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Volume Growth and Wood Density of Plus Tree Progenies of Pinus contorta in Two Swedish Field Trials
Abstract
Seventy‐four half‐sib families of lodgepole pine (Pinus contorta ssp. latifolia Engelm.) plus trees were measured for vigour, height growth, stem diameter, wood density and ring width in two Swedish field trials at age 9. Height growth, wood density and ring width differed between families within provenances with variance components of 3–8 %. Coefficients of variation were highest for height growth and lowest for ring width. Heritabilities were similar for height growth and wood density but lower for ring width. These genetic parameters seemed to be equal for all provenances. Indirect selection for high dry stem biomass was more effective using height growth than wood density, and a correlated response in wood density of 2.1 % of mean by selecting the 15 highest parent trees was indicated. Juvenile wood density looks uncertain as a selection criterion for mature wood density.
... The degree of genetic variation for wood-quality characteristics including wood density, latewood proportion and soluble substance concentration, and their relationships to growth traits have been studied for lodgepole pine introduced to some European countries (Fries 1986;Stephan and Liesebach 1995). However, the same species growing in largely different environments may perform very differently not only in growth traits (e.g., Tigerstedt 1993) but also in wood quality (Zobel and van Buijtenen 1989). ...
... These negative relationships indicate that trees with rapid diameter growth are more likely to have lower density earlywood, a smaller proportion of latewood and as a result, lower overall disk density. These results agree with the negative correlation between wood density and diameter found by Yanchuk (1986) in a provenance and family test and between wood density and ring width reported by Fries (1986) and Stephan and Liesebach (1995) in lodgepole pine. ...
... These results are similar to an earlier study in lodgepole pine in Europe. Fries (1986) found no correlation between wood density and height (r = 0.121) and concluded that selection for height is efficient for indirectly improving biomass production for this species. ...
The effects of selection using indices of height growth and wood density based on Pilodyn pin penetration (PIN) and the relationships among growth traits and wood properties were investigated in lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.). Four subpopulations were constructed by selecting 10 open-pollinated families in each of four categories: (i) fast height growth and high wood density, (ii) slow height growth and high density, (iii) fast height growth and low density, and (iv) slow height growth and low density. Eleven-year growth, PIN, and wood-density traits generated from X-ray densitometry were analyzed. We found that selection of subpopulations using indices of height and PIN resulted in significant differences among subpopulations in most growth and wood-density parameters. However, PIN underestimated the wood density of families with large diameter. Disk density was found to be moderately negatively correlated with diameter growth, weakly negatively correlated with stem volume, but not significantly correlated with height. Selection for latewood proportion to improve wood density in lodgepole pine is likely to result in a reduction in growth and biomass production; however, selection for total latewood volume or simply height has the potential to increase both growth and wood density.
... The degree of genetic variation for wood-quality characteristics including wood density, latewood proportion and soluble substance concentration, and their relationships to growth traits have been studied for lodgepole pine introduced to some European countries (Fries 1986;Stephan and Liesebach 1995). However, the same species growing in largely different environments may perform very differently not only in growth traits (e.g., Tigerstedt 1993) but also in wood quality (Zobel and van Buijtenen 1989). ...
... These negative relationships indicate that trees with rapid diameter growth are more likely to have lower density earlywood, a smaller proportion of latewood and as a result, lower overall disk density. These results agree with the negative correlation between wood density and diameter found by Yanchuk (1986) in a provenance and family test and between wood density and ring width reported by Fries (1986) and Stephan and Liesebach (1995) in lodgepole pine. ...
... These results are similar to an earlier study in lodgepole pine in Europe. Fries (1986) found no correlation between wood density and height (r = 0.121) and concluded that selection for height is efficient for indirectly improving biomass production for this species. ...
Changes in growth and wood density traits were investigated across annual rings of 12-year-old trees from four selected subpopulations in lodgepole pine (Pinus contorta Dougl. Ex Loud var. latifolia Engelm) based on X-ray densitometry profile data. Four subpopulations were constructed based on height growth and wood density as follows: 1) fast growth and high wood density (FH); 2) slow growth and high density (SH); 3) fast growth and low density (FL); and 4) slow growth and low density (SL). Annual ring density was initially high, declined with age until age 10, and then plateaued. Significant differences among subpopulations were found for ring density, earlywood and latewood densities, ring width, earlywood width, latewood proportion, and earlywood width after age 6. Wood density decreased less from the pith to the bark in both overall and earlywood densities in the FH subpopulation, resulting in denser, more homogeneous wood than in other subpopulations. This suggests that it may be possible to increase wood density and homogeneity in juvenile wood of this species by selecting FH families. Overall ring density may be better improved by selecting for earlywood and latewood components separately. The earliest age of which families combining fast growth and high wood density can be accurately identified is about 7 years.
