The standard error of estimate for this equation is 0.24 of site index. A computer 

 program in FORTRAN IV (360) to evaluate this equation is shown in figure 9. 



SUBROUTINE nFSITE< A»H,S I ) 

 DI MENS ION B( 18) , X( 1ft) 

 = A 

 P = H 



DATA B/AO. 98 A66, 45 21, 15 3,1230 59. 4, -5, 33 286P E-9 , 3 . 7PC B03F-1 1 ,216o64 

 11 5,-15 8121, 5,1 894C31o »-lo023059E-10, -6. 06861 2, -25351 •09» 3,3 51286E- 

 2 5,1, 702471 F-3, 398, 3 672, -8, 8665 41 E-9 , 4, 001 91 E-15 , -4, 692924E-9, -I , 66 

 34066E-21/ 



SI=0,0 



P2=p«P 



P3=P2*P 



P4=P2*P2 

 P5=P4«p 



012=S0PT(0) - ■ 



015=0*012 



Q2=0*0 



04=02*02 



X( 1) =1,0/0 12-0,14142132 



X{ 2) =l,0/( 02*01 2)-5,656 854E-5 



X( 3)=l,0/( 02*0*012)-lol31371E-6 



X( 4) =( 02-2 500,0 )*( 2+2500, 0» 



X{ 5)=0*04-3, 125E8 



X(6)=P*{ l,0/015-2,8 2842 6E-3» 



X( 7)=P«( 1, 0/04-1, 6E-7) 



X{ 8) =P*{ 1. 0/( 04*Q)-3,2F-«?) 



X(9)=o*X(4) 



X( 10 >=P2*( 1,0/02-0,0004) 



X(11)=P*X(8) 



X( 12)=P2*( 0-50. 0) 



X( 13)=P3*( 1.0/0-0,02) 



Xt 14)=P*X( 11 ) 



X( 15) =P3*( 015-3 53, 5 534) 



X( 16)=P2*X(9) 



X( 17)=P5*X(1 ) 



X( 18) =P5*( 04*012-0. 4419 41 6E 8) 

 DO 1 1=1,18 

 1 SI=SI + B(n *X('I ) 

 SI=SI+H 

 RETURN 

 END 



Figure 9. — A site index estimating subroutine for inland Douglas-fir. 



Although it provides less precise results, 

 5 



S = H + E l^-Z-, 

 ^=l 



where 



ki = 101.08708 

 k2 = 122.04763 



16 



) 



a shorter equation is: 



Zi = (A-l/2 _ 50-1/23 

 Z2 = H (A"^"^ - 50" ^•^) 



