weighted, mean square error for this model was 0.78244674. The coefficient of determina- 

 tion, R2, was 0.8285 for 201 observations. See figure 5 for a graph of this function. 



BA = 25 25 50 25 50 



Bosal Area in the 4, 5, and 6 Inch Diameter Glosses In Square Feet/Acre 



Figure 5 . --Predicted total number of ingrowth trees by site index classes (S) , 

 total basal area classes (BA) , and the basal area in the 4-, 5-, and 6-inch 

 diameter classes. 



25 



