Estimating Basic Density of Eucalyptus Wood by Non-destructive Methods.
Name: ÉRICA PATRÍCIA PINTO QUEIROZ
Publication date: 23/07/2024
Examining board:
Name | Role |
---|---|
GLAYCIANNE CHRISTINE VIEIRA DOS SANTOS ATAIDE | Examinador Externo |
GRAZIELA BAPTISTA VIDAURRE DAMBROZ | Presidente |
HENRIQUE FERRAÇO SCOLFORO | Examinador Externo |
IZABEL CHRISTINA GAVA DE SOUZA | Examinador Externo |
PAULO RICARDO GHERARDI HEIN | Examinador Externo |
Summary: The analysis of basic density (BD) using the traditional method requires significant time and operational resources, which limits the ability to conduct a more comprehensive sampling that represents the environmental and genotypic variations of plantations. Therefore, evaluating wood quality through faster and non-destructive techniques becomes a necessity. Non-destructive methods (ND) offer a quick, economical alternative with greater sample representativeness. Thus, the general objective was to evaluate the accuracy of different nondestructive methods in estimating the BD of wood from young eucalyptus genetic materials, as well as to train and validate linear mixed models for this purpose. Five eucalyptus clones were studied, aged 6.8, 6.6, and 7.2 years, from three different growth sites: Nova Viçosa (Bahia - BA), São Miguel Arcanjo (São Paulo - SP), and Açailândia (Maranhão - MA), respectively. At the BA site, 5 trees with average diameter, 3 with lower diameter, and 3 with higher diameter were collected, totaling 11 trees per clone. At the SP and MA sites, 5 trees of average diameter were collected per clone. At all sites, discs were sampled at positions of 0%, DBH, 25%, 50%, 75%, and 100% of commercial height to obtain basic density by destructive method. For BD determination by ND methods, four devices (Pilodyn, Resistograph, Near-Infrared Spectroscopy (NIR), and Increment Borer) were applied to living trees at 1.3 m height from the ground (DBH). In modeling through Linear Mixed Models (LMM), the density obtained by the destructive method (observed density) was used as the dependent variable, while the independent variables were those provided by the equipment, along with dendrometric variables. The random effect of the clone was also included in the equations to improve estimates. Pilodyn, Resistograph, and NIR readings proved significant in estimating the basic wood density of eucalyptus clones for the BA site alone, with differences between observed and estimated basic density of 4 kg/m³ for Resistograph, 6 kg/m³ for Pilodyn, and 3 kg/m³ for NIR. When estimating BD by growth site with only average trees, the coefficients of equations generated by increment borer, both for site-specific LMM and global LMM, were not statistically significant. Pilodyn obtained significant equations only for the SP site, justified by the greater range of BD variation for this site due to higher Mean Annual Increment (MAI), while NIR estimated significantly for all sites. Pilodyn and NIR were also able to estimate BD when grouping all sites. The influence of genetic material and growth site on equipment variables and on the basic density of eucalyptus wood was evidenced through LMM in this study.