Modulus of elasticity and tensile strength of Douglas-fir roots

1991 ◽  
Vol 21 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Paul R. Commandeur ◽  
Marvin R. Pyles
Keyword(s):  
Tensile Strength ◽  
Modulus Of Elasticity ◽  
Douglas Fir ◽  
Coast Range ◽  
Wood Fibers ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Average Tensile Strength ◽  
Average Form ◽  
Moduli Of Elasticity

The modulus of elasticity and the tensile strength were determined for a sample of live Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) roots collected in the Oregon Coast Range. Most of the roots displayed both a "form" modulus of elasticity and a "material" modulus of elasticity. The form modulus occurred as a tortuous root straightened out, whereas the material modulus developed following this initial straightening as the wood fibers within the root directly resisted elongation. The average form and material moduli of elasticity were, respectively, 185 and 503 MPa, whereas the average tensile strength was 17 MPa.

Correlations Between Overtopping Vegetation and Development of Douglas-Fir Saplings in the Oregon Coast Range

1987 ◽  
Vol 2 (4) ◽  
pp. 117-119 ◽  
Author(s):  
Samuel S. Chan ◽  
John D. Walstad
Keyword(s):  
Pseudotsuga Menziesii ◽  
Tree Height ◽  
Douglas Fir ◽  
Morphological Features ◽  
Diameter Growth ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Sapling Growth ◽  
Stem Diameter Growth

Abstract The response of Douglas-fir (Pseudotsuga menziesii) saplings to overtopping vegetation on three northeast-facing sites in the Oregon Coast Range was studied for two years. As amount of overtopping brush increased, sapling growth (as indicated by size) generally decreased. Basal stem diameter growth was most reduced, but similar reductions in growth occurred for tree height and other morphological features. West. J. Appl. For. 2(4):117-119, October 1987.

scholarly journals Douglas-Fir Beetle Response to Artificial Creation of Down Wood in the Oregon Coast Range

2006 ◽  
Vol 21 (3) ◽  
pp. 117-122 ◽  
Author(s):  
Darrell W. Ross ◽  
Bruce B. Hostetler ◽  
John Johansen
Keyword(s):  
Tree Mortality ◽  
Large Diameter ◽  
Douglas Fir ◽  
Coast Range ◽  
Managed Forests ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Management Objectives ◽  
Baited Traps ◽  
Before And After

Abstract Douglas-fir beetle populations were monitored before and after thinning and felling of trees to create down wood in an 88-year-old Douglas-fir plantation in the Oregon Coast Range. Treatments included an unthinned control, thinning to a target of 75 trees/ha, and thinning to a target of 150 trees/ha. Actual mean tree densities on the plots after thinning were 406, 102, and 154, for the control, 75 trees/ha, and 150 trees/ha treatments, respectively. Fifty trees/ha were felled and left on all thinned plots to create down wood for ecological values. Catches in pheromone-baited traps indicated that the local beetle population increased for 1 year in response to felling and leaving large diameter trees in partial shade. Douglas-fir beetle entrance holes and brood were significantly more abundant on the sides of felled trees and wood borers were significantly more abundant on the upper surface suggesting that treatments that provide maximum exposure of felled trees will create the least favorable habitat for Douglas-fir beetles. However, there were no differences in Douglas-fir beetle entrance holes or brood densities in felled trees between the two thinning intensities. Douglas-fir beetle-caused tree mortality was significantly higher on thinned plots with residual felled trees compared with unthinned controls, although infestation levels were low on all plots (<2 trees/ha). The small increase in beetle-caused tree mortality associated with leaving felled trees would be unlikely to interfere with resource management objectives. These results are applicable to mature, managed forests west of the Cascades with relatively low Douglas-fir beetle populations. In different regions and stand types, or under different environmental conditions, beetle populations could increase to higher densities, remain at high densities longer, and cause higher levels of tree mortality. West. J. Appl. For. 21(3):117–122.

scholarly journals Effects of Swiss Needle Cast on Three Douglas-Fir Seed Sources on a Low-Elevation Site in the Northern Oregon Coast Range: Results after Five Growing Seasons

2001 ◽  
Vol 16 (1) ◽  
pp. 31-34 ◽  
Author(s):  
Walter W. Kastner ◽  
Steve M. Dutton ◽  
David M. Roché
Keyword(s):  
Douglas Fir ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Needle Cast ◽  
Growing Seasons ◽  
Seed Sources ◽  
Coastal Fog ◽  
Swiss Needle Cast ◽  
Natural Stands

