Spiral grain in plantation trees of Piceaabies

1994 ◽  
Vol 24 (8) ◽  
pp. 1662-1671 ◽  
Author(s):  
Frede Danborg
Keyword(s):  
Standard Deviation ◽  
Ring Width ◽  
Specific Pattern ◽  
Annual Rings ◽  
Basic Pattern ◽  
Angle Variation ◽  
Spiral Grain ◽  
Grain Angle ◽  
Slow Decline ◽  
Large Trees

The spiral-grain angle of Norway spruce (Piceaabies (L.) Karst.) was measured on diametrical strips from five stands 23–47 years old, on soils of high and moderate fertility, most of which had been thinned heavily. Ninety-five small, average, and large trees from each stand were sampled from which 261 discs were sawn at heights ranging from 1.3 to 12 m. The basic pattern was typical for a conifer; spirality was left-handed in the inner annual rings, peaking in ring numbers 3 to 8, followed by a slow decline towards straight grain, or even right spirality, near the bark. The between-tree variation was statistically significant in all stands, with standard deviation near 1°. A stand may exhibit a specific pattern of grain angle variation along the bole, but no variation with height in stem could be generally applied for Piceaabies. For the three stands grown on fertile soils, the larger trees exhibited larger grain angles than the smaller trees. However, a consistent positive effect of ring width was only statistically significant for one stand. A subsample of 24 stem discs including 421 annual rings measured twice on two diametrical strips at right angles (i.e., crosses) showed fairly good accordance between the two directions, with a pooled standard deviation of 0.5°. The results support earlier conducted studies with respect to complex and perplexing variations in the basic pattern of spirality typical for a conifer.

Identification en forêt de chênes sessiles (Quercus petraea) présentant un angle du fil du bois intrinsèquement faible

1999 ◽  
Vol 29 (12) ◽  
pp. 1958-1965 ◽  
Author(s):  
E Guilley ◽  
M Loubère ◽  
G Nepveu
Keyword(s):  
Ring Width ◽  
Quercus Petraea ◽  
Tree Age ◽  
Radial Increment ◽  
Mixed Effect ◽  
Individual Tree ◽  
General Direction ◽  
Spiral Grain ◽  
Grain Angle ◽  
Breast Height

Grain angle on bark (angle between the general direction of bark fissures and the axis of the trunk) was assessed at the four cardinal points at breast height (1.3 m) on 82 standing sessile oaks (Quercus petraea Liebl.). After felling, wood spiral grain was measured at breast height from cambium to pith along two diametrically opposite radii. A mixed-effect model that links the tangent of grain angle to radial position (age and distance from the pith) allows to estimate two individual parameters of grain angle. In the field, nondestructive measurements of grain angle (subcortical spiral grain or spiral grain on bark) on an individual tree combined with information on the tree stand allow to estimate one of the two parameters that describes the change in grain angle for a given radial increment. This parameter is independent of mean ring width, tree age and circumference, and site characteristics; it should allow a more accurate identification and selection of standing trees with low wood spiral grain.

Assessing Spiral Grain Angle by Light Transmission: – Proof of Concept –

IAWA Journal ◽  
2012 ◽  
Vol 33 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Mark Riddell ◽  
Dave Cown ◽  
Jonathan Harrington ◽  
John Lee ◽  
John Moore
Keyword(s):  
Light Transmission ◽  
Wood Properties ◽  
Assessment Method ◽  
Wood Products ◽  
Automated System ◽  
Angle Variation ◽  
Spiral Grain ◽  
Grain Angle ◽  
3 Dimensional ◽  
Spiral Grain Angle

Spiral grain measurements are subject to a high degree of variation and interpretation, depending on the assessment method used. A new measurement approach was tested whereby light was directed through disc samples on a flatbed scanner and the deviation along the grain assessed by means of a template to allow the mapping of grain angle variation radially and tangentially within discs. Initial results showed that the approach was valid for green discs up to 35 mm thick and small enough to fit on an A4 scanner. Comparisons with traditional scribing and cleaving methods were favourable, indicating that the light transmission approach could allow much faster and more accurate data acquisition. The possibility of using larger discs would enhance the ability to assess spatial variation in grain angle and minimise the effects of sample reference geometry with respect to the tree axis (disc tilt and parallax). Further work may also be required to ensure that reliable spiral grain values are obtained from both sapwood and heartwood. The ultimate goal is to develop an automated system for reconstructing stem characteristics from measurements on large fresh green discs to enable the 3-dimensional mapping of individual stem variations in key wood properties and modelling the impacts of silviculture and genetics on wood products.

