36 



sible area. Thinnings of this nature at times ^hen abundant young 

 cones promise a sure crop of Douglas fir seed should result in a thrifty- 

 stand of fir reproduction. 



Owing to its comparative tolerance of shade, the management of 

 Douglas fir in j^ellow pine stands is fairly simple. Where Douglas 

 fir is to be encouraged it should be favored by marking to larger 

 minimum limits than yellow pine, but enough of the latter should be 

 left to afford light shade for the fir seedlings. Brush burning may 

 be practiced with due precautions to prevent forest fires, since in this 

 zone no active competition from lodgepole pine is to be feared. 



Throughout this region, as in all others, the encouragement of 

 Douglas fir should not be attempted in situations which are mani- 

 festly better adapted to other species. The dry soils at lower alti- 

 tudes are especially fitted for yellow pilie, and attempts to force fir 

 into such situations will result in scrubby timber, very inferior to the 

 pine which grows there naturally. In like manner, situations best 

 fitted for lodgepole pine forests should be managed as such. The 

 middle ground, where Douglas fir flourishes naturally, may often be 

 extended somewhat into the lodgepole pine type on the one hand and 

 the yellow pine type on the other; but further attempt to supplant 

 either of these species with Douglas fir is hazardous. 



SOUTHERN ROCKY MOUXTAIX REGION. 



In the southern part of the Eocky Mountain region yellow pine 

 assumes chief importance in the commercial forest. Douglas fir is 

 neither as abundant nor as valuable as in the northern States. WTien 

 it grows in mixture with yellow pine the latter should be favored in 

 management, except in mining regions, where Douglas fir timber is 

 in demand for props, stulls, and lagging, on account of its greater 

 durability. Xext to yellow pine, however, Douglas fir should be 

 given preference in the management of mixed forests ; and white fir, 

 Mexican white pine, and other less important trees which compete 

 with it should be discriminated against. 



In this region a soil cover of brush is beneficial, and is often abso- 

 lutely necessary to secure a satisfactory stand of reproduction. So 

 injurious to young seedlings is the drying effect of the summer sun 

 that it forms one of the principal enemies of reproduction in the drier 

 parts of this region. In many places seedlings are to be found only 

 under the cover of brush, where the soil is protected from complete 

 desiccation. Brush piles also afford some protection against damage 

 from stock, which is also an important enemy to reproduction. It is 

 therefore inadvisable to burn brush in this region except where the 

 fire danger is especially great. The brush should be loosely massed 

 in isolated piles at a distance of at least 10 feet from seed trees. 



[Cir. 150] 



