MICROFIBRIL ANGLES IN THE ROOT WOOD OF PINUS RADIATA AND PINUS NIGRA

IAWA Journal ◽  
2001 ◽  
Vol 22 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Junji Matsumura ◽  
Brian G. Butterfield
Keyword(s):  
Pinus Radiata ◽  
Growth Ring ◽  
Microfibril Angle ◽  
Pinus Nigra ◽  
Growth Rings ◽  
Stem Wood ◽  
The Third ◽  
Tracheid Length ◽  
Angle Change ◽  
Wood Tracheid

Microfibril angles of the S2 layer and tracheid lengths were measured in the root wood of Pinus nigra, and the root and stem wood of Pinus radiata. Within 10 mm (the first 2–3 growth rings) from the root centre, microfibril angles were large in the wood of both species, ranging from 25° to 40°. Beyond 10 mm (the fourth growth ring and beyond) from the root centre, microfibril angles were small. This pattern of microfibril angle change in root wood differs from those normally found in stems where angles are large until the 10–15th rings. Root wood tracheid length also showed a different pattern in radial direction from that normally observed in stem wood. Tracheids of Pinus radiata root wood were long in the first ring, decreasing to the third ring and then increased to the seventh ring. Beyond the seventh ring tracheid length was stable at around 3 to 3.5 mm. It was noted that microfibril angles were not influenced by tracheid length in root wood.

Distribution of juvenile wood in two stems of Larixlaricina

1986 ◽  
Vol 16 (5) ◽  
pp. 1041-1049 ◽  
Author(s):  
K. C. Yang ◽  
C. A. Benson ◽  
J. K. Wong
Keyword(s):  
Juvenile Wood ◽  
Growth Ring ◽  
Ring Width ◽  
Tree Level ◽  
Growth Rings ◽  
Vertical Variation ◽  
Strong Negative Correlation ◽  
Ring Number ◽  
Tracheid Length ◽  
Growth Ring Width

The distribution and vertical variation of juvenile wood was studied in an 81-year-old dominant tree and an 83-year-old suppressed tree of Larixlaricina (Du Roi) K. Koch. Two criteria, growth ring width and tracheid length, were used to demarcate the boundary of juvenile wood. The width of juvenile wood, expressed in centimetres and the number of growth rings, decreased noticeably from the base to the top of the tree. The volume of juvenile wood decreased in a similar pattern. These decreasing trends had a strong negative correlation with the year of formation of cambial initials at a given tree level. The length of these cambial initials decreased with increasing age of formation of the cambial initials. In the juvenile wood zone, there was a positive linear regression between the growth ring number (age) and the tracheid length. The slopes of these regression lines at various tree levels increased as the age of the year of formation of the cambial initials increased. At a given tree level, the length of tracheids increased from the pith to a more uniform length near the bark. However, the number of years needed to attain a more uniform tracheid length decreased from the base to the top of the tree. These relationships suggest that the formation of juvenile wood is related to the year of formation of the cambial initials. Consequently, the juvenile wood is conical in shape, tapering towards the tree top.

An analysis of an outbreak of the woodwasp, Sirex noctilio F. (Hymenoptera, Siricidae), in Pinus radiata

1975 ◽  
Vol 65 (3) ◽  
pp. 491-500 ◽  
Author(s):  
J. L. Madden
Keyword(s):  
Pinus Radiata ◽  
Growth Ring ◽  
Summer Rainfall ◽  
Growth Patterns ◽  
Site Quality ◽  
Sirex Noctilio ◽  
Growth Rings ◽  
Plantation Management ◽  
Previous Season ◽  
Ring Analysis

AbstractThe development of an outbreak of the woodwasp, Sirex noctilio F., in a 30-year-old population of Pinus radiata in Tasmania was traced by growth ring analysis of killed trees. The outbreak probably developed from small foci; it reached its peak when the trees were 18–19 years old and then declined rapidly. Attack per tree was directly related to the density of emergents from trees killed in the previous season and the intensity of oviposition drilling was modified by the rainfall during the emergence season; the frequency of treble oviposition drills was directly related to summer rainfall. Survival of insects within trees declined with the years; this was related to the greater vigour and resistance of the surviving trees, but was apparently modified by spring rainfall. Resinosis and polyphenols associated with growth rings in stems living in 1964 indicated an increase in the proportion of trees resisting attack during the outbreak. The growth patterns of attacked and unattacked trees, and the obvious susceptibility of the weaker understorey trees, are discussed and due attention to site quality and plantation management are recommended to reduce Sirex attack in future.

