共查询到20条相似文献，搜索用时 31 毫秒
1.
Context
The development of multiple trait selection indices for solid (structure) wood production in the Scots pine (Pinus sylvestris L.) breeding program requires genetic variances and covariances estimated among wood quality traits including stiffness.Aims
Genetic control and relationships among Scots pine growth, fiber, and wood quality traits were assessed by estimating heritability, phenotypic and genetic correlation using a Scots pine full-sib family trial.Method
Wood quality traits including clearwood and dynamic acoustic stiffness were measured using SilviScan and Hitman in a 40-year-old progeny trial and by sampling increment cores of 778 trees of 120 families. Genetic parameters were estimated using the mixed model by the ASReml software.Results
Heritability ranged from 0.147 to 0.306 for growth, earlywood, transition wood and latewood proportion traits and from 0.260 to 0.524 for fiber dimension, wood density, MFA and stiffness traits. The highly unfavorable genetic correlation between diameter and whole core density (?0.479) and clearwood stiffness (?0.506) and dynamic acoustic stiffness (?0.382) was observed in this study.Conclusion
The unfavorable genetic correlations between growth traits and stiffness indicate that multiple traits selection using optimal economic weights and optimal breeding strategies are recommended for the advanced Scots pine breeding program. 相似文献2.
? Context
A clear understanding of the genetic control of wood properties is a prerequisite for breeding for higher wood quality in Populus tomentosa Carr. hybrid clones.? Aims
The experiments aimed at unraveling genetic and environmental effects on wood properties among triploid hybrid clones of P. tomentosa.? Methods
We used 5-year-old clonal trials established in Northern China to assess the heritability of wood density and fiber traits. Two hundred seventy trees from nine clones were sampled in five sites.? Results
Site had a very significant effect on all recorded traits. Despite this large site effect, a tight genetic control was detected and clonal repeatability varied between 0.53 and 0.95. Significant genotype?×?environment interactions were detected for most of the traits. Moderate to tight correlation were evidenced among traits but they were not consistent with that in several cases that were site-dependent.? Conclusions
Our results revealed a tight genetic control over several wood properties and therefore breeding programs might be able to improve wood density, fiber length, and coarseness in these hybrids. 相似文献3.
Variation of wood color parameters of Tectona grandis and its relationship with physical environmental factors 总被引：1，自引：0，他引：1
? Context
Teak??s wood color is considered an important attribute in the marketing phase and it has been influenced by environmental setting, stand conditions and management, plant genetic source, and age. However, there is a lack of understanding about how the environmental factors might affect the teak??s wood color planted in short-rotation forest plantations.? Aims
The aim of this study is to understand the relationship, gathered from generated information, between edaphic and climatic variables and their effects in the wood color variation of Tectona grandis from trees in forest plantations.? Methods
Twenty-two plots were grouped in five cluster sites that shared similar climatic and soil conditions. Data about soil??s physical?Cchemical properties and climatic variables were collected and analyzed. Representative trees were harvested next to each plot in order to obtain a wood sample per tree at a diameter breast height. Wood color was measured using standardized CIELab??s chromaticity system.? Results
After comparing the wood change color index (?E*) in the five studied clusters, it was found that heartwood produced from drier and fertile sites had more yellowish-brown color. The heartwood b* color index resulted with significant correlations (R?>?0.5, P?<?0.05) among nine climatic and eight edaphic variables.? Conclusion
It was concluded that climatic variables should be considered as the first-order causal variables to explain wood color variation. Hence, darker b* wood color was associated with dry climates; also, with deeper and fertile sites. 相似文献4.
