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1.
Summary The variation of six wood properties was studied within and between six trees ofPinus kesiya Royle ex Gordon (syn.P. khasya Royle;P. insularis Endlicher) grown in Zambia from seed of Assam provenance and exhibiting 24 annual rings at 5 ft. above ground. There were no important variations in latewood width (mean 0.8 mm) or grain angle (-1.7°). Total ring width (5.2 mm), latewood percentage (19.5%), tracheid length (4.8 mm) and density (0.50 g/cm3) exhibited systematic patterns of variation within trees that could be related to ring number and height by quadratic polynomials, which explained 70 to 90% of the variation. The most important source of random variation was the difference between individual trees and it is recommended that for plantation surveys many trees should be sampled by 3 to 4 annual rings on two radii at breast height.The wood samples were kindly supplied by the Zambia Forest Research Division. Laboratory work was undertaken at the Tree Improvement Research Centre, Agricultural Research Council of Zambia, P. O. Box 1210, Kitwe, Zambia. The authors wish to acknowledge the laboratory assistance of MissP. Waters, Mrs.G. A. R. Howell and Mr.J. F. Morgan. Data was processed on the IBM 360 computer of the Anglo-American Corporation, Kitwe, and on the KDF 9 computer of the Oxford University Computing Laboratory. 相似文献
2.
Jeffery Burley 《Wood Science and Technology》1970,4(4):255-266
Summary The variation of six wood properties was studied within and between eighteen trees of Pinus kesiya Royle ex Gordon (syn. P. khasya Royle; P. insularis Endlicher) grown in Zambia from seed of Burma provenance and exhibiting 16 annual rings at 5 ft. above ground. Three trees represented each of two size classes in each of three thinning treatments. Thinning effects were poorly estimated but heavy thinning increased ring width, decreased latewood percentage and caused marginal decreases in tracheid length and density. The two tree classes differed in ring width characteristics. Individual trees varied particularly in density; significant height effects were detected for tracheid length and density. Latewood width (mean 0.9 mm) and grain angle (-1.2°) varied little but total ring width (5.8 mm), latewood percentage (19.6%), tracheid length (4.6 mm) and density (0.46 g/cm3) exhibited systematic patterns of variation within trees; quadratic polynomials including ring number and height as independent variables explained 80 to 90% of the variation. Radial differences were often statistically significant but practically unimportant. For plantation surveys many trees should be sampled by 3–4 annual rings on two radii at breast height.Wood samples were supplied by the Zambian Forest Research Division. Laboratory work was undertaken at the Tree Improvement Research Centre, Agricultural Research Council of Zambia, P. O. Box 1210, Kitwe, Zambia. The author acknowledges the laboratory assistance of Miss P. Waters, Mr. J. Mweetwa, Mr. F. Mulimbwa and Mr. N. Phiri. Data were processed on the IBM 360 computer of the Anglo-American Corporation, Kitwe, and on the KDF 9 computer of the Oxford University Comuting Laboratory; Mr. I. A. andrew, Mr. P. G. Adlard and Mrs. T. Posner assisted at various stages. 相似文献
3.
Summary Intra-increment circumferential variation in tracheid length at breast-height in deodar (Cedrus deodara (Roxb.) Loud. vern. diar) has been studied with the main objective of evolving an efficient sampling procedure for the purpose of comparing tracheid length amongst individual trees of forest stands. It has been studied in five sampling strata namely: whole-annual ring, whole-earlywood, whole-latewood, first-firmed earlywood and last-formed latewood. Tracheid length shows significant circumferential variation in whole-annual ring, whole-earlywood, whole-latewood and last-formed latewood. However, when the mean tracheid length of two opposite directions is compared with the mean tracheid length of eight cardinal directions in these sampling strata, then no significant difference is observed. First-formed stratum of an annual ring exhibits statistically consistent values around the circumference and thus sampling from any random radial direction can serve the purpose for the comparison of inherent values of tracheid length amongst the deodar trees.The financial assistance given by Himachal Pradesh University as H.P.U. Junior Research Fellowship to second author is highly acknowledged 相似文献
4.
