MGMT 



90000 



72000 



54000 



36000 



IBOOO 



000 

 POO 



PCB 

 RCA 

 PCI 



Figure 49 — Effect of tfiinning on total yield of grand fir plantations (merchant- 

 able board feet [Scribner]), site index 70. 



MGMT 



PCA 

 PCI 

 PCB 

 POO 

 000 



Figure 50 — Effect of thinning on total yield of grand fir plantations (merchantable 

 board feet (Scribner]), site index 90. 



40 



