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Copper-based preservatives are used for wood protection, which leads to an enrichment of copper tolerant microbial communities in respective soil environments. In this study impregnated pine wood specimens (2 × 2 × 36 cm) were half buried in two field sites with (North Germany, NG) and without (Central Germany, CG) a long preservative history and incubated for 17 and 36 weeks. Pine sapwood specimens were impregnated with either CuTriQAC (containing copper, triazoles and quaternary ammonium compounds), Cu (containing only copper) or water (H 2 O) as control. The effect of preservative treatment at the wood-soil interface, 1 mm and 7 mm into wood was assessed by quantitative PCR and amplicon sequencing of the fungal ITS region and bacterial 16S rRNA gene of both field sites over time. Fungal and bacterial copy numbers decreased in 1 mm and only fungal in 7 mm into CuTriQAC treated wood in both sites but not in Cu treated wood. Both Cu and CuTriQAC treated wood shifted the richness, evenness of the bacterial and, to a lesser extent, the fungal community composition inside wood. In conclusion, Cu and CuTriQAC treated wood caused a selection towards microfungal ascomycetes and defined bacterial genera, which majority of genera were previously described as diazotrophs. • Quaternary ammonium compounds/triazoles supported Cu to reduce fungal copy numbers. • Bacterial but not fungal community composition shifted in pine wood specimen. • Copper-containing wood preservatives reduced fungal and bacterial richness. • Microfungal ascomycetes were abundant in Cu and CuTriQAC treated wood. • Bacteria in Cu and CuTriQAC treated wood were previously described as diazotrophs. [ABSTRACT FROM AUTHOR]

1. Ecological stoichiometry theory was applied to investigate how a consumer contends with an extreme elemental mismatch between its food and its body via symbiotic facilitation. 2. The beetle Dendroctonus brevicomis LeConte develops in bark, a substrate extremely low in nitrogen (N) and phosphorus (P). Its survival there depends on interactions with mutualist and antagonist fungi. 3. This study found that mutualists transfer N and P from sapwood and phloem into bark, where beetles feed, whereas the antagonist moves these elements only to phloem, resulting in starvation of the insect. However, even with mutualists, N and P concentrations remained low in bark, resulting in low N and extremely low P concentrations in the beetle. 4. The N:P ratios found in D. brevicomis larvae were the highest thus far reported for beetles and among the highest for insects and invertebrates. This suggests that the beetle has evolved additional, nutrient‐sparing adaptations. [ABSTRACT FROM AUTHOR]

Genetic materials interact with the environment in specific ways, therefore their responses in wood need to be better understood. The present study sought to evaluate the influence of different climatic conditions in Minas Gerais, Brazil on Eucalyptus grandis × Eucalyptus urophylla wood. Two six-year-old clones were cultivated in Belo Oriente, Ferros, Santa Bárbara, Itabira and Peçanha. Five trees from each clone were sampled from the base to top direction. Wood density, heartwood/sapwood ratio, vessels, fibres, and extractive and lignin contents were determined, as well as their correlation with environmental variables. Vessel diameters, heartwood/sapwood ratio, and extractive and lignin contents all increased due to higher water availability in Santa Bárbara and Itabira. In both genetic materials, the variables linked to growth and wood quality were related to environmental factors. [ABSTRACT FROM AUTHOR]

Summary: Trait variability in space and time allows plants to adjust to changing environmental conditions. However, we know little about how this variability is distributed and coordinated at different organizational levels.For six dominant tree species in northeastern Spain (three Fagaceae and three Pinaceae) we quantified the inter‐ and intraspecific variability of a set of traits along a water availability gradient. We measured leaf mass per area (LMA), leaf nitrogen (N) concentration, carbon isotope composition in leaves (δ13C), stem wood density, the Huber value (Hv, the ratio of cross‐sectional sapwood area to leaf area), sapwood‐specific and leaf‐specific stem hydraulic conductivity, vulnerability to xylem embolism (P50) and the turgor loss point (Ptlp).Differences between families explained the largest amount of variability for most traits, although intraspecific variability was also relevant. Species occupying wetter sites showed higher N, P50 and Ptlp, and lower LMA, δ13C and Hv. However, when trait relationships with water availability were assessed within species they held only for Hv and Ptlp.Overall, our results indicate that intraspecific adjustments along the water availability gradient relied primarily on changes in resource allocation between sapwood and leaf area and in leaf water relations. See also the Commentary on this article by Skelton et al.223: 505–507. [ABSTRACT FROM AUTHOR]