CAMBIAL BEHAVIOR WITH REFERENCE TO CELL LENGTH AND RING WIDTH IN PINUS STROBUS L.

1962 ◽  
Vol 40 (8) ◽  
pp. 1057-1062 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Inverse Relationship ◽  
Ring Width ◽  
Pinus Strobus ◽  
Growth Patterns ◽  
Cell Length ◽  
Annual Rings ◽  
Forest Types ◽  
Thuja Occidentalis ◽  
Cambial Cells ◽  
Individual Trees

The relationships between width of annual rings, length of wood cells, and frequency of anticlinal (multiplicative) divisions in fusiform cambial cells were studied by reference to trees of various growth patterns. The trees selected ranged from 8 to 20 in. diameter and included both open-grown specimens with branches close to the ground and forest types with tall, slender shafts. Much fluctuation was noted among individual trees, but in general there was, in the peripheral growth, an inverse relationship between length of wood cells and width of annual rings. The frequency of anticlinal divisions in the cambium remained at a more or less uniform rate in trees with rings from 1.5 to 5 mm wide, but rose sharply when ring width fell below 1.3 mm. This was in contrast to the situation observed earlier in Thuja occidentalis where the rise in frequency of anticlinal divisions was slight and occurred only in trees with rings less than 0.3 mm wide.

Inheritance of spiral grain in the juvenile core of Pinus radiata

2007 ◽  
Vol 37 (1) ◽  
pp. 116-127 ◽  
Author(s):  
Washington Gapare ◽  
Adrian Hathorn ◽  
Dominic Kain ◽  
Colin Matheson ◽  
Harry Wu
Keyword(s):  
Pinus Radiata ◽  
Genetic Gain ◽  
Radiata Pine ◽  
Correlated Response ◽  
Lower Grade ◽  
Tangential Plane ◽  
Individual Tree ◽  
Spiral Grain ◽  
Grain Angle ◽  
Selection For

Spiral grain is the angular arrangement of fibres in a tangential plane with reference to the pith or vertical tree axis. Spiral grain angles exceeding 5° can cause wood to twist, which may result in a considerable amount of waste and degrade. We assessed spiral grain at breast height in two related progeny tests of radiata pine (Pinus radiata D. Don) aged 8 and 9 years established at two different sites in Australia. Radial trends for grain angle at the two sites were similar. Mean spiral grain (MSG) across the two trials was 4.3° with a standard deviation of 1.5° and a range of 0.8–10°. Estimates of individual tree heritabilities on a single-site basis for individual rings and MSG suggested that spiral grain is lowly to highly inherited (h2 = 0.11 ± 0.08 to 0.66 ± 0.21 for individual rings and 0.44 ± 0.12 for MSG). Additive genotypic correlations between individual rings grain angle and MSG were generally high, above 0.71, suggesting a favourable expected correlated response of mean grain angle in the juvenile wood to selection for grain angle of individual rings. Selection to reduce spiral grain on any of rings 2–4 (at a selection intensity of 1.755, i.e., selecting the best 10% of trees) would result in a predicted correlated genetic gain in MSG of 1.0°. Our results suggest that selection could be performed in any of the individual rings 2, 3, or 4 (equivalent to ages 4–6) and still achieve at least 75% of the genetic gain possible from selection on the mean of all rings 1–5 (MSG). This suggests that there is an optimum stage (rings 2–4) in which selection for this trait should take place. Our results suggest that a reduction in spiral grain angle in the juvenile core is one strategy to reduce the amount of lower grade timber owing to twist.

GROWTH AND MORPHOGENESIS IN THE CANADIAN FOREST SPECIES: I. THE CONTROLS OF CAMBIAL AND APICAL ACTIVITY IN PINUS RESINOSA AIT.

