Pinus Radiata Trees Research Articles

Impacts of tending on attributes of radiata pine trees and stands in New Zealand – a review

Impacts of tending on attributes of radiata pine trees and stands in New Zealand – a review

Sirex noctilio infestation led to inevitable pine death despite activating pathways involved in tolerance

Defense-related metabolome traits in pine species after infestation by Sirex noctilio are largely unknown, despite, in most cases, trees being overwhelmed. Using LC-MS-based untargeted metabolomics, we revealed the systemic metabolic changes induced by this insect in 14-year-old Pinus radiata trees, the most affected species worldwide. An immediate metabolome alteration was expressed in needles after infestation, including the up-regulation of flavonols, flavan-3-ols, oxyneolignans, auxins, proline, and tryptophan, among others. The flavan-3-ols (catechin and procyanidin B1) suggested a rapidly induced photoprotection mechanism aided by diverting proline as an alternative substrate for respiration to compensate for the progressive chlorosis that degrades photosystems. Meanwhile, glutathione, glutamate, and ascorbate levels significantly dropped in needles, which may indicate the critical oxidative stress that trees had to face since the onset of the infestation. They were not fully replenished after long-term infestation, and redox homeostasis was probably not achieved, compromising tree survival. Nevertheless, a huge auxins overexpression detected in needles throughout the infestation may reflect tolerance against the premature senescence caused by the woodwasp venom. In contrast, the metabolome of wood tissues remained initially unchanged, although it seems to collapse after three months. Overall, the metabolomics strategy adopted in this work evidenced its usefulness in uncovering the fundamental roles of plants’ chemical defense that govern interactions with specific stressors.

Strength and stiffness of radiata pine at elevated temperatures: a complete data set

ABSTRACT Wood processing operations, such as timber drying, are increasingly employing high temperatures, and the development and optimisation of these operations is often reliant on modelling from experimental data. These model outputs are only accurate if the experimental data has been collected under similar conditions. In this research, the Modulus of Elasticity (MoE) and yield stress in compression and tension of two Pinus radiata trees are presented for a range of 6–30%MC between 20 and 150°C in the three grain directions. Results indicate that in all grain directions both MoE and yield stress decrease with increasing moisture content and increasing temperature, and this effect is more pronounced with the combination of high temperature and high moisture content. For both MoE and yield stress, differences were seen between testing in compression and in tension, and this relationship varied with grain direction and test conditions. This underscores the importance of accounting for the direction of applied forces when modelling the behaviour of wood. Overall, this data set indicates that yield stress and MoE can vary considerably according to temperature, moisture content, grain direction and the direction of the applied force.

Predicting resin pockets and blemishes in radiata pine lumber from log properties

Background: Resin pockets and blemishes in pruned logs of radiata pine (Pinus radiata D.Don) can reduce the value of clear and moulding grades of lumber. External resin features (ERF) on the bark of the logs have proved an effective method of predicting the incidence of resin pockets in the lumber. Resin canals have been associated with resin blemishes in radiata pine, and could prove useful in improving the prediction of the grade recovery of lumber. Methods: Pruned butt logs of radiata pine trees from two forests in the North Island, New Zealand, were selected for low, moderate, and severe levels of external resin features (ERF) on the bark, and for low, average, and high resin canal diameter, frequency and brightness from breast height increment cores. The relationships were evaluated between these properties, and the lumber resin features and grade recovery of the logs. Results: The number of resin pockets, the blemish rating, and the percentage of boards with resin streaks and resinous heartwood increased, and the recovery of clears and moulding grade boards and the lumber value declined, with the severity of the ERF class of the logs. Multiple regression models gave good predictions of the grade recovery and loss of lumber value, using the log ERF class, volume, heartwood content, and number of Type 1 resin pockets on the ends of the logs, as independent variables. The resin canal properties did not improve the regression models. Resin blemishes were associated with Type 2 resin pockets, and were more frequent in the forest where false growth rings were present. This suggests the constitutive resin flow from resin canals, rather than the resin canal size and frequency, is more important in determining the incidence of resin blemishes. Conclusions: The prediction of the grade recovery of lumber using the ERFs of radiata pine logs, was supplemented by the log volume, heartwood content and number of Type 1 resin pockets on the ends of the logs. The environmental factors that drive the constitutive resin enrichment of resin canals, such as drought conditions that give rise to false growth rings, could be useful in improving the prediction of grade recovery for forest stands.

