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1.
The ring characteristics and screw withdrawal resistance (SWR) of naturally regenerated Taiwan yellow cypress (Chamaecyparis obtusa var. formosana) trees were explored. Significant differences in average ring width (RW), earlywood width, latewood width, ring density (RD),
earlywood density (ED), latewood density (LD), highest density (Dmax), lowest density (Dmin), latewood percentage (LWP), and SWR were observed between trees, rings (SWR excluded), and tree height positions. The RW
components in the radial direction increased from the pith outward to about the 3rd to 5th ring and then decreased to about
the 25th ring; it was almost constantly sustained toward the bark side. The RD in the radial direction slowly decreased from
the pith outward to the bark side. Average ring width and ring density were significantly affected by the various tree growth
rates, radial ring numbers, and tree height positions. ED, LD, Dmax, Dmin, and LWP were the most important factors determining the overall RD. RW did not correlate with tree RD. SWR is correlated
with ED, RD, Dmin, LWP, and intra-ring density variation (IDV). Thus, the SWR can be used to predict wood density and in nondestructive evaluation
of a living tree. 相似文献
2.
Robert Sykes Bob Kodrzycki Gerald Tuskan Kirk Foutz Mark Davis 《Wood Science and Technology》2008,42(8):649-661
Clonal variability among trees has been studied and found to have profound effects on nearly all measured phenotypes. However,
when estimating wood properties it is important to consider variability within the tree. The position in which a tree is sampled
could have a large influence on biomass characterization. We looked at variability in lignin content as height increases and
as the number of rings from the pith increase in Populus species. Seven trees were destructively sampled; subsamples were obtained along a 2.4 m length of each stem and across increment
rings. All samples were analyzed by pyrolysis molecular beam mass spectroscopy to map the variability across sampling heights
and/or ring positions in lignin content. The results of this study indicate that when sampling a tree, there is more variability
from ring to ring than at different heights going up the stem. 相似文献
3.
Guillermo Riesco Muñoz Marcos Barrio Anta 《European Journal of Forest Research》2010,129(6):1037-1045
Forty young trees from a stand of maritime pine in the southern mountains of Galicia, Spain (42°21′N: 8°01′W) were felled
to obtain the material required for studying density and shrinkage in clear and small wood specimens. The wood ranged from
light to moderately heavy, and the dimensions remained reasonably stable with varying moisture content. The results were consistent
with those obtained in previous studies of adult trees, except for axial shrinkage, which was very high and variable in this
study. The between-tree variation in wood properties was high considering that the sampled trees came from the same stand.
However, the relationships between density and height in the stem were similar in all trees. A general model for the prediction
of volumetric shrinkage was developed, with oven-dry density and ring width as predictor variables. The model is feasible
for estimation of wood quality in living trees. It is applicable to tree selection for thinning and for genetic improvement
of stock. 相似文献
4.
Yoshitaka Kubojima Seiichi Kanetani Takeshi Fujiwara Youki Suzuki Mario Tonosaki Hiroshi Yoshimaru Hiroharu Ikegame 《Journal of Wood Science》2008,54(6):443-450
A dead tree of Pinus armandii Franch. var. amamiana (Koidz.) Hatusima (abbreviated to PAAm) was obtained from a natural habitat on Tanega-shima Island and various properties
of its wood were investigated. Grain angle was measured and soft X-ray analysis was undertaken to obtain the density in each
annual ring. Unit shrinkage and dynamic properties were measured by shrinkage, bending, and compression tests. Variations
of wood properties in the radial direction, relationships of wood properties to density, and annual ring width were examined.
Roughly speaking, variations in the radial direction of the grain angle, twist angle by drying, Young’s modulus and strength
in static bending, absorbed energy in impact bending, compressive Young’s modulus, compressive strength, and compressive proportional
limit corresponded to the variation of annual ring width. As a result, it was determined that if PAAm is afforested artificially
for the purposes of lumber production and conservation, the annual rings of logs should not be too widely spaced. Wood properties
of PAAm were similar to those of Japanese black pine (Pinus thunbergii Parl.), which is another representative pine on Tanegashima Island.