... Earlier studies in several tree species have shown that genetic correlations between growth traits and WD are negatively correlated, but may also vary with environmental factors (e.g., location, site conditions) [78]. Moreover, different results concerning the relationships between growth rate and WD may be expected, given that WD is a complex trait influenced by many factors [79]. For instance, either negative [13], or no/minor and negative [14] genetic correlation relationships were reported for WD and HT in white spruce. ...
Tree improvement programs often focus on improving productivity-related traits; however, under present climate change scenarios, climate change-related (adaptive) traits should also be incorporated into such programs. Therefore, quantifying the genetic variation and correlations among productivity and adaptability traits, and the importance of genotype by environment interactions, including defense compounds involved in biotic and abiotic resistance, is essential for selecting parents for the production of resilient and sustainable forests. Here, we estimated quantitative genetic parameters for 15 growth, wood quality, drought resilience, and monoterpene traits for Picea glauca (Moench) Voss (white spruce). We sampled 1,540 trees from three open-pollinated progeny trials, genotyped with 467,224 SNP markers using genotyping-by-sequencing (GBS). We used the pedigree and SNP information to calculate, respectively, the average numerator and genomic relationship matrices, and univariate and multivariate individual-tree models to obtain estimates of (co)variance components. With few site-specific exceptions, all traits examined were under genetic control. Overall, higher heritability estimates were derived from the genomic- than their counterpart pedigree-based relationship matrix. Selection for height, generally, improved diameter and water use efficiency, but decreased wood density, microfibril angle, and drought resistance. Genome-based correlations between traits reaffirmed the pedigree-based correlations for most trait pairs. High and positive genetic correlations between sites were observed (average 0.68), except for those pairs involving the highest elevation, warmer, and moister site, specifically for growth and microfibril angle. These results illustrate the advantage of using genomic information jointly with productivity and adaptability traits, and defense compounds to enhance tree breeding selection for changing climate.
... According to Polge [28], differences in density may arise simply from differences in the anatomy of the wood modified by the effect of extractives, and, as described by Fries [29] and Mitchell and Denne [30], they may also derive from anatomical differences, such as in cell types and quantitative distribution, thickness of cell walls, and size of cell cavities through the wood. Importantly, the cell wall substance adsorbs and desorbs moisture to and from the environment because wood is a hygroscopic material. ...
Using a non-destructive approach, this study investigated the density and anatomical features of stem wood from five commercial trees in Nigeria: Gmelina arborea, Nauclea diderrichii, Triplochiton scleroxylon, Terminalia mantaly, and Terminalia catappa. The increment borer was used to take samples from three trees of each of the five species at breast height (1.37 m). The species' density, fiber length (FL), fiber diameter (FD), lumen width (LW), and cell wall thickness (CWT) were all measured. Result of the mean values of density for the five wood species were 475.05 kg/m 3 , 645.18 kg/m 3 , 590.05 kg/m 3 , 651.73 kg/m 3 , and 752.65 kg/m 3 for G. arborea, T. catappa, T. scleroxylon, N. diderrichii and, T. mantaly, respectively. It was observed that wood samples of T. mantaly had the highest (752.65 kg/m 3) density, followed by N. diderrichii (651.73 kg/m 3) and G. arborea had the lowest (475.05 kg/m 3). Fiber assessment showed that N. diderrichii had the longest (1.50 mm) FL while T. catappa had the shortest (0.93 mm) FL. However, N. diderrichii had the highest mean FD (36.45 μm), and T. mantaly had the lowest (15.01 μm). Investigation of the derived values showed that T. mantaly had the highest value (70.20) for slenderness ratio, and G. arborea had the lowest (36.90). Coefficient of flexibility was observed to be highest in G. arborea (56.09%). All the species in this study had Runkel ratio above 1 except G. arborea (0.86). The study showed that influence of species was significant (P< 0.05) on the density, anatomical properties and derived values and that utilization potentials varies.
... To date, several studies have investigated genetic control of growth, survival, form traits (Fries 1986;Ericsson et al. 1994), and wood quality traits (Hayatgheibi et al. 2017) in Swedish lodgepole pine plantations. However, G × E for growth and wood quality has not been yet quantified in lodgepole pine. ...