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.

Comparative studies on the mechanical properties and microstructures of outerwood and corewood in Pinus radiata D. Don

Twenty-year-old Pinus radiata trees imported from New Zealand were investigated, and a comparison was made between the outerwood (rings 16–20) and corewood (rings 4–6) in terms of mechanical properties, anatomical characteristics, microfibril angle (MFA), relative crystallinity, crystallite size and lignin content to determine the relationship between their mechanical properties and microstructures. The results demonstrated that the mechanical properties of the Pinus radiata outerwood were significantly better than those of the corewood. The outerwood had a modulus of rupture (MOR) of 106 MPa, a modulus of elasticity (MOE) of 11.4 GPa, and compressive strength parallel to the grain of 38.7 MPa, and the MOR, MOE and compressive strength parallel to the grain of the corewood were 78.9 MPa, 7.12 GPa and 29.3 MPa, respectively. The observed microstructures of the Pinus radiata outerwood and corewood were different, mainly due to differences in cell wall thickness, MFA, and relative crystallinity. The double wall thickness of the tracheid cells of the corewood and outerwood were 3.65 and 5.02 µm, respectively. The MFA data indicated that the average MFA of the outerwood was 14.0°, which was smaller than that of the corewood (22.3°). With X-ray diffraction, the relative crystallinity of the corewood was determined to be 35.7%, while that of the outerwood was 40.2%. However, the crystallite size of the outerwood cell wall shows no obvious difference from that of the corewood. Imaging FTIR spectroscopy showed a slightly higher relative content of lignin in the cell wall of the outerwood. The correlation between the microstructures and mechanical properties showed that the corewood with a thin cell wall, large MFA and low relative crystallinity had poor mechanical properties, while the outerwood with a thicker tracheid, smaller MFA and higher relative crystallinity had better mechanical properties. This means that the MFA, relative crystallinity and cell wall thickness synergically affect the mechanical properties of Pinus radiata in different radial locations.

Variation in constitutive and induced chemistry in the needles, bark and roots of young Pinus radiata trees

Variation in constitutive and induced chemistry in the needles, bark and roots of young Pinus radiata trees

Effects of nutrient removal by harvesting practices and fertiliser addition on end-of-rotation radiata pine wood quality

With intensification of forest management, there has been increasing focus on the impacts of harvest residue removal on tree growth and long-term site productivity. The intensity of harvest removals, which has a direct impact on the available nutrient pools, influences tree growth and are also likely to impact the quality of wood formed. This study focused on the effects of harvesting residue removal practices (whole tree + forest floor, whole tree and stem only) at the end of the previous rotation and repeated fertiliser addition during the current rotation on selected wood quality attributes. Growth, wood density and standing tree acoustic velocity data were collected from almost 600 radiata pine (Pinus radiata D. Don) trees from long term site productivity trials across New Zealand (Woodhill, Tarawera and Berwick Forests). A sample of 116 trees were felled to obtain detailed wood quality measurements on logs and cross-sectional discs at different heights along the stem. There was little or no effect of different levels of harvesting removal on any of the measures of wood quality. However, repeated fertiliser addition throughout the course of the rotation (up to 3200 kg N ha−1 at Woodhill Forest) did result in adverse impacts on wood density, stiffness, branch size and heartwood content. The degree to which these affect returns to forest growers and end-product performance will depend on the market segment that logs are being sold into. It is recommended that nutritional strategies aimed at increasing forest productivity should incorporate studies to evaluate their potential adverse impacts on wood quality.