Shakti S. Chauhan Monika Sharma Jimmy Thomas Luis A. Apiolaza David A. Collings John C. F. Walker 《Annals of Forest Science》2013,70(4):439-449
? Introduction
There has been an increasing interest in very early selection of radiata pine to reduce the breeding cycle for solid wood products. For such selection, new approaches are required to assess wood quality in wood from very young stems.? Methods
Nursery seedlings of clones of radiata pine were grown in leant condition using two leaning strategies for 18–20 months. Opposite wood and compression wood were isolated from the leaning stems and tested for dynamic modulus of elasticity, density, longitudinal shrinkage, volumetric shrinkage and compression wood area using new methods evolved for testing small size samples quickly and reliably. The methods were tested for their efficiency in differentiating clones by their wood properties.? Results
Leaning of stems provided distinct opposite and compression wood for testing. Automated image analysis method used for compression wood area assessment was found to be a quick and effective method for processing large number of samples from young stems. Compression wood was characterised by high basic density, high longitudinal shrinkage and low volumetric shrinkage than that of opposite wood. Acoustic velocity in opposite wood had a strong negative association with longitudinal shrinkage. The study signifies the importance of preventing mixing of opposite wood with compression wood while assessing wood quality in young stems thus making leaning a critical strategy. The comparison of wood properties of opposite wood revealed significant differences between clones. Opposite wood of the clone with the lowest dynamic modulus of elasticity exhibited the highest longitudinal shrinkage.? Conclusion
Significant differences in measurable wood properties between clones suggest the prospects of early selection for solid wood products. 相似文献5.
Blaise Ratcliffe Foster J. Hart Jaroslav Klápště Barry Jaquish Shawn D. Mansfield Yousry A. El-Kassaby 《Annals of Forest Science》2014,71(3):415-424
Context
Wood quality traits are important to balance the negative decline of wood quality associated with selection for growth attributes in gymnosperm breeding programs. Obtaining wood quality estimates quickly is crucial for successful incorporation in breeding programs.Aims
The aims of this paper are to: (1) Estimate genetic and phenotypic correlations between growth and wood quality attributes, (2) Estimate heritability of the studied traits, and (3) Assess the accuracy of in situ non-destructive tools as a representative of actual wood density.Methods
Wood density (X-ray densitometry), tree height, diameter, volume, resistance drilling, acoustic velocity, and dynamic modulus of elasticity were estimated, along with their genetic parameters, for 1,200, 20-year-old trees from 25 open-pollinated families.Results
Individual tree level heritabilities for non-destructive evaluation attributes were moderate ( $ {\widehat{h}}_i^2=0.37-0.42 $ ), wood density and growth traits were lower ( $ {\widehat{h}}_i^2=0.23-0.35 $ ). Favorable genetic and phenotypic correlations between growth traits, wood density, and non-destructive evaluation traits were observed. A perfect genetic correlation was found between resistance drilling and wood density (r G ?=?1.00?±?0.07), while acoustic velocity and dynamic modulus of elasticity showed weaker genetic correlations with wood density (r G ?=?0.25?±?0.24;?0.46?±?0.21, respectively).Conclusion
This study confirmed that resistance drilling is a reliable predictor of wood density in western larch, while the weak genetic correlations displayed by acoustic velocity and dynamic modulus of elasticity suggest limited dependability for their use as fast in situ wood density assessment methods in this species. 相似文献6.
Tahiana Ramananantoandro Miora F. Ramanakoto Andraina H. Rajemison Florent Eyma 《Annals of Forest Science》2013,70(6):649-658
Context
The knowledge of consumer preferences in wood furniture is crucial for the wood processing industries.Aim
This study aims to identify the attributes of wood that affect the preferences of consumers from the city of Antananarivo, Madagascar, for wooden furnishings.Methods
Quantitative measurements of the density and aesthetic properties of 12 wood species were carried out. The properties measured were the colour in the CIEL*a*b* colour space, the texture through greyscale image processing, and the density. Then, the wood specimens were subjected to sensory analysis with 100 consumers.Results
The results showed that the "density" was a prime criterion in choosing a wood species. Concerning the visual aspect, Antananarivo consumers generally liked slightly dark wood colour (L* around 52), tending towards yellow, with a visible oriented texture. The influence of socio-economic factors was also highlighted.Conclusion
These results are of prime importance in the search for alternative species to replace precious woods that are becoming rare. 相似文献7.
