scholarly journals Genetic control of stiffness of standing Douglas fir; from the standing stem to the standardised wood sample, relationships between modulus of elasticity and wood density parameters. Part I

1999 ◽  
Vol 56 (2) ◽  
pp. 133-143 ◽  
Author(s):  
Cécile Mamdy ◽  
Philippe Rozenberg ◽  
Alain Franc ◽  
Jean Launay ◽  
Nicolas Schermann ◽  
...  
Keyword(s):  
Genetic Control ◽  
Wood Density ◽  
Modulus Of Elasticity ◽  
Wood Sample ◽  
Douglas Fir

Genetic relationships between wood density components and cambial growth rhythm in young coastal Douglas-fir

1994 ◽  
Vol 24 (9) ◽  
pp. 1871-1876 ◽  
Author(s):  
Jesus Vargas-Hernandez ◽  
W.T. Adams
Keyword(s):  
Genetic Control ◽  
Wood Density ◽  
Genetic Relationships ◽  
Growth Period ◽  
Wood Formation ◽  
Douglas Fir ◽  
Increment Core ◽  
Growth Rhythm ◽  
Cambial Growth ◽  
Growth Initiation

To better understand the genetic control of wood formation in coastal Douglas-fir (Pseudotsugamenziesii var. menziesii (Mirb.) Franco), and to assess the potential impact of selecting for increased wood density on adaptation of trees, genetic relationships of wood density, and its components, with cambial growth rhythm traits were examined in a 15-year-old progeny test. Timing of diameter growth during the 1987 growing season was available from an earlier study, and wood formation traits were estimated by X-ray densitometry of increment core samples. Wood formation traits were under weak genetic control [Formula: see text]. Lengths of earlywood and latewood formation were mostly determined by the timing of latewood transition. Overall core density was negatively correlated with the dates of cambial growth initiation (rA = −0.41) and latewood transition (rA = −0.62), and positively correlated with the date of cambial growth cessation (rA = 0.40). As a result of these relationships, higher wood density was associated with a longer duration of cambial growth (rA = 0.67) and a slower rate of wood formation (rA = −0.37). All density components showed similar relationships with cambial phenology and wood formation traits. Selection for increased wood density is expected to cause only a slight extension of the cambial growth period, but it would also cause an earlier transition to latewood formation, negatively affecting growth rate.

Genetic variation of wood density components in young coastal Douglas-fir: implications for tree breeding

1991 ◽  
Vol 21 (12) ◽  
pp. 1801-1807 ◽  
Author(s):  
Jesus Vargas-Hernandez ◽  
W. T. Adams
Keyword(s):  
Genetic Control ◽  
Wood Density ◽  
Genetic Relationships ◽  
Genetic Correlations ◽  
Density Variation ◽  
Douglas Fir ◽  
Control Individual ◽  
Individual Tree ◽  
Breast Height ◽  
Efficiency Of Selection

The genetic control of wood density components (earlywood density, latewood density, and latewood proportion) and their relationships with overall density in coastal Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) were examined to assess the usefulness of this information in breeding for wood density. The genetic relationships of wood density with intraring density variation and bole volume growth were also investigated. Increment cores were taken at breast height from 15-year-old trees of 60 open-pollinated families. Averages across each core for overall wood density, its components, and intraring density variation were determined by using X-ray densitometry. Bole volume at age 15 for the same trees was derived from tree height and diameter at breast height measurements. Although wood density components varied significantly among families and were under moderate genetic control (individual-tree heritability (hi2) > 0.24), none had a higher heritability than overall density (hi2 = 0.59). Density components had strong genetic correlations with overall density (r ≥ 0.74) but were also strongly related among themselves (0.57 ≤ r ≤ 0.92). Thus, density components have limited value in improving the efficiency of selection for overall density. Overall density was positively correlated with intraring density variation (r = 0.72) and negatively correlated with bole volume (r = −0.52). Comparison of several selection indices incorporating wood density and one or more growth traits, however, showed that it is possible to obtain substantial gains in bole volume without loss in (or even with a modest increase in) wood density. By restricting the response in wood density, the change in intraring density variation can also be limited.

scholarly journals An examination of the genetic control of Douglas-fir vascular tissue phytochemicals: Implications for black bear foraging

1999 ◽  
Vol 123 (2-3) ◽  
pp. 245-251 ◽  
Author(s):  
Bruce A. Kimball ◽  
G.R. Johnson ◽  
Dale L. Nolte ◽  
Doreen L. Griffin
Keyword(s):  
Genetic Control ◽  
Vascular Tissue ◽  
Black Bear ◽  
Douglas Fir

Heritability and phenotypic and genetic correlations of coastal Douglas-fir (Pseudotsuga menziesii) wood quality traits

