2 BULLETIN 722, U. S. DEPARTMENT OF AGRICULTURE. 



figures \vliich can be applied to the practical operations of forestry. 

 Meinecke/ in a recent paper on this subject, has clearly expressed 

 the need of concentrated work upon single tree species, with a special 

 aim to secure accurate data adaptable to practical use. In order to 

 make a beginning in suppljdng the fundamental knowledge for a 

 solution of some of the more vital problems bearing on the regula- 

 tion of the forest with regard to the peculiarities and activities of 

 the more economic fmigi, a series of detailed studies has been in- 

 stituted, beginning with the western hemlock (Tsuga lietero'pTiylla) . 

 In the present study, an attempt has been made to secure for two 

 principal tj^Qs of the typical stand all available data bearing on the 

 relationship of decay tp the many factors concerned in its inception, 

 development, and spread, and to determine, if possible, which of the 

 factors concerned in the life history of western hemlock has the 

 greatest influence in the development or retardation of decay. 



PRESENT STATUS OF WESTERN HEMLOCK IN THE TRADES. 



The regulation of hemlock in the northwestern forests is probably 

 one of the most difficult silvicultural problems with which foresters 

 have to deal. Not only has this species for many years in some 

 parts of the West been considered little more than a "weed" in the 

 forest, to be removed in as expedient and thorough a manner as 

 possible, but a widespread prejudice on the part of the lumber trade 

 has kept the products of western hemlock much in the background. 



The common occurrence of heart-rot, the susceptibility to fire and 

 frost, etc., have also led to a much advanced theory of a general 

 decadence of this really valuable species. Western hemlock can not 

 be considered in any sense a decadent tree, as is evidenced by its 

 splendid height and diameter growth in localities where it reaches its 

 best development. There are approximately 90,000,000,000 feet board 

 measure of western hemlock in the United States and Alaska, and 

 most of this is found in Washington and Oregon.^ Only recently 

 have the millmen placed hemlock upon the market under its rightful 

 name. In 1908, 90,000,000 feet of western hemlock were reported 

 cut, and this increrased to 248,000,000 feet in 1910.2 The rapid 

 increase in cut tends to show that the true value of western hemlock 

 is hereafter to be recognized and that the prejudice against its name 

 is gradually disappearing. 



Several mill owners with whom the subject of the soundness and 

 durability of hemlock lumber has been discussed state that too fre- 

 quently the lumber decays rapidly after being sawed. This is not 



' Meinecke, E, P. Forest pathology in forest regulation. U. S. Dept. Agr. Bui. 27.5, 62 p. 1916. 

 -■ Hanzlik, E. J., and Oakleaf, H. B. Western hemlock; its forest characteristics, proper! ies, and uses. 

 III. Timberman, v. 15, no. 12, p. 25. 1914. 



