Table 1 . -- Location, elevation, and age class of stands sampled 



Area 



National Forest 

 and State 



Elevation 



Stand 

 age class 







Feet 



Years 



Bishop Burn 



Targhee (Idaho) 



6,500 



41-50 



Moose Creek Plateau 



Targhee (Idaho) 



£ nnn 

 o 3 uuu 



Q 1 _ Qf) 



o 1 - y\J 



Bostetter Station 



Sawtooth (Idaho) 



7,500 



51-60 



Sheep Creek Park 



Ashley (Utah) 



8,400 



71-80 



Horse Creek 



Bridger (Wyoming) 



7,900 



21-30 



Table 2. -- Specific gravity of lodgepole pine at breast height calculated by the increment core and stem 

 section methods, and average tree specific gravity by the stem section method 









Core b.h. 



Section 



b.h. 





Tree 







Density 







Diameter 



specific gravity 



specific gravity 



specific gravity 







Area 



Trees 



range 





95-percent 





95-percent 





95-percent 







95-percent 







(d.b.h.) 



Mean : 



confidence 



Mean : 



confidence 



Mean 



confidence 



Mean : 



confidence 











limits 





limits 





limits 







limits 





Number 



Inches 



















Pounds 



per cu. ft. 



Bishop Burn 



10 



3.5- 6.3 



0.394 



+0.029 



0.406 



+0 



.078 



0.388 



±0 



049 



24 



2 



+2.7 



Moose Creek 



9 



5.2-11.8 



.416 



+ .072 



.428 



+ 



.068 



.414 



+ 



079 



25 



8 



+4.9 



Plateau 





























Bostetter 



5 



5.3- 8.1 



.356 



+ .030 



.367 



+ 



.048 



.375 



+ 



.042 



23 



4 



+2.6 



Station 





























Sheep Creek 



10 



4.1- 8.5 



.399 



+ .055 



.402 



+ 



.140 



.415 



+ 



044 



25 



9 



+2.8 



Park 





























Horse Creek 



10 



2.2- 5.1 



.352 



+ .035 



.365 



+ 



.068 



.352 



+ 



062 



22 



7 



+3.8 



All 



44 



2.2-11.8 



.386 



+ .067 



.396 



+ 



.078 



.392 



+ 



.068 



24 



5 



+4.2 































The average specific gravity for lodgepole pines at breast height estimated by the 

 increment core method in this study (0.386), agrees closely with that given for the 

 species (0.38) in the Wood Handbook.—/ According to this handbook, lodgepole and ponder- 

 osa pine have approximately the same specific gravity. However, the value for trees in 

 this study is slightly less than that found by Conway and Minor— 'for ponderosa pine in 

 Arizona by the same method (0.404). 



Variations in specific gravity within the sample trees were also studied. Speci- 

 fic gravities of the disk cross sections taken at successive heights were plotted for 

 the 44 trees. Figure 1 shows the usual exponential curve for this relationship. Al- 

 though specific gravity decreases from stump height up to 20 feet, little change occurs 

 above that; the same relation was found for ponderosa pine in Arizona.^/ 



4/ U.S. Forest Service. Wood handbook. U.S. Dept. Agriculture, Agr. Handb. 72, 

 528 pp. , illus. 1955. P. 76. 



5/ Conway, Errett M. , and Charles 0. Minor. Specifc gravity of Arizona ponderosa 

 pine pulpwood. U.S. Forest Serv. Rocky Mountain Forest and Range Expt. Sta. Res. Note 

 54, 3 pp. , illus. 1961. 



6/ Ibid. 



2 