Cyclophytic effects on wood structure in Pinus radiata D. Don. I. Densitometry and grain angle

1988 ◽  
Vol 18 (4) ◽  
pp. 406-412 ◽  
Author(s):  
Richard S. Dodd ◽  
Nancy K. Walker
Keyword(s):  
Pinus Radiata ◽  
Growth Ring ◽  
Structural Characteristics ◽  
Wood Formation ◽  
Density Variation ◽  
Wood Structure ◽  
Growth Rings ◽  
Tree Form ◽  
Ring Density ◽  
Latewood Density

Wood structural characteristics were compared in 11-year-old Pinusradiata trees from hedge- and tree-form donors (H and T) to examine the effects of apical ageing (cyclophysis) on wood formation. Although the differences were small, T plants tended to produce wood with narrower growth rings and lower density in the first two rings. T plants showed a greater contrast between density at the end of one growth ring and the beginning of the next. The lower mean growth ring density in T plants was mainly due to a lower earlywood density with little difference in latewood density or latewood percentage. Although differences in density from early- to late-wood were greater in T plants, there was no difference between H and T plants in within-ring density variation. This was due to greater fluctuations in density across growth rings of H plants, perhaps because these plants were less buffered against the environment. Differences in wood structure between H and T plants were not the same for all clones, as shown by significant interactions in the analyses of variance. These different responses may have resulted from differences in the effectiveness of hedging in slowing apical maturation, or from differences in rates of maturation.

Morphological Features of Tracheid Tips Associated With Compression Wood Formation in Larix Leptolepis Gord.

IAWA Journal ◽  
1985 ◽  
Vol 6 (3) ◽  
pp. 245-253 ◽  
Author(s):  
Nobuo Yoshizawa ◽  
Shuichi Matsumoto ◽  
Toshinaga Idei
Keyword(s):  
Compression Wood ◽  
Growth Ring ◽  
Wood Formation ◽  
Morphological Features ◽  
Larix Leptolepis ◽  
Growth Rings ◽  
Wood Development ◽  
Tracheid Length ◽  
Ring Compression ◽  
Angular Displacements

Variation in the morphological features of tracheid tips was observed within and among sterns of larch (Larix leptolepis Gord.) with several different angular displacements from the vertical. The formation of compression wood increased with an increasing angle of stern deviation. Decrease in tracheid length occurred with thc development of compression wood within a growth ring. Compression wood also was accompanied by an increase in the occurrence of abnormal tips. Flattened and Lshaped tips of tracheids increased in number with the development of compression wood and the number of smoothly tapered tips decreased, indicating that the intrusive growth between adjacent cells does not proceed smoothIy in compression wood. It is considered that the spatial readjustment of developing cells is restricted in compression wood, and results from the great increase in the rate of cell division. A negative correlation between tracheid length and morphological abnormalities of tracheid tips was found within growth rings, apparently associated with the severity of compression wood development.

Modeling Microfibril Angle of Larch Using Linear Mixed-Effects Models

2011 ◽  
Vol 267 ◽  
pp. 516-520
Author(s):  
Yao Xiang Li ◽  
Li Chun Jiang
Keyword(s):  
Mixed Model ◽  
Growth Ring ◽  
Microfibril Angle ◽  
Model Performance ◽  
Ordinary Least Squares ◽  
Mixed Effects ◽  
Mixed Effects Models ◽  
Growth Rings ◽  
Linear Mixed Effects ◽  
Breast Height

Earlywood microfibril angle (MFA) was determined at each growth ring from disks at breast height (1.3 m) from 6 dahurian larch (Larix gmelinii. Rupr.) trees grown in northeastern China. Significant variation in microfibril angle was observed among growth rings. MFA at breast height varied from 7.5°to 21.5°between growth rings and showed a descreasing trend from pith to bark for each tree. A second order polynomial equation with linear mixed-effects was used for modeling earlywood MFA. The LME procedure in S-Plus is used to fit the mixed-effects models for the MFA data. The results showed that the polynomial model with three random parameters could significantly improve the model performance. The fitted mixed-effects model was also evaluated using a separate dataset. The mixed model was found to predict MFA better than the original model fitted using ordinary least-squares based on absolute and relative errors.

Effect of Physiological Age and Site on Microfibril Angle in Pinus Radiata

IAWA Journal ◽  
1996 ◽  
Vol 17 (4) ◽  
pp. 421-429 ◽  
Author(s):  
L. A. Donaldson
Keyword(s):  
Pinus Radiata ◽  
Juvenile Wood ◽  
Microfibril Angle ◽  
Basic Density ◽  
Seed Orchard ◽  
Physiological Age ◽  
Growth Rings ◽  
Physiological Aging ◽  
Breast Height ◽  
Old Trees

The effect of physiological age (shoot age at propagation) and site on microfibril angle was examined for seedlings (physiological age = 0 years) and cuttings (physiological age = 5-16 years) of Pinus radiata D. Don. Two trials were examined by measuring microfibril angle in alternate growth rings on breast height discs. In the first trial, two sites were compared for ll-year-old trees propagated from seedlings, and cuttings of comparable genotype, at 0 and 5 years physiological age, respectively. In the second trial, a single site was examined comparing 25-year-old trees propagated from open pollinated seedlings, and cuttings physiologically aged by 12-16 years, originating from 10 seed-orchard clones. In each trial there was a significant effect of physiological age for microfibril angle in the first 9 growth rings with a greater effect in the trees of greater physiological age. Physiological aging produced a significant decrease in microfibril angles in the juvenile wood, on average reducing microfibril angle to values below 35° in trees aged by 12-16 years. Juvenile wood size, as indicated by the point at which microfibril angle gradient changes, was reduced by an average of two rings in both sets of aged cuttings examined. There was no effect of site in the material examined. Differences were consistent among seedling/ramet pairs of similar genotype. The use of aged cuttings rather than seedlings should result in increased stiffness of the juvenile wood and reduced longitudinal shrinkage. However, other changes associated with physiological aging, such as reduced basic density and growth rate, may affect the practicality of using highly.