Genetic parameters, performance of provenances, and genotype by environment interaction (G × E) for diameter at breast height (DBH), survival, and modulus of elasticity of time-of-flight (MOEtof) (an indirect measure of stiffness), were investigated in six lodgepole pine progeny trials, aged 33–36 years, within three breeding zones in northern Sweden. Provenances of Yukon origin had the highest growth but lowest stiffness at higher latitude, while those of British Columbia (BC) origin grew faster at lower latitudes and had highest stiffness within zone 5. Combined-site heritability estimates ranged from 0.09 to 0.19 for DBH, from 0.19 to 0.27 for MOEtof, and from 0.13 to 0.26 for survival. Type-B genetic correlations ( ) were generally high for all studied traits, except for DBH and survival in zone 4 ( = 0.74 and 0.40, respectively) and for MOEtof in zone 2 ( = 0.46). On the basis of the results obtained in this study, G × E for stiffness in northern Sweden and unfavourable growth-stiffness genetic correlation should be considered in selective breeding programmes of lodgepole pine. To achieve the highest stiffness for lodgepole pine, provenances of Yukon origin should be planted at lower latitudes and those of BC origin should be planted at lower elevations within the tested breeding zones.
... Another primary objective of the present study was to examine the correlations between growth traits and wood properties. Given different species, statistical methods or research quality, the results of the genetic correlations were different for the three cases as follows: no significant correlations (Fries 1986;Wang et al. 1999), negative correlations (Belonger et al. 1996;Ivkovich and Koshy 2002;Ukrainetz et al. 2008) and positive correlations (Williams and Megraw 1994;Moura et al. 1998). In the present study, DEN P and MOE P showed no significant genetic correlations with growth traits. ...
The initial introduction of Pinus elliottii (PEE) to China occurred in the 1930s, and the planting of this conifer species has now attained close to 3 million ha in the subtropical zone of southern China. A large-scale genetic improvement program for PEE was implemented in southern China to produce fast-growing trees with high wood quality to address the severe shortage of timber production over the last two decades. In this paper, selection for stem volume, basic wood density (DEN) and modulus of elasticity (MOE) was based on the Smith–Hazel index, and a total of approximately 2 000 individual trees from 158 PEE open-pollinated families were selected at 22 years of age. The DEN and MOE for each tree were determined by non-destructive evaluation techniques using the Pilodyn and Hitman Director ST300® acoustic velocity device. The heritabilities and genetic and phenotypic correlations for the traits that were measured were estimated using the residual maximum likelihood approach in the flexible mixed modelling program ASReml-R. The results showed that the heritability estimates for the wood properties were between 0.292 and 0.309, and the heritabilities of the growth traits ranged from 0.129 to 0.216. The genetic correlation between the DENP and acoustic velocity (V ) with MOEP was 0.45 and 0.95, respectively. An indirect selection based on V was observed to be highly effective for determination of MOE. It indicated that V can be integrated into tree improvement programs as a useful index of MOE by ranking candidate families or individuals within the selection population. The genetic correlations between the growth traits and wood properties were not significant. By contrast, the phenotypic correlations between them were significantly positive, but the correlation coefficients were very low. The appropriate selection index (I4), which placed 10 times as much weight on DEN and MOE as the equal emphsis method, was determined as the appropriate selection index.
... The statistical model used for individual tree-based multitrait analyses of the data set was constructed with a fixed-effects part and a random part. The fixed effects included block effects (the sampled area was subdivided into seven almost square, equal-sized blocks) with annual ring width as an optional covariate, since wood density comparisons between trees are often less reliable without adjustment for ring width (see, for examples, FRIES, 1986;ZAMUDIO et al., 2002). ...
Wood density was analysed and annual ring width was measured on increment cores from 1400 trees in a 30-year-old full-sib progeny test of Scots pine (Pinus sylvestris L.) in north Sweden. Genetic parameters for wood density were analysed separately for ten outer annual rings, and for simple averages of the five most recent years. The evaluation included genetic correlations with height and stem diameter. Heritabilities of density estimated separately for each annual ring was 0.14-0.26 without any age trend, and jointly for the ten or five latest rings 0.30-0.33; for height growth it was 0.30-0.42 and for stem diameter 0.11-0.13. Additive genetic correlations with height and stem diameter were negative with the simplest statistical model (r̂A = -0.425 and 0.511, respectively) but vanished or diminished when ring width was added as covariate. Density breeding values calculated for the parent trees for each of ten annual rings separately varied considerably between parent trees and between years, tending to increase with increasing age, with a substantial increase between the ages 14 to 16 years from the pith. This age fits well with literature data on the change from juvenile to mature wood. The genetic correlation for wood density between rings from different years was high: r̂A = 0.8 ten years apart, increasing to 1.0 for neighbouring rings. The high genetic correlations for wood density between the innermost and outermost annual rings indicate possible strong covariation between juvenile and/or transition wood and mature wood. The annual variation in wood density in relation to genetic regulation, phenology, environmental conditions, and development from juvenile to mature age is discussed.
