15000 



12000 



9000 



6000 



3000 



MGMT 



000 

 POO 



PCB 



PCI 

 PCA 



Figure 39 — Effect of thinning on standing volume of grand fir plantations (total cubic 

 feet), site index 50. 



24000 



20000 



16000 



12000 



8000 



4000 



MGMT 



000 

 POO 



PCB 

 PCA 

 PCI 



10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 



AGE 



Figure 40 — Effect of ttiinning on standing volume of grand fir plantations (total 

 cubic feet), site index 70. 



35 