In order to study the wood property of Beilschmiedia, the volume and the quality method were used to determine the bark percentage, and the drainage method was used to determine the wood volume, then the measured data were analyzed. The results showed that the average bark volume percentage and bark mass percentage were 6. 42% and 8. 20% respectively, showing an increasing trend in the tree height direction. From pith to sapwood, the green density change of south and north was similar, showing an increasing trend, and the basic density change of south and north also showed an increasing trend. The basic density decreasing direction with increasing height, the average was 0. 619 g/cm~3. But the green density had no obvious regularity, the average was 1. 021 g/cm~3.The moisture content of green wood in the south and north was decreasing and then increasing direction from pith to sapwood. The moisture content of green wood in the south and north generally showed an increasing trend with the increase of tree height, with an average value of 65. 55%. The study provided scientific data for processing using of Beilschmiedia wood. [ABSTRACT FROM AUTHOR]

Copyright of Forest Research is the property of Forest Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tree trunks not only provide physical support for canopy leaves but also supply and store water for transpiration. However, the relationships between trunk hydraulic properties and canopy leaf physiology in tropical trees are not well-understood. In this study we concurrently measured morning and midday canopy leaf photosynthesis (A), stomatal conductance (g s), and leaf water potentials (Ψ L) in 40 tropical trees representing 14 species at the beginning of the rainy season in Xishuangbanna, Southwest China. We also measured trunk sapwood capacitance (C), wood density, and sap flux density to assess their association with canopy leaf physiology. Among the 14 studied species, only three and four species did not show a significant midday reduction in A and g s respectively. The diurnally maximum A and g s were significantly positively related to sapwood hydraulic capacitance, maximum sap flux density (midday), and sap flux density at 11:00. Those species with lower wood density and higher C showed a lower reduction in Ψ L at midday, whereas, species with high C , and large values of maximum sap flux density also showed high carbon assimilation at midday. Our results provide new insights into the close coordination between canopy physiology and trunk sapwood hydraulic properties in tropical trees. • Tropical trees show significant variations in diurnal canopy gas exchange behavior. • There is coordination among trunk capacitance, water flow rate, and canopy gas exchange. • Diurnal leaf water fluctuation is strongly correlated with trunk wood density. [ABSTRACT FROM AUTHOR]

This paper describes the chemical composition of sapwood (SW) and heartwood (HW) of Pinus halepensis Mill stem. Extractives were first isolated by accelerated solvent extraction and then analysed by gas chromatography-mass spectrometry (GC-MS). The cellulosic polysaccharide content present in the pre-extracted wood samples was determined with acid hydrolysis and GC. The hemicelluloses content was determined with acid methanolysis and GC. Free monomers were additionally analysed by GC. The amount of lignin was determined gravimetrically by the Klason lignin method and the acid-soluble lignin was determined by a UV method. Formic and acetic acids in wood were determined after alkaline hydrolysis and analysed by HP-SEC. It was found that lipophilic and hydrophilic extractives were more abundant in heartwood (1.6% and 2.5%) than in sapwood (1.1% and 1.8%). Celluloses content was higher in sapwood (42.5%) than in heartwood (39.7%), whereas lignin, hemicelluloses and sugar monomer contents were more abundant in heartwood (28.9%, 26.8% and 0.3%) than in sapwood (28.0%, 24.5% and 0.2%). The variation in acetic and formic acids and ash contents between sapwood (0.7%, 0.2% and 0.5%) and heartwood (0.6%, 0.1% and 0.4%) was small. The acetylation degrees were found to be slightly similar in sapwood (0.4) and heartwood (0.3). [ABSTRACT FROM AUTHOR]