Structure, growth and growing space efficiency of Pinus radiata (D. Don) trees as affected by their social position

Currently, silvicultural prescriptions such as thinning monospecific stands from above and transitioning from monospecific to mixed-species stands are scrutinised regarding their ability to reduce stress and damage. That the quantity and quality of the trees harvested by intermediate and final cuts will vary depending on the chosen prescription is likely but more or less neglected so far. Here we analyse 60 Pinus radiata (D. Don) trees earmarked for removal from the Jonkershoek thinning experiment at the West Cape, South Africa. The experiment comprises both thinning from above and below allowing for comparison of the structure and growth of dominant and subdominant trees removed at 11 years old. Thinning from above removed mainly dominant trees which were on average 44.3% larger in tree diameter, only 8.5% larger in tree height, but 83% larger in crown projection area and more than 25% tapering than subdominant trees extracted by thinning from below. The courses of diameter growth over age of the dominant trees were degressively asymptotic; those of subdominant trees were S-shaped, due to competitive pressure. The volume growth was exponential in both groups. However, the dominant trees achieved 2–3 times higher stem volumes at 10 years of age. Tree structure and growth were highly correlated: the mean annual volume increment showed a Pearson correlation of r = 0.64 with crown length, r = −0.76 with the current ratio of stem slenderness, and r = −0.70 with the competition index by Hegyi. Thus, crown length, slenderness and the competition index were most relevant in explaining tree growth. The analysis of the mode of competition indicated in both groups and in total a sub-proportional increase of stem growth with increasing size. Interestingly, growing space efficiency in terms of mean annual volume growth per crown projection area was similar in both groups.

A comparison between traditional ordinary least-squares regression and three methods for enforcing additivity in biomass equations using a sample of Pinus radiata trees

Background: Additivity has long been recognised as a desirable property of systems of equations to predict the biomass of components and the whole tree. However, most tree biomass studies report biomass equations fitted using traditional ordinary least-squares regression. Therefore, we aimed to develop models to estimate components, subtotals and above-ground total biomass for a Pinus radiata D.Don biomass dataset using traditional linear and nonlinear ordinary leastsquares regressions, and to contrast these equations with the additive procedures of biomass estimation.Methods: A total of 24 ten-year-old trees were felled to assess above-ground biomass. Two broad procedures were implemented for biomass modelling: (a) independent; and (b) additive. For the independent procedure, traditional linear models (LINOLS) with scaled power transformations and y-intercepts and nonlinear power models (NLINOLS) without y-intercepts were compared. The best linear (transformed) models from the independent procedure were further tested in three different additive structures (LINADD1, LINADD2, and LINADD3). All models were evaluated using goodness-of-fit statistics, standard errors of estimates, and residual plots.Results: The LINOLS with scaled power transformations and y-intercepts performed better for all components, subtotals and total above-ground biomass in contrast to NLINOLS that lacked y-intercepts. The additive model (LINADD3) in a joint generalised linear least-squares regression, also called seemingly unrelated regression (SUR), provided the best goodness-of-fit statistics and residual plots for four out of six components (stem, branch, new foliage and old foliage), two out of three subtotals (foliage and crown), and above-ground total biomass compared to other methods. However, bark, cone and bole biomass were better predicted by the LINOLS method.Conclusions: SUR was the best method to predict biomass for the 24-tree dataset because it provided the best goodness-of-fit statistics with unbiased estimates for 7 out of 10 biomass components. This study may assist silviculturists and forest managers to overcome one of the main problems when using biomass equations fitted independently for each tree component, which is that the sum of the biomasses of the predicted tree components does not necessarily add to the total biomass, as the additive biomass models do.

Evaluación del predio forestal San Vicente con fines de manejo y conservación ubicado en el cantón guano, Ecuador

La presente investigación se basa en la ordenación de los rodales que integran el predio forestal San Vicente, y es complementada por la descripción de su situación actual y el cálculo de indicadores dasométricos. Estos fueron componentes requeridos para la generación de estrategias de manejo técnico, mediante la aplicación del muestreo sistemático al instalar parcelas circulares de 250 m2 para el rodal uno, el censo al rodal 2 y el muestreo exploratorio a los rodales 3, 4 y 5. Según los resultados, el predio San Vicente está caracterizado por un rodal formado por cinco bloques de árboles de Pinus radiata, el rodal dos por árboles de Cupressus macrocarpa, el rodal 3 consta de dos bloques de Eucalyptus globulus en estado latizal bajo, el rodal cuatro o zona de conservación formado por especies arbóreas, arbustivas y herbáceas y un quinto rodal o zona aprovechada. De acuerdo a lo expuesto, se propone aplicar raleo a una intensidad del 20 al 30% para los bloques del rodal uno, actividad de poda a los árboles de Cupresus macrocarpa del rodal dos, el rodal 3 requiere un manejo gradual de los árboles de Eucalyptus globulus en estado de latizal bajo; con fines de madera aserrada y postes se podría dejar entre 1-3 rebrotes por tocón, y para combustible (leña) un número mayor a tres; el rodal cuatro, se dejará como está y que los factores del sitio incidan hasta el próximo monitoreo entre 2-4 años. Finalmente, para el rodal cinco, se plantea reforestar con el uso de plántulas de Pinus radiata a un distanciamiento de 3m x 3 m a fin de establecer nuevamente el sistema de uso del suelo, propiciando la generación de beneficios ecológicos, económicos y sociales al aplicar criterios de manejo sustentable para la gestión de los recursos forestales del predio evaluado.