This study was presented in part at the 56th Annual Meeting of the Japan Wood Research Society, Hiroshima, August 2007 相似文献
5.
José Ángel Pulgar Lorenzo Guillermo Riesco Muñoz 《European Journal of Forest Research》2018,137(4):507-515
The laurel (Laurus nobilis L.) is a common species in southern Europe, but the properties of its wood are not well described in the literature and from that perspective any novel information is valuable. Because of that, a group of laurels was felled for the analysis of wood properties on small defect-free specimens (17 trees and 1250 valid specimens). The sampled wood was moderately heavy and unstable. The following mean values were obtained (density at 12% moisture content 699 kg m?3; basic density 566 kg m?3; total volumetric shrinkage 18.0%; volumetric shrinkage coefficient 0.59%). Highly significant inter-tree and intra-tree variation was observed for most of the properties considered. The inter-tree variation was attributed to tree dimensions, being remarkable that volumetric, radial and tangential shrinkage coefficients were significantly related to breast height diameter and slenderness. The trends of these variables suggest that in trees older than those used in the study (24–41 years old) the dimensional stability would increase. As regards the inter-tree variation, a low but highly significant decrease was found for density at highest positions in the tree. Volumetric and linear shrinkage diminish very significantly along the stem. Due to the uniformity of density and the increment of wood dimensional stability along the trunk, the harvesting of the full stem is advisable. 相似文献
6.
Md Qumruzzaman Chowdhury Futoshi Ishiguri Kazuya Iizuka Yuuya Takashima Kahoru Matsumoto Tokiko Hiraiwa Megumi Ishido Hiroyuki Sanpe Shinso Yokota Nobuo Yoshizawa 《Journal of Wood Science》2009,55(2):139-143
Radial variations of wood properties (basic density, fiber length, vessel element length, and compression strength) in plantation-grown
Casuarina equisetifolia in Bangladesh were investigated for effective utilization of the wood. Samples disks at breast height were randomly collected
from trees in a 10-year-old plantation in Cox’s Bazar Forest Division, Bangladesh. The basic density showed a near-constant
value up to 30 mm from the pith and then rapidly increased up to 60 mm from the pith. The fiber length and vessel element
length gradually increased from the pith to bark. When radial variation of wood properties was determined according to relative
distance from the pith, similar radial patterns were observed among the sample trees, indicating that the wood properties
in C. equisetifolia may be related to the growth rate. The compression strength parallel to the grain (CS) increased from the pith to bark. A
significant positive correlation was found between the air-dried density and the CS. The results obtained indicated that wood
around the pith has a relatively low density, and wood outside the pith area has a relatively high density, suggesting that
it could be used as structural lumber.
Part of this report was presented at the 58th Annual Meeting of Japan Wood Research Society, Tsukuba, March 2008 相似文献
7.
The fast growth of Tetracentron sinense is a potential valuable timber resource, but whether its anatomy and chemical components are suitable for timber is unknown. We used light microscopy and SEM to examine the anatomical structure and FITR to measure the chemical components of the phloem and xylem of this tree. Radial variations in growth ring width and tracheid dimensions were also evaluated. The sieve tube, phloem parenchyma cell and sclereids clusters were the main cells in phloem, and the tracheid was the fundamental cell in xylem. An unusual tracheid type, fiber-tracheids or vessel-liked elements was visible. Wood rays nonstoried, uniseriate and multiseriate, including heterogeneous II, occasionally I, and usually 3–6 cells wide. The mean growth-ring width was 2.53 ± 0.46 mm, and the percentage of late wood was over 60%. For radial variation, growth-ring width increased at an early growth stage, and reached the largest increment during years 11–15, then decreased. The maximum growth-ring width was 5.313 mm. During late growth (60–85 years), trees also maintained a high radial growth increment. Radial variation in the percentage of late wood was uniform, about 50–70%, throughout the growth years. Growth patterns in the length and width of early and late wood were similar as the trees aged. From the FTIR results, the chemical components differed significantly between xylem and phloem, hemicellulose in particular was higher in the xylem than in the phloem, where it was apparently absent. All of these suggest that the composition of phloem in T. sinense is very similar to that of hardwood, and it has higher growth ratio and uniform wood properties. 相似文献
8.