Key message: A total of 43 phyla (395 genera) of bacteria and 11 phyla (309 genera) of fungi were identified from normal sapwood (SW), wetwood (WW) and their transition zone wood (TW) in living poplar trees, with bacteria showing significantly higher diversity than fungi. Highly variable community diversities and compositions were found for bacteria but not for fungi among WW, TW and SW. Overall, 22 phyla (95 genera) bacteria and three phyla (11 genera) fungi were significantly different in relative abundance between WW and SW. Nine wood chemical properties were significantly correlated with the relative abundance of top 15 bacterial and fungal genera in all samples. Wetwood represents an abnormal condition of heartwood in living poplar trees. The cause of wetwood formation is still poorly understood, but it is generally considered to involve microbial activities. To facilitate a better understanding of wetwood formation, we sequenced the 16S rRNA and ITS (Internal Transcribed Spacer) genes of distinct regions (16S V4, ITS1) to precisely identify the microbial communities in normal sapwood (SW), wetwood (WW) and their transition zone wood (TW). Nine chemical properties of the wood samples were further determined to elucidate the correlations between the microbial communities and wood characteristics. The total sequences of 16S V4 and ITS1 from WW, TW and SW were assigned to 43 bacterial phyla (395 genera) and 11 fungal phyla (309 genera), indicating a significantly higher diversity of bacteria than fungi. Among SW, TW and WW, significant variations in community diversity and composition were found for bacteria but not for fungi. WW had the highest bacterial and lowest fungal diversities, while SW exhibited the highest fungal diversity. TW generally exhibited intermediate levels between WW and SW. Between WW and SW, 22 bacterial phyla (95 genera) were significantly different in relative abundance. Nine wood chemical properties were significantly correlated with the relative abundance of top 15 bacterial and fungal genera in all wood samples. [ABSTRACT FROM AUTHOR]

Elevated CO2 affects C cycling processes which in turn can influence the nitrogen (N) and phosphorus (P) concentrations of plant tissues. Given differences in how N and P are used by plants, we asked if their stoichiometry in leaves and wood was maintained or altered in a long-term elevated CO2 experiment in a mature Eucalyptus forest on a low P soil (EucFACE). We measured N and P concentrations in green leaves at different ages at the top of mature trees across 6 years including 5 years in elevated CO2. N and P concentrations in green and senesced leaves and wood were determined to evaluate both spatial and temporal variation of leaf N and P concentrations, including the N and P retranslocation in leaves and wood. Leaf P concentrations were 32% lower in old mature leaves compared to newly flushed leaves with no effect of elevated CO2 on leaf P. By contrast, elevated CO2 significantly decreased leaf N concentrations in newly flushed leaves but this effect disappeared as leaves matured. As such, newly flushed leaves had 9% lower N:P ratios in elevated CO2 and N:P ratios were not different in mature green leaves (CO2 by Age effect, P = 0.02). Over time, leaf N and P concentrations in the upper canopy slightly declined in both CO2 treatments compared to before the start of the experiment. P retranslocation in leaves was 50%, almost double that of N retranslocation (29%), indicating that this site was P-limited and that P retranslocation was an important mechanism in this ecosystem to retain P in plants. As P-limited trees tend to store relatively more N than P, we found an increased N:P ratio in sapwood in response to elevated CO2 (P < 0.01), implying N accumulation in live wood. The flexible stoichiometric ratios we observed can have important implications for how plants adjust to variable environmental conditions including climate change. Hence, variable nutrient stoichiometry should be accounted for in large-scale Earth Systems models invoking biogeochemical processes. [ABSTRACT FROM AUTHOR]

Fibre direction cylindrical specimens from the sapwood and heartwood areas of Paulownia wood were heat treated at 180, 190, and 200°C split in eight groups of ten specimens each. Air and water permeability were measured, thereafter. Results demonstrated that heat treatment had a positive effect on air permeability both in sapwood and heartwood specimens. That increase might be attributed to the development of cell wall micro-checks caused by thermal degradation and fracture of the vessel tyloses. Liquid permeability was significantly decreased as a result of heat treatment. [ABSTRACT FROM AUTHOR]