Summary Individual fibre lengths were measured on the projected images of macerated tissue samples of seven Eucalyptus species grown in a replicated species trial in Zambia. Analyses of variance and variance components were used to study variation between species, replications, distances from the pith, radial positions, microscope slides and individual fibres. The overall mean was 0.93 mm and little variation was attributable to the main factors (fixed effects); two-thircs of total variation was due to differences between fibres within samples. Variance components for random factors were used to compare different sampling strategies; the size of acceptable difference for hardwoods (0.10 ... 0.14 mm) is considerably less than that for conifers and samples of 80 ... 200 fibres may be necessary. Differences between microscope slides were unimportant and two or more slides would be necessary only to facilitate location of the large numbers of fibres or to provide a check on operators.Laboratory work was carried out at Tree Improvement Research Centre, Kitwe, Zambia. 相似文献
5.
6.
《Scandinavian Journal of Forest Research》2012,27(5):462-469
Abstract Wood properties, including tracheid cross-sectional dimensions, show a large degree of variation. To improve the properties of products made from wood, different methods to control variation have been developed. This study aims to determine the theoretical efficiency of three control strategies: the fractionation of pulped tracheids into earlywood and latewood, the separation of juvenile and mature wood, and sorting of logs according to tree size. The efficiency of each method was studied by first constructing virtual trees from measured tracheid cross-sectional dimensions, then simulating the efficiency of above-mentioned methods. The tracheid dimension data include Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.). The simulations show that separation into earlywood and latewood classes has the highest theoretical efficiency and yields the lowest variances in raw material. Classification into juvenile and mature wood groups is the second most efficient method, and the sorting of logs according to the size class of the tree is the least efficient method. It was also concluded that the variation in cell-wall thickness and radial diameter mainly originates from differences between earlywood and latewood, whereas the variation in tangential diameter mainly originates from differences between mature and juvenile wood. 相似文献
7.
Tangential pitting in black spruce tracheids 总被引：1，自引：0，他引：1
Zoltan Koran 《Wood Science and Technology》1977,11(2):115-123
Tangential pit features were studied in a 55-year old black spruce (Picea mariana (Mill) B.S.P.) tree by means of light and electron microscopy.It was found that tangential pitting is lacking from the greatest part of the growth ring, except for the last four tangential rows of latewood tracheids and the first row of early wood tracheids. The average number of pits per tangential wall of a 3.55-mm-long tracheid is 234, 144, 28, 4 and zero, respectively, in the last 5 tangential rows of latewood tracheids, starting at the growth-ring boundary.On the average, tangential pits measure 5.4 m in diameter, possess oval to elliptical apertures, and are randomly distributed uniformly over the tangential tracheid wall. All tangential intertracheid pits are bordered and in that respect are similar to those in the radial walls. Although most of the pits contain membranes with tori, some at the growth-ring boundary lack tori and exhibit randomly oriented microfibrillar structure. 相似文献
8.
Luis G. Esteban Juan A. Martín Paloma de Palacios Francisco García Fernández 《European Journal of Forest Research》2012,131(3):633-645
Region of provenance is defined as an area with uniform ecological conditions where stands with similar phenotypic or genetic
features are found. This study assesses the effect of differing climate conditions of eight Spanish regions of provenance
of Pinus nigra Arn. subsp. salzmannii on earlywood anatomical traits measured in samples from basal discs from mature trees. Results showed that variation in wood
biometry between provenances was high and more pronounced than intrapopulation variation. When comparing P. nigra with other Mediterranean pines, high intertracheid wall strength values are associated with better adaptation of pines to
arid conditions. However, the intraspecific variations of this parameter in P. nigra did not follow the same pattern, due to the influence of mechanical support requirements. Trees subject to greater aridity
were characterised by short tracheids, apparently resulting from their poorer growth, and high frequency of rays and ray parenchyma
cells, which would allow trees to store greater amounts of starch, which is the source of metabolites invested in minimising
the limitations imposed by water stress. Severe winter cold spells were strongly associated with high axial resin canal frequency
and large radial resin canals, creating a powerful, preformed defence system. Increased tracheid lumen involved an increase
in the size of bordered pits, favouring sap flow between tracheids, in addition to an increase in the maximum diameter of
cross-field pits, favouring the flow of water and metabolites between the axial and radial systems. The high influence of
region of provenance on structural variation in P. nigra shows the importance of provenance in the selection of seed origin for reforestation. 相似文献
9.