Genotypic diversity and distribution of Sphaeropsis sapinea within Pinus radiata trees from northern Spain

AbstractSphaeropsis sapinea is an important latent pathogen of Pinus spp., outbreaks of which have a considerable impact on plantations. This study considers the population diversity and distribution of S. sapinea in northern Spain at different spatial scales from single plantations to a wide area covered by Pinus radiata trees. Estimation of genotypic diversity is an important component of the analysis of the genetic structure of plant pathogen populations. Ten simple sequence repeat (SSR) markers were used, together with vegetative compatibility tests, to study the genetic diversity among S. sapinea isolates. Polymorphism analysis at SSR loci is a simple and direct approach for estimating the genetic diversity of S. sapinea isolates. From a total of 86 isolates collected from four different areas, 14 microsatellite haplotypes and 13 vegetative compatibility groups (VCGs) were identified. The percentage of maximum genotypic diversity, based on Stoddart and Taylor's index, for microsatellites of the northern Spain population ranged from 14.6% to 38.1% and from 8.0% to 29.4% for VCGs. Analysis of these markers and vegetative compatibility groups confirmed that S. sapinea reproduces mainly asexually due to its reduced genotypic diversity in spatially close populations. Isolates of S. sapinea from northern Spain populations were predominantly monomorphic at the tested SSR loci. Vegetative compatibility groups also indicate a low level of genetic variability in these samples, which appear to be clonal.

In vitro GROWTH OF ECTOMYCORRHIZAL FUNGI ASSOCIATED WITH Pinus radiata PLANTATIONS IN CHILE

A comparative study of in vitro growth of three species of ectomycorrhizal fungi (ECMF) (Rhizopogon luteolus, Suillus granulatus and Suillus luteus) was performed. Fungal material was collected in adult Pinus radiata plantations. Isolation and purification of the strains were performed on potato-dextrose-agar medium and the evaluation of the radial growth rate and the increase in mycelial biomass, under different culture conditions, was performed on the Modified Melin Norkrans growth medium. The effects of temperature (24, 28 and 32 ºC) and pH (4.8, 5.3, 5.8, 6.3 and 6.8) of the growth medium were tested for the three fungal species in two independent assays. The results indicate that the temperature had a significant effect on the radial growth rate (RG) and mycelial biomass increase (MB) in all of the evaluated fungal species. The highest RGR and MBI were recorded in R. luteolus, and the lowest values for these variables were registered in S. luteus. Rhizopogon luteolus had the highest sensitivity to pH changes. Meanwhile, there was no pattern in S. granulatus and S. luteus growth response under different pH conditions. When cultivated in vitro, the three studied species of ECMF presented adaptation, exponential, declining and stationary growth phases. The in vitro growth responses recorded in the present study showed the great potential of R. luteolus to be used in future programs using mycorrhizal inoculation in the production of Pinus radiata trees in nurseries in Chile.

Evaluacion De Dos Instrumentos De Medicion En La Determinación Del Área Basal En Pinus Radiata

This study compares the diameter of data obtained from utilizing two measuring instruments (the caliper and diameter tape). This instrument is the two most commonly used instruments for measuring tree diameters in forest inventory procedures. The measurement of diameter has a high implication in the estimation of the basal area and stand volume. It is therefore imperative to ensure accurate measurement of the diameter of trees in a stand. This work evaluated data taken with these two diameter measuring instruments. In order to evaluate the performance of the measuring instruments, parallel measurement of the diameter at breast height (DBH) of a sample of Pinus radiata trees in a plantation were measured. Also, the basal area of the stand was determined for both instruments. It was concluded through the analysis of variance (ANOVA) that there is no significant (p =0.958) difference between the averages of the calculated basal areas from the diameter measurements obtained by the diameter tape and the caliper. The estimated value from the diameter tape was 0,04190829, while the caliper was 0,04145599. Thus, the use of the two measurement tools led to similar results in the calculation of the cross-sectional areas of pine trees measured at breast height.