Balanites aegyptiaca (L.) Delile provides wood and other essential products for farming and pastoralist communities in the West African Sahel.
In this region, mean annual rainfall decreases in general from south to north and from west to east, so one might expect clinal
variation in fitness-related traits in relation to the rainfall gradients. This paper presents results from a provenance/progeny
test of 11 provenances sampled in Niger and established at one relatively dry site in Niger. The objectives were to evaluate
phenotypic correlations (Pearson r) between tree growth (height, stem diameter) and basic density of the wood, and clines in growth and density at 13 years.
Tree growth and wood density were positively correlated, and the correlations differed among provenances. Mean tree height
and stem diameter of provenances increased, in general, from the more humid to the drier parts of the sample region. Results
suggest that selection of faster-growing trees could lead to an increase in wood volume and density in the subsequent generation,
especially in certain provenances; that provenances from drier areas are better adapted to drought; and that tree improvement
and conservation programs should collect seeds from populations in the drier areas for planting and conservation. 相似文献
9.
Kana Yamashita Yasuhiko Hirakawa Hiroshi Nakatani Motoyoshi Ikeda 《Journal of Wood Science》2009,55(3):161-168
The transverse shrinkage variation within trees was examined for five sugi cultivars. The within-tree trends of tangential
shrinkage (α
T) were different by cultivar, whereas radial shrinkage (α
R) increased from pith to bark in most cultivars. The tangential/radial shrinkage ratio (α
T/α
R) decreased from pith to bark in most cultivars, because the radial variation of α
R was larger than that of α
T. The cultivars showed significant differences among cultivars in α
T, α
R, and α
T/α
R, but the difference among cultivars for α
T/α
R was smaller. The relationships between transverse shrinkage and microfi bril angle (MFA), basic density (BD), tree ring parameters,
and modulus of elasticity were examined. The α
T and α
R showed positive relationships with BD, latewood percentage, latewood density, and modulus of elasticity, and negative relationships
with MFA and ring width. The relationships with earlywood density were weak. Sugi exhibited variation in transverse shrinkage
within stem and among cultivars, with the variation affected by MFA, density, and tree ring parameters.
Part of this article was presented at the 56th Annual Meeting of the Japan Wood Research Society, Akita, Japan, August 2006,
and the 57th Annual Meeting of the Japan Wood Research Society, Hiroshima, Japan, August 2007 相似文献
10.
Wood formation of trees that grow along the seasons has an annual rhythm. Due to this rhythm, physiological research on the mechanism of wood formation has been difficult to conduct in a typical experimental room. In the present study, we observed the wood tissue formation in a shortened annual cycle system, which was developed for poplar trees grown in a growth chamber with dormant and non-dormant cycles. Poplar trees were grown in this system by repeating the cycle three times. The resulting wood tissue consisted of three growth rings and very similar structures were observed around the ring boundary of the wood in a field-grown stem. This result suggests that the shortened annual cycle system can be adopted as a model for physiological, cell biological and molecular research of wood and annual ring formation. 相似文献
11.