2008 ◽  
Vol 38 (6) ◽  
pp. 1536-1546 ◽  
Author(s):  
Nicholas K. Ukrainetz ◽  
Kyu-Young Kang ◽  
Sally N. Aitken ◽  
Michael Stoehr ◽  
Shawn D. Mansfield
Keyword(s):  
Cell Wall ◽  
Genetic Control ◽  
Pseudotsuga Menziesii ◽  
Wood Quality ◽  
Genetic Correlations ◽  
Douglas Fir ◽  
Correlated Response ◽  
Sample Population ◽  
Quality Traits ◽  
Glucose Content

Genetic control and relationships among coastal Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii) growth and wood quality traits were assessed by estimating heritability and phenotypic and genetic correlations using 600 trees representing 15 full-sib families sampled from four progeny test sites. Heritability estimates ranged from 0.23 to 0.30 for growth traits, 0.19 for fibre coarseness, from 0.21 to 0.54 for wood density, from 0.16 to 0.97 for cell wall carbohydrates, and 0.79 and 0.91 for lignin content at two sites, Squamish River and Gold River, respectively. Glucose content, indicative of cell wall cellulose composition, and lignin were shown to be under strong genetic control, whereas fibre coarseness was shown to be under weak genetic control. Phenotypic correlations revealed that larger trees generally have longer fibres with higher fibre coarseness, lower density, lower carbohydrate content, a greater proportion of cell wall lignin, and higher microfibril angle. Genetic correlations and correlated response to selection suggest that breeding for height growth would result in a reduction in wood quality, whereas breeding for improved earlywood density in Douglas-fir would result in negligible reductions in volume and appears to be an ideal target for selecting for improved wood quality (density) while maintaining growth in the sample population.

Comparison of decomposition models using wood density of Douglas-fir logs

1985 ◽  
Vol 15 (6) ◽  
pp. 1092-1098 ◽  
Author(s):  
Joseph E. Means ◽  
Kermit Cromack Jr ◽  
Paul C. MacMillan
Keyword(s):  
Wood Density ◽  
Residence Time ◽  
Forest Floor ◽  
Exponential Model ◽  
Douglas Fir ◽  
Decay Class ◽  
Decomposition Models ◽  
Independent Variable ◽  
The Mean ◽  
Single Exponential

Logs of Pseudotsugamenziesii (Mirb.) Franco that had been on the ground for up to 313 years were grouped into five decay classes that ranged from 1, essentially undecayed, to 5, soft and incorporated into the forest floor but still identifiable. The mean residence times on the forest floor were 7, 17, 33, 82, and 219 years for decay classes 1 through 5, respectively. The single-exponential model of litter decomposition was fitted to the density of these logs. The summation-exponential model was constructed by summing single-exponential models fitted to lignin, cellulose, and the acid detergent soluble fraction. Both models gave virtually identical, statistically significant fits to the data. Wood density of these Douglas-fir logs decreased more slowly than that of most species other researchers have studied. The single-exponential model gave mineralization rates (k) of 0.0063 and 0.0070 year−1 when residence time and decay class age (mean residence time of the decay class), respectively, were used as the independent variable. Lignin decayed more slowly than cellulose or the fraction soluble in hot acid detergent, both of which decayed at rates that were not significantly different; thus, the summation-exponential model is recommended when these constituents are of interest.

Effects of Density Control and Fertilization on Log Wood Quality from a Douglas-fir Stand in Western Oregon, USA

2019 ◽  
Vol 66 (2) ◽  
pp. 191-201
Author(s):  
Rapeepan Kantavichai ◽  
Eric C Turnblom ◽  
Eini C Lowell
Keyword(s):  
Specific Gravity ◽  
Modulus Of Elasticity ◽  
Juvenile Wood ◽  
Wood Quality ◽  
Stand Density ◽  
Quality Attributes ◽  
Douglas Fir ◽  
Stem Wood ◽  
Density Control ◽  
Heartwood Percentage

Abstract This study aimed to investigate the effects of juvenile spacing (precommercial thinning), thinning, and fertilization on Douglas-fir butt log (first 4.9 m) and second log (4.9–10 m) quality attributes: juvenile wood percentage, heartwood percentage, rings per inch, specific gravity, and modulus of elasticity. A 41-year-old, 36.6 m site index Douglas-fir stand in western Oregon, USA was selected as the first stand to explore. Nine common silviculture pathway treatments of juvenile spacing, thinning, and fertilization were applied to independent 0.404-hectare plots. Ninety-nine trees were felled and disks cut at five heights along the stem. Wood properties were measured and calculated from the disks for log quality attributes. There was no effect of silvicultural treatments on log heartwood percentage, but significant effects on other log quality attributes were observed. Juvenile wood percentage and rings per inch declined with stand density control and fertilization treatment. Responses to thinning and fertilization in log specific gravity depend on juvenile spacing. Also, thinning and juvenile spacing were shown to have impacts on log modulus of elasticity.

scholarly journals Effects of live crown on vertical patterns of wood density and growth in Douglas-fir

