Figure 1. — Geographical 

 distribution of 

 sample trees. 



I 

 ■ 



I 

 ■ 



L. 



■ 



MONTANA 



IDAHO 



—I 



1 



■ 



\ 



a 



\ 



I 



I 



■ 



I 



■ 

 I 



WYOMING 



UTAH 



; approximately 15 trees 



To allow estimation of periodic basal area increment of individual trees in liotli 

 managed and unmanaged stands, screenings were conducted only with prediction variables 

 appropriate to each situation. Variables, or combinations of variables such as stand 

 basal area and age, that would express past increment, were ruled out of the models that 

 could apply to thinned stands. Although such variables would show a close correlation 

 with subsequent increment, manipulation of stand density would change these variables 

 so that the coefficients derived from our data would not apply. 



Basic stand variables included in the analysis were lodgepole pine site index at 

 100 years--with corrections made for stand density (Alexander and others 1967), lati- 

 tude, elevation, number of trees per acre, and basal area. Individual tree variables 

 included were d.b.h., height, crown length, and age at breast height. Additionally, 

 various other interaction terms and values derived from the measured variables were 

 calculated and included in the analysis. 



Crown competition factor (CCF) (Krajicek and others 1961) was calculated with the 

 equation developed for lodgepole pine by Alexander and others (1967) : 



N 



CCF = (0.00365 ID^^ + 0.01676 ZD^ + 0.01925 N) / A 



where 



D = D.b.h. of ith tree in plot 

 N = Number of trees in plot 

 A = Area in acres of plot 



3 