Shaopeng Yin Zhenhai Xiao Guohui Zhao Xin Zhao Xiaoyang Sun Ying Zhang Fuwei Wang Shuchun Li Xiyang Zhao Guan-Zheng Qu 《林业研究》2017,28(4):687-697
The growth traits (tree height, diameter at breast height, and stem straightness degree) and wood properties [wood density (WD), fiber length, fiber width, ash content (AC), lignin content, cellulose content, hemicellulose content (HEC), and holocellulose content] of 208 26-year-old Larix olgensis clones were analyzed. Except for WD and AC, there were significant differences (p < 0.01) for all traits among clones. The phenotypic coefficient of variation and repeatability of all traits were 9.34–35.33% and 0.218–0.930, respectively. Tree height and diameter at breast height showed significant positive correlation; however, the correlation coefficients among growth characteristics and wood properties were mostly not significant. Ten clones (L70, L56, L82, L90, L59, L91, L61, L92, L86, and L64) were selected as excellent clones under a selection rate of 5%, using tree height, diameter at breast height, and stem straightness degree as evaluation indexes, providing genetic gains of 28.69, 17.96, and 0.67%, respectively. Ten clones (L88, L305, L59, L66, L253, L304, L277, L298, L248, and L293) were selected as excellent clones using wood properties as an evaluation index, with a selection rate of 5%, providing genetic gains in WD, fiber length, fiber width, cellulose content, and HEC of 4.14, 3.64, 9.28, 6.77, and 9.61%, respectively. This study provides a theoretical basis for selecting excellent L. olgensis clones. 相似文献
12.
13.
Kana Yamashita Yasuhiko Hirakawa Hiroshi Nakatani Motoyoshi Ikeda 《Journal of Wood Science》2009,55(1):1-7
The longitudinal shrinkage variations within trees and the relationship with density, microfibril angle, and modulus of elasticity
were examined for five sugi cultivars selected for different within-tree distributions of density, microfibril angle, and
modulus of elasticity. The cultivars showed significant differences in longitudinal shrinkage and in its within-tree distribution.
The within-tree distributions were categorized into two types: (1) large values of longitudinal shrinkage near the pith that
decreased with height and from pith to bark, (2) small values of longitudinal shrinkage near the pith that increased slightly
from pith to bark. There were strong relationships between longitudinal shrinkage and microfibril angle, and modulus of elasticity,
with large values of longitudinal shrinkage associated with large microfibril angle and low modulus of elasticity. Sugi exhibited
large variation in longitudinal shrinkage within stem and among cultivars, with the variation strongly affected by microfibril
angle.
Part of this article was presented at the 56th Annual Meeting of the Japan Wood Research Society, Akita, Japan, August 2006 相似文献
14.
Geographic variation in tree growth and wood density of <Emphasis Type="Italic">Guazuma crinita</Emphasis> Mart. in the Peruvian Amazon 总被引：1，自引：0，他引：1
Guazuma crinita Mart. is a fast-growing timber tree in the Peruvian Amazon. A trial of 11 Peruvian provenances was established in three planting
zones. Tree growth at 6, 12, 18 and 30 months and wood density at 32 months were analyzed across and within zones. Zones accounted
for more variation than provenances. Density varied significantly due to provenances in the analysis across zones, whereas
growth exhibited strong provenance by zone interactions. The local provenance grew well and produced relatively dense wood
in all zones. The relative magnitude of variation due to provenances depended on the planting zone. Density was greater in
the lower than in the upper stem. Density increased with longitude from the more humid to the drier part of the sample region.
In general, correlations indicated that larger trees had lower density and a larger difference in density between the lower
and upper stem, but the strength of these relationships depended on the provenance and zone. Results suggest that fast-growing
provenances can be selected at an early age without significantly reducing wood density. The local provenance is recommended
for reforestation pending future research demonstrating the superiority of foreign provenances. Some practical implications
for tree-improvement programs are discussed. 相似文献
15.
The wood quality from 50- to 70-year-old Tectona grandis trees from an unmanaged forest in East Timor was assessed. The aim was to evaluate teak in mature stands that had undergone
uncontrolled disturbances, e.g., fire and local community usage. Heartwood represented 91% of the tree radius at a height
of 1.7 m, and sapwood contained on average nine rings. The mean ring width showed within-tree and between-tree variability.
