Inventory 



• Growing stock volume amounts to 5.9 billion cubic feet and sawtimber volume totals 21.2 

 billion board feet.^ 



• An additional 395 million cubic feet of sound wood volume is contained in rough, rotten, and 

 salvable dead trees. 



• The most dominant single species — Douglas-fir ( PseudotsuRa menziesii [Mirb.] Franco) — 

 constitutes 2.2 billion cubic feet of growing stock and some 8 billion board feet of 

 sawtimber. 



• Forest industry controls 44 percent of the total growing stock and 46 percent ot tne 

 sawtimber volume. 



• Nearly 70 percent of the trees over 5.0 inches d.b.h. are poletimber size. 



• But, nearly three-quarters of the growing stock volume is contained in sawtimber stands. 



• Two-thirds of the growing stock volume is contained in stands dominated by either Douglas- fir 

 or lodgepole pine. 



• Flathead and Missoula counties combined account for more than one-third of the growing stock 

 and sawtimber volume. 



Components of Change 



• Net annual growth amounted to 129.9 million cubic feet of growing stock and 461.6 million 

 board feet of sawtimber. 



• The annual mortality of 28.7 million cubic feet offsets 18 percent of total annual growth of 

 growing stock. 



• Mortality reduced the annual sawtimber increment by 89.7 million board feet--16 percent. 



• Total removals from growing stock equaled 125.6 million cubic feet. This represents 2.1 

 percent of the standing inventory and 96.7 percent of the net annual growth. 



• Removals from sawtimber amounted to 804.9 million board feet or 3.8 percent of standing 

 inventory and 174.4 percent of net annual growth. 



HOW THE INVENTORY WAS CONDUCTED 



The inventory was designed to provide reliable statistics primarily at the State and 

 study-area levels. Procedures were as follows: 



1. Initial area estimates were based on the classification of 84,795 sample points 

 systematically placed on the latest resource aerial photography available. The sample points were 

 summarized and grouped into strata for subsequent field sampling. The photo points, adjusted to 

 meet known land areas, were used to compute area expansion factors for the field samples. 



2. Land classification and estimates of timber characteristics and volume were based on 

 observations and measurements recorded at 2,512 ground sample locations. Sample trees were 

 selected using a 10-point cluster that includes fixed plots (1/300 acre) for trees less than 5.0 

 inches diameter at breast height (d.b.h.) and variable plots (40 basal area factor) for trees 5.0 

 inches d.b.h. or larger. 



'in this report all reference to sawtimber volume is in International 1/4-inch rule. 