2002 ◽  
Vol 32 (3) ◽  
pp. 439-447 ◽  
Author(s):  
Barbara L Gartner ◽  
Eric M North ◽  
G R Johnson ◽  
Ryan Singleton
Keyword(s):  
Wood Density ◽  
Juvenile Wood ◽  
Growth Ring ◽  
Ring Width ◽  
Douglas Fir ◽  
Mature Wood ◽  
Node Number ◽  
Growth Ring Width ◽  
Residual Variation ◽  
Wide Range

It would be valuable economically to know what are the biological triggers for formation of mature wood (currently of high value) and (or) what maintains production of juvenile wood (currently of low value), to develop silvicultural regimes that control the relative production of the two types of wood. Foresters commonly assume the bole of softwoods produces juvenile wood within the crown and mature wood below. We tested that assumption by comparing growth ring areas and widths and wood density components of the outer three growth rings in disks sampled from different vertical positions of 34-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. The 18 trees were sampled from one site and had a wide range of heights to live crown. Most of the variance (63–93%) in wood characteristics (growth ring area: total, earlywood, latewood; growth ring width: total, earlywood, latewood; latewood proportion: by area, width; and ring density: total, earlywood, latewood) was due to within-tree differences (related to age of the disk). Stepwise regression analysis gave us equations to estimate wood characteristics, after which we analyzed the residuals with a linear model that included whether a disk was within or below the crown (defined as the lowest node on the stem with less than three live branches). After adjusting for tree and disk position, only 2–10% of the residual variation was associated with whether the disk was in or out of the live crown. There were no statistically significant differences at p = 0.05 between a given disk (by node number) in versus out of the crown for any of the factors studied. Moreover, the wood density characteristics were not statistically significant at p = 0.30. This research suggests that there was no effect of the crown position on the transition from juvenile to mature wood as judged by wood density. Therefore, we found no evidence to support the concept that tree spacing and live-branch pruning have a significant effect on the cambial age of transition from juvenile to mature wood in Douglas-fir trees of this age.

Mechanical Characteristics of Historical Beams of Picea Abies Wood: Assessment by Ultrasound

2014 ◽  
Vol 1618 ◽  
pp. 257-262
Author(s):  
Javier Ramón Sotomayor-Castellanos ◽  
José María Villaseñor-Aguilar
Keyword(s):  
Picea Abies ◽  
Moisture Content ◽  
Wood Density ◽  
Modulus Of Elasticity ◽  
Mechanical Characteristics ◽  
Structural Members ◽  
Full Size ◽  
Ultrasound Waves ◽  
Ultrasound Measurements ◽  
Speed Of Ultrasound

ABSTRACTFive historical full-size wood structural beams of Picea abies were tested with ultrasound. The speed of ultrasound, the modulus of elasticity, the moisture content and the wood density were measured for each specimen. The speed of the ultrasound waves in the radial, tangential and longitudinal directions was 1,769 m/s, 1,599 and 5,713 m/s respectively. The modulus of elasticity in the radial, tangential and longitudinal directions was 1,353 MPa, 1,069 MPa and 13,863 MPa respectively. The moisture content was on average 11.92% and the density was on average 422 kg/m3. Wood parameters such as density and orthotropic directions had influence in ultrasound measurements. In spite of local weakness in the beams, they had enough strength to be considered full structural members.

Genetic variation in direct and indirect measures of wood stiffness in coastal Douglas-fir

2008 ◽  
Vol 38 (9) ◽  
pp. 2476-2486 ◽  
Author(s):  
Marilyn L. Cherry ◽  
Vikas Vikram ◽  
David Briggs ◽  
Daniel W. Cress ◽  
Glenn T. Howe
Keyword(s):  
Wood Density ◽  
Indirect Selection ◽  
Douglas Fir ◽  
Dry Density ◽  
Green Wood ◽  
Bending Tests ◽  
Wood Stiffness ◽  
Indirect Measures ◽  
Standing Trees ◽  
Relative Gains

We studied wood stiffness (estimated by modulus of elasticity, MOE), wood density, wood moisture content, and growth in a progeny test (50–130 families per trait; 1–3 sites) of coastal Douglas-fir ( Pseudotsuga menziesii var. menziesii (Mirb.) Franco). We measured MOE directly using lumber bending tests (MOEbl) and indirectly using tools (HM200 and ST300) that can be used to measure acoustic velocity in logs (VelHM) or standing trees (VelST). Acoustic MOEs in logs and standing trees (MOEHM and MOEST) were obtained from the velocities and green wood density. For backward selection, we estimated genetic gains in MOEbl of 8.6%–12.3%. Relative efficiencies (REs), the relative gains in MOEbl expected from indirect selection for correlated traits, were 78%–93% for the HM200 traits, 57%–58% for the ST300 traits, 38% for the basic wood density of basal discs (Denbd), and 98% for the oven-dry density of logs estimated from the lumber (Denol). The HM200 is an efficient tool for improving MOEbl, but gains will be lower using the ST300 on standing trees. Indirect selection on Denbd should be used with caution because the RE was low and Denbd was negatively correlated with growth (–0.49 to –0.73).

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