The chemical compositions of heartwood and sapwood were similar. Within-tree chemical variation occurred only in terms of
extractives, which increased from the pith (8.3%) to the heartwood-sapwood transition (12.7%) and decreased in the sapwood
(9.2%). Overall, the wood properties of teak from a unmanaged forest in East Timor were comparable to those reported for plantation
teaks of other origin: 607 kg/m3 basic density, 3.5% and 5.2% radial and tangential shrinkage, 141 N/mm2 modulus of rupture, 10684 N/mm2 modulus of elasticity, and 50 N/mm2 maximum crushing strength in compression parallel to the grain. Disturbances on individual tree growth arising from the unmanaged
status of the stand were evidenced by higher within-tree variability of ring width. However, the longitudinal and radial variations
of wood density and mechanical properties were of low magnitude and in a degree that did not negatively impact on timber quality. 相似文献
16.
I investigated the relationships between stem surface area outside bark and other stem dimensions for Japanese cedar (Cryptomeria japonica D. Don) and Japanese cypress (Chamaecyparis obtusa Endl.) trees. The stem dimensions used here were the basal area and the product of diameter at breast height (dbh) and total tree height. The regression equation of the stem surface area s against basal area g was s = 184.216g for the cedar trees and s = 156.878g for the cypress trees. The slope of the equation was significantly different between the two species. For the same dbh, the cedar trees tended to have a higher total tree height than the cypress trees. The cedar trees also had a larger surface area of relative stem form than the cypress trees. These results indicated that the difference in the slope was produced by the differences in both the stem slenderness and tapering between the two species. On the other hand, the regression equation between the stem surface area and the product of dbh and total tree height dh was s = 1.937dh for the cedar trees and s = 1.921dh for the cypress trees, whereas no significant difference in the slope was found. The obtained slopes for the cedar and cypress trees seemed to be in accord with that for other coniferous species reported in earlier studies, suggesting that the variation in the slope among coniferous species would be small. The estimation from the basal area would provide a simpler means for estimating the stem surface area and would be useful in obtaining an approximation of the surface area. By contrast, the estimation from the product of dbh and total tree height would provide a more accurate and precise estimate as well as a wider applicable range, i.e., a parameter for physiological growth models. In conclusion, it could not be judged which regression equation examined in the present study was superior to the other, and thus it was important to select an appropriate equation depending both on the purpose and on the time and labor available. 相似文献
17.
Young trees were harvested to explore non-destructive methodologies to estimate live branch dry weights in young fast-growing Eucalyptus species under different spacing and fertilizer treatments. Branch growth can vary with silvicultural management such as spacing, fertilizing and thinning, and over relatively short periods in response to environmental conditions. Many published regressions based on standard measurements of height and diameter are site, age and treatment specific. The aim of this study was to improve our capacity to predict woody crown dry weight, based on stem measurements, and to minimize (or eliminate) treatment effects on the resulting model. In young trees, branches are temporary support structures for foliage and are often discarded as the base of the green crown rises. As temporary structures they represent an investment of biomass and nutrient elements, and are subject to selection pressures to maximize the return on investment by the tree. Trees were harvested from existing plantation experiments located in south-eastern Queensland for E. grandis W. Hill ex Maiden (ranging from 0.28 to 15.85 m in height, to 5 years old) and south-western Australia for E. globulus Labill. (0.10–34.4 m in height, to 10.2 years) in order to examine the impact of spacing, nitrogen and phosphorus fertilization on early growth. Relationships to estimate crown woody biomass from non-destructive measurements were developed, and these relationships tended to have different slopes and intercepts for trees with predominantly juvenile foliage and those with intermediate or adult foliage. Dry weight of whole-crown live branch wood (Wbranch) was related to heights and/or diameter at breast height (DBH), but the regressions parameters were different, depending on treatment. The relationships became more generic (i.e. less dependent on treatment effects) between Wbranch and stem sectional area at the height of the base of the green crown (SACB), consistent with the pipe model theory (R2 > 0.91 for the two species for trees with intermediate/adult leaves). However, Wbranch was more closely related again to the stem volume above the base of the green crown and treatment effects were not significant (VCon,gc, R2 > 0.93). Branches exit the stem below the green crown, and for E. grandis the best relationship was on stem volume above the lowest live branch (VCon,llb, R2 0.94). Limited sampling from four other species with similar or contrasting crown characteristics indicated that the relationship could be applied quite generally. Individual E. grandis branch woody dry weight was closely related to the conical volume of the main (first order) branch (Vcon,br, R2 0.98). The whole crown equivalent, branch woody dry weight plus stem dry weight above the lowest live branch, was also closely related to the stem volume within the woody crown (VCon,llb, R2 0.97–0.99). While the slope of this relationship was still significantly different between trees with juvenile and intermediate/adult foliage, it had a similar form, suggesting that trees with juvenile foliage allocated a different proportion of their woody biomass within the crown to branches than older trees. 相似文献
18.
