46 BULLETIN 418. U. S. DEPARTMENT OF AGRICULTURE. 
APPENDIX C. 
INSTRUCTIONS FOR MARKING TIMBER IN THE YELLOW PINE REGION, 
DISTRICT 6. 
East of the Cascade Mountains in Oregon and Washington, the commercial forests, 
consist largely of yellow pine, either in pure stands or in mixed stands with Douglas 
fir, white and grand fir, western larch, and lodgepole pine. 
Since these forests are primarily uneven-aged, they should be managed by the 
selection system (or a modified form of the selection system). It should be the aim, 
therefore, to cut over each portion of these forests periodically. From the data now at 
hand it is evident that the period between cuttings (the cutting cycle) should be about 
60 years, and that no trees should be cut until they are 180 years old; i. e., the 
rotation should be 180 years. 
The following general principles should govern the marking of timber in forests of 
this region: 
GENERAL PRINCIPLES FOR ALL TYPES. 
1. The cutting should be fundamentally an improvement cutting; and the officer 
who is marking the timber should decide first what is to be left, and then mark for 
cutting what is not reserved. His aim should be to leave the forest in the best con- 
dition for development during the coming cutting cycle, so that it will produce a good 
crop in the next cutting. 
2. Aim to mark for cutting the thoroughly mature trees of all species and all those 
which will not survive and make good growth until the next cutting, 60 years hence. 
3. Aim to reserve as the basis for the next crop a well-distributed stand of thrifty 
saplings, poles, and young standards, each of which is capable of living and growing 
until the next cutting. The trees which are reserved should be considered not as 
"seed trees," but as the nucleus of a later cutting. 
4. On the average from 20 to 25 per cent of the estimated volume of the trees over 
12 inches in diameter should be reserved. Where most of the timber is thoroughly 
mature or decadent, it may be wisdom to leave a smaller percentage; where most of 
the timber is young and thrifty, a much larger proportion should be reserved. In 
general, make the cutting as light as is consistent with allowing the logger to do prac- 
tical, profitable logging, aiming thereby to extend the improvement cutting over a 
larger area, instead of making it a heavy cutting on only a small area. 
5. An area should not be included within the limits of a timber sale in which there 
is not enough mature timber to make it worth the while of the logger to go into that 
area for the mature timber alone, thereby necessitating marking immature timber in 
order to make the logging profitable. 
6. Do not hesitate to make the marking somewhat groupwise, if all the trees over a 
certain area are thoroughly ripe, except in exposed situations where gaps in the forest 
canopy are not desirable or where there is danger that the reproduction will be 
endangered. Yellow pine occurs to some extent even-aged in groups; and it will be 
necessary often to remove the old groups in their entirety. Avoid, however, making 
a clearance over an area larger than an acre. 
7. Mark for cutting the following classes of trees of all species throughout the region 
in the following order of preference: 
(a) All spike-topped, seriously fire-scarred, lightning-struck, or otherwise defec- 
tive yet merchantable trees. Do not, however, consider that every tree 
that has a fire scar or a thin crown or some other deformity has got to be 
removed. Few perfect trees are to be found, and small basal scars or s imil ar 
injuries in no way impair the health of the trees. 
(b) All insect-infested trees. 
(c) All suppressed trees which apparently would not thrive and make good growth 
even if released . 
(d) All thoroughly mature trees of all species which apparently will not survive 
until the next cutting. 
8. In general, the species should be favored in marking in the following order of 
preference: Western yellow pine, sugar pine, western larch, Douglas fir, white (or 
grand) fir, and lodgepole pine. The last two species should be considered forest weeds, 
and always marked heavily where better species are present. 
The forests of this region may be, for the convenience of discussion, grouped into 
three classes: (A) practically pure stands of yellow pine; (B^mixed stands in which 
there is a good deal of yellow pine; (C) mixed stands in which there is little or no 
yellow pine. The marking in each type involves some considerations peculiar to 
that type. 
