A NATIONAL PLAN FOR AMERICAN FORESTRY 1433 



that in most operations there will be a definite financial, as well as 

 silvicultural, advantage. 



Slash disposal and subsequent protection on a more intensive and 

 effective scale than at present should cost not over $1.50 an acre over 

 present costs, or between 3 and 4 cents per thousand board feet. 

 This presupposes a good job of disposal and 5 cents an acre spent 

 annually for extra prevention and suppression measures for 10 years 

 after logging. It should always be remembered that expenditures 

 for really efficient protection of a property under operation may save 

 the owner a much greater sum in standing timber and equipment 

 preserved against a single bad fire. 



THE DOUGLAS FIR TYPE PROPER 



This type is ordinarily even-aged, and largely Douglas fir. As the 

 stands become older they are invaded by shade- tolerant hemlock. 

 The climate is such that the fire hazard is more acute and of longer 

 duration than in the fog belt, both in virgin woods and in cut-overs. 

 This t} r pe is less adapted to tree selection than the fog-belt 

 forest. Reproduction of Douglas fir is prolific, provided seed is 

 available and the site conditions have not become too unfavorable; 

 but Douglas fir must become established in openings, as after clear 

 cutting. Clear cutting, with high-speed machinery, is the usual 

 logging practice. 



A digest follows of measures which will insure leaving this type 

 reasonably productive. These are given in detail in Department 

 Bulletin 1493, already referred to, but are here somewhat modified in 

 the light of subsequent information. 



SELECTION CUTTING 



A substantial part of all lands currently logged will be left with 

 an adequate supply of seed if, under the principles of economic 

 selection, only those trees, or more often groups and patches of trees, 

 are selected for cutting that show a proper conversion value. Un- 

 touched patches of timber, from a few acres to hundreds of acres in 

 size, will remain. These may be second growth on the border of 

 merchantability, low-grade old growth, heavy admixtures of species 

 at present inferior, or inaccessible areas hard to log now. Leaving 

 uncut islands, strips and sidehills in this way, for economic reasons 

 alone, has a most important silvicultural effect in that it breaks up 

 the tract for better protection, provides a seed supply for a consider- 

 able part of the clear-cut areas, and tends to promote closer utiliza- 

 tion on the land that is logged, thereby leaving less debris on the 

 ground. 



RESERVE STRIP 



In another substantial portion of the Douglas fir type, where 

 practically all the trees are profitable to cut, economic selection might 

 result in clear cutting of large continuous areas. Even in the absence 

 of slash fires many such areas will not reproduce satisfactorily be- 

 cause of lack of seed. To prevent devastation it is therefore necessary 

 to adopt one of two alternatives: (1) Such modification of logging 

 plans staggered settings, logging alternate spurs, etc. as will leave 

 uncut timber standing adjacent to cut-over land long enough to 

 reseed it; or (2) more permanent reservation (ordinarily for not less 



