The potential of improving western hemlock pulp and paper quality. I. Genetic control and interrelationships of wood and fibre traits

1998 ◽  
Vol 28 (6) ◽  
pp. 863-870 ◽  
Author(s):  
John N King ◽  
C Cartwright ◽  
J Hatton ◽  
A D Yanchuk
Keyword(s):  
Growth Rate ◽  
Wood Density ◽  
Genetic Selection ◽  
Fibre Length ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Phenotypic Correlation ◽  
Family Effects ◽  
Heritability Estimates ◽  
Fibre Traits

This paper reports relationships between wood and fibre traits and investigates the potential for using genetic selection to improve traits that will increase both the yield and the value of the western hemlock (Tsuga heterophylla (Raf.) Sarg.) pulp wood resource. Strong family effects were present in the internal wood and fibre properties of relative wood density, average fibre length, and fibre coarseness. Heritability estimates for these traits ranged from 0.5 to 0.9. Heritability estimates for growth variables of height and diameter ranged from 0.15 to 0.2. Beside the moderate to high heritabilities for internal wood variables, coefficients of variation at the individual and family mean level ranged from 7.5to 13% and from 4 to 6.5%, respectively. Correlations at an individual phenotypic and genetic level showed adverse correlations between growth rate and both relative wood density (negative correlation) and fibre coarseness (positive correlation). A significant negative phenotypic correlation between relative wood density and coarseness would appear to be due to the fact that both traits were strongly correlated to growth rate. The partial correlation controlling for diameter between coarseness and diameter was nonsignificant. Power analysis demonstrated that pulp and fibre traits could beassessed effectively using as few as six individuals per family.

The effects of initial tree spacing on the fibre properties of plantation-grown coastal western hemlock

2003 ◽  
Vol 33 (12) ◽  
pp. 2460-2468 ◽  
Author(s):  
Paul Watson ◽  
Cameron Garner ◽  
Robin Robertson ◽  
Sandy Reath ◽  
Wai Gee ◽  
...  
Keyword(s):  
Wood Density ◽  
Kraft Pulp ◽  
Fibre Length ◽  
Small Diameter ◽  
Stocking Density ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Economic Implications ◽  
Fibre Properties ◽  
Cell Wall Properties

Fundamental wood and fibre properties determine end product quality potential. They are affected by silvicultural practices. Initial stand stocking density has significant economic implications for both forest managers and industrial end users. An evaluation of the wood density and fibre properties of 38-year-old coastal western hemlock (Tsuga heterophylla (Raf.) Sarg.) planted at five different spacings was completed. We determined that the wood density was not affected by spacing. At the widest spacing, the outer wood fibre length was significantly shorter than at the four tighter spacings. Fibre coarseness and cell wall properties were similar at all spacings. This implies that wood chips prepared from a range of small-diameter thinnings material will not adversely affect kraft pulp fibre properties.

Wood density of western hemlock: effect of ring width

1994 ◽  
Vol 24 (3) ◽  
pp. 638-641 ◽  
Author(s):  
Jeffrey D. DeBell ◽  
John C. Tappeiner II ◽  
Robert L. Krahmer
Keyword(s):  
Growth Rate ◽  
Wood Density ◽  
Growth Rates ◽  
Ring Width ◽  
Western Hemlock ◽  
X Ray ◽  
Breast Height ◽  
Latewood Density ◽  
Earlywood Width ◽  
Average Wood

Wood density of western hemlock (Tsugaheterophylla (Raf.) Sarg.) was determined by X-ray densitometry of strips from breast-height samples consisting of rings 20–24 from the pith. Ring parameters were averaged over the 5 years for each strip. Wood density was negatively correlated with radial growth rate. Average wood density dropped from 0.47 to 0.37 g/cm3 as average ring width increased from 2 to 8 mm. Wood density decreased at higher growth rates primarily because earlywood width increased while latewood width remained the same; as a result, percentage of latewood decreased. Earlywood density decreased slightly at higher growth rates, but latewood density was not significantly related to growth rate.