... Currently, there is a growing interest in the establishment of plantations of lodgepole pine. The experience of silvicultural practices of this species in Swedish conditions is described along with the initial progress in tree breeding (Fries 1986) although not much data on wood and fibre characteristics are available in the literature. The establishment of lodgepole pine provenance trials in Latvia, using the material from Canada and also selections from trees growing in Sweden, has been carried out since the 1980s. ...
Wood anatomical properties of 27-year-old Scots pine (Pinus sylvestris L.) (n = 32) and lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm) (n = 19) sample trees grown in Latvia were investigated. Stem diameters, growth rings, and dimensions of 150 earlywood (EW) and 150 latewood (LW) tracheids per sample tree were measured. Lodgepole pine demonstrated significantly (P < 0.05) larger stem diameters (21%), wider growth rings (8%), and higher LW content (15%) than Scots pine. Tracheid dimensions such as lumen area and diameter, and mean tracheid diameter of EW were significantly higher in Scots pine, while tracheid wall thickness was higher in lodgepole pine. Lumen area and diameter of LW were significantly higher in lodgepole pine. Scots pine had tracheids with larger average lumen area (10%) and diameter (5%), radial diameter (8%) and tracheid diameter (3%), while lodgepole pine had thicker tracheid walls (6%) and longer fibres (10%). Tracheid wall thickness and average diameter of EW and LW cells increased from pith to cambium in both pine species. The number of tracheids was assumed to play more important role than tracheid size in the increment of the stems and growth rings of lodgepole pine.
... In general , most of conifers with dense wood , espe - cially the hard pines , show little or no meaningful relationships between growth rate and wood density ( Zobel and Jett 1995 ; Zobel and Van Buijtenen 1989 ) . In lodgepole pine , height growth is not related to wood density at all ( Fries 1986 ; Wang et al . 1999 ) . ...
Selection for both growth and wood quality is the primary goal of many tree breeding programs. In order to investigate the impacts of such selection on adaptive traits, observations were made on phenology, drought resistance, xylem conductance and xylem vulnerability to cavitation of 2-year-old seedlings of lodgepole pine (Pinus contorta Dougl. Ex Loud var. latifolia Engelm) from four subpopulations: (1) fast height growth and high wood density (FH); (2) slow height growth and high density (SH); (3) fast height growth and low density (FL); and (4) slow height growth and low density (SL). Results showed that the impact of the selection on phenology was minor; differences in growth among subpopulations were mainly attributable to maximal growth rate and the duration of the period of rapid growth. The FL subpopulation showed a significantly stronger productivity decline in response to moderate drought compared to the two slower-growing subpopulations. The FH subpopulation showed significantly higher xylem specific conductivity than the two slower-growing subpopulations, and greater resistance to cavitation than the other three subpopulations, suggesting the possibility of selecting families that combine fast growth, high wood density and drought tolerance.
... III), and this was similar to or slightly lower than heritabilities for earlywood, latewood and total densities recorded in many other studies, e.g. Fries (1986) studying Pinus contorta; Hannrup et al. (2000) and Fries and Ericsson (2006) studying Scots pine; Gwaze et al. (2002) studying Pinus taeda; Ivkovich et al. (2002) studying Picea engelmannia and Picea glauca; Li and Wu (2005) and Zamudi et al. (2005) studying Pinus radiata; Bouffier at al. (2008a;2008b) studying Pinus pinaster; and Ukrainetz (2008) studying Pseudotsuga menziesii. An additional general pattern is that the estimated heritabilities for ED and LD are of similar size, although Louzada et al. (2002), Bouffier et al. (2008b) and Ukrainetz (2008) recorded a higher value for ED than LD. ...
• Each annual ring in pines consists of earlywood and latewood with considerable difference in density and width. To get a better determination of the genetic regulation of total wood density in Scots pine (Pinus sylvestris L.), density and width of those ring sections were measured in annual ring numbers 12 to 21 of Scots pines in a full-sib progeny test. Tree height and stem diameter were also measured.
• Heritabilities for the annual ring sections increased with age for earlywood density from 0.08 to approximately 0.25; latewood density showed similar reductions. Heritability over all 10 annual rings was 0.25 for earlywood density, 0.22 for latewood density, 0.29 for height and 0.10 for stem diameter. Genetic correlations between earlywood and latewood density and growth traits were negative, while they were strongly positive between densities of adjacent annual rings (0.70–1.0).
• Despite the higher heritability of earlywood density, the strong positive genetic correlation between those traits indicates little benefit from focusing solely on earlywood density when selecting for wood density. Analysing earlywood and latewood separately does not benefit from including the width of the corresponding ring section as a covariate. Juvenile wood may possibly turn into mature wood 15–20 y from the pith.