Climate as possible reproductive barrier in Pinus radiata (D. Don) interspecific hybridisation

Historically, interspecific hybridisation with Pinus radiata D. Don had limited success. The effect of environmental conditions and position of pollination bags in the tree were investigated as possible hybridisation barriers. The study was conducted in a P. radiata seed orchard in the Southern Cape (South Africa). Field data were compared to the climatic conditions at natural and commercial provenances of seven Mesoamerican Pinus species identified as possible hybrid partners. In vitro pollen studies were used to confirm whether interspecific crosses with P. radiata might be feasible within predefined climatic parameters. The temperature ranges for both top and northern side of P. radiata pine trees in the seed orchard was similar to the natural distribution of P. radiata, P. elliottii Engelm. and P. taeda L. in the USA. Results suggested that pollen of P. elliottii and P. taeda might be more suited to result in the successful pollination of P. radiata than the other Mesoamerican pine species tested in this study. Furthermore, the combination of minimum temperature and precipitation also showed a closer correlation to successful hybridisation with P. radiata for both P. elliotii and P. taeda. However, pollen tube elongation studies did not support these results, suggesting that mean temperature might not be the only determining factor of hybridisation success. Three circadian temperature models that mimic natural conditions were developed for Karatara and Sabie (Tweefontein, Witklip and Spitskop). These models will be tested in future in vitro studies to further evaluate temperature fluctuations between day and night regimes as a possible reproductive barrier limiting hybridisation success between P. radiata and other Mesoamerican pine species.

Detection and mapping of resin canals by image analysis in transverse sections of mechanically perturbed, young Pinus radiata trees

We describe a novel, semi-automatic method for the detection, visualisation and quantification of axially oriented resin canals in transverse sections of Pinus radiata D. Don (radiata pine) trees. Sections were imaged with a flatbed scanner using circularly polarised transmitted light, with the resin canals that contained only primary cell walls appearing dark against a bright background of highly-birefringent tracheids. These images were analysed using ImageJ software and allowed for a non-biased, automated detection of resin canals and their spatial distribution across the entire stem. We analysed 8-month-old trees that had been subjected to tilting to induce compression wood and rocking to simulate the effects of wind. These experiments showed that both rocking and tilting promoted the formation of wood and confirmed that resin canals were most common adjacent to the pith. Both the rocking and tilting treatments caused a decrease in the number of resin canals per unit area when compared to vertical controls, but this change was due to the increased formation of wood by these treatments. In tilted samples, however, analysis of resin canal distribution showed that canals were more common on the lower sides of stems but these canals were excluded from regions that formed compression wood.

Efecto del método de propagación y sitio sobre atributos fustales en árboles de Pinus radiata a la edad de 17 años

La tasa de plantaciones de pino radiata en Chile ha requerido aumentar la escala de producción de plantas aplicando propagación vegetativa. Sin embargo, se desconoce si existen diferencias de crecimiento y atributos fustales entre árboles reproducidos mediante semillas o estacas. Esta investigación cuantifica el efecto del método de propagación y sitio sobre atributos fustales de pino radiata a la edad de 17 años. Los atributos evaluados fueron: forma fustal, localización del centro de volumen y centro de gravedad, y ahusamiento en trozas. Los datos se obtuvieron de un ensayo silvícola sin raleo ni poda ubicado sobre suelos de ceniza volcánica y arenas. En cada sitio se establecieron dos parcelas (30 m × 21 m), considerando una densidad inicial de 1428 individuos por hectárea de la misma familia genética. Dentro de cada sitio se asignó en forma aleatoria a cada parcela, plantas propagadas por semilla o por estacas de un año de edad. La combinación de métodos de propagación y sitios definieron un diseño factorial 2 × 2. En cada tratamiento, se seleccionaron 20 individuos para muestreo destructivo. Los resultados indican que no hubo efectos significativos de los métodos de propagación para el factor y cociente de forma, centro de volumen y gravedad. Tampoco hubo efectos significativos de los sitios ni interacción entre factores. Sin embargo, el ahusamiento de la primera troza basal (0 m - 3 m) evidenció efectos significativos de ambos factores. Se puede concluir que individuos propagados por estacas y establecidos en arenas presentan trozas basales más cilíndricas que individuos establecidos en suelos derivados de cenizas volcánicas.