1953 ◽  
Vol 31 (4) ◽  
pp. 471-513 ◽  
Author(s):  
G. H. Duff ◽  
Norah J. Nolan
Keyword(s):  
Ring Width ◽  
Pinus Resinosa ◽  
Cambial Activity ◽  
Annual Rings ◽  
Forest Species ◽  
Extrinsic Factors ◽  
Intrinsic Factors ◽  
Complex Relation ◽  
Growth Studies ◽  
Two Stages

The anomalous complexity of the annual rings of young trees which generally disqualifies them from use in growth studies is, in P. resinosa, found to arise from a remarkably thorough organization of ring width and therefore of cambial activity in the tree under the influence of intrinsic determinants. The pattern is manifest when the widths of the internodal wood rings of a single year are followed in sequence from internode to internode down the tree from the apex. A similarly patterned view of the rings is obtained when the ring widths are traced in the ring sequence, conventional for growth studies, that passes from ring to ring in a given internode. The controlling intrinsic factors are held to be nutritional gradients in the axis inferred from the distribution of foliage and light along the axis of trees growing in the forest and in the open.In both types of sequence the pattern obscures the variations induced by random extrinsic factors and severely limits the value of these sequences for examining the effect of such factors. This disability can be avoided by the use of a third sequence of ring widths in which each term is the width of a ring which was laid down in an internode different but of the same age at the time of ring formation as the others in the sequence. Such sequences have never been used in growth studies. Yet they are found to be unpatterned and the effect of the fluctuating extrinsic factors can be examined effectively in them and in them alone.The complex relation between the responses of the cambium thus determined and those of the apical growing point to the random extrinsic factors is found to derive from the discontinuity of terminal growth introduced by the winter pause between bud formation and axial extension. These two stages of terminal growth are influenced by the extrinsic factors of the two different years. The effect on the cambium is simpler than this but is determinably related to that on the apical growing point.The results afford the ground for a first advance toward the removal of the disqualification of the use of young trees in studies of growth and of its factorial control.

scholarly journals Genetic parameters for spiral-grain angle in two 19-year-old clonal Norway spruce trials

2002 ◽  
Vol 59 (5-6) ◽  
pp. 551-556 ◽  
Author(s):  
Bj�rn Hannrup ◽  
Michael Grabner ◽  
Bo Karlsson ◽  
Ulrich M�ller ◽  
Sabine Rosner ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Genetic Parameters ◽  
Spiral Grain ◽  
Grain Angle ◽  
Spiral Grain Angle

scholarly journals Leptin levels show diurnal variation throughout puberty in healthy children, and follow a gender-specific pattern

2001 ◽  
pp. 43-51 ◽  
Author(s):  
C Ankarberg-Lindgren ◽  
J Dahlgren ◽  
B Carlsson ◽  
S Rosberg ◽  
L Carlsson ◽  
...  
Keyword(s):  
Body Composition ◽  
Standard Deviation ◽  
Diurnal Variation ◽  
Sex Steroids ◽  
Pubertal Development ◽  
Specific Pattern ◽  
Healthy Children ◽  
Serum Leptin ◽  
Pubertal Boys ◽  
Gender Specific

OBJECTIVE: To investigate the levels and diurnal rhythm of serum leptin in healthy children, and to investigate the association between leptin levels and sex steroids. METHODS: Four girls and four boys, all healthy volunteers, were followed longitudinally throughout puberty. Their chronological ages ranged from 8.7 to 19.5 years, and body composition, expressed as weight-for-height standard deviation scores (SDS), ranged between -1.7 and +2.4. Serum leptin, oestradiol and testosterone concentrations were measured by radioimmunoassay at 1000, 1400, 1800, 2200, 0200 and 0600 h. RESULTS: In all girls and boys, both prepubertally and during pubertal development, serum leptin levels increased during the night, with no difference in relative peak amplitude. In boys, the leptin concentrations increased until the initiation of puberty and then declined, whereas in girls, the concentrations increased throughout puberty. The inter-individual variation in mean leptin levels among girls decreased to 11% at the time of menarche. A positive correlation was found for both oestradiol and testosterone versus leptin in girls throughout puberty (r=0.64 and r=0.71 respectively, P<0.001). A negative correlation was found between leptin and testosterone in boys in mid- and late puberty (r=-0.66, P<0.01). No correlation was found between oestradiol and leptin in boys or between testosterone and leptin in pre- and early pubertal boys. CONCLUSION: Serum leptin concentrations show diurnal variation throughout pubertal development in both girls and boys. The changes in leptin levels during puberty follow a gender-specific pattern, probably due to an influence of sex steroids on leptin production.

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