Modeling the Transition from Juvenile to Mature Wood Using Modulus of Elasticity in Lodgepole Pine

2013 ◽  
Vol 28 (4) ◽  
pp. 135-142 ◽  
Author(s):  
Mingliang Wang ◽  
James D. Stewart
Keyword(s):  
Modulus Of Elasticity ◽  
Lodgepole Pine ◽  
Mature Wood

Bending of a conifer branch at subfreezing temperatures: implications for snow interception

1990 ◽  
Vol 20 (8) ◽  
pp. 1251-1253 ◽  
Author(s):  
R. A. Schmidt ◽  
J. W. Pomeroy
Keyword(s):  
Modulus Of Elasticity ◽  
Lodgepole Pine ◽  
Ice Crystals ◽  
Subalpine Fir ◽  
Linear Decrease ◽  
Model Predictions ◽  
Snow Loads ◽  
In Cells

Ice crystals in cells of frozen wood increase the wood's modulus of elasticity so that branches become more rigid at colder temperatures. As temperature increases after a snowstorm, melting of crystals within the cells allows increased bending of branches under intercepted snow loads. Measurements of the force that produced a 10-cm deflection of branch tips of subalpine fir (Abieslasiocarpa (Hook.) Nutt.) and lodgepole pine (Pinuscontorta var. latifolia Engelm.) showed a linear decrease as temperature rose from −12 to 0 °C. Model predictions for the bending of a tapered branch supported the hypothesis that increased bending can explain unloading of intercepted snow under certain conditions when warming occurs after snowstorms.

scholarly journals Genetic control of transition from juvenile to mature wood with respect to microfibril angle in Norway spruce (Picea abies) and lodgepole pine (Pinus contorta)

2018 ◽  
Vol 48 (11) ◽  
pp. 1358-1365 ◽  
Author(s):  
Haleh Hayatgheibi ◽  
Nils Erik Gustaf Forsberg ◽  
Sven-Olof Lundqvist ◽  
Tommy Mörling ◽  
Ewa J. Mellerowicz ◽  
...  
Keyword(s):  
Picea Abies ◽  
Genetic Control ◽  
Norway Spruce ◽  
Pinus Contorta ◽  
Juvenile Wood ◽  
Lodgepole Pine ◽  
Microfibril Angle ◽  
Mature Wood ◽  
Direct Selection ◽  
Narrow Sense Heritability

Genetic control of microfibril angle (MFA) transition from juvenile wood to mature wood was evaluated in Norway spruce (Picea abies (L.) Karst) and lodgepole pine (Pinus contorta Douglas ex Loudon). Increment cores were collected at breast height (1.3 m) from 5664 trees in two 21-year-old Norway spruce progeny trials in southern Sweden and from 823 trees in two lodgepole pine progeny trials, aged 34–35 years, in northern Sweden. Radial variations in MFA from pith to bark were measured for each core using SilviScan. To estimate MFA transition from juvenile wood to mature wood, a threshold level of MFA 20° was considered, and six different regression functions were fitted to the MFA profile of each tree after exclusion of outliers, following three steps. The narrow-sense heritability estimates (h2) obtained for MFA transition were highest based on the slope function, ranging from 0.21 to 0.23 for Norway spruce and from 0.34 to 0.53 for lodgepole pine, while h2 were mostly non-significant based on the logistic function, under all exclusion methods. Results of this study indicate that it is possible to select for an earlier MFA transition from juvenile wood to mature wood in Norway spruce and lodgepole pine selective breeding programs, as the genetic gains (ΔG) obtained in direct selection of this trait were very high in both species.

Ortet-Ramet Relationships of Wood-Specific Gravity in Lodgepole Pine

1990 ◽  
Vol 5 (2) ◽  
pp. 40-42 ◽  
Author(s):  
A. D. Yanchuk ◽  
M. R. Carlson ◽  
J. C. Murphy
Keyword(s):  
Specific Gravity ◽  
Analysis Of Variance ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Small Diameter ◽  
Heritability Estimate ◽  
Mature Wood ◽  
Broad Sense Heritability ◽  
Breeding Populations ◽  
High Repeatability

Abstract Two 8-year-old grafted ramets from 12 lodgepole pine (Pinus contorta var. latifolia) ortets (wild stand parent trees) were sampled at each of three sites and were assessed for specific gravity with small diameter cores. The broad-sense heritability estimate from the analysis of variance was 0.62, but estimates derived by regressing clone means from ramets on ortet values were 0.49 and 0.54 for juvenile and mature wood, respectively. This relatively high repeatability for specific gravity suggests wild-stand ortet values may be useful for identifying low specific gravity clones in seed orchards, or potential low specific gravity families in breeding populations of lodgepole pine. West. J. Appl. For. 5(2):40-42, April 1990.