Effects of genetic selection for growth on frost hardiness in western hemlock

1999 ◽  
Vol 29 (4) ◽  
pp. 509-516 ◽  
Author(s):  
Mats Hannerz ◽  
Sally N Aitken ◽  
John N King ◽  
Sonya Budge
Keyword(s):  
Genetic Gain ◽  
Genetic Selection ◽  
Seed Orchard ◽  
Vancouver Island ◽  
Tsuga Heterophylla ◽  
Frost Hardiness ◽  
Western Hemlock ◽  
Spring Frost ◽  
Queen Charlotte Islands ◽  
Sib Families

Fall and spring frost hardiness was determined from electrolytic leakage of artificially frozen needle segments in 22 full-sib families of western hemlock (Tsuga heterophylla (Raf.) Sarg.) from British Columbia and Washington State representing different levels of genetic gain, and of four provenance materials (stand progenies from the Queen Charlotte Islands, Vancouver Island, and Oregon Cascades, and seed-orchard progenies from the northern Oregon Coast Range). Samples for freeze testing were collected in a 5-year-old trial at Jordan River on southwestern Vancouver Island. Height and date of bud flush were recorded in the field. Genetic gain among the full-sib families was not correlated with fall frost hardiness, but high-yielding families displayed a lower spring frost hardiness and an earlier bud flush than low-yielding families. Both fall and spring frost hardiness increased and height growth decreased with the latitude of provenances. The highest growth, earliest bud flush and lowest fall and spring frost hardiness was demonstrated by the Oregon provenances, while the lowest growth, latest bud flush and highest hardiness was found for the Queen Charlotte Islands provenance.

Effects of release from suppression on wood functional characteristics in young Douglas-fir and western hemlock

2006 ◽  
Vol 36 (8) ◽  
pp. 2038-2046 ◽  
Author(s):  
Heidi J Renninger ◽  
Barbara L Gartner ◽  
Frederick C Meinzer
Keyword(s):  
Moisture Content ◽  
Wood Density ◽  
Growth Ring ◽  
Specific Conductivity ◽  
Ring Width ◽  
Wood Properties ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Growth Ring Width

Little is known of wood properties in trees that were initially suppressed and subsequently released from suppression. The purpose of this study was to assess differences in growth ring width, specific conductivity (Ks), tracheid dimensions, moisture content, and wood density in suppressed Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees and trees released from suppression averaging 12–18 years of age. Growth ring width was 370% higher for Douglas-fir and 300% higher for western hemlock trees released from suppression, and Ks was 182% higher for Douglas-fir and 42% higher for western hemlock trees released from suppression. Earlywood width was approximately four times greater after release in both species, whereas the relative increase in latewood width was much greater in Douglas-fir. Tracheids were 25% wider and 11% longer in released Douglas-fir trees. In western hemlock, released trees had 19% wider tracheids that were approximately the same length as those in suppressed trees. Moisture content was 66% greater in released Douglas-fir and 41% greater in released western hemlock. Wood density decreased by 21% in Douglas-fir trees and by 11% in western hemlock trees released from suppression. However, wood density of released trees did not differ from average reported values, implying that wood from released trees may be suitable for many of its traditional applications.