... Negative genetic correlations between these traits have also been reported in other coniferous species (Chang and Kennedy 1967, Bendtsen 1978, McKinley et al. 1982, Dean et al. 1983, Loo et al. 1984, Fries 1986). ...
Typescript (photocopy). Thesis (Ph. D.)--Oregon State University, 1991. Includes bibliographical references (leaves 115-123).
Some properties of wood, such as maximum moisture content, cell-wall density and porosity, are not well known, even though they affect the performance of chemical preservatives, glues and coatings on wood. This knowledge gap was addressed in the present study by analysing these physical properties in laurel (Laurus nobilis L.) wood. Laurel is a common hardwood tree in southern Europe. Seventeen laurel trees were felled for the study, and 300 defect-free specimens were obtained from the trees for analysis. The following mean values were obtained: wood maximum moisture content, 114%; cell-wall oven-dry density, 1198 kg m−3; and oven-dry wood porosity, 45%. Significant inter- and intra-tree variations in the three properties were observed. The inter-tree variation was mainly attributed to the tree age, and the trend suggests that wood maximum moisture content and porosity are expected to be lower in older trees than those under study. The values of the three properties were slightly, but statistically significantly, lower at the highest positions in the tree. Harvesting of the basal logs of young trees is therefore advisable only if more porous wood is required, and commercial exploitation of the whole trunk of mature trees is recommended if more compact wood is required. The variation in cell-wall density was not negligible, although this variable is often assumed to be approximately constant for all wood species. Maximum moisture content and wood porosity can be estimated using bulk or apparent density as a predictor variable.
Transverse section of Sitka spruce was analysed according to the Euclid's second theorem (EST) in order to determine whether EST could be used for establishing wood growth ring characteristics. The results were adjusted so as to provide comparability between radial width of earlywood (E) and latewood (L) throughout the whole annual ring of the experimental sample. It was observed that, although the EST gives only the approximate mean for E and L, the calculation of the mean radial width of E and L was reliable and confirmed by video scanning method. When considering its integrity, this method could only be used effectively, if the growth rings have the same pattern and show the rarefied variations. ---------------- This article has been published in Drvna Industrija (Wood Industry) in 2004, and the citation tag for this article is: Usta, I., Despot, R., Hasan, M. (2004). Possible use of Euclid`s second theorem to determine the growth ring characteristics. Drvna Industrija (Wood Industry), 55 (2004/3): 123-127.
Family by site interaction from 4 progeny test sites for 9-year height and its impact on estimation of genetic correlation between greenhouse traits and 9-year height were investigated in 110 families of Pinus contorta ssp. latifolia from Alberta, Canada. Significant family by site interaction, site and family effects were observed in 9-year height among 4 progeny test sites. The estimated narrow-sense heritability was from 0.127 to 0.277 for individuals and was from 0.247 to 0.475 for family means. 25 greenhouse seedling traits (height, diameter, bud, branch and biomass) in 2 growing seasons were jointly studied with 9-year tree height at the 4 progeny test sites. The genotype by site interaction had a significant impact on green-house-field family-means and genetic correlations. Only 9-year tree height in the best site (site B), which had more similar growing conditions to the greenhouse, had significant family-mean and genetic correlations with greenhouse seedling traits. Seedling traits of height increment at the dormancy induction period between 2 growing seasons (HG1, r(g) = 0.52), height at the second growing season (H3, r(g) = 0.36) and height (r(g) =0.37) and diameter (r(g)=0.42) at harvest, had the highest and significant family-mean and genetic correlation. The pattern of greenhouse-field family-mean and genetic correlations among 4 sites indicates that early testing should be conducted under simulated field conditions. The implications of genotype by site interaction on early selection were discussed for lodgepole pine.
Various methods were progressively investigated to determine wood density within the most reliable void volume (porosity) values. Three softwood species of Bornmulleriana fir (Abies bornmulleriana Mattf.). Eastern spruce (Picea orientalis Lipsky), and Scots pine (Pinus sylvestris L.) grown indigenously in Turkey were selected to obtain a comparison among the green volume (GV), oven dry (OD) and maximum moisture content (MMC) methods. Volume definition had a great effect on density, which tended to vary significantly between and also within species caused by differences in the ratio of cell wall to air spaces. Accordingly: (a) GV might not give more accurate density figures than the others, as this method varies depending on the moisture content, which may be time-of-year dependent: (b) OD may also give unreliable results if the experimental blocks are not dried properly due to the direct reflection of the amount of space occupied by water: (c) MMC gives the most reliable results as the ranges of density are very close to each other along the same stake, and, it can thus be recommended for common use on account of its accuracy. ---------------- This article has been published in Turkish Journal of Agriculture and Forestry in 2003, and the citation tag for this article is: Usta, İ. (2003). Comparative study of wood density by specific amount of void volume (porosity). Turkish Journal of Agriculture and Forestry, 27 (1): 1-6.