1 Introduction A number of studies have been carried out to examine the process of liquid impregnation into different kinds of wood (Stamm and Raleigh, 1967; Bolton and Petty, 1978; Olsson et al., 2001). Different techniques and methods have been developed so far to obtain quanti- tative and qualitative information about this process (Stamm, 1953; Stone, 1956; Rudman, 1965). Penetra- tion of liquid in wood depends on several factors. The penetration rate and amount varies in different spec… 相似文献
10.
Summary The cross-sectional view of pitting between various cell types inPinus banksiana Lamb. was studied at the ultrastructural level. Cell types inPinus banksiana include longitudinal tracheids, ray tracheids, ray parenchyma cells, buffer cells and epithelial cells. Two common characteristic features of bordered pit-pairs between longitudinal tracheids are an initial pit border and a thickened torus at the center of the pit membrane. The shape and size of the pit border and torus of bordered pit-pairs between two compression wood cells, and between the last-formed latewood longitudinal tracheid and first-formed earlywood longitudinal tracheid were different from those in the earlywood and latewood longitudinal tracheids. The pit border on the ray tracheid side varied in size and shape due to wall dentation. No initial pit border was found on the pit border of the ray tracheid side. The shape of bordered pit-pairs between two ray tracheids varied considerably due to irregularity of the dentate cell wall. The size of bordered pit-pairs in longitudinal tracheids was between 16 m to 20 m, which was twice the diameter of bordered pit-pairs in ray tracheids. Bordered pitpairs at the end wall of two ray tracheids appeared to be the smallest at 5 m, Pit aspiration occurred in the bordered pit-pairs with or without a torus. In the heartwood zone, some half-borders pit-pairs between tracheary and ray parenchyma cells showed an additional secondary wall on the ray parenchyma cell side. Plasmodesmata were found in the half-bordered pit-pairs as well in the simple pit-pairs. Blind pits were observed between a ray tracheid and a longitudinal tracheid. Bordered pit-pairs between two buffer cells were also observed. The possible functions of buffer cells were discussed.Use of transmission electron microscope provided by the Science Instrumentation Lab, Lakehead University and the technical assistance provided by Mr. A. MacKenzie, Director of Science Instrumentation Lab are gratefully appreciated 相似文献
11.
Key message
Onset and cessation of radial and height increment of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) in southern Finland were independent phenomena. They both contributed to the increment period duration, which was a more crucial factor defining the magnitude of annual radial and height increment.Context
Phenology of diameter and height increment is a critical component of growth, also contributing to damage and survival of trees.Aims
We quantified annual variation in intra-annual tracheid production and height increment of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.).Methods
The number of tracheids and the day of the year for the onset and cessation of tracheid production were monitored from microcores collected repeatedly during growing seasons 2001–2012 in southern Finland. Weekly height increment was also measured in an adjacent sapling stand in 2008–2012.Results
The first tracheids in pine were found around mid-May and in spruce a week later. The cessation of the tracheid production occurred during the last week of August for both tree species. Increment onset and cessation were independent phenomena, both contributing to the magnitude of tracheid production via increment period duration, which appeared to be a more crucial factor defining the number of tracheids. Duration of the height increment period was also related to shoot length but the connection was less tight than the link between the duration of tracheid production and the number of tracheids. A thermal threshold around 100 d.d. (degree days) was found for the onset of radial increment. No single environmental factor triggered the cessation of tracheid production, but in some years, soil water availability appeared to play a role.Conclusion
The results indicate that extending growing seasons due to the climatic warming may increase growth in the Finnish forests.12.