Three-dimensional distribution of water in the heartwood of Cryptomeria japonica D. Don was observed by soft X-ray photography. The within-tree variation in the distribution of “wet areas” (water-accumulated
areas in heartwood) was enormous, as was the variation among trees. Although we found no universal pattern of changes in wet
area distributions along the stem axes of all trees, similarities among individual trees within each cultivar and clone were
observed. The difference between the two kinds of wetwood in C. japonica – genetically defined wetwood and secondarily induced wetwood – is discussed, as is the use of soft X-ray photography in Japanese
tree breeding programs.
Received: December 21, 2001 / Accepted: May 1, 2002
Part of this paper was presented at the 46th Annual Meeting of the Japan Wood Research Society, Kumamoto, Japan, April 1996
Correspondence to:R. Nakada 相似文献
19.
Tougiani Abasse John C. Weber Boubacar Katkore Moussa Boureima Mahamane Larwanou Antoine Kalinganire 《Agroforestry Systems》2011,81(1):57-66
Balanites aegyptiaca (L.) Delile. is one of the priority indigenous fruit trees for rural communities in the West African Sahel. As part of a
participatory tree domestication program in Niger, phenotypic variation in fruit and seed morphology was assessed in four
natural populations in eastern Niger. Measured variables were weight of the fruit, seed coat and kernel; length and width
of the fruit and seed (25 trees per population, 30 fruits per tree). Derived variables were the tree’s coefficient of variation
(CVs) for each measured variable, and two sets of factor scores from principal components analysis of tree means and CVs.
ANOVA indicated significant variation in all measured variables due to trees nested in populations. ANOVA and simple linear
regression indicated significant geographic variation in some variables: the drier parts of the sample region tended to have
heavier fruits and kernels, longer/narrower seeds, and lower within-tree variability in fruit and seed width. Length and width
were strongly correlated between fruits and seeds, fruit weight was moderately correlated with seed dimensions, and CVs of
fruit weight and width were moderately correlated with the CV of seed width. Some hypotheses for the geographic variation
are presented, and some practical implications of the correlations for tree domestication programs are discussed. 相似文献
20.
Wei Wang Yuichi Hanai Chisato Takenaka Rie Tomioka Kazuya Iizuka Hajime Ozawa 《Journal of Forest Research》2016,21(5):251-258
Absorption of radiocesium (137Cs and 134Cs) through bark, and its subsequent translocation into wood and needles, has been suggested as a potential source of tree contamination, but the process is not well understood. Field experiments were conducted to confirm whether Cs could enter a Japanese cedar tree through the bark and how Cs moves within a tree. Stable Cs (133Cs) was applied to the bark at 1.2-m height on 10- and 26-year-old Japanese cedars. The 133Cs concentrations were determined in the bark, sapwood, and heartwood (for 26-year-old cedar only) of stem disks from several heights, as well as in current-year needles from the canopy. The 133Cs concentrations were considerably higher in the sapwood and heartwood of stem disks from 1.2-m height in treated trees than in untreated trees, suggesting that 133Cs penetrated the bark to enter the wood. The average 133Cs concentrations were higher in the heartwood than the sapwood, indicating 133Cs accumulation in the heartwood. High 133Cs concentrations in the needles of treated trees implied acropetal movement of 133Cs to actively growing organs. Our results demonstrate that Cs can enter Japanese cedar trees through the bark and that Cs is transported radially to the heartwood and vertically to the apex. 相似文献