Wood density and tracheid length are two traits that significantly affect wood products. Genetic correlations were estimated to evaluate the effect on these traits from a selection for traits included in the Swedish Pinus sylvestris L. breeding programme. Measurements from a non-contiguous single-tree plot progeny trial with controlled matings between 30 parent trees was used. Heritabilities were high for the wood traits, intermediate for the growth capacity traits and low for the stem traits, with the exception of branch angle. Wood density showed no or non-significant negative genetic correlations with the growth capacity traits and a positive correlation with relative branch diameter. Tracheid length showed positive genetic correlations with height and a positive correlation with relative branch diameter. A selection that increased height growth at the age of 13 yrs by 10% was expected to decrease mean wood density at 33 yrs by 1%. The expected correlated response to tracheid length from the same selection was a 3% increase in the juvenile and mature wood.
Genetic parameters were estimated, using the restricted maximum likelihood method, for 1112 open-pollinated progenies of Pinuscontorta Dougl. ex Loud. var. latifolia Engelm. plus trees selected from among 83 undisturbed stands in the interior of the Yukon and British Columbia, and five similar stands in Alberta. The progenies were grown in Swedish test plantations. Tree condition, height, and ramicorn whorl frequency were assessed at ages ranging between 8 and 12 years. On the harshest sites, weather and fungal damage, e.g., caused by Gremmeniellaabietina (Lagerb.) Morelet, were also assessed. Categorical data were transformed into values on a normal score scale to improve the efficiency of the evaluation. The genetic coefficients of variation in tree height ranged between 8 and 17%. The heritabilities for tree height, including stand genetic variation, were estimated to range between 0.10 and 0.54. Genetic correlations between tree height and trunk leaning were usually high and positive, as were correlations between height and ramicorn whorl frequency. At one site, heritability estimates for trunk injury and (or) canker and fungal and (or) weather damage were 0.12 and 0.18, respectively.
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.
Fibre length, fibre width, tree height and stem diameter in 25-yr-old Scots pine (Pinus sylvestris L.) were investigated by genetic analysis. The analysis was carried out on nearly 400 trees for all traits simultaneously using multiple-trait, individual tree equations with simultaneous variance estimation. Narrow-sense heritabilities were estimated at about 0.3 for all traits except for stem diameter, which was lower (0.17). Low genetic coefficients of variation for fibre length may be partially explained by the sampling method, which was 5 mm increment boring resulting in fibre fragmentation, but the method served well for heritability and correlation analysis. The additive genetic correlation was strongly negative between fibre length and stem diameter, and strongly positive between fibre width and growth traits. The pair of fibre traits showed mutually strong negative additive-genetic but weak positive environmental correlation. The pair of growth traits showed no genetic but strong positive environmental correlation. Other correlation estimates were minor and uncertain, with the exception of a weak negative environmental correlation between fibre length and stem diameter. An additional approach, where stem diameter was regarded as a covariate, revealed positive environmental correlation between fibre length and tree height and negative environmental correlation between fibre width and tree height.
A unified presentation, a synthesis, and an evaluation of the methods employed in the estimation of heritability in plants are presented. Asexual, cross‐fertilizing, and self‐fertilizing diploid species, as well as annual and perennial ones, are considered. All broad‐ and narrow‐sense heritabilities are defined on individual and family bases for prediction of response to selection for a target population of environments in space and time. Narrow‐sense heritabilities are defined in cross‐fertilizing species for expected response to variations of mass, half‐sib, and full‐sib family selection for the next generation and the long term, and similarly in self‐fertilizing species. The use of both collateral and lineal relatives to estimate heritability is discussed, and the biases present in the estimators are given. Many departures and variations of the common procedures are discussed. The standard errors of heritability estimators and confidence intervals are presented.
Species, provenances and even individual trees are known to differ in stem volume yield capacity, even when grown on the same site. Increased knowledge of the fundamental mechanisms for different productivity is essential for the success of breeding research and for the maximization of yield. Genetically homogeneous tree materials were selected on the basis of expected differences in stem volume yield capacity and trees were sampled and destructively analysed. The hypothesis to be tested was that yield capacity is correlated to certain traits of trees. High correlations with stem volume yield capacity were shown for harvest index, needle‐use efficiency and mineral‐nutrient‐use efficiency. Only weak correlations were shown for needle longevity and nitrogen concentration in needles. Also, indications were found that phenotypic plasticity was correlated positively to stem volume growth capacity. An attempt to correlate the ability to retranslocate nitrogen from dying needles with yield capacity failed.