Cyclophytic effects on wood structure in Pinusradiata D. Don. II. Tracheid morphology

1988 ◽  
Vol 18 (4) ◽  
pp. 413-420 ◽  
Author(s):  
Richard S. Dodd
Keyword(s):  
Growth Ring ◽  
Anatomical Variation ◽  
Radiata Pine ◽  
Growth Rings ◽  
Tree Form ◽  
Ring Number ◽  
Tracheid Length ◽  
Rate Of Increase ◽  
The Difference

The effects of apical ontogeny on xylem morphology in Pinusradiata were examined in grafted trees and in clonal pairs of trees grown from cuttings from hedge- and tree-form donors (H and T). At the time of sampling the grafted rootstocks were 21 years old, and trees from H and T plants were 11 years old from the date of planting rooted cuttings. In grafted trees tracheids were longer, and the rate of increase in tracheid length was greater above the graft. Since growth rings were narrower above the graft, the difference in rate of increase in tracheid length above and below the graft was greater when plotted against distance from pith than against growth ring number. In comparisons of H and T plants, T plants (expected to be at a later stage of apical ontogeny) produced fewer but longer and wider tracheids. Cell wall volumes per tracheid were greater in T plants, but because the tracheid diameters in H plants were smaller, wall volumes per unit tracheid volumes were consistently greater in H plants. The role of apical ontogeny in explaining patterns of anatomical variation within the stem is discussed. H and T plants of radiata pine were from the three mainland populations: Año Nuevo, Monterey, and Cambria. The Año Nuevo population produced the greatest numbers and the largest tracheids. The Monterey population had the shortest tracheids amongst H plants, but their tracheid lengths were equal to those of the Año Nuevo population in T plants.

Aggregate Rays in New Zealand Nothofagus Blume (Fagaceae) Stem Wood and their Influence on Vessel Distribution

IAWA Journal ◽  
1987 ◽  
Vol 8 (1) ◽  
pp. 53-57 ◽  
Author(s):  
T. M. Middleton
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Zealand ◽  
Composite Structures ◽  
Growth Ring ◽  
Stem Wood ◽  
Scanning Electron

Aggregate rays occur in the stem wood of Nothofagus solandri var. cliffortioides (Hook. f.) Poole (mountain beech), N. solandri var. solandri (Hook. f.) Gerst. (black beech), N. truncata (Col.) Ckn. (hard beech), and N. fusca (Hook. f.) Gerst. (red beech), but not in N. menziesii (Hook. f.) Gerst. (silver beech). The composite structures visible in transversely sawn wood consist of groups of narrow xylem rays separated by fibres; vessels are frequently absent. The influence of aggregate rays on vessei distribution was studied using scanning electron microscopy and tested statistically. Indented growth ring boundaries are associated with the presence of aggregate rays. Aggregate rays occur in saplings. In larger trees aggregate rays taper out beyond 6 cm from the stem centre.

scholarly journals Jahrringe als Indikatoren für extreme Standortsbedingungen im Gebirge: Schnee, Lawinen und Permafrost | Growth rings as indicators of extreme site conditions in the mountains: snow, avalanches and permafrost

2004 ◽  
Vol 155 (6) ◽  
pp. 208-212 ◽  
Author(s):  
Peter Bebi ◽  
Alejandro Casteller ◽  
Andrea Corinna Mayer ◽  
Veronika Stöckli
Keyword(s):  
Natural Hazards ◽  
Growth Ring ◽  
Management Strategies ◽  
Extreme Conditions ◽  
Site Conditions ◽  
Snow Avalanches ◽  
Growth Rings ◽  
Survival And Growth ◽  
Ring Analysis

Snow, avalanches, and permafrost are extreme site conditions for plants. Reactions and adaptations to such extreme conditions can be reconstructed with growth ring analysis and linked with corresponding climate and disturbance data. On the basis of five case studies in and around the long-term research site Stillberg, near Davos, we discuss both the potential and the limits of dendroecology to understand the effect of such extreme site conditions. Despite some uncertainties in reliably assigning plant reactions, growth ring analysis is a valuable addition to better understand the effects of extreme site conditions on the survival and growth of plants. This can lead to improved management strategies associated with natural hazards, especially in the case of avalanches.

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