LODGEPOLE PINE 



Site Index 



The procedure for estimating site index is based on the curves developed by 

 Alexander (1). Like Lynch's curves for ponderosa pine, Alexander's curves for lodge- 

 pole pine can be used when stand density is heavy enough to have inhibited height 

 growth of the dominant stand. This is thought to take place at densities where the 

 crown competition factor -2^ is greater than 125. Thus, two different procedures have 

 been devised for estimating site index; where CCF is 125 or less a straightforward 

 calculation by means of two equations will suffice. 



The equations are: 



SI = H + bi (In A - In 100) + b2 (A^ - lOO^) + bj (A^ - 100^) 



+ bi, [(H/A) - (H/lOO)] + bs [CH/A2) - (H/lOO^)] + 



be [(H/A2.5) _ CH/1002-5)], 



where 



SI = site index at a base age of 100 years b2 = -0.21973907 X 10~^ 

 H = height of dominant stand = 0.61670435 X 10~^ 



A = total age of an even-aged stand b^ = -64.32135 



bi = 18.310745 bj = 9528.3711 



bg = -34848.289 



and 



S = cq + C]^ SI , 



where 



S = site index at a 50-year base age 



Co = 1.029546 

 Ci = 0.6297251. 



In stands where CCF exceeds 125 site index must be adjusted upward to compensate 

 for the reduction in height of the dominant stand due to stocking density. Let g(A) be 

 a function of age: 



g(A) = bi,[(l/A) - 0.01] + b5[(l/A2) - 0.0001] + h^[[l/k^'^) - 0.00001] 



and 



k = 0.8188667 X lO"^ (CCF-125). 



Then 



P - l-k[g(A) + 1]. 



-'For an explanation of crown competition factor, see Krajicek, Brinkman, and 

 Gingrich (6) . 



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