880 JOURNAL OF FORESTRY 



B. To harvest the crop and establish a new stand of white pine and other 

 desirable species and incidentally to secure the benefit of increased growth on 

 any trees which may be left. 



Application to Classified Stands 



A. I. Improvement thinnings will be made in these stands whenever practi- 

 cable. 



A. 2. In these stands a partial cutting will be made which will leave not less 

 than fifty trees per acre and preferably more. These will include trees 6 inches 

 d. b. h. and over, exclusive of hemlock and defective trees. A flexible diameter 

 limit of 14 inches to i6 inches will be used as a guide in leaving a sufficient basis 

 for a second cut. Where this will result in leaving less than six white pines per 

 acre, the diameter limit will be raised to provide for at least this number. 



The aim will be to secure an even distribution of thrifty trees which will havc- 

 sufficient space for subsequent crown development. This may involve the leav- 

 ing of trees above the general diameter limit or the cutting of some below. 



After white pine, the species to favor will be spruce, cedar, larch, and Douglas 

 fir, in the order named. 



B. I. The merchantable trees will be cut with the primary object of securing 

 reproduction. To supplement the supply of seed in the duflf, two to six white- 

 pine trees of seed-bearing size and condition will be left per acre; also two to 

 six trees per acre, preferably of larch, or, if larch is not present, of Douglas 

 fir, should be reserved as seed insurance against fire. The number of seed trees 

 will vary inversely as their seed-productive capacities. Two trees i8 inches or 

 over d. b. h. may be considered the equivalent in seed-productive capacity of 

 six trees i2 inches or 14 inches d. b. h. As far as possible, seed trees should be 

 selected with reference to their windfirmness. 



In addition to the prescribed reservation of seed trees, any thrifty white pines 

 below 14 inches d. b. h. should be left. 



Where it is possible to select groups of short, full-crowned trees on ridges, 

 the seed trees on adjoining slopes should be combined in these groups. If the 

 ridges are not pronounced, or if there is no marked difference in the timber, no 

 attempt should be made to leave the seed trees in groups. 



Spruce, white fir, and hemlock will be cut to the lowest merchantable size. 

 Where cedar is desirable and should be favored, seed trees of this species may 

 be left. 



In general, reproduction openings must be at least one-quarter acre in extent 

 to be effective. This involves the cutting or killing of all hemlock, all defective 

 white fir, and trees of any species unmerchantable on account of defect, and the 

 destruction of all thickets of white fir and hemlock reproduction which will in- 

 terfere with white-pine reproduction. Ordinarily sound, small trees of white 

 fir will not be cut or killed unless necessary in order to open the stand suffi- 

 ciently for thrifty white-pine reproduction. 



B. 2. These stands will be clean-cut, with the reservation of two to six seed 

 trees each of white pine and larch or Douglas fir per acre, as specified under 

 B.I. 



B. 3. White-pine reproduction will be expected chiefly from seed in the duff, 

 to be supplemented by planting of blanks if necessary. White pines should be 

 left as seed trees only when they are unmerchantable on account of defect. 