Wood density of young-growth western hemlock: relation to ring age, radial growth, stand density, and site quality

2004 ◽  
Vol 34 (12) ◽  
pp. 2433-2442 ◽  
Author(s):  
Dean S DeBell ◽  
Ryan Singleton ◽  
Barbara L Gartner ◽  
David D Marshall
Keyword(s):  
Growth Rate ◽  
Wood Density ◽  
Ring Width ◽  
Stand Density ◽  
Age And Growth ◽  
Western Hemlock ◽  
Site Class ◽  
Ring Density ◽  
Wide Range ◽  
Young Growth

Breast-high stem sections were sampled from 56 western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees growing in 15 plots representing a wide range of tree and site conditions in northwestern Oregon. Growth and wood density traits of individual rings were measured via X-ray densitometry, and relationships of ring density and its components to age and growth rate were analyzed. Ring density was highest (0.49 g/cm3) near the pith, declined to 0.40 g/cm3 at age 10, remained stable to about age 25, and then increased gradually and remained between 0.43 and 0.44 g/cm3 from age 38 to 45 and beyond. A negative influence of rapid growth on whole ring density was greatest at young ages and diminished with time, becoming nonsignificant beyond age 30. Earlywood density, latewood density, and latewood proportion were all negatively related to ring width at young ages, but by age 21-25, latewood proportion was the only component of ring density that remained significantly diminished by increased growth rate. Residual differences in wood density (after age and growth rate were considered) did not appear to be related to either stand density or site class. Overall, young-growth hemlock trees are relatively uniform in wood density and likely to be more so if grown in intensively managed stands.

Revisiting the transition between juvenile and mature wood: a comparison of fibre length, microfibril angle and relative wood density in lodgepole pine

Holzforschung ◽  
2009 ◽  
Vol 63 (4) ◽  
Author(s):  
Shawn D. Mansfield ◽  
Roberta Parish ◽  
C. Mario Di Lucca ◽  
James Goudie ◽  
Kyu-Young Kang ◽  
...  
Keyword(s):  
Wood Density ◽  
Lodgepole Pine ◽  
Fibre Length ◽  
Microfibril Angle ◽  
Ring Width ◽  
Mature Wood ◽  
Radial Increment ◽  
Breast Height ◽  
Tracheid Length ◽  
Fibre Traits

AbstractIn an attempt to examine the dynamic inter-relationship among wood density and fibre traits [tracheid length and microfibril angle (MFA)] in lodgepole pine (Pinus contorta), 60 trees were sampled in three age classes from four sites in central British Columbia. Breast height discs were taken and relative wood density was measured along two radii. Tracheid length was assessed on isolated 5-year increments from pith to bark at breast height for each tree. MFA was determined every 50 μm and the 5-mm composite intervals from pith to bark per disc at breast height were used in the analysis. Segmented regression was employed to identify the “juvenile to mature wood” transition point, which revealed transition ages of 31, 18 and 15 for wood density, fibre length and MFA, respectively. These traits were related to primary growth, expressed as area increment, ring width, percent earlywood and height increment during the juvenile wood phase. Comparisons of wood and fibre traits showed a higher congruence between the time of transitions for fibre length and MFA (Pearson correlation coefficient 0.52) than that between fibre length and wood density (0.07), and MFA and wood density (0.16). The cessation of early rapid radial increment growth terminated before wood and fibre transitions to mature wood occurred. Fibre length was significantly, but not strongly, related to ring width and percent earlywood (0.35 for both). The duration of juvenile fibre production was not significantly related to height growth.

scholarly journals Realized Sampling Variances of Estimates of Genetic Parameters and the Difference Between Genetic and Phenotypic Correlations

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1409-1416 ◽  
Author(s):  
Kenneth R Koots ◽  
John P Gibson
Keyword(s):  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Phenotypic Correlation ◽  
Parameter Estimates ◽  
Sampling Variance ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Heritability Estimates

Abstract A data set of 1572 heritability estimates and 1015 pairs of genetic and phenotypic correlation estimates, constructed from a survey of published beef cattle genetic parameter estimates, provided a rare opportunity to study realized sampling variances of genetic parameter estimates. The distribution of both heritability estimates and genetic correlation estimates, when plotted against estimated accuracy, was consistent with random error variance being some three times the sampling variance predicted from standard formulae. This result was consistent with the observation that the variance of estimates of heritabilities and genetic correlations between populations were about four times the predicted sampling variance, suggesting few real differences in genetic parameters between populations. Except where there was a strong biological or statistical expectation of a difference, there was little evidence for differences between genetic and phenotypic correlations for most trait combinations or for differences in genetic correlations between populations. These results suggest that, even for controlled populations, estimating genetic parameters specific to a given population is less useful than commonly believed. A serendipitous discovery was that, in the standard formula for theoretical standard error of a genetic correlation estimate, the heritabilities refer to the estimated values and not, as seems generally assumed, the true population values.

