WESTERN YELLOW PINE IN OREGON. 29 



umneasurable factors — ^lessened number of trees per acre after cut- 

 ting, occasional loss of some trees on account of accidents, increased 

 growth after cutting due to more growing space — point to the con- 

 clusion that central and eastern Oregon yeUow-pine timberland can 

 be counted upon to yield annually for an indefinite time from 75 

 board feet per acre on poor sites to 175 board feet on good sites. 

 This is not large when compared with the 800 or 1,000 board feet per 

 acre per year yields of the best Douglas-fir forests west of the Cas- 

 cades; but the chmate in the yeUow-pine belt is such that the pro- 

 ductivity of the forest soil is inevitably not large. 



CHARACTERISTICS OF THE WOOD. 



Botanically western yellow pine belongs to the subfamily of the 

 hard or "yellow" pines rather than to that of the soft or "white" 

 pines. In characteristics the wood is midway between the two. It 

 is described as f oUows : ^ 



Rather light, not strong, grain fine, even, often twisted; annual rings variable in 

 width, summerwood l:»road or narrow, resinous; resin passages medium and rather 

 numerous; medullary rays not numerous, prominent; color very light yellow to red- 

 dish, thick sapwood almost white; not durable in untreated condition, but readily 

 receives treatment. 



The smaller trees, i. e., the so-called "bull pines," and the centers 

 of the larger trees have a coarse-grained wood, in which the annual 

 rings are prominent and the summerwood rather hard, resembUng 

 that of some of the southern yeUow pines. The outside of the larger 

 trees, particularly of the slower-growing ones, is soft, uniform- 

 textured, and resembles strongly the wood of the eastern white pine, 

 western white pine (Idaho white pine), and sugar pine. The wood 

 from the outside of the lower logs of old trees is apt to be fairly clear 

 of knots, the worst defect in tliis lumber; but that from the upper 

 part of the tree and from young trees is almost always knotty, even 

 though the outside of the log may appear fairly smooth. Much of 

 the ycllow-pme timber cut in Oregon is so soft and white that it is 

 shipped east and used with satisfaction for purposes for which real 

 white pines and sugar pine have been used previously. Tlie char- 

 acter of the wood varies with the situation, a fact well known to 

 lumbermen, who find that the timber in certain localities produces 

 a larger percentage of the high-grade soft "shop" lumber than that 

 in other localities where it is similar in exterior appearance. 



The following statistics summarize the characteristics of the wood.^ 



Average weight of oven-dry wood, 20.5 pounds per cubic foot. (Sargent.) (Excep- 

 tionally soft, light specimens from central Oregon weighed, air dry, 22 pounds per 

 cubic foot.) 



> Forest Service Bulletin 90, "Uses of Commercial Woods of the United States; II, Pines." 

 2 For further description of the wood, see Forest Service IJulletin 101, " Western Yellow Pine in Ari- 

 zona and Now Mexico," by T. S. Woolsey, p. 33. 



