7. Size-class distribution 

 of saw-timber trees 



WESTERN LARCH 



PONDEROSA PINE 



ENGELMANN 



SPRUCE 



DOUGLAS -FIR 



LODGEPOLE PINE 



| I l.O" -20.9" D.B.H 



I 21.0" D.BH S LARGER 



The timber in Montana is 

 small. Fifty-three per- 

 cent of the total saw- 

 timber volume is in the 

 small size class (11.0" 

 to 20.9"). Marked dif- 

 ferences occur between 

 species. At one extreme 

 is western larch with 28 

 percent in the small size 

 class and at the other 

 extreme is lodgepole pine 

 with 99 percent of the 

 volume in the small size 

 class . 



8. For all species combined the net growth exceeds the commodity 

 drain in both board-foot and cubic-foot volume. The situation, 

 however, is reversed for ponderosa pine where the annual drain 

 in board-foot volume exceeds the net growth by about 78 million 

 board feet. For the other species the favorable growth/drain 

 relationship indicates the feasibility of increased industrial 

 activity. 



-5- 