Miloš Ivković Washington Gapare Harry Wu Sergio Espinoza Philippe Rozenberg 《Annals of Forest Science》2013,70(5):525-534
? Context
The correlation between tree ring width and density and short-term climate fluctuations may be a useful tool for predicting response of wood formation process to long-term climate change.? Aims
This study examined these correlations for different radiata pine genotypes and aimed at detecting potential genotype by climate interactions.? Methods
Four data sets comprising ring width and density of half- and full-sib radiata pine families were used. Correlations with climate variables were examined, after the extraction of the effect of cambial age.? Results
Cambial age explained the highest proportion of the ring to ring variation in all variables. Calendar year and year by family interaction explained a smaller but significant proportion of the variation. Rainfall had a positive correlation with ring width and, depending on test site, either a negative or positive correlation with ring density. Correlations between temperature during growing season and ring density were generally negative.? Conclusion
Climate variables that influence ring width and wood density can be identified from ring profiles, after removing the cambial age effect. Families can be selected that consistently show desirable response to climate features expected to become prevalent as a result of climate change. 相似文献8.
9.
Variations of wood basic density with tree age and social classes in the axial direction within Pinus massoniana stems in Southern China 总被引：1，自引：0，他引：1
Xiangwen Deng Liyun Zhang Pifeng Lei Wenhua Xiang Wende Yan 《Annals of Forest Science》2014,71(4):505-516
Context
Reliable estimates of wood density (WD) within individual trees could maximize the value of Pinus massoniana for specific end-use.Aim
We examined and quantified the axial patterns of WD in trees with different social status in the stands.Methods
Wood disks were sampled at the bottom, breast height, and middle of each 1-m sections from 108 stems, harvesting from three social classes in subtropical forests. A mixed-effects model was designed to quantify axial variation.Results
The WD at different height was significantly different from the whole-stem WD (WWD) except the relative height of 0.1. An overall decrease of 133.8 kg m?3 in WD was found from stem base to top. WD was significantly influenced by relative heights, tree age, and social class. WD of each relative height in mature trees was significantly higher than that of younger trees. Tree social class can affect WD development in the axial direction at age classes 2 and 3. Combining the fixed plus random effects, the final model explained 91 % of the observed variation in WD.Conclusion
The WD development patterns in the axial direction vary considerably among tree age, diameter at breast height, and social class. To distinguish and supply timber for specific end-uses, we should use the axial variation in disk WD (DWD) instead of WWD directly. The accurate predictions of WD provided by the model could be used to optimally classify logs into different product classes and maximize economic benefits. We can use DWD at the relative height of 0.1 instead of WWD of a single tree. 相似文献10.
Martha Salas Víctor Nieto Liliana Perafán Alejandro Sánchez Nuno M. G. Borralho 《Annals of Forest Science》2014,71(3):405-414
Aims
The objective of this study was to compare the merit of the Colombian landrace relative to the various Australian native races of Eucalyptus globulus Labill. ssp. globulus and study the genetic control of key traits such as growth, wood density, and leaf phase change in the unique conditions of the Colombian highlands.Methods
The genetic study was based on open-pollinated families from native Australian and Colombian landrace origin, tested across four trials spanning two generations of breeding. A multisite mixed linear model with genetic groups was fitted to the data to estimate race merit and the variance and covariances between traits, ages, and sites.Results
Race effects for growth were small and only significant at the older site. In contrast, races differ significantly for height to phase change and density. The Colombian landrace and South and NE Tasmania races changed leaf type at a higher tree height. King Island and Recherche Bay had low density values, whereas the Colombian landrace had the highest. Heritability was moderate for growth traits (between 0.09 and 0.40), high for height to phase change (between 0.42 and 0.69), and moderate for wood density (0.28). The genetic correlation between growth and height to phase change was in general positive, but variable across sites. There was no correlation between growth and density. Despite large differences in growth between trials, pairwise genetic correlations suggest that genotype-by-site interaction is negligible. However, there was a poor correspondence between first-generation (ex-native stands) and second-generation families (ex-multi-provenance progeny trial). This suggests that breeding value estimates based on native open-pollinated material are unreliable.Conclusion
Results confirm negligible race differences for growth, but not for wood density. Future breeding efforts should include the various genetic backgrounds including the Colombian landrace which constitutes a very important source, especially because of its high density. Despite a low Genotype by Environment interaction, the poor genetic correspondence between the first- and second-generation trials indicates that selections for growth should be based on information coming mainly from the advanced-generation trials. 相似文献11.
