HEIGHT, FT 

 160 -I 



140 



120 - 



loo- 

 se - 



60 

 40 H 

 20 



MONSERUD'S HT. 

 PROJECTION CURVES 



STEELE & COOPER 



. : - -" - f I I I I 



25 50 75 100 125 150 175 200 



AGE, BREAST HEIGHT 

 Figure 19a.— Comparison of 

 Monserud's (1984) curves projecting 

 Douglas-fir height growth to those 

 generated from western larch site 

 index and Douglas-fir age, employ- 

 ing authors' equations (table 3). 



HEIGHT, FT 

 160 



140 



120 



100 



80 



60- 

 40- 

 20- 



SITE INDEX 



— MONSERUD'S 



PROJECTION CURVE 



■"■ STEELE & COOPER 



25 50 75 100 125 150 175 200 



AGE, BREAST HEIGHT 

 Figure 19b.— Comparison of 

 Monserud's (1984) curves projecting 

 Douglas-fir height growth to those 

 generated from Engelmann spruce 

 site index and Douglas-fir age, 

 employing authors' equations 

 (table 3). 



SUMMARY OF METHOD TO PREDICT 

 SITE INDEX AND HEIGHT 



To predict the stand site index or height of a species 

 from associated species, the following methodology 

 should be followed. Select all sample trees from a stand 

 uniform in overstory species composition, age structure, 

 habitat type, and topography. Even-aged stands (no 

 more than a 20-year range in the age of the dominant 

 and codohiinant trees) (Alexander 1967) are preferred. 

 Uneven-aged stands may be sampled, avoiding or 

 rejecting trees that have suffered past suppression. 

 Select two to five site trees of the predictor species (used 

 to predict site index of the desired species). Site trees 

 should be dominant or codominant, undamaged (no 

 broken or forked tops, excessive sweep or crook, or 

 disease), and unsuppressed (normal pattern of ring 

 growth on the increment core) (Alexander 1967). Com- 

 pute the site index of each site tree from the site curves 



presented in appendix A and average the values to 

 arrive at a mean stand site index. Estimation of total 

 age must be done with the values given in table 1. 



Site index of an associated species can be computed 

 from the equations in table 2 or read from the graph of 

 the independent species (figs. 1 through 9) if the mean 

 stand site index falls within the range of site index 

 given for the independent variable in table 2. If more 

 than one species is sampled and used to estimate the 

 site index of the desired species, then a more reliable 

 estimate can be made by averaging the site index 

 estimates. 



Height of an associated species can be predicted from 

 the equations in table 3, provided: (1) the mean stand 

 site index of the observed species is within the range of 

 site index given for the predictor variable, and (2) the 

 age at which the absent species height is to be predicted 

 is also within the age range given for the predicted 

 variable. 



11 



