Some Tree Growth – Wood Property Relationships of Eucalypts

1975 ◽  
Vol 5 (3) ◽  
pp. 424-432 ◽  
Author(s):  
J. E. Nicholson ◽  
W. E. Hillis ◽  
N. Ditchburne

The relationship between level of longitudinal growth strain and stress, modulus of elasticity, basic density, volumetric shrinkage, fiber classification, and stem form was investigated with 10 Eucalyptusregnans regrowth trees. Close relationships were observed. It is suggested that variations in these properties within trees are closely controlled, possibly to enable optimum positioning of the tree crown in relation to its immediate environment. The concept of fiber structure varying as a response to environment is supported by the observed variation in wood properties within and between trees of this species. The often-reported association between eccentric radial growth and reaction wood was not substantiated in this study.The data indicate that if economically justifiable, it would be possible to segregate trees that are likely to contain material that is hard to season.


2017 ◽  
Vol 3 (1) ◽  
pp. 1-5
Author(s):  
Futoshi Ishiguri ◽  
Kazuko Makino ◽  
Imam Wahyudi ◽  
Jun Tanabe ◽  
Yuya Takashima ◽  
...  

The present study clarified the relationship between the growth and wood properties of 54-year-old Agathis sp. trees planted in Indonesia. Stem diameter, pilodyn penetration, and stress-wave velocity (SWV) were measured for all trees (35 trees) in a plot (30  30 m) located almost at the center of a stand. Based on the mean stem diameter, 10 standard trees in a plot were selected for measuring the basic density (BD) and compressive strength parallel to grain (CS). Core samples (5 mm in diameter) were collected from the 10 selected trees to determine BD and CS. The mean stem diameter, pilodyn penetration and SWV in the plot were 40.2  11.3 cm, 23.4  2.1 cm, and 3.85  0.43 km/s, respectively. No  significant correlation coefficeint (r = -0.327, no significance at 5% level) was obtained between stem diameter and SWV. The mean BD and CS in the 10 trees were 0.42  0.03 g/cm3  and 28.1  2.7 MPa, respectively. A significant positive  correlation was observed between BD and CS. Analysis of variance (ANOVA) revealed a significant difference between BD and CS values of the 10 trees, indicating that wood properties may differ among trees with the same standard growth in a stand. From these results, we concluded that wood quality improvement in this species could be achieved by selecting  trees with high density and strength in tree breeding programs.



Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Shakti Chauhan ◽  
Kenneth Entwistle

Abstract When a log is sawn along the length, an outward bending or deflection of two half rounds arises from the release of growth stresses in the log. The relationship between this outward bending and the peripheral longitudinal growth strain in logs from a 10-year-old Eucalyptus nitens plantation was investigated. In total, 63 trees were felled and two logs (one bottom and an upper log) were cut from each felled tree. A strong association was observed between the measured longitudinal growth strain and the outward bending produced by splitting the log along its axis. A mathematical model was developed that enables calculation of the relationship between the surface axial growth stress and the opening of the split log. This involves calculation of the lateral deflection of a tapered cantilever beam of semi-circular cross-section under a known bending moment. The relationship between the opening of the slit log and the surface axial stress showed good agreement with the measured data on 126 logs. The model equation is effective in predicting the growth stress from the magnitude of the log distortion. This log sawing or splitting method is quick and reliable for assessing the surface growth stresses in small diameter trees. It could have potential in breeding programs for identifying families or clones for low-growth stresses of superior eucalypts for sawn timber production.



Holzforschung ◽  
2020 ◽  
Vol 74 (12) ◽  
pp. 1089-1097
Author(s):  
José Clailson Franco Coelho ◽  
Graziela Baptista Vidaurre ◽  
João Gabriel Missia da Silva ◽  
Maria Naruna Felix de Almeida ◽  
Ramon Ferreira Oliveira ◽  
...  

AbstractThe relationship between grain angle and wood properties has not been focus of researches in wood industry. The aim of this study was to establish grain angle variations in commercial Eucalyptus logs and their effects on physical-mechanical wood properties. Wood maximum angular deviation (MAD) was correlated with density, volumetric shrinkage, compressive strength parallel to grain, flexural strength and stiffness as determined by bending and acoustic methods in wood of seven Eucalyptus grandis × Eucalyptus urophylla clones at 13 years old. The relationship between MAD at pith-bark and base-top positions and its effect on the physical and mechanical properties were evaluated. Amplitude of MAD values was small for the seven clones, and the mean was 6.2°. The grain deviation decreased by only 8% in base-top direction, and the correlations among MAD and three logs heights were small and negative (r = −0.13). MAD values presented an increasing trend of 33% in pith-bark direction, with a small positive correlation (r = 0.42). Basic density (BD) presented a significant correlation with the MAD (r = 26). There was no significant correlation between the MAD and volumetric shrinkage, mechanical properties and modulus of elasticity dynamic (determined by stress wave timer, ultrasound or transverse vibration).





