UTILIZATION AND MANAGEMENT OP LODGEPOLE PINE. 



CHARACTERISTICS OF THE WOOD. 



The wood of lodgepole pine is straight grained, with narrow rings 

 in which the resinous bands of summerwood are conspicuous, though 

 relatively small when compared with the springwood. It is more 

 resinous than eastern white pine (Pinus strobus), but less so than the 

 yellow pines of the South and West. In color it varies from almost 

 white to a light yellow or yellow-brown, with a tinge of red in the 

 heartwood. Its specific gravity (oven dry) is about 0.38, and its 

 weight varies from 25 to 30 pounds per cubic foot. The wood is fairly 

 soft — about the same as eastern white spruce (Picea canadensis) — 

 and is easily worked. Though not so strong as Douglas fir of the 

 Pacific coast (Pseudotsuga taxifolia), a heavier wood, tests made by the 

 Forest Service show it to be practically as strong as western yellow pine 

 (Pinus ponderosa), and stronger than Engelmann spruce {Picea engel- 

 manni) and Alpine fir (Abies lasiocarpa), three woods of more nearly 

 its weight. Tests made on lodgepole pine and western red cedar 

 ( Thuja plicata) telephone poles cut green and seasoned showed lodge- 

 pole pine to be the stronger, both in crossbending and in compression 

 parallel and perpendicular to the grain. The strength of fire-killed 

 lodgepole-pine poles was found to be approximately the same as that 

 of red cedar poles cut green and seasoned. Lodgepole pine is not 

 durable in contact with the soil, but is easy to treat with preserva- 

 tives. Plate I shows magnified sections of the wood. Table 2 gives 

 figures of strength for green and air-seasoned lodgepole pine com- 

 pared with figures for other Rocky Mountain woods. 



Table 2. — Strength of green 1 and air-seasoned 1 lodgepole-pine timber, compared with 

 other Rocky Mountain species. 



[Based on tests of small, clear specimens, 2 by 2 inches in cross section, with a 28-inch span in the bending test.] 



Species and locality. 



Rings 

 per 

 inch. 



Spe- 

 cific 

 grav- 

 ity.! 



Mois- 

 ture 

 con- 

 tent. 



Static bending. 



Modu- 

 lus of 

 rup- 

 ture. 



Modu- 

 lus of 

 elas- 

 ticity. 



Work 



to 

 maxi- 

 mum 

 load. 



Com- 

 pression 

 parallel 

 to grain 

 (crushing 

 strength). 



Com- 

 pres- 

 sion 

 perpen- 

 dicular 

 to grain 



(fiber 

 stress at 

 elastic 

 limit). 



Lodgepole pine, Grand County, 

 Colo 



Lodgepole pine, Johnson County, 

 Wyo 



Douglas fir, Johnson County, Wyo. 



Western yellow pine, Coconino 



County, Ariz 



Western yellow pine, Douglas 



County, Colo 



Western yellow pine, Missoula 



County, Mont 



Engelmann spruce, Grand County, 



Colo 



Engelmann spruce, San Miguel 



County, Colo 



Alpine fir, Grand County, Colo 



21 



0.370 

 .392 

 .371 

 .390 

 .418 

 .435 

 .353 

 .384 

 .391 

 .411 

 .371 



Per 

 cent. 



44 



11.0 



58 



12.0 



32 



12.0 



98 



11.6 



93 



13.8 

 119 



Lbs. per 

 sq. in. 

 5,130 

 8,740 

 5,170 

 8,750 

 6,340 

 9,320 

 4,760 

 8,150 

 5,460 

 9,400 

 4,950 



1,000 



lbs. per 



sq. in. 



1,015 



1,270 



972 

 1,176 

 1,242 

 1,392 



879 

 1,103 

 1,053 

 1,263 



865 



Inch-lbs. 

 per 



cu. in. 

 5.1 

 6.7 

 5.3 

 5.2 

 7.0 

 6.3 

 4.9 

 4.6 

 6.0 

 7.0 

 5.2 



Lbs. per 

 sq. in. 

 2,530 

 5,520 

 2,400 

 5,330 

 2,920 

 6,050 

 2,220 

 5,220 

 2,600 

 4,920 

 2,370 



Lbs. per 

 sq. in. 

 364 

 779 

 332 

 824 

 427 

 744 

 342 

 790 

 410 

 714 

 313 



17 



{....;: 



.325 

 .342 

 .299 

 .314 

 .306 

 .321 



45 

 12.8 

 156 

 16.8 

 47 

 15.9 



4,550 

 7,740 

 3,850 

 5,860 

 4,450 

 5,960 



1,074 

 798 

 990 

 861 



887 



4.8 

 5.4 

 5.0 

 5.4 

 4.4 

 3.4 



2,170 

 4,560 

 1,800 

 "3,060 

 2,060 

 3,400 



302 

 589 

 279 

 447 

 307 

 504 



1 Based on oven-dry weight and volume when tested for strength. 

 Note. — Values for green timber on first line, for air-dry on second line, opposite species and locality. 



