Metabolite profiling reveals complex relationship between developing xylem metabolism and intra-ring checking in Pinus radiata

Globally, there has been an increasing amount of wood harvested from younger, fast-growing trees derived from plantation forests. As a consequence, producers and industrial consumers of wood products are becoming increasingly concerned with not only growth rates, but specific wood attributes that affect processing efficiencies and final product quality. Intra-ring checking is a problem that down-grades an unacceptably high proportion of radiata pine clearwood. Methods of identifying trees prone to this undesirable behaviour have been relatively destructive and time consuming, and from a breeding perspective, to date, there is no reliable method of predicting which selected progeny will later show a propensity to check. Using 120, 7-year-old Pinus radiata clones sampled from a common site, displaying difference in the propensity to form intra-ring checks, a GC/MS-based global metabolic profiling technique was employed to demonstrate that metabolomics can be used to accurately identify the checking phenotype. Metabolic profiling coupled with statistical tests was then used to develop models with greater than 90% efficiency to predict the intra-ring checking phenotype. Moreover, an inspection of unique metabolites contributing to the models indicated that coniferin, which is often found as a storage compound in rays, is a strong indicator of intra-ring checking, and indeed those genotypes that displayed the propensity to check inherently had a greater number of ray cells per unit area.

Non-Destructive Assessment of the Elastic Properties of Low-Grade CLT Panels

The use of cross-laminated timber panels (CLT) made of low-grade structural timber has steadily increased in developing countries. These panels usually present several natural defects, which can cause a high local variation of their orthotropic elastic properties, generating future structural serviceability problems. Our work aims to estimate the local variability of the elastic properties in low-grade CLT panels by combining nondestructive transverse vibration testing, numerical simulations, and regional sensitivity analysis (RSA). Four three-layer Radiata pine CLT panels were subjected to transverse vibration tests with supports at four points. Besides, a series of numerical simulations of the panels, considering the local variability of the elastic properties of the panels in eight zones, were carried out using the finite element method. Then, RSA analysis was performed to study in which ranges of values the panels’ elastic properties generated lower differences between the measured versus simulated dynamic properties. Finally, a structural quality control indicator was proposed for the CLT panels based on keeping low the probability that the elastic properties in the central zones do not exceed minimum acceptable values. The results obtained suggest that the proposed methodology is suitable for segregating CLT panels with high concentrations of defects such as pith presence.

Radiata Pine Wood Treated with Copper Nanoparticles: Leaching Analysis and Fungal Degradation

Radiata pine is the main wood species used in the Chilean construction industry, but it must be protected due to its low natural durability. Chemical protection of wood by impregnation allows for a more efficient utilization of the forest resources by extending its useful life. The use of nanoparticles in wood protection has garnered great interest during the last decade, due to their unique physicochemical properties, different from those of larger sized materials. In this research, the impregnation of radiata pine wood with copper nanoparticles (CuNP) was studied in terms of retention, penetration, leaching, and its protective effect against wood rot fungi growth according to EN 113, AWPA A3-91, A9-18, and E11-16. Penetration analysis confirmed a uniform distribution across the wood, with total penetration in the impregnated samples with the highest concentration solution of CuNP. Retention values of the impregnated wood increased proportionally with the concentration of nanoparticles evaluated by EDXRF. Leaching analysis showed copper removal during the first hours of the test, with a constant leaching rate up to 144 h. Impregnated wood mass loss (ML) due to exposure to Gloeophyllum trabeum and Rhodonia placenta fungi were significantly reduced regardless of the CuNP concentration or fungi tested, with an ML smaller than 5% and smaller than 14% for leached samples.

Morphology, anatomy and essential oil characterization of Pinus radiata needles in the conditions of the Southern Coast of the Crimea

The paper presents data on the dendrometric parameters, a needle anatomy and an essential oil characterization of a radiate pine (Pinus radiata D. Don) in the conditions of the Southern Coast of the Crimea. The research was carried out on the model trees (age 70-80 years) growing in the territory of the Montedor Park. For research collected pine needles radiant cuts were made on the freezing microtome (MZ-2, Ukraine), were stained with Sudan III and examined with a light microscope Mikmed-5 (LOMO, Russia) equipped with a digital camera MS-3 (LOMO, Russia). The essential oil from the needles was extracted by hydrodistillation on Ginsberg devices and examined on a gas chromatograph 6890N (Agilent Technology, USA). The studies showed that radiata pine trees achieve their genetically determined parameters, compared to those in the nature habitats in Monterey (California, USA). A needle anatomical investigation clearly demonstrated typical structure. In the essential oil composition, predominance of monoterpenes, in particular a-and (3-pinenes with a large content of the latter was demonstrated. The peculiarity of P. radiata essential oil under the conditions of the Southern Coast of the Crimea, compared to some other regions, was the presence of limonene, which determined the stronger coniferous smell.