An analysis of the pattern of genetic variation in Vitellaria paradoxa using RAPD markers 总被引：3，自引：2，他引：3
Vitellaria paradoxa C.F.Gaertn. is one of the most economically and socially important tree species in the Sudano-Sahelian region. Little is known of the pattern of variation within its natural range. Eight populations covering most of the natural range from Senegal to Uganda were sampled and leaves of 118 individual trees were collected. An analysis of molecular diversity was carried out using random amplified polymorphic DNA (RAPD) markers. Fifteen random primers generated 67 polymorphic and 15 monomorphic RAPD loci ranging from size 1670 bp to 280 bp. Shannon's diversity index varied from Central Africa/Ndele (0.374) to Uganda/Amoya (0.350) but the differences between populations were smaller than the population standard errors. Correspondence analysis of unrooted neighbour-joining trees suggested that genetic distances between populations were correlated with geographic distances. This trend was confirmed by a Mantel test giving a coefficient of correlation between genetic and geographic distances of R = 0.88 (P = 0.0001). Result of AMOVA (analyses of molecular variance) showed that 14.8% (P = 0.002) of the RAPD variation was distributed among populations. Nested analysis of variance indicated that variance between the western and eastern groups of population represented 8.7% (P = 0.001) of the total variation and the variation amongst populations within group was 9.5% (P = 0.001). Eighty two percent of the variation was explained by variation amongst individuals within populations. The origin of genetic structure and level of diversity may be explained by the glacial refugia, the biological traits of Vitellaria paradoxa and by the impact of semi-domestication. Based on these results, sampling options of the natural populations are suggested for in or ex situ conservation. For the development of Vitellaria paradoxa breeding population, the sampling should consist of many individual trees selected within a few populations to capture a large proportion of variation.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
13.
The technology of steam explosion was applied to pre-treat sub-alpine fir (Abies lasiocarpa (Hook.) Nutt.) lumber and to improve its drying characteristics. Effects of steam explosion on the appearance and structure of the lumber are discussed in this paper. The structure of the wood was examined using light microscope (LM) and scanning electron microscope (SEM). The following results were obtained. With increasing temperature, pressure, and explosion cycles the color of the lumber darkened gradually. No significant structural difference between treated and untreated samples was observed using LM when the treatments were carried out at temperatures below 130°C with ten explosion cycles (group A or B). Some fractures were observed in bordered pit pairs between tracheids after 20 explosion cycles at 130°C (group C). More fractures occurred in bordered pit pairs between earlywood tracheids at a temperature of 160°C (group D). More or less fractures in pits between ray parenchyma cells and earlywood tracheids were observed using SEM in all four cases of treatments. Although no change in bordered pits in the tracheid walls between group A and the control group was discovered, groups B, C, and D showed different extents of ruptures in bordered pits, which may lead to break aspirated pits and improve permeability. In these groups, wrinkles and separations in the inner tracheid walls and detachments in middle lamella also occurred and became more serious as temperature or cycles of the treatment increased. 相似文献
14.
《Scandinavian Journal of Forest Research》2012,27(1-4):45-58
Flooding of soil for 55 days altered the rate of growth and stem anatomy of 9‐month‐old Cryptomeria japonica seedlings. Although flooding did not affect height growth it reduced the rate of dry weight increment of seedlings while increasing stem diameter. The reduction in dry weight increment of seedlings resulted largely from decay of roots and, to a lesser extent, from inhibition of growth of roots and needles. The increased diameter growth of flooded seedlings resulted largely from an increase in bark thickness associated with increased phloem production and greater amount of intercellular space. Flooding reduced xylem increment in submerged stems but increased it above the water level because of larger tracheids rather than more tracheids per radial file. Flooding also increased lumen diameters of tracheids, decreased tracheid wall thickness (as a proportion of tracheid diameter), and stimulated formation of axial parenchyma cells in the xylem. Cryptomeria japonica seedlings adapted to flooding by forming adventitious roots, primarily on the original root system and submerged portion of the stem. Such new roots originated in the xylem ray parenchyma. Flooding stimulated ACC synthesis in roots and ethylene production in stems. The role of ethylene in alteration of stem anatomy is discussed. 相似文献
15.
