Temporal variation in δ13C, wood density and microfibril angle in variously irrigated Eucalyptus nitens

2009 ◽  
Vol 36 (1) ◽  
pp. 1 ◽  
Author(s):  
David M. Drew ◽  
E. Detlef Schulze ◽  
Geoffrey M. Downes

Wood can serve as a record of past climate, recording tree responses to changing conditions. It is also valuable in understanding tree responses to environment to optimise forest management. Stable carbon isotope ratios (δ13C), wood density and microfibril angle (MFA) are potentially useful wood property parameters for these purposes. The goal of this study was to understand how δ13C varied over time in response to cycles of soil drying and wetting and to variation in temperature in Eucalyptus nitens Deane & Maiden, in concert with wood density and MFA. δ13C increases did not necessarily occur when water stress was highest, but, rather, when it was relieved. Our hypothesis is that this was a result of the use of previously fixed carbohydrate reserves when growth and metabolic activity was resumed after a period of dormancy. MFA in particular showed concomitant temporal variation with δ13C. A peak in δ13C may not coincide temporally with an increase in water stress, but with a decrease, when higher growth rates enable the final incorporation of earlier stored photosynthate into mature wood. This has implications for using δ13C as a tool to understand past environmental conditions using radial measurements of wood properties. However, interpreting this data with other wood properties may be helpful for understanding past tree responses.

Holzforschung ◽  
2002 ◽  
Vol 56 (3) ◽  
pp. 244-252 ◽  
Author(s):  
R. Wimmer ◽  
G.M. Downes ◽  
R. Evans ◽  
G. Rasmussen ◽  
J. French

Summary Fibre length, microfibril angle and wood density were measured in eight-year-old Eucalyptus globulus clones planted on three different sites. Samples were chipped and pulped, and the pulps beaten prior to preparation of 60g/m2 handsheets. Eleven physical handsheet properties, together with pulp freeness, were measured using standard methods. Direct relationships between wood properties and pulp/paper properties were studied using path analysis. Fibre length had a strong, direct effect on tear index, bending stiffness, freeness, pulp yield and active alkali consumption. Wood density was a strong predictor of most handsheet properties: high density woods produced bulkier, more porous sheets with higher bending stiffness, while lower density woods produced smoother, denser sheets with higher tensile strength.The effect of microfibril angle was small and more evident in handsheets made from beaten pulp.


Trees ◽  
2012 ◽  
Vol 26 (6) ◽  
pp. 1771-1780 ◽  
Author(s):  
Jane Medhurst ◽  
Geoff Downes ◽  
Maria Ottenschlaeger ◽  
Chris Harwood ◽  
Rob Evans ◽  
...  

2005 ◽  
Vol 35 (5) ◽  
pp. 1156-1172 ◽  
Author(s):  
Roderick D Ball ◽  
Mike S McConchie ◽  
Dave J Cown

Wood anatomical characteristics of twenty-nine 6-year-old Pinus radiata D. Don trees, selected to represent the extremes of intraring checking, were assessed with SilviScan. Derived ring-level summary variables were calculated from the SilviScan pith-to-bark wood property traces, based on ring means, standard deviations, and quantiles. Incidence of checking was assessed on discs that had been oven dried using a standardized method, and evidence for associations between wood characteristics and checking was evaluated at the tree and ring level using Bayesian statistical methods. Bayes factors of 39.1, 14.9, and 7.8 were obtained at the tree level, representing moderate to good evidence for associations between ring medians of wood density, tracheid radial diameter, and cell wall thickness, respectively. Increasing wood density, decreasing tracheid radial diameter, and increasing cell wall thickness were associated with reduced incidence of checking. These are parameters expected a priori to contribute to tracheid cells' resistance to collapse under drying stresses. A generalized linear model with radial diameter and cell wall thickness as independent variables had a concordance of 83% for predicting the checking status of trees.


Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 686
Author(s):  
Laurence Schimleck ◽  
Jorge L. M. Matos ◽  
Antonio Higa ◽  
Rosilani Trianoski ◽  
José G. Prata ◽  
...  

Loblolly pine (Pinus taeda L.) is one of the most important commercial timber species in the world. While the species is native to the southeastern United States of America (USA), it has been widely planted in southern Brazil, where it is the most commonly planted exotic species. Interest exists in utilizing nondestructive testing methods for wood property assessment to aid in improving the wood quality of Brazilian grown loblolly pine. We used near-infrared hyperspectral imaging (NIR-HSI) on increment cores to provide data representative of the radial variation of families sampled from a 10-year-old progeny test located in Rio Negrinho municipality, Santa Catarina, Brazil. Hyperspectral images were averaged to provide an individual NIR spectrum per tree for cluster analysis (hierarchical complete linkage with square Euclidean distance) to identify trees with similar wood properties. Four clusters (0, 1, 2, 3) were identified, and based on SilviScan data for air-dry density, microfibril angle (MFA), and stiffness, clusters differed in average wood properties. Average ring data demonstrated that trees in Cluster 0 had the highest average ring densities, and those in Cluster 3 the lowest. Cluster 3 trees also had the lowest ring MFAs. NIR-HSI provides a rapid approach for collecting wood property data and, when coupled with cluster analysis, potentially, allows screening for desirable wood properties amongst families in tree improvement programs.


Holzforschung ◽  
2006 ◽  
Vol 60 (5) ◽  
pp. 574-579 ◽  
Author(s):  
Jun Li Yang ◽  
Henri Baillères ◽  
Robert Evans ◽  
Geoff Downes

Abstract Longitudinal surface strain was measured or estimated using three different methods along the stems of nine trees of 10-year-old Eucalyptus globulus Labill. Wood samples were collected close to the location where the strain was measured or estimated. Microfibril angle (MFA), cellulose crystallite width (Wcryst), microdensity and Young's modulus along the grain (EL) were determined using the SilviScan-2 technology at high spatial resolution. Relationships of measured strain and estimated strain to wood properties were established. The quality of the relationships depends on a particular wood property. Strain was more closely related to mean Wcryst than to any other wood properties. Its relationship with MFA was the next closest. Based on the results of regression analysis, we propose that Wcryst may be suitable for the prediction of surface strain at a moderate level of reliability. Adding measurement of MFA, microdensity and EL does not significantly improve the prediction quality. The strain measurement method also affects the results. The best relationships were obtained with longitudinal displacement measured by the CIRAD method. Strain measured by the strain gauge method gave weak relationships, possibly owing to variation in the cambium age of the specimens.


2011 ◽  
Vol 41 (7) ◽  
pp. 1422-1431 ◽  
Author(s):  
Michael S. Watt ◽  
Branislav Zoric ◽  
Mark O. Kimberley ◽  
Jonathan Harrington

Detailed radial measurements of wood properties at four heights (0, 1.4, 5, and 20 m) were taken from 24-year-old Pinus radiata D. Don growing at four final crop stockings (200, 350, 500, and 1100 stems·ha–1). Using these measurements, the objectives of the study were to examine pith-to-bark trends at several heights to (i) determine how stocking influenced modulus of elasticity (MoE), wood density, and microfibril angle (MFA), (ii) quantify the relations among these properties and age at different stocking levels, and (iii) develop a graphical model for MoE across the stocking range. The influence of stocking on all wood properties was primarily expressed through a highly significant interaction between age and stocking. Wood properties in the highest stocking treatment diverged from those in the lowest stocking treatment at tree age 5 to reach a maximum difference of 92 kg·m–3 (488 vs. 580 kg·m–3) at tree age 18 for density, –5.7° (29.2° vs. 23.5°) at tree age 10 for MFA, and 5.1 GPa (12.1 vs. 17.2 GPa) at tree age 20 years for MoE. Graphical predictions from the model show greatest gains in MoE at high final crop stocking to occur over the lower part of the stem.