Height development, stem diameter and dry weight of plus tree progenies of lodgepole pine (Pinus contorta ssp. latifolia) from controlled cross pollination, open pollination and selfing were evaluated in a nursery trial. Early growth was slow in year 1 but more rapid in year 2, and it showed higher correlation with total increment than late growth. Nursery growth was uncorrelated with 10‐year‐height in field. The controlled crosses started growth faster and became higher than the two other types of materials. The family variance within all types differed also significantly. Mother clone had larger influence on 2nd‐year‐growth than father clone. Height and diameter growth were slightly influenced by latitudinal but not altitudinal origin. Prolepsis was independent on both. Specific combining ability (SCA) decreased while general combining ability (GCA) increased by age. For dry weight, SCA was more important than GCA.
Increment core samples were collected from 5 17-year-old provenances at each of 5 sites in the Pacific Northwest region and subjected to growth rate and wood density analyses. Measurements on the whole cores showed that geographic location of the growing site is the main factor influencing rate of growth and wood properties. Tree-ring components were studied by means of a scanning densitometer and again no consistent provenance effects were found. The significance of the results to future tree breeding programmes is discussed.
The static bending, compression parallel to the grain and toughness properties of loblolly pine (Pinus taeda L.) grown at different rates were determined to examine the influence of fast growth rate. The tests were done on clear wood of butt logs from 143 trees of similar diameters from three populations of loblolly pine from the same locality in South Carolina; namely, a naturally regenerated forest 41 years old, a plantation of ordinary commercial stock 25 years old, and a research plantation of 15 year-old trees from parents selected for fast growth rate and good form. In general, the younger the tree, the lower its mechanical properties. For example, the modulus of rupture of the inner and outer wood of the 15-year-old trees was on average 48 and 76 percent, respectively, of that of the outer wood of the 41-year-old trees. The inner wood from all populations was lower in density and mechanical properties than the wood from the outer zones. Over 40% of the cross-section of the 15-year old trees was low density juvenile wood compared with about 6% for the 41-year-old trees. Consequently, lumber from fast- grown pines may be expected to have mechanical properties singificantly different from those of slow-grown trees of similar diameter. The most significant differences among the mechanical properties of clear wood from the three age groups related to the differences in density of the wood. (Refs. 13).
Heritability estimates for wood specific gravity of loblolly pine (Pinustaeda L.) in east Texas were high and relatively constant for all ages of wood sampled, but tracheid length was found to have low heritability at all ages. Heritability estimates for tracheid length declined with age after age 4 years. Coefficients of genetic prediction indicated that specific gravity of age 2 wood is a reliable predictor of wood specific gravity at age 25. Genetic covariances between juvenile and mature tracheid length were approximately zero. Coefficients of genetic prediction and genetic correlations between specific gravity and height and diameter at age 20 years indicated a strong negative relationship.
In this paper a formula is developed for estimating the sampling variance of a genetic correlation estimated from analyses of variance and covariance. The formula holds provided the heritability estimate of neither character is zero. However, the development assumes a constant number of offspring per sire, k, and the effect of varying values of k is discussed briefly. The efficiency of experiments from which genetic parameters are to be estimated has also been investigated and optimum values of k are given for various combinations of phenotypic and genetic parameters.
Statistisk inferens. Studentlitteratur
- G Angsmark
Angsmark, G. 1968. Statistisk inferens. Studentlitteratur, 2nd ed. Lund, Sweden, 1-276.
Vad vinner man med contorta? (What is the gain with lodgepole pine?) Sv
- B Elfving
Elfving, B. 1985. Vad vinner man med contorta? (What is the gain with lodgepole pine?) Sv. Skogsvärdsförb. Tidskr. 3, 28-33.
Selection of Pinus contorta var. latifolia in northeastern British Columbia and southern Yukon Forestry in Faculty of Forestry
- J B Engleson
Engleson, J. B. 1971. Selection of Pinus contorta var. latifolia in northeastern British Columbia and southern Yukon. B.Sc. thesis, Forestry in Faculty of Forestry, University of British Columbia, Vancouver, B.C., 1-135.
A mercury immersion method for determining the wood density of increment core sections
- B Ericson
Ericson, B. 1959. A mercury immersion method for determining the wood density of increment core sections. For. Res. Inst. of Swed. Dept. For. Yield Res. Rep. No. 1, 1-31.
Ved och sulfatmassa från tall i orörda bestånd (Wood and sulphate pulp of Scots Pine from virgin stands)
- B Ericson
- T Johnson
- A Persson
Ericson, B., Johnson, T. & Persson, A. 1973. Ved och sulfatmassa från tall i orörda bestånd (Wood and sulphate pulp of Scots Pine from virgin stands). Royal Coll. For. Dept. For. Yield Res. Res. Notes No. 25, 1-143.