The effect of surface fire on tree ring growth of Pinus radiata trees

Pinus radiata trees showed significantly reduced basal area increments and increased latewood/earlywood ratios, when their stem was charred by surface fires even if no needle damage occurred. An interaction of fire damage and precipitation on growth was observed. Heat from forest fires is able to penetrate beyond the bark layer and damage or completely kill a tree’s cambium. Short-term growth reductions following surface fires have been reported for some species. However, most studies have in common that they describe a compound effect of stem and foliage damage. This study investigated the impact of surface fires on the radial growth of Pinus radiata, where only the stem of trees was charred, while no needle damage was recorded. Tree ring measurements were performed on cores obtained at breast height. Analysis of variance and tests, based on annual basal area increment values were calculated to quantify pre- and post-fire growth differences of tree ring width and latewood/earlywood ratios. The analysis revealed significant growth reductions following a surface fire on P. radiata in the year on which the fire occurred as well as in the following year. As a consequence of the fire, basal area increment and latewood/earlywood ratios were significantly reduced. An interaction of fire damage and precipitation on growth was observed. The obtained results show how fires without crown damage can affect growth and tree ring structure of P. radiata trees and indicate that stem char could be associated with a significant decrease in ring width and latewood/earlywood ratio.

Single-tree water use and water-use efficiencies of selected indigenous and introduced species in the Southern Cape region of South Africa

In South Africa, the development of a plantation tree industry using fast-growing introduced species was accelerated by the limited extent of indigenous forests. However, concerns about the impacts of plantations on the country’s limited water resources has initiated forest hydrology research and subsequent regulation of the industry since 1972. The forestry industry’s continued efforts to sustainably meet fibre and timber demands for the country’s growing economy have prompted questions whether indigenous tree species can provide an additional low water-use form of forestry. Single-tree water use and water-use efficiencies of three indigenous species (Ilex mitis, Ocotea bullata and Podocarpus latifolius) and one introduced species (Pinus radiata) in the Southern Cape region of South Africa were quantified. The heat-pulse velocity method was used to collect hourly sap flow data over a 12-month period. Hourly weather and soil-water data were concurrently recorded and tree growth rates were determined for the year. Biophysical water-use efficiency was calculated as the ratio of utilisable biomass gained per volume of water transpired. Patterns of water use through the year were different for the different species. Pinus radiata had higher transpiration volumes and water-use efficiency levels than the indigenous species. The most transpiring Pinus radiata tree had a transpiration volume that was 4.7 times that of the most transpiring indigenous tree. Indigenous species’ relatively lower water-use efficiencies were more a consequence of slow growth rates and not high water-use rates, which could be attributed to competition for resources in the dense indigenous forest. Potential implications for further hydrological research on the development of water-use-efficient tree production systems are discussed.

Biogenic Formaldehyde: Content and Heat Generation in the Wood of Three Tree Species

Global trends in allowable formaldehyde (CH2O) emissions from nonstructural wood-based composites require a renewed consideration of biogenic CH2O from wood. Increment cores from living Virginia pine (Pinus virginiana), yellow-poplar (Liriodendron tulipifera), and radiata pine (P. radiata) trees were used to measure CH2O and CH2O generation due to heating (200 °C, 10 min). Significant variations within and between trees of the same species were observed. Tissue types (juvenile/mature, heartwood/sapwood) sometimes correlated to higher CH2O contents and greater heat-generation potential; however, this did not always depend upon species. Heating increased CH2O levels 3–60-fold. Heating with high moisture levels generated more CH2O than that generated from dry specimens. Radiata pine generated extraordinarily high CH2O levels when heated, far exceeding the other species. It was suggested that pine extractives might catalyze CH2O generation, perhaps in lignin. Regarding wood-based composites, findings suggeste...