Populus grandidentata
(Bigtooth Aspen)
Populus tremuloides
(Quaking Aspen)
Aspen (the genus Populus) is composed of 35 species which contain the cottonwoods and poplars. Species in this group are native to Eurasia/north Africa [25], Central America [2] and North America [8]. All species look alike microscopically. The word populus is the classical Latin name for the poplar tree.
Other Common Names
Populus grandidentata American aspen, aspen, bigtooth aspen, Canadian poplar, large poplar, largetooth aspen, large-toothed poplar, poplar, white poplar
Populus tremuloides American aspen, American poplar, aspen, aspen poplar, golden aspen, golden trembling aspen, leaf aspen, mountain aspen, poplar, popple, quaking asp, quaking aspen, quiver-leaf, trembling aspen, trembling poplar, Vancouver aspen, white poplar
Distribution: Quaking aspen ranges from Alaska through Canada and into the northeastern and western United States. In North America, it occurs as far south as central Mexico at elevations where moisture is adequate and summers are sufficiently cool. The more restricted range of bigtooth aspen includes southern Canada and the northern United States, from the Atlantic coast west to the prairie.
The Tree: Aspens can reproduce sexually, yielding seeds, or asexually, producing suckers (clones) from their root system. In some cases, a stand could then be composed of only one individual, genetically, and could be many years old and cover 100 acres (40 hectares) or more. Most aspen stands are a mosaic of several clones.
Aspen can reach heights of 120 ft (48 m), with a diameter of 4 ft (1.6 m). Aspen trunks can be quite cylindrical, with little taper and few limbs for most of their length. They also can be very crooked or contorted, due to genetic variability. The bark of the two species can be quite variable in color and degree of furrowing. The leaves of aspen can vary from nearly round to ovate, with small to large teeth. Aspen trees are dioecious, that is, they occur as either male or female trees.
General Wood Characteristics: The sapwood of aspen is white, blending into the light brown heartwood. The wood of aspen has a uniform texture; is straight grained, light and soft; and has good dimensional stability and low to moderate shrinkage.
Weight |
|
|
|
|
Species |
MC |
SGa |
Weightb |
|
lb/ft3 |
kg/m3 |
|||
Populus |
Green |
0.36 |
43 |
689 |
grandidentata |
12% |
0.39 |
27 |
433 |
(bigtooth aspen) |
Ovendry |
0.41 |
NA |
NA |
Populus tremuloides |
Green |
0.35 |
43 |
689 |
(quaking aspen) |
12% |
0.38 |
26 |
417 |
|
Ovendry |
0.40 |
NA |
NA |
aReferences: specific gravity, green and 12%, (98); specific gravity, ovendry, (59).
bReference (59).
Mechanical propertiesa |
|
|
|
|
Property Green |
|
Dry |
||
Populus grandidentata (bigtooth aspen)b |
|
|
||
MOE |
1.12 x 106 lbf/in2 |
7.722 GPa |
1.43 x 106 lbf/in2 |
9.860 GPa |
MOR |
5.40 x 103 lbf/in2 |
37.233 MPa |
9.10 x 103 lbf/in2 |
62.745 MPa |
C| | |
2.50 x 103 lbf/in2 |
17.238 MPa |
5.30 x 103 lbf/in2 |
36.544 MPa |
Cl |
0.21 x 103 lbf/in2 |
1.448 MPa |
0.45 x 103 lbf/in2 |
3.103 MPa |
WML |
5.70 in-lbf/in3 |
39.302 kJ/m3 |
7.70 in-lbf/in3 |
53.092 kJ/m3 |
Hardness |
370 lbf |
1645.76 N |
420 lbf |
1868.16 N |
Shear| | |
0.73 x 103 lbf/in2 |
5.033 MPa |
1.08 x 103 lbf/in2 |
7.446 MPa |
Populus tremuloides (quaking aspen)c |
|
|
||
MOE |
0.86 x 106 lbf/in2 |
5.929 GPa |
1.18 x 106 lbf/in2 |
8.136 GPa |
MOR |
5.10 x 103 lbf/in2 |
35.165 MPa |
8.40 x 103 lbf/in2 |
57.918 MPa |
C| | |
2.14 x 103 lbf/in2 |
14.755 MPa |
4.25 x 103 lbf/in2 |
29.304 MPa |
Cl |
0.18 x 103 lbf/in2 |
1.241 MPa |
0.37 x 103 lbf/in2 |
2.551 MPa |
WML |
6.40 in-lbf/in3 |
44.128 kJ/m3 |
7.60 in-lbf/in3 |
52.402 kJ/m3 |
Hardness |
300 lbf |
1334.40 N |
350 lbf |
1556.80 N |
Shear| | |
0.66 x 103 lbf/in2 |
4.551 MPa |
0.85 x 103 lbf/in2 |
5.861 MPa |
aRelatively low strength, moderate stiffness and shock resistance. bReference (98) except for hardness (59).
cReference (98).
Drying and shrinkagea,b |
|
|
|
|
Percentage of shrinkage |
||
Type of shrinkage |
0% MC |
6% MC |
20% MC |
Tangential |
|
|
|
Populus grandidentata (bigtooth aspen) |
7.9 |
6.3 |
2.6 |
Populus tremuloides (quaking aspen) |
6.7 |
5.4 |
2.2 |
Radial |
|
|
|
Populus grandidentata (bigtooth aspen) |
3.3 |
2.6 |
1.1 |
Populus tremuloides (quaking aspen) |
3.5 |
2.8 |
1.2 |
Volumetric |
|
|
|
Populus grandidentata (bigtooth aspen) |
11.8 |
9.4 |
3.9 |
Populus tremuloides (quaking aspen) |
11.5 |
9.2 |
3.8 |
aWater soaked material can develop “wetwood” from bacteria, causing a collapse in the zone between sapwood and heartwood during drying.
bReferences: 0% MC, (98); 6% and 20% MC (90).
Kiln drying schedulea
|
4/4, 5/4, 6/4 |
8/4 |
10/4 |
12/4 |
16/4 |
Condition |
stock |
stock |
stock |
stock |
stock |
Normal wood |
T12-E7 |
T10-E6 |
T8-E5 |
T8-E5 |
T7-C4 |
Wet streak or collapse prone |
Table 109 |
Table 110 |
NA |
NA |
NA |
aReferences (6, 86).
Working Properties: Aspen does not split when nailed, machines easily with a slightly fuzzy surface, and turns, bores and sands well. It holds nails poorly to fairly well, but glues, prints, and holds paint well. It is easily pulped by all commercial processes.
Durability: Rated as slightly or nonresistant to heartwood decay. Preservation: Extremely resistant.
Uses: Pulp for books, newsprint and fine printing papers. Fiberboard, wafer board, sheathing, decking, decorative applications, boxes, crates, pallets, furniture parts, lumber core, veneer, match sticks, tongue depressors, paneling, excelsior.
Toxicity: Sawdust may cause dermatitis (40, 64, 105). Additional Reading: 29, 55, 68, 70, 74.
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