Volymfunktioner for stående träd av ask, asp, klibbal och contorta-tall (Tree volume functions for ash, aspen, alder and lodgepole pine in Sweden) (Fraxinus excelsior L., Populus tremula L
- H Eriksson
Eriksson, H. 1973. Volymfunktioner for stående träd av ask, asp, klibbal och contorta-tall (Tree volume functions for ash, aspen, alder and lodgepole pine in Sweden) (Fraxinus excelsior L., Populus tremula L., Alnus glutinosa (L.) Gartn., Pinus contorta Dougl. var. latifolia (Engelm.)).
Wood density as a criterion for thinning Douglas fir
- J M Harris
Harris, J. M. 1967. Wood density as a criterion for thinning Douglas fir. N.Z. J. For. 12, 54-62.
Physical properties, resin content, and tracheid length of lodgepole pine grown in New Zealand
- J M Harris
Harris, J. M. 1971. Physical properties, resin content, and tracheid length of lodgepole pine grown in New Zealand. N.Z. J. For. Sci. 3 (1), 91-109.
Contortan—en snabbt växande nykomling
- O Martinsson
Martinsson, O. 1982. Contortan—en snabbt växande nykomling. Skogsfakta. Biologi och skogssköt-sel 2, 1-4.
The search for Alberta's super-quality trees has begun
- M Micko
- E Wang
- F Taylor
Micko, M., Wang, E. & Taylor, F. 1981. The search for Alberta's super-quality trees has begun. Agric. & For. Bull. 4 (2), 36-39.
The effect of environmental factors on wood characteristics. 1. The influence of irrigation on Pinus radiata from South Australia
- J W P Nicholls
Nicholls, J. W. P. 1971. The effect of environmental factors on wood characteristics. 1. The influence of irrigation on Pinus radiata from South Australia. Silvae Genet. 20 (1-2), 26-33.
Ved och pappersmassa från gran och tall i olika förband (Wood and pulp of Norway spruce and Scots pine at various spacings)
- A Persson
Persson, A. 1975. Ved och pappersmassa från gran och tall i olika förband (Wood and pulp of Norway spruce and Scots pine at various spacings). Royal Coll. For. Dept. For. Yield Res. Res. Notes No. 37, 1-145.
Gödslingseffekter i plant-och ungskog (Growth response to fertilization with nitrogen in young stands). The Institute for Forest Improvement
- F Pettersson
Pettersson, F. 1984. Gödslingseffekter i plant-och ungskog (Growth response to fertilization with nitrogen in young stands). The Institute for Forest Improvement, årsbok 1984, Sweden, 87-116.
The Swedish Pinus contorta tree improvement and seed production program In: Proceedings of the IUFRO working party meeting 1980 on Pinus contorta provenances (S2-02-06) in Norway and Sweden
- O Rosvall
Rosvall, O. 1980. The Swedish Pinus contorta tree improvement and seed production program. In: Proceedings of the IUFRO working party meeting 1980 on Pinus contorta provenances (S2-02-06) in Norway and Sweden. Swe. Univ. Agric. Sei. Dept. For. Gen. Res. Notes No. 30, 329-343.
Kvalitet och tillväxt hos 27-åriga tallkloner utvalda efter sågtimmerkvalitet
- P Rudebjer
Rudebjer, P. 1984. Kvalitet och tillväxt hos 27-åriga tallkloner utvalda efter sågtimmerkvalitet. Examensarbete i skogsgenetik. Swedish University of Agricultural Sciences. Department of Forest Yield Research, Garpenberg, 1-55.
Skogsstatistisk årsbok 1985 (Statistical Yearbook of Forestry
- Skogsstyrelsen
Skogsstyrelsen (National Board of Forestry). 1985. Skogsstatistisk årsbok 1985 (Statistical Yearbook of Forestry 1985). Borgströms Tryckeri AB, Motala, Sweden, 1-248.
Plus tree selection of Pinus contorta var. latifolia in central British Columbia. Faculty of Forestry
- O Sziklai
Sziklai, O. 1972. Plus tree selection of Pinus contorta var. latifolia in central British Columbia. Faculty of Forestry, Univ. of British Columbia, Vancouver, B.C., 1-64.
Inheritance of wood specific gravity in an unimproved loblolly pine population: 20 years of results
- J T Talbert
- J B Jett
- R L Bryant
Talbert, J. T., Jett, J. B. & Bryant, R. L. 1983. Inheritance of wood specific gravity in an unimproved loblolly pine population: 20 years of results. Silvae Genet. 32 (1-2), 33-37.
Sweden: The Institute for Forest Improvement
- F Pettersson