David P. Blackburn Matthew G. Hamilton Chris E. Harwood Thomas G. Baker Brad M. Potts 《Annals of Forest Science》2013,70(5):461-470
Context
Stem straightness is an important trait for growers and processors of Eucalyptus globulus logs for solid-wood products.Aims
The aims of the study were to determine the extent of genetic variation in stem deviation from straightness in E. globulus and assess the utility of a six-point subjective scoring method as a selection criterion for stem straightness.Methods
Two E. globulus progeny trials, grown under solid-wood product regimes, were studied. At age 9 years (post-thinning), stem straightness was measured using both image analysis and a six-point subjective scale. Diameter at breast height (DBH; 1.3 m) was measured at both age 5 (pre-thinning) and age 9 years.Results
Significant additive genetic variation was observed. Strong, positive and significant additive genetic correlations were observed between the stem straightness assessment methods and between DBH at ages 5 and 9 years. Significant positive genetic correlations were shown between subjectively scored stem straightness and DBH at both ages 5 and 9 years.Conclusion
The six-point subjective scoring method is a cost-effective selection criterion for stem straightness in E. globulus. The image measurement technique may be applied where objective estimates of stem straightness are required, for training purposes and to verify subjective scores. 相似文献12.
Aims
This study aims to evaluate the effects of wood ash application on nutrient dynamics and soil properties of an acidic forest soil (Arenosol).Methods
Treatments were loose and pelleted ash application (11?Mg?ha?1), alone or together with N fertiliser, and control treatment in a lysimeter experiment. Nutrient leaching was followed during a 2-year period and soil chemical and biological properties were evaluated at the end of the experiment.Results
Wood ash increased leaching of total N, NH 4 + -N, base cations and P, mainly during the first months, the effect being more pronounced for the loose formulation. At the end of the study period, a positive effect on soil nutrient availability and soil acidity reduction was seen. The application of loose and pelleted ash alone decreased N leaching and increased N microbial biomass at the end of the experiment. The C dynamics was weakly affected.Conclusion
Wood ash can be used to improve nutrient availability and balance nutrient exported by tree harvesting in acid forest soils, the effects at short-term being stronger for loose than for pelleted ash. However, their application should be carried out when vegetation is established to minimise nutrient losses at short-term and reduce the potential risk for water bodies. In N-limited soils, wood ash should be applied with N fertilisers to counteract N immobilisation. 相似文献13.
Giulia Attocchi 《Annals of Forest Science》2013,70(7):663-673
Context
Avoidance or control of epicormic shoots is among the major silvicultural challenges for the production of high-quality oak timber. In northern Europe, contemporary oak silviculture aims to produce valuable timber on a relatively short rotation, applying early, heavy thinning combined with artificial pruning.Aims
The aim of this study was to analyse the effects of pruning and stand density on the production of new epicormic shoots on young trees of pedunculate oak (Quercus robur L.).Methods
The study was based on two field experiments in even-aged stands of pedunculate oak subjected to different thinning practices and early selection of potential future crop trees. From ages 13 to 15 years, stem density was reduced to 300 trees ha?1, 1,000 ha?1 or stands remained unthinned. Pruning was conducted on selected trees at ages 22–24 years. At that age, the stem density in unthinned control plots ranged from 2,500 to 3,100 ha?1. All treatments were replicated twice within each experiment.Results
Pruning led to an overall increase in the total production of new epicormic shoots. More epicormic shoots were produced in the lower part of the stem (0–3 m in height) than in the upper part (3–6 m). The number of new epicormic shoots increased with increasing stand density.Conclusion
Early, heavy thinning combined with high pruning at regular intervals may help shorten the rotation length for pedunculate oak without further reduction in wood quality than that which is caused by wider annual growth rings. 相似文献14.
