24000 



16000 



_j 12000 - 



8000 



4000 



MGMT 



000 



POO 



PCB 

 PCI 

 PCA 



Figure 67— Effect of thinning on total yield of western larch plantations (merchantable 

 board feet [Scribner]), site index 50. 



36000 



30000 



uj 24000 



18000 



12000 - 



6000 



MGMT 



000 

 POO 



PCA 

 PCB 

 PCI 



Figure 68 — Effect of thinning on total yield of western larch plantations (merchantable 

 board feet [Scribner]), site index 70. 



54 