Revisiting the transition between juvenile and mature wood: a comparison of fibre length, microfibril angle and relative wood density in lodgepole pine

Holzforschung ◽  
2009 ◽  
Vol 63 (4) ◽  
Author(s):  
Shawn D. Mansfield ◽  
Roberta Parish ◽  
C. Mario Di Lucca ◽  
James Goudie ◽  
Kyu-Young Kang ◽  
...  
Keyword(s):  
Wood Density ◽  
Lodgepole Pine ◽  
Fibre Length ◽  
Microfibril Angle ◽  
Ring Width ◽  
Mature Wood ◽  
Radial Increment ◽  
Breast Height ◽  
Tracheid Length ◽  
Fibre Traits

AbstractIn an attempt to examine the dynamic inter-relationship among wood density and fibre traits [tracheid length and microfibril angle (MFA)] in lodgepole pine (Pinus contorta), 60 trees were sampled in three age classes from four sites in central British Columbia. Breast height discs were taken and relative wood density was measured along two radii. Tracheid length was assessed on isolated 5-year increments from pith to bark at breast height for each tree. MFA was determined every 50 μm and the 5-mm composite intervals from pith to bark per disc at breast height were used in the analysis. Segmented regression was employed to identify the “juvenile to mature wood” transition point, which revealed transition ages of 31, 18 and 15 for wood density, fibre length and MFA, respectively. These traits were related to primary growth, expressed as area increment, ring width, percent earlywood and height increment during the juvenile wood phase. Comparisons of wood and fibre traits showed a higher congruence between the time of transitions for fibre length and MFA (Pearson correlation coefficient 0.52) than that between fibre length and wood density (0.07), and MFA and wood density (0.16). The cessation of early rapid radial increment growth terminated before wood and fibre transitions to mature wood occurred. Fibre length was significantly, but not strongly, related to ring width and percent earlywood (0.35 for both). The duration of juvenile fibre production was not significantly related to height growth.

The effects of crown ratio on the transition from juvenile to mature wood production in lodgepole pine in western Canada

2007 ◽  
Vol 37 (8) ◽  
pp. 1450-1459 ◽  
Author(s):  
Shawn D. Mansfield ◽  
Roberta Parish ◽  
James W. Goudie ◽  
Kyu-Young Kang ◽  
Peter Ott
Keyword(s):  
Fixed Effects ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Wood Quality ◽  
Stand Density ◽  
Mature Wood ◽  
Tree Age ◽  
Wood Production ◽  
Crown Length ◽  
Pine Trees

Crown depth, tree spacing, and stand density have major effects on wood quality and fibre characteristics of trees. Lodgepole pine ( Pinus contorta Doug. ex Loud.) trees from a mixture of plantation and fire origin stands were employed to determine how crown ratio, a surrogate for stand density, affected mature wood production. In total, 104 trees were sampled, ranging from 24 to 110 years of age, from stands in western Alberta and interior British Columbia, Canada. Samples taken along the bole were measured for wood density, which was subject to segmented regression analysis to identify the transition point from juvenile to mature wood production. On average, the lodgepole pine trees were 31 (±17 SD) years old before mature wood production began. A mixed-effects model, in which combination of fixed effects (tree age, height of the sample disc relative to crown base, and crown length) and random effects (site, trees nested in sites, and discs nested in both trees and sites) proved to be the best predictor of years of mature wood production along the bole. The transition from juvenile to mature wood was shown to be below the crown base in trees <50 years old with deep crowns, and above the crown base otherwise.

Pengaruh Tekanan dan Penggunaan Conplast terhadap Sifat Mekanik Eternit dari Abu Cangkang Sawit

2016 ◽  
Vol 8 (15) ◽  
pp. 47-54
Author(s):  
Haspiadi Haspiadi
Keyword(s):  
Mechanical Properties ◽  
Oil Palm ◽  
Modulus Of Elasticity ◽  
Modulus Of Rupture ◽  
Palm Shell ◽  
Oil Palm Shell ◽  
Density Values ◽  
Test Result

The purpose of this research is to know the influence of pressure and use of conplast against mechanical properties which are a Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) of plasterboard. The study is done because still low quality of plasterboard made from a mixture of ashes of oil-palm shell especially of the mechanical properties compared to the controls. The method of this reserach used variation of printed pressure and the addition of conplast. Test result is obtained that the highest value of Modulus of Elasticity (MOE) 90875.94 Kg/cm2, Modulus of Rupture (MOR) 61.16 Kg/cm2 and density values in generally good printed at the pressure 60 g/cm3 and the addition of conplast 25% as well as the composition of the ash of palm shell oil 40%: limestone 40%: cement 15%: fiber 5% and 300 mL of water. ABSTRAK Tujuan dari penelitian ini adalah untuk mengetahui pengaruh tekanan dan penggunaan conplast terhadap sifat mekanik yaitu kuat lentur dan keteguhan patah eternit berbahan dasar abu cangkang sawit. Penelitian ini dilakukan karena masi rendahnya mutu eternit berbahan campuran abu cangkang sawit dari bolier khususnya sifat mekanik dibandingkan dengan kontrol. Metode penelitian yang digunakan adalah dengan variasi tekanan cetak dan penambahan conplast. Hasil uji diperoleh bahwa kuat lentur tertinggi sebesar 90875,94 Kg/cm2 dan keteguhan patah sebesar 61,16 Kg/cm2, yang dicetak pada tekanan 60 g/cm3 dan penambahan conplast 25% dengan komposisi  abu cangkang sawit 40 %: kapur 40 % : semen 15 %: serat 5 % dan air 300 mL.Kata Kunci :  Abu cangkang sawit, conplast, kuat lentur, keteguhan patah.

Sign in / Sign up

Export Citation Format

Share Document