228 Forestry Quarterly. 



Western Hemlock, Amabilis Fir, Lowland Fir, and Douglas Fir ; 

 in Oregon, with Douglas Fir, Lowland Fir, and Amabilis Fir; in 

 California, with Douglas Fir, Lodgepole Pine, Red Fir, and 

 Shasta Fir." (Sudworth.) 



In the humid climate of northern Idaho, Western White Pine 

 forms the determining feature of the forest type as a whole, 

 although the percentage of the species varies very widely in 

 different localities. It is the predominant tree in the white pine 

 flats between 2,200 feet and 4,500 feet elevation, and to a con- 

 siderable extent at somewhat higher corresponding elevation on 

 the moist southerly slopes. It frequently exists in almost pure 

 stands, but more often other species form 10 to 50% of the 

 merchantable volume. On northerly exposures its codominant 

 associates are Western Larch and, to a less extent, Douglas Fir, 

 Engelmann Spruce, and White Fir, {Abies grandis) ; while under 

 the main stand. Western Red Cedar, Western Hemlock, and 

 White Fir usually form a lower story, or an undergrowth. On 

 southerly exposures, including those sloping to the southeast and 

 southwest, Douglas Fir is the usual associate, while in some 

 localities White Fir, Lodgepole Pine, Western Larch, and oc- 

 casionally Yellow Pine, are found. Here as a rule there is no 

 understory of cedar and hemlock. 



The detailed range of Western White Pine in Idaho and Mon- 

 tana is given below. 



Commercial Distribution in District I. — Western White Pine 

 is of the highest commercial value of any species wherever found. 

 Throughout the entire panhandle of Idaho, from the Middle Fork 

 of the Clearwater River to beyond the Canadian boundary, it 

 makes the best growth of any species and produces the bulk of 

 the merchantable timber. The per acreage yield is far greater 

 than that of any other species grown in the region. In the Priest 

 River Valley on the Kaniksu Forest, where the species reaches 

 its maximum development, the white pine type occupies about 

 80% of the entire area. Approximately 42% of the merchan- 

 table timber of this type, or 34% of the entire stand of the region, 

 is Western White Pine, according to J. E. Lieberg's estimate. In 

 places the stand is found to be 90% pure, although in the 

 majority of typical well developed stands the White Pine forms 

 only 60 to 70% of the merchantable volume. Western Red Cedar 

 frequently forms 5 to 10%, while the remainder is principally 



