SITE INDEX 



80000 



60000 



20000 



90 



80 



70 



60 



50 



40 



10 20 30 40 50 60 70 80 90 100 110 130 130 140 150 



AGE 



Figure 3 — Natural regeneration yield curves tor Inland Northwest forests of tfie 

 grand fir-cedar-hemiock ecosystem (merchantable board feet [Scribner], 4.5-inch 

 top, stems greater than 7 inches d.b.h.). 



SITE INDEX 



100 



90 



80 



70 



60 

 50 



40 



Figure 4— Quadratic mean diameter vs. age for natural regeneration in Inland 

 Northwest forests. 



6 



