FOREST PLANTING IN THE INTERMOUNTAIN REGION. 



23 



type in this region available for planting to western yellow pine the 

 best are: (1) Open stands of brush where the trees may be planted 

 on the north sides of rather isolated clumps of brush; (2) low brush 

 that will shade the trees for only a few years; (3) dense stands of 

 brush or aspen, cleared or heavily thinned within a few years of 

 planting; (4) open areas at the higher elevations within the type; 

 and (5) areas having favorable soil moisture conditions secured by 

 clearing the native vegetation from otherwise suitable areas. 



3. For field planting 2-1 is the best age class of stock to use. 



4. The first establishment of plantations in the permanent brush 

 type is most easily secured under rather dense cover. In the open 

 it is naturally best on the moister sites. 



5. Survival after the first year or two is best under cover, up to a 

 certain optimum density which is heavier at low altitudes than at 

 high. Survival as high as 78 per cent at the end of the fourth year 

 has been attained. On the other hand, the most vigorous trees were 

 found on moist sites in the open. 



6. Growth is best on the moister sites in the open where there is 

 plenty of available soil moisture and heat, and decreases with de- 

 creasing altitude, adverse soil conditions, slope, or exposure. The 

 growth rate may in some cases reach 3 inches in height per annum 

 the fourth year after planting. 



DOUGLAS FIR. 



Douglas fir occurs naturally thoughout the region and is usually 

 found in mixture with white fir from the upper edge of the western 

 yellow pine type or permanent brush zone to the lower edge of the 

 Engelmann spruce type; while scattered trees are found in warmer 

 situations well within the spruce and on cool sites, such as northern 

 aspects down to the upper edge of the pinon-juniper type. Inas- 

 much as the aspen type frequently alternates with Douglas fir at the 

 same elevations, it is natural that this species should have been 

 planted under aspen at the outset. 



Class of planting stock. — The general requirements as to the age 

 class of Douglas fir stock most desirable for field planting are quite 

 similar to those given above for western yellow pine. However, a 

 few exceptions are worthy of note. In underplanting aspen it is 

 necessary to use vigorous and sturdy transplants which will stand up 

 straight during heavy snowfalls and during leaf falls in the autumn. 

 Table 11 gives a comparison of 3-0, 2-2, 3-1, and 3-2 classes of 

 Douglas fir stock. 



Table 11. — Comparison of age classes of Douglas fir stock. 



Age class. 



Average 

 diameter 

 ofstem 

 at root 

 collar. 



Average 

 length 

 of top. 



Average 

 length 

 ofroot. 



Average 

 weight 

 of top. 



Average 

 weight 

 ofroot. 



Ratio of 



weight of 



root to 



weight of 



entire 



plant. 



2-2.. . . 



Inches. 



0.16 



.08 



.14 



.18 



Inches. 

 4.7 

 6.0 

 6.6 

 6.5 



Inches. 

 11.4 

 11.4 

 11.3 

 11.3 



Grams. 

 3.64 

 1.62 

 3.82 

 5.78 



Grams. 



2.12 



.46 



2.54 



1.78 



Per cent. 

 36.8 



3-0 



3-1 



3-2 



22.1 

 39.9 

 23.5 