The present research study described the anatomical characteristics and physical properties of two timber species from San Gabán, department of Puno. The macroscopic and microscopic characters were described according to the standard list of the IAWA (1989), and the physical properties according to Peruvian Technical Standards. The results show both species with diffuse porosity, Miconia amazonica with medium pores, vessel length 365 μm, simple perforation plate, parenchyma in bands, heterogeneous rays, height 120 μm. Erithrina ulei with straight grain, medium texture and medium gloss, veined overlapping arches, with sapwood susceptible to fungal attack, diameter of pores 246.2 μm and vessel length 253.5 μm, 2-4 pores/mm2, simple perforation plate, confluent paratracheal parenchyma, stratified, heterogeneous and homogeneous rays, both have libriform fibers, length 1747 μm, 770 μm, and wall thickness 3.3 μm, 3 μm, respectively. Miconia amazonica, basic density and volumetric contraction medium (0.57 g/cm³ and 12.73% respectively), while Erythrina ulei, very low density (0.29 g/cm³), low volumetric contraction (8.12%) and both species have very stable wood. [ABSTRACT FROM AUTHOR]

Aim: Information on the amount of carbon stored in the living tissue of tree stems (sapwood) is crucial for carbon and water cycle applications. Here, we aim to investigate sapwood‐to‐stem proportions and differences therein between tree genera and derive a sapwood biomass map. Location: Northern Hemisphere boreal and temperate forests. Time period: 2010. Major taxa studied: Twenty‐five common tree genera. Methods: First, we develop a theoretical framework to estimate sapwood biomass for a given stem biomass by applying relationships between sapwood cross‐sectional area (CSA) and stem CSA and between stem CSA and stem biomass. These measurements are extracted from a biomass and allometry database (BAAD), an extensive literature review and our own studies. The established allometric relationships are applied to a remote sensing‐based stem biomass product in order to derive a spatially continuous sapwood biomass map. The application of new products on the distribution of stand density and tree genera facilitates the synergy of satellite and forest inventory data. Results: Sapwood‐to‐stem CSA relationships can be modelled with moderate to very high modelling efficiency for different genera. The total estimated sapwood biomass equals 12.87 ± 6.56 petagrams of carbon (PgC) in boreal (mean carbon density: 1.13 ± 0.58 kgC m−2) and 15.80 ± 9.10 PgC in temperate (2.03 ± 1.17 kgC m−2) forests. Spatial patterns of sapwood‐to‐stem biomass proportions are crucially driven by the distribution of genera (spanning from 20–30% in Larix to > 70% in Pinus and Betula forests). Main conclusions: The presented sapwood biomass map will be the basis for large‐scale estimates of plant respiration and transpiration. The enormous spatial differences in sapwood biomass proportions reveal the need to consider the functionally more important sapwood instead of the entire stem biomass in global carbon and water cycle studies. Alterations in tree species distribution, induced by forest management or climate change, can strongly affect the available sapwood biomass even if stem biomass remains unchanged. [ABSTRACT FROM AUTHOR]

The influence of birch false heartwood was investigated relative to the physical and mechanical properties of wood-plastic composites. Birch wood (sapwood and false heartwood) particles were modified with 5 wt% NaOH (by wood content) and 5 wt% 3-aminopropyl-triethoxysilane (by wood content) before being compounded with polypropylene in a corotating twin-screw extruder. The compounded composites were then injection moulded into standard test samples. The resulting composites were grouped into four categories: birch sapwood, modified birch sapwood, false heartwood, and modified false heartwood. Neat polypropylene samples were produced as a reference. The samples were tested for their tensile and flexural properties, water absorption, thickness swelling, and ultraviolet aging. The compositions of the composites were analysed using Fourier transform infrared spectroscopy. The results showed that the tensile strength of all of the samples decreased after water absorption. Water absorption decreased the impact strength of all of the composites. Ultraviolet radiation degraded the neat polypropylene and lowered the mechanical properties of all of the composites. Surface chalking was observed in all of the wood-plastic composites exposed to ultraviolet aging, with colours ranging from brown and brownish black to white. [ABSTRACT FROM AUTHOR]