Jean-Daniel Bontemps Pierre Gelhaye Gérard Nepveu Jean-Christophe Hervé 《Annals of Forest Science》2013,70(4):329-343
? Context
While historical increases in forest growth have been largely documented, investigations on historical wood density changes remain anecdotic. They suggest possible density decreases in softwoods and ring-porous hardwoods, but are lacking for diffuse-porous hardwoods.? Aims
To evaluate the historical change in mean ring density of common beech, in a regional context where a ring-porous hardwood and a softwood have been studied, and assess the additional effect of past historical increases in radial growth (+50 % over 100 years), resulting from the existence of a positive ring size–density relationship in broadleaved species.? Methods
Seventy-four trees in 28 stands were sampled in Northeastern France to accurately separate developmental stage and historical signals in ring attributes. First, the historical change in mean ring density at 1.30 m (X-ray microdensitometry) was estimated statistically, at constant developmental stage and ring width. The effect of past growth increases was then added to assess the net historical change in wood density.? Results
A progressive centennial decrease in mean ring density of ?55 kg?m?3 (?7.5 %) was identified (?10 % following the most recent decline). The centennial growth increase induced a maximum +25 kg?m?3 increase in mean ring density, whose net variation thus remained negative (?30 kg?m?3).? Conclusions
This finding of a moderate but significant decrease in wood density that exceeds the effect of the positive growth change extends earlier reports obtained on other wood patterns in a same regional context and elsewhere. Despite their origin not being understood, such decreases hence form an issue for forest carbon accounting. 相似文献15.
Shengkan Chen Qijie Weng Fagen Li Mei Li Changpin Zhou Siming Gan 《Annals of Forest Science》2018,75(1):16
Key message
Growth and wood chemical properties are important pulpwood traits. Their narrow-sense heritability ranged from 0.03 to 0.49 in Eucalyptus urophylla × E. tereticornis hybrids, indicating low to moderate levels of genetic control. Genetic correlations were mostly favorable for simultaneous improvement on growth and wood traits. Additive and non-additive genetic effects should be considered in making a hybrid breeding strategy.Context
Eucalypt hybrids are widely planted for pulpwood production purposes. Genetic variations and correlations for growth and wood chemical traits remain to be explored in Eucalyptus interspecific hybrids.Aims
Our objectives were to clarify the heritability of growth and wood chemical traits and determine the genetic correlations between traits and between trials in E. urophylla × E. tereticornis hybrids.Methods
Two trials of 59 E. urophylla × E. tereticornis hybrids derived from an incomplete factorial mating design were investigated at age 10 for growth (height and diameter) and wood chemical properties (basic density, cellulose content, hemi-cellulose content, lignin content, and syringyl-to-guaiacyl ratio). Mixed linear models were used to estimate genetic parameters.Results
Narrow-sense heritability estimates were 0.13?0.22 in growth and 0.03?0.49 in wood traits, indicating low to moderate levels of additive genetic control. Genetic correlations were mostly positively significant for growth with basic density and cellulose content but negatively significant with hemi-cellulose and lignin contents, being favourablefavorable for pulpwood breeding purpose. Type-B correlations between sites were significant for all the traits except diameter and lignin content.Conclusion
Hybrid superiority warrants the breeding efforts. An appropriate breeding strategy should be able to capture both additive and non-additive genetic effects.16.