[目的]通过测定和分析广西融水种源红心杉木优树材质性状指标,以了解该地区红心杉木材性状变异规律。[方法]以广西融水种源60株20年生的红心杉木优树为研究材料,测定单株材积、红心率、基本密度、组织比量、管胞性状、微纤丝角等10个材质性状指标,分析各材性性状指标分布和变异规律及性状间的相关关系。[结果]表明:红心率、基本密度、木射线比量、管胞比量、管胞长、管胞宽、管胞长宽比等性状数据分布服从正态分布。融水两个地区红心杉优树轴向薄壁细胞比量的变异系数分别为35.08%和44.97%,变异较大。管胞比量变异系数分别为3.28%和3.56%,变异较小。红心率、木射线比量、管胞长、管胞宽、微纤丝角等性状差异极显著(P0.01),轴向薄壁细胞比量差异显著(P0.05)。10个材质性状间存在12对表型显著相关。[结论]测定的10个性状均是连续性数量性状。早、晚材的管胞长度、管胞宽度和管胞长宽比等性状数据呈从心材至边材逐渐增加的规律。作为重要经济性状的红心率与木射线比量呈极显著正相关(P0.01),单株材积与轴向薄壁细胞比量呈显著正相关(P0.05),而单株材积与基本密度的相关性不显著,这使红心杉木生长量与材性相结合的遗传改良成为可能。 相似文献
16.
Cortical microtubules (MTs) in differentiating compression wood tracheids of Taxus cuspidata stems were visualized by confocal laser microscopy. They were oriented obliquely at an angle of about 45° to the tracheid axis during formation of the secondary wall. Artificial inclination altered the pattern of alignment of MTs. Banding MTs were helically oriented late during the formation of the secondary walls. These results indicate that MTs might control the orientation and localized deposition of cellulose microfibrils in the secondary walls of compression wood tracheids.Part of this report was presented at the 46th annual meeting of the Japan Wood Research Society, Kumamoto, April 1996 相似文献
17.
Roman Gebauer Roman Plichta Emilie Bednářová Jiří Foit Václav Čermák Josef Urban 《European Journal of Forest Research》2018,137(1):57-67
While needles represent a proportionally large fraction of whole-plant hydraulic resistance, no studies to date have investigated how source–sink disturbances affect needle xylem structure. In this study, we evaluated structural changes in xylem in current-year needles of Scots pine 227 and 411 days after stem girdling (hereafter referred to as DAG). Maximum and minimum tracheid lumen diameters and therefore also the size of tracheid lumen areas increased in needles 227 DAG compared to control needles. In contrast, tracheid dimensions were similar in needles 411 DAG as in the control needles, but smaller xylem area and lower number of tracheids resulted in the lower theoretical needle hydraulic conductivity of those needles. Several needle xylem parameters were intercorrelated in both control and girdled trees. These observed changes provide a new understanding of the processes that occur following a source–sink disturbance. Considering anatomical parameters such as the number of tracheids, tracheid dimension, or needle xylem area, which are rarely described in physiological studies, could be helpful, for example, in understanding to tree hydraulic systems or for modeling gas exchange. Finally, empirical equations were developed to calculate needle theoretical hydraulic conductivity and the number of tracheids in needles using an easily measurable parameter of needle xylem area. 相似文献
18.
Cornelia Krause Sergio Rossi Maxime Thibeault-Martel Pierre -Y. Plourde 《Annals of Forest Science》2010,67(4):402-402
19.
Tracheid characteristics ofPicea koraiensis from natural stand in Liangshui area and plantation in Mao'ershan area were studied. The results of variance analysis showed
that the tracheid length, diameter, and thickness of tracheid wall were significant differences between the growth rings.
All those characteristics tend to increase from heart-center to bark. In natural stand, it has positive correlation between
the characteristics. In plantation, the tracheid length has positive correlation with the trachied diameter, while both the
trachied length and the trachied diameter has negative correlation with the thickness of trachied wall. The tracheid length
and diameter have no significant difference in growth between natural stand and plantations. The thickness of tracheid wall
from the plantation is a little thicker than that from the natural stand before 15 years.
Foundation item: This paper was part of State 9th Five-Year Plan project of “Early Mensuration ofPicea koraiensis (nakai)”.
Biography: REN Xu-qin (1973-), female, graduate student in Northeast Forestry University, Harbin 150040, P. R. China.
Responsible editor: Song Funan 相似文献