FOREST PLANTING IN THE INTERMOUXTAlX REGION. 



13 



this leads to rather crowded spacing on the edges of clumps, but highloss 

 is to be expected in such places and the final result will not indicate 

 too close spacing. 



RESULTS OF FIELD PLANTING. 



Because of its importance and character, western yellow pine 

 has been planted much more commonly than any other species in 

 the treeless brush belt. The successful forestation of this belt, as 

 potential yellow-pine land, would be of great importance in the 

 silvicultural management of the central Utah forests. A large pro- 

 portion of the earlier forestation work has, however, been unsuccessful. 



WESTERN YELLOW PIXE. 



Class of planting stock. — Aside from the factor of suitability of site, 

 which is oi the greatest importance, the age class of stock necessary 

 for success on a given area shoidd receive the most careful considera- 

 tion in the intermoimtain region. In selecting western yellow pine 

 for field planting, the relative size and development of fibrous roots 

 is very essential, and therefore the age class of western yellow pine 

 planting stock has been the subject of careful study in this region. 

 The relative size of the classes studied is shown in Table 7. 



Age class. 



Source of seed (forest). 



Table 7. — Comparison of different age classes of western yellow pine firsts. 



Ratio of 



weight 



of root 



to weight 



of entire. 



plant 



Per cent. 

 28.8 

 23.2 

 27.2 

 22.6 

 32.5 

 27.5 

 25.2 

 21.6 

 33.8 

 33.0 

 34. S 



1-2(1917)1.. 

 2-0(1917)1.. 

 2-1(1917)1.. 

 3-0(1917)1.. 

 3-1(1917)1.. 

 2-1(1919)..- 

 2-0(1920)... 

 2-0(1920)... 

 2-1(1920)-.. 

 2-1 (1920)-. 

 1-1-1 (1920). 



Ashley 



Salmon 



Sevier, Ashley. 



Sevier 



Boise 



Salmon 



do 



Sevier 



Salmon 



Sevier 



do 



Average 











diameter 



Average 



Average 



Average 



Average 



of stem 



length 



length 



weight 



weight 



at root 



of top. 



of root. 



of top. 



of root. 



collar. 











Inches. 



Inches. 



Inches. 



Grams. 



Grams. 



0.17 



3.2 



12.0 



2. B0 



1.13 



.13 



3.3 



11.6 



1.79 



.54 



.16 



3.1 



11.6 



2.89 



1.08 



.17 



5.6 



12.3 



1.00 



1.17 



.18 



5.1 



11.8 



4.66 



2.24 



.18 



6.2 



10.1 



5.10 



2.05 



.1-4 



2.5 



12.0 



3.85 



1.30 



.11 



2.2 



9.1 



1.49 



.41 



.13 



4.0 



11.2 



1.32 



2.21 



.11 



3.2 



11.5 



4.22 



2.C8 



.16 



2.9 



10.5 



3.79 



2.02 



i Vnavoidablv air-dried for 30 days. 



The best general criterion of stock suitable for field planting is 

 the balance between the root and the top, which is most conven- 

 iently expressed by weight. But for the experienced nurseryman the 

 actual appearance of the plant is the most satisfactory guide, for a 

 root system that weighs heavy in proportion to the top may yet be 

 composed mainly of large coarse roots with few lateral, fibrous root- 

 lets. The best class of planting stock is that which has a small top 

 and a large fibrous root system. Such a balance is essential in 

 western yellow pine, which tends toward a less satisfactory develop- 

 ment. A well-balanced transplant is especially necessary io develop 

 for use on severe sites, such as those found in the mtermountain 

 region. A study of Figure 3 shows that, in both the Utah and Idaho 

 forms of western yellow pine, the 2-1 stock is superior as far as re- 

 lative root development is concerned. Two and three year seedling 

 stock has satisfactory tops, but the root development is very poor; 

 1-2 and 2-2 stock is unsatisfactory because there is a tendency for 

 the transplant to develop a decided tap root during the second year 

 in the transplant bed. 