Aims
The aim of this study was to test the hypothesis that heavy predation of fallen fruits reduces the predation of neighboring post-dispersed seeds.Methods
We performed a seed/fruit removal cafeteria experiment to assess the effects of seed species, of fruit species, and of density of fallen fruits on seed predation by wood mice (Apodemus sp.). In total, 6,930 seeds and 9,660 fruits from seven species were used. A generalized linear mixed model procedure was used to test these effects.Results
Seed predation was significantly affected by the species of both seeds and neighboring fruits, but not by their density. Multiple comparison tests showed that most of treatments tested had no significant effects of species and density of neighboring fruits on seed removal. However, seed removal was significantly lower in some treatments with fruits than in the treatments without fruits for one of the seven seed species tested. Seed removal of two species tested was significantly differed among some treatments with different fruit species.Conclusion
Most of the results in this study do not support our overall hypothesis. However, a part of results supported our hypothesis, suggesting that seed removal is affected by complex interactions between the preference of wood mice for fruits and fruiting environment. 相似文献17.
Key message
Pilodyn and acoustic velocity measurements on standing trees, used for predicting density and stiffness, can be good genetic selection tools for black spruce. Genetic parameters and selection efficiency were conserved in two breeding zones with contrasted bioclimatic conditions.Context
Given the recent progress made in the black spruce genetic improvement program, the integration of juvenile wood mechanical properties as selection criteria is increasingly relevant.Aims
This study aims to estimate the genetic parameters of in situ wood density and modulus of elasticity (MoE) measurements and to verify the efficiency of various measuring methods used for large-scale selection of black spruce based on wood quality.Methods
Height, diameter, wood density, and some indirect measures of density (penetration and drilling resistance) and MoE (acoustical velocity and Pilodyn) were estimated on 2400 24-year-old trees of 120 open-pollinated families in progeny trials located in the continuous boreal or mixed forest subzones.Results
Heritability of growth, density, and indirect density measurements varied from low to moderate and was moderate for acoustical velocity in both vegetation subzones. Expected genetic gains for wood properties based on in situ methods were higher for MoE proxy estimation combining Pilodyn and acoustic velocity.Conclusion
Acoustic velocity is a good predictor of MoE. It is virtually unaffected by the environment and can be used on a large scale in the same manner as the Pilodyn for density. Using a proxy estimation that combines both methods helps optimize genetic gain for MoE.18.
Valentine Lafond Guillaume Lagarrigues Thomas Cordonnier Benoît Courbaud 《Annals of Forest Science》2014,71(2):173-186
Context
Climate change is expected to increase forest vulnerability through disturbances such as windstorms and droughts. Forest managers are therefore investigating strategies to increase forest resistance and resilience, especially by promoting uneven-aged and mixed forests through group selection, and by reducing stand stocking and large trees proportion. However, there is little information on the long-term impacts of these two practices.Aims
The objectives of this study were (1) to develop an original silviculture algorithm designed for uneven-aged management and (2) to use it to assess the effects of the above-mentioned management methods in long-term simulations.Methods
We simulated individual and group selection techniques in order to study the effects of group size, harvesting intensity and their interactions on wood production, stand heterogeneity, and regeneration in mountain spruce–fir forests. We used the spatially explicit individual-based forest model Samsara2 to simulate forest dynamics.Results
Our simulation results confirmed the positive effect of group selection practices on structure diversity and regeneration but not on spruce maintenance. Increasing harvesting intensity enabled forest destocking but decreased structure diversity and led to non-sustained yields for the most intensive scenarios.Conclusion
As adaptation measure, we thus recommend moderate group selection harvesting creating 500 m2 gaps. 相似文献19.
Yannick Curnel Dominique Jacques Notburga Gierlinger Luc E. Pâques 《Annals of Forest Science》2008,65(8):810-810
20.
Christopher D. Morhart Gerry C. Douglas Christian Dupraz Anil R. Graves Michael Nahm Pierluigi Paris Udo H. Sauter Jonathan Sheppard Heinrich Spiecker 《Annals of Forest Science》2014,71(5):527-542