IAWA Journal ◽  
2007 ◽  
Vol 28 (4) ◽  
pp. 473-484 ◽  
Author(s):  
P. David Jenes ◽  
Laurence R. Schimleck ◽  
Chi-Leung So ◽  
Alexander Clark III ◽  
Richard F. Daniels

Near infrared (NIR) spectroscopy provides a rapid method for the determination ofwood properties of radial strips. The spatial resolution of the NIR measurements has generally been limited to sections 10mm wide and as a consequence the estimation of wood properties of individual rings or within rings has not been possible. Many different NIR instruments can be used to collect NIR spectra from the surface of radial strips at relatively high spatial resolution and the purpose of this study was to compare wood property calibrations obtained using NIR spectra collected in 5 mm and 2 mm seetions with several different NIR instruments. We found that calibrations based on spectra collected in 5 mm seetions had good statistics, with those based on the Bruker Vector 22/N spectrometer the strongest. Of the three properties examined (density, microfibril angle and stiffness), density had the weakest statistics. When the spatial resolution was decreased to 2 mm, calibration and prediction statistics were weaker than those at 5 mm. RPDp's were relatively low with the highest being 1.76 for predicted stiffness based on NIR spectra obtained using the ASD Field Spec Pro spectrometer. Based on the low RPDp's, we conclude that none of the instruments examined were suitable for scanning radial strips at a spatial resolution of 2 mm.


Holzforschung ◽  
2009 ◽  
Vol 63 (4) ◽  
Author(s):  
Laurence R. Schimleck ◽  
Charles Espey ◽  
Christian R. Mora ◽  
Robert Evans ◽  
Adam Taylor ◽  
...  

Abstract A total of 30 Caesalpinia echinata (pernambuco) sticks were ranked based on their suitability for making high quality bows and were assigned to one of the three following categories: 0=very poor to poor, 1=good to very good, and 2=excellent. From the end of each stick a sample was cut for wood property and near infrared (NIR) spectroscopic analysis. Wood properties measured included air-dry density, extractives content, microfibril angle, stiffness and wood color. NIR spectra were evaluated by principal component analysis (PCA) and on the PC scores. Poor quality samples were discriminated from those of good to very good and excellent quality; however, samples from the two higher quality groups were mixed. Based on relationships observed between PC scores and wood properties, we suggest that, of the measured properties, density and stiffness were the most important in sample discrimination based on quality. Samples ranked in the excellent category had high average density (1119 kg m-3) and stiffness (25.2 GPa) and relatively low extractives content (21.2%) compared to samples in the very poor to poor category (density= 938 kg m-3, stiffness=18.9 GPa and extractives content=24.9%).


IAWA Journal ◽  
2017 ◽  
Vol 38 (1) ◽  
pp. 99-104
Author(s):  
Laurence R. Schimleck ◽  
Jorge Luis Monteiro de Matos ◽  
Charles Espey

Caesalpinia echinata Lam. (pernambuco or pau-brasil) is recognized as the premier raw material for manufacturing stringed instrument bows. Several studies have identified properties considered important in determining the suitability of pernambuco wood for bow manufacture including density, modulus of elasticity (MOE), and, possibly, microfibril angle (MFA). No research has been conducted on how these properties vary within individual trees; however, an understanding of how pernambuco wood properties vary within trees is important as it may assist in the identification of trees or provenances most suited for the establishment of plantations, aid in developing an understanding of management practices on wood property variation for plantation-grown pernambuco and also facilitate the identification of regions within trees that possess optimal properties for bow manufacture. Radial variation in density, MFA and MOE was examined using SilviScan for three radial strips representing differing levels of wood quality in terms of perceived suitability for making high-quality bows. The lowest quality sample showed considerable radial variation compared to the higher quality samples for all properties and it also had the lowest average density. It was not possible to identify a strong pith to bark trend for any of the wood properties examined.


Sign in / Sign up

Export Citation Format

Share Document