Spiral grain in a clonal trial with Sitka spruce

1998 ◽  
Vol 28 (6) ◽  
pp. 911-919 ◽  
Author(s):  
Jon Kehlet Hansen ◽  
Hans Roulund
Keyword(s):  
Standard Deviation ◽  
Compression Wood ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Spiral Grain ◽  
Compass Direction ◽  
Phenotypic Standard Deviation ◽  
The Mean ◽  
Clonal Trial ◽  
Residual Variances

Grain angles to the left in seven clones of Sitka spruce (Picea sitchensis (Bong.) Carr.) decreased from the pith and outwards and with height. Effects of compression wood and compass directions were non-significant. Clones differed significantly but interacted with height levels, ring numbers, compass direction, and compression wood. However, the interaction with compression wood was small. Furthermore, some interaction with compass direction could possibly be attributed to eccentric stems and stem axis choice. The repeatability was 72% for averages of ramets measured in five height levels and most rings from the pith. The mean spiral grain was 2.2°, and the phenotypic standard deviation between averages of ramets was 1.07°. Genetic gains of 1° from phenotypic selections based on several measurements were suggested using these values. Variations between ramets and residual variances accounted for most of the variation. Thus, as many ramets as possible should be sampled to obtain the best estimates of mean clonal levels. Clone interactions with height levels and ring numbers from the pith were less important. This was also explained by correlations of 0.83–0.98 among clone averages at 1.3 m for single rings and overall clone means. Only significant effects ring widths were present within clones.

scholarly journals Competition Effects in a Young Sitka Spruce (Picea sitchensis, Bong. Carr) Clonal Trial

2011 ◽  
Vol 60 (1-6) ◽  
pp. 149-155 ◽  
Author(s):  
S. Brotherstone ◽  
I. M. S. White ◽  
R. Sykes ◽  
R. Thompson ◽  
T. Connolly ◽  
...  
Keyword(s):  
Genetic Effect ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Ratio Test ◽  
Nested Models ◽  
Future Performance ◽  
Residual Level ◽  
Competition Effects ◽  
Clonal Trial ◽  
Performance Results

Abstract In the analysis of forestry experiments, there may be a need to adjust for competition between plots before predicting deployment performance in the field but there have been few attempts to investigate this. Our analysis looked at diameter data from a 19-year old Sitka spruce clonal trial growing in Scotland. Using a sequence of nested models, a likelihood ratio test indicated that fitting competition at both the genetic and residual level provided a significantly better fit than models which either ignored competition or fitted it at just the genetic or just the residual level. A strong negative genetic correlation of −0.93±0.05 was found between the direct genetic effects and competition effects. This was not significantly different from −1, indicating that competition is almost exactly proportional to the direct genetic effect and that a tree will exert a competitive effect which is closely related to its own genetic merit for size. At the residual level, the correlation between direct and competition effect was estimated as −0.17±0.03. We conclude that competition exists at both the genetic and environmental levels and including it in genetic evaluation systems gives a better prediction of future performance. Results also demonstrate that it is possible to obtain useful information about competition effects from a single-tree plot experiment.

Genetic parameters for spiral grain in two 18-year-old progeny trials with Sitka spruce in Denmark

1998 ◽  
Vol 28 (6) ◽  
pp. 920-931 ◽  
Author(s):  
Jon Kehlet Hansen ◽  
Hans Roulund
Keyword(s):  
Genetic Correlations ◽  
Sitka Spruce ◽  
Diameter Growth ◽  
Environment Interaction ◽  
Stem Form ◽  
Narrow Sense Heritability ◽  
Spiral Grain ◽  
Stem Straightness ◽  
The Mean ◽  
The Individual

The spiral grain at ring 10 at 1.3 m was investigated in two trials with 64 open-pollinated families of age 18 years from plus-trees of Sitka spruce (Piceasitchensis (Bong.) Carr.) selected from 16 populations. Significant differences were found between the families on both sites, and the individual narrow-sense heritability of the spiral grain was 0.63 and 0.78, assuming half-sib families. The mean spiral grain was 3.8 and 4.1° to the left in the two trials and the individual standard deviations 1.86 and 1.62°. No signs of genotype– environment interaction was found. Genetic correlations with diameter growth, stem form, and pilodyn were not apparent in the trials. Reductions of the mean spiral grain by 0.5–1° in the juvenile wood seems possible even with simultaneous gains for stem straightness and diameter growth, either from selections among plus-trees grafted in a clonal seed orchard or from the progenies in the trials.

Strength properties of wind- and snow-damaged stems of Picea sitchensis and Pinus sylvestris in comparison with undamaged trees

1999 ◽  
Vol 29 (5) ◽  
pp. 595-599 ◽  
Author(s):  
A D Cameron ◽  
R A Dunham
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Compression Wood ◽  
Outer Part ◽  
Sitka Spruce ◽  
Strength Properties ◽  
Picea Sitchensis ◽  
Modulus Of Rupture ◽  
Clear Wood ◽  
Pine Trees

This study compared the strength properties of wood taken from Sitka spruce (Picea sitchensis (Bong.) Carr.) and Scots pine (Pinus sylvestris L.) trees damaged as a result of wind and snow. The spruce trees were located in triplets of stems of similar diameter that had snapped, overturned (i.e., uprooted), or remained undamaged as a result of wind and snow. The pine trees were located in pairs of similar-sized stems that had snapped or remained undamaged. None of the pine trees overturned. Clear wood (wood without knots and sloping grain) from the outer part of the stem of snapped Sitka spruce and Scots pine trees was less stiff (lower modulus of elasticity (MOE)) than wood taken from the same location from overturned (spruce only) or standing trees. Modulus of rupture and density were unaffected. Damaged trees of both species were found to have significantly more compression wood within the test samples in comparison with undamaged trees. These findings suggest that trees that either overturn or snap are bending more than undamaged trees (because of their low MOE) thereby introducing a greater component of crown weight to the overall forces acting on the stem, and that this may be associated with compression wood.

Detection of β-1-4-galactan in compression wood of Sitka spruce [Picea sitchensis (Bong.) Carrière] by immunofluorescence

Holzforschung ◽  
2007 ◽  
Vol 61 (3) ◽  
pp. 311-316 ◽  
Author(s):  
Clemens Altaner ◽  
Adrian I. Hapca ◽  
J. Paul Knox ◽  
Michael C. Jarvis
Keyword(s):  
Monoclonal Antibody ◽  
Cell Wall ◽  
Cross Sections ◽  
Compression Wood ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Outer Cell ◽  
Physiological Reactions ◽  
S2 Layer ◽  
Outer Cell Wall

Abstract β-1-4-Galactan has been detected in Sitka spruce [Picea sitchensis (Bong.) Carrière] by an immunofluorescence procedure. The anti-β-1-4-galactan monoclonal antibody LM5 was found to bind to compression wood (CW) tissue as identified by cell morphology features. In cross-sections, year rings with very fine bands of galactan-containing tissue were found. Cells in these bands expressed no morphological CW features. This finding was interpreted to imply that β-1-4-galactan synthesis is one of the first physiological reactions of CW formation. In cases where the CW character was pronounced, galactan was exclusively located in the outer cell-wall layers and was absent from the majority of the inner S2 layer.

At Least One Standard Deviation Above the Mean

1969 ◽  
Vol 14 (9) ◽  
pp. 470-471
Author(s):  
M. DAVID MERRILL
Keyword(s):  
Standard Deviation ◽  
The Mean
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