QS MISC. PUBLICATION 11, U. S. DEPT. OF AGRICULTURE 



narily growing slowly and belong to the mature or decadent class. Such trees 

 should be cut unless they are needed for seeding purposes. Marking will 

 usually remove from 65 to 75 per cent of the merchantable volume of the stand 

 in trees 10 inches d. b. h. and over, though the percentage must be determined by 

 the condition of the stand. 



In some instances the stands along the upper slopes and crests of ridges are 

 composed mainly of large, poorly formed trees, most of which should be cut 

 from the standpoint of maturity. However, these trees, by reason of their 

 commanding position, are valuably situated as seed trees, and a sufficient num- 

 ber should be left in these situations to provide ample seed insurance. 



Hewed ties. — On the very limited areas of this type, chiefly on poor sites, 

 which will be managed on a hewed-tie basis, trees 13 inches d. b. h. and over 

 will be considered mature, and unless needed for seed or protection will be 

 marked. Trees below this size will be marked only when, on account of defect, 

 it will not pay to leave them for the next cut. 



Dougas fir type. — Saw timber and hewed railroad ties are the major prod- 

 ucts to be obtained from this type. By limiting cutting to trees which are 

 commercially mature and to thinnings, thrifty stands of well-formed Douglas 

 fir, occurring on favorable sites, will be allowed to grow to saw-timber size. 

 However, a great deal of Douglas fir occurs in isolated patches or on steep 

 or rocky slopes where saw-timber production will be impracticable. Such 

 stands will be cut on the basis of maximum production of hewed railroad ties, 

 even though this means cutting some trees before volume growth culminates. 



Clear cutting would practically never be justified in this type. Because of 

 the great variation in Douglas fir saw-timber stands it is impossible to sug- 

 gest any diameter guides that would be helpful in marking. The ideal way to 

 mark this type would be to remove trees that are commercially mature, mak- 

 ing improvement thinnings, the products being marketed in the form of saw 

 logs, railroad ties, and mine props. This is merely the selection system. In 

 many cases such close utilization is impossible, but this ideal should be ap- 

 proached as closely as economic conditions permit. 



Where market conditions permit, crowded stands of immature poles will be 

 thinned from below for the production of mine ties, mine props, telephone poles, 

 or other small-sized products. See discussion, under " Thinning," 



Douglas fir is also the climax type on many areas now supporting stands of 

 other species, such as lodgepole pine. A very conservative policy will be fol- 

 lowed in removing Douglas fir from such stands. 



Engelmann spruce type. — This type is especially well adapted to the selec- 

 tion system of cutting. Saw logs will be the most important product obtained 

 and this should constantly be kept in mind. Trees that are mature and those 

 that are diseased or seriously defective should be marked. Care should be 

 exercised in marking not to be influenced by the increasing market that is 

 developing for railroad ties of this species. If not guarded against, this 

 tendency to be influenced by the market might result in marking immature 

 trees of this species to a greater extent than defect, disease, or a desirable 

 thinning warrants. 



Usually a sufficiently dense stand of young and middle-aged trees will remain 

 after cutting to protect itself against windthrow. If trees much taller than 

 the new canopy are left, they will afford little or no additional protection to 

 the remaining stand and are the ones most likely to blow down. Accordingly, 

 care should be taken not to leave tall trees, the crowns of which will extend 

 much above the general crown level of the stand remaining after cutting. 



Approximately 60 per cent of the merchantable volume of the stand will be 

 removed by following this policy. 



Mixed types. — Mixed types will be marked in the manner prescribed for the 

 major species involved. Small patches of a different species within areas where 

 railroad ties are being produced, but where sawmills are not planned on at the 

 time of the next cut, will be marked on the same principles as the rest of the 

 sale area. This is illustrated by Engelmann spruce occurring in patches on 

 north slopes or in strips along streams within a lodgepole pine stand that is 

 adapted to the production of hewed ties. 



Marking to favor more desiraMe species. — Occasional stands are found in 

 which the overstory of merchantable timber is of a different and less desirable 

 species than the understory. An example is a stand of blue spruce with an 

 understory of Douglas fir, or a stand of decadent lodgepole that is coming up 

 to Engelmann spruce. In such cases it is permissible and advisable to mark 