Abstract Douglas-fir (Pseudotsuga menziesii var. menziesii) seedlings grown from three seed sources were evaluated for 5 yr on a high-disease-hazard site for their relative tolerance to Swiss needle cast. The seed sources were: (1) seed collected from trees showing an apparent degree of tolerance to Swiss needle cast in natural stands in the coastal fog belt, (2) open-pollinated seed orchard seed collected from random single-pair crosses of parent trees in natural stands outside of the coastal fog belt, but west of the Oregon Coast Range summit, whose progeny demonstrated an apparent degree of disease tolerance in coastal Douglas-fir progeny test sites, and (3) standard reforestation seed purchased from a commercial vendor. There were no significant differences among seed sources in basal diameter and total height for all five growing seasons. Needle retention varied among seed sources over the 5 yr period, but current-year needle retention did not vary significantly after the fifth growing season, and retention of 1- and 2-yr-old needles was relatively low for all seed sources. The intense disease pressure on this site may have overwhelmed expression of disease tolerance among seed sources. We do not recommend planting Douglas-fir on such high-hazard sites. West J. Appl. For. 16(1):31–34.

Ethanol in Douglas-fir with black-stain root disease (Leptographium wageneri)

1998 ◽  
Vol 28 (8) ◽  
pp. 1207-1212 ◽  
Author(s):  
Rick G Kelsey ◽  
Gladwin Joseph
Keyword(s):  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Root Disease ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Coos Bay ◽  
Root Collar

Diseased and healthy Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) were identified at two black-stain root disease centers, caused by Leptographium wageneri var. pseudotsugae Harrington & Cobb, in the Oregon Coast Range near Coos Bay. Phloem and sapwood near the root collar were sampled monthly for 1 year, whereas roots were sampled in October and November. Ethanol concentrations in sapwood of diseased trees near the root collar were 4-24 times higher than in healthy trees for all months of a year, except January and June. Roots from diseased trees in October had 5 times more ethanol in the phloem and 19 times more ethanol in the sapwood than corresponding tissue from healthy trees. Ethanol concentrations in roots from diseased trees in November were no different from October. Within trees, ethanol concentrations varied substantially among positions around the root collar and among different roots. Ethanol may play an important role in the biology of L.wageneri and beetle-pathogen interactions in Douglas-fir. Ethanol also may be useful in detecting stressed or diseased trees.

Relationship Between Occurrence of Laminated Root Rot and Site Characteristics in Douglas-Fir Forests of the Northern Oregon Coast Range

1994 ◽  
Vol 9 (1) ◽  
pp. 14-17 ◽  
Author(s):  
Walter W. Kastner ◽  
Donald J. Goheen ◽  
Robert L. Edmonds
Keyword(s):  
Root Rot ◽  
Basal Area ◽  
Douglas Fir ◽  
Slope Position ◽  
Coast Range ◽  
Plant Association ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Disease Occurrence ◽  
Site Characteristics

Abstract In the northern Oregon Coast Range 70- to 100-yr old Douglas-fir (Pseudotsuga menziesii) stands were evaluated to determine rate of infection by laminated root rot, caused by (Phellinus weirii), whether local disease occurrence was associated with site characteristics, and impacts of P. weirii on the number of trees and basal area. Overall infection rate was 5.6%, but varied from 0.0 to 14.7% among stands. There was a significant association between occurrence of P. weirii and slope position. The rate of infection on ridges, upper slopes, middle slopes, and lower slopes was 13.0, 7.3, 4.1, and 0.0%, respectively. Occurrence of P. weirii was independent of plant association and aspect. Infected plots contained 25% less live Douglas-fir basal area and 35% fewer live Douglas-fir trees per ac than uninfected plots. West. J. Appl. For. 9(1):14-17.

Senecio Sylvaticus in Relation to Douglas-Fir Clear-Cut Succession in the Oregon Coast Range

Ecology ◽  
1968 ◽  
Vol 49 (6) ◽  
pp. 1101-1107 ◽  
Author(s):  
Neil E. West ◽  
William W. Chilcote
Keyword(s):  
Douglas Fir ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Clear Cut ◽  
Senecio Sylvaticus

Management, Morphological, and Environmental Factors Influencing Douglas-Fir Bark Furrows in the Oregon Coast Range

2013 ◽  
Vol 28 (3) ◽  
pp. 97-106 ◽  
Author(s):  
Christopher D. Sheridan ◽  
Klaus J. Puettmann ◽  
Manuela M.P. Huso ◽  
Joan C. Hagar ◽  
Kristen R. Falk
Keyword(s):  
Environmental Factors ◽  
Douglas Fir ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Factors Influencing
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