2012 ◽  
Vol 430-432 ◽  
pp. 508-511
Author(s):  
Peng Xiang Peng ◽  
Kai Fu Li ◽  
Kun Nan Liang ◽  
Kai Meng Xu

In order to understand the effects of geographical provenances of teak on wood properties and improve the quality of afforestation in china, research was carried on wood properties of eight provenances of teak at age 27 in Ledong Country, Hainan Island. The slices revealed that the constructional characteristics from different geographical provenances of teak were very similar. But the effect of geographical provenance on teak wood properties was highly significant. The relationship results for properties of teak showed that properties of most wood species had the obvious relation with basic density, which can be used to guide the selection of the teak provenance in the early planting to improve the quality of teak.



CERNE ◽  
2017 ◽  
Vol 23 (3) ◽  
pp. 291-297
Author(s):  
Walter Torezani Neto Boschetti ◽  
Juarez Benigno Paes ◽  
Graziela Baptista Vidaurre ◽  
Marina Donária Chaves Arantes ◽  
João Gabriel Missia da Silva

ABSTRACT This study aims to evaluate the quality of normal, tension and opposite wood of eucalyptus trees lengthwise, in straight and inclined stems, affected by wind action. It also aims to explain the pulping parameters resultant from the quality of the wood. The trees were grouped into four tilt ranges, ranging from 0 to 50º, and the basic density, chemical composition of the wood, and performance in kraft pulping were assessed. Normal and tension wood had similar basic densities; while for opposite wood, the density was lower, being responsible for a decrease in reaction wood density. The chemical composition of the wood was influenced by the presence of reaction wood in the stem. Tension and opposite wood showed lower levels of extractives and lignin and higher holocellulose content when compared to normal wood, with favorable wood quality for pulping. The increase in holocellulose content and the reduction of lignin and extractives content contributed positively to a more delignified pulp and reduction of the Kappa number. However, after cooking the reaction wood under the same conditions as those of normal wood, reaction wood pulping tends to have a lower screen yields. Due to differences in basic density and chemical constituents between opposite and normal wood, it is recommended not to designate the opposite wood as normal wood.



2012 ◽  
Vol 64 (2) ◽  
pp. 605-611 ◽  
Author(s):  
M. Krstic ◽  
N. Stavretovic ◽  
V. Isajev ◽  
I. Bjelanovic

The study was carried out in Serbian spruce (Picea omorika Panc/Purkyn?) plantations in the western Serbia. The paper presents results of the analysis of crown development. The following elements were analyzed: total tree height, height of the crown base, absolute and relative crown length, maximal crown diameter, coefficient of crown spreading and degree of crown girth. We discuss approaches to the modeling of tree crown growth and development, growing under favorable environmental and stand conditions, without anomalies in development. In order to establish the relationship between analyzed factors, regression analyses were applied. Data fitting was by the analytic method, by the implementation of Prodan?s functions of growth, linear and parabolic function. Received models can be used for the simulation of various growth and developing processes in forest.



2000 ◽  
Vol 30 (1) ◽  
pp. 136-144 ◽  
Author(s):  
C A Raymond ◽  
A Muneri

The effects of N and P fertilizers applied to Eucalyptus globulus Labill. at plantation establishment on basic density, fibre length, fibre coarseness, predicted pulp yield, and N and P concentration in the wood were examined by sampling four fertilizer factorial trials: three in Victoria and one in Western Australia. Treatments sampled were control, maximum levels of N and P by themselves and combined. Growth responses varied across sites with significant growth responses at the Victorian sites but no response at the Western Australian site. An interaction was suggested between rainfall and the effects of the fertilizer; wood properties at the drier sites were detrimentally affected by fertilizer but there was little effect at the wetter sites. On the two drier sites, application of both N and P, alone or in combination, resulted in changes in density, shorter fibres, and slightly lower predicted pulp yield. Addition of both N and P increased the levels of these nutrients in the wood at the three Victorian sites. Changes occurred in wood properties in the absence of growth responses to the applied fertilizer indicating that these changes were not induced by changing tree growth rate.



IAWA Journal ◽  
2006 ◽  
Vol 27 (3) ◽  
pp. 243-254 ◽  
Author(s):  
Teresa Quilhó ◽  
Isabel Miranda ◽  
Helena Pereira

Within-tree variations in fibre length, width, wall thickness and wood basic density of Eucalyptus grandis × E. urophylla (urograndis) were studied in five 6.8-yr-old seedling trees and five 5.6-yr-old trees from one clone from Brazil. Samples were taken at 5%, 25%, 35%, 55%, 65% and 90% of stem height and five radial positions (10%, 30%, 50%, 70% and 90% of radius). The tree average fibre length, width and wall thickness were in seed and clone trees: 0.955 mm and 1.064 mm, 18 μm and 20 μm, 3.6 μm and 4.4 μm respectively. The axial variation of fibre dimensions was very low, while there was a consistent but small increasing trend from pith to periphery. The basic density ranged from 397–464 kg/m3 to 486–495 kg/m3 respectively in seedling and clone trees with a low variation along the stem. In comparison with other eucalypt pulpwood, e.g. E. globulus, the urograndis hybrid showed similar fibre dimensions and lower basic density. Overall the within-tree variation of these wood properties was low and age had a small impact on the variation of density and fibre dimensions.



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