Growth ofPseudotsuga menziesiiandTsuga heterophyllaseedlings along a light gradient: resource allocation and morphological acclimation

1997 ◽  
Vol 75 (9) ◽  
pp. 1424-1435 ◽  
Author(s):  
D. Mailly ◽  
J. P. Kimmins
Keyword(s):  
Leaf Morphology ◽  
Biomass Accumulation ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Low Light ◽  
Growing Seasons ◽  
Light Levels ◽  
Light Gradient ◽  
Relative Light Intensity

Silvicultural alternatives that differ in the degree of overstory removal may create shady environments that will be problematic for the regeneration of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Gradients of light in the field were used to compare mortality, growth, and leaf morphological acclimation of two conifer species of contrasting shade tolerances: Douglas-fir and western hemlock (Tsuga heterophylla (Raf.) Sarg.). Results after two growing seasons indicated that Douglas-fir mortality occurred mainly at relative light intensity (RLI) below 20%, while western hemlock mortality was evenly distributed along the light gradient. Height, diameter, and biomass of the planted seedlings increased with increasing light for both species but at different rates, and maximum biomass accumulation always occurred in the open. Douglas-fir allocated more resources to stem biomass than western hemlock, which accumulated more foliage biomass. Increases in specific leaf area for Douglas-fir seedlings occurred at RLI ≤ 0.4 and red/far red (R/FR) ratio ≤ 0.6, which appear to be the minimal optimum light levels for growth. Conversely, western hemlock seedlings adjusted their leaf morphology in a more regular pattern, and changes were less pronounced at low light levels. These results, along with early mortality results for Douglas-fir, suggest that the most successful way to artificially regenerate this species may be by allowing at least 20% of RLI for ensuring survival and at least 40% RLI for optimum growth. Key words: light, light quality, leaf morphology, acclimation.

TOXICITY OF SMOKE FROM SPOROPHORES OF THE INDIAN PAINT FUNGUS AND WOOD FROM WESTERN HEMLOCK TO YELLOWFEVER MOSQUITOES

1987 ◽  
Vol 119 (12) ◽  
pp. 1109-1115
Author(s):  
W.P.L. Osborn ◽  
J.H. Borden
Keyword(s):  
British Columbia ◽  
Aedes Aegypti ◽  
Combustion Products ◽  
Tsuga Heterophylla ◽  
Water Soluble ◽  
Western Hemlock ◽  
Aqueous Extracts ◽  
Smoke Water

AbstractTo mitigate the effects of mosquitoes, settlers in the Revelstoke area of British Columbia reportedly burned the sporophores of the Indian paint fungus, Echinodontium tinctorium (Ell. & Ev.) Ell. & Ev., a pathogen of western hemlock, Tsuga heterophylla (Raf.) Sarg., and true firs, Abies spp. Larval and adult yellowfever mosquitoes, Aedes aegypti (L.), were exposed to aqueous extracts of smoke (smoke-waters) from E. tinctorium sporophores, and from western hemlock sapwood and heartwood. Smoke-waters were of approximately equal toxicity to larvae. Fungus smoke-water, but not sapwood or heartwood smoke-waters, lost 50% of its potency in 5 months. Vapors from fungus smoke-water were significantly more toxic to adult mosquitoes than those from sapwood or heartwood. Thus smoke from E. tinctorium sporophores and T. heterophylla wood apparently contain different water-soluble combustion products toxic to A. aegypti.

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