An eco-friendly agent mainly consisting of activated glucose (AG) and citric acid (CA) was investigated for its potential wood modification applications. Scots pine (Pinus sylvestris L.) sapwood was treated with AG and CA both individually and in combination. The treatments with the combined agent resulted in an increase in the weight percent gain and decrease in the leaching ratio, which suggested a synergy between the two components for their fixation in wood. The dynamic vapor sorption behavior indicated an increased sorption at a higher AG concentration. Compared with the AG treatment, the CA treatment more effectively improved the dimensional stability of the wood. The modulus of elasticity was not influenced by the treatments, and the modulus of rupture was slightly reduced. Incorporation of AG in the CA inhibited the decrease in impact strength of wood compared to treatment with CA alone, which was a result of reduced crosslinking from the CA within the wood matrix. Fourier transform infrared (FTIR) spectroscopy revealed an enhanced absorbance, indicating development of ester bonds due to the treatment. [ABSTRACT FROM AUTHOR]

The use of wood contributes to the global transformation into a bio-based community. There are, however, challenges. The growth of mold, rot fungi, and algae on the coated surface is of major concern due to decreased aesthetic service life and shorter maintenance intervals. The colonization of a coated surface requires the presence of spores, nutrients, and a sufficient amount of water. This work studied the influence of using heartwood and sapwood on the moisture content (MC) and growth of microorganisms on the surface of coated Norway spruce boards [Picea abies (L.) Karst.]. The results revealed a relationship of heartwood samples having a lower MC and a lower or equal degree of biological growth on the coated surface than sapwood samples. The relationship was valid through a range of densities (309–548 kg/m3) and two different coating systems based on either an alkyd or an acrylic resin. Furthermore, the choice of coating color (red compared to white) affected the MC as the red-colored samples had a lower MC, combined with no growth of microorganisms. [ABSTRACT FROM AUTHOR]

Copyright of Anadolu Journal of Agricultural Sciences / Anadolu Tarım Bilimleri Dergisi is the property of Ondokuz Mayis Universitesi, Ziraat Fakultesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Furniture manufacturers using Acacia mangium wood often experience difficulties in getting high glossy and attractive finished surface. Such problems may be attributed to poor surface wettability as well as the anatomical structure of the wood itself. This study evaluates the effects of surface treatment on the wettability of A. mangium wood. Acacia mangium lumber was segregated into sapwood and heartwood prior to sanding. Two types of solvents, methanol and sodium hydroxide (NaOH) at different concentrations (2, 4, 6, 8, 10, 12 and 14%) were used to treat the wood surface. The treated surfaces were evaluated for surface roughness and contact angle according to ISO 4287 and ASTM D7334-08 respectively. The results showed that untreated sapwood of A. mangium had significantly rougher surface compared with heartwood after treatment with methanol and NaOH. NaOH-treated surface had relatively lower contact angle than methanol-treated wood and experienced complete wetting within 4.2 s for sapwood and 6.8 s for heartwood. The surface was darker and the grain was less visible. Methanol-treated sapwood and heartwood took 6.4 and 12.1 s respectively to be completely wet but retained its original colour. Their wood grain was clearer and much enhanced. Based on both wettability and appearance, the best results were given by 6% methanol for sapwood and 4% methanol for heartwood. [ABSTRACT FROM AUTHOR]

Summary: While recent reports demonstrate that the direct emission of methane from living tree trunks may be a significant terrestrial emission source, there has been debate whether tree emissions are due to transport from soils or produced in the wood environment itself. Reports of methanogens from wood of trees were prominent in the literature 40 years ago but have not been revisited with molecular ecology approaches.We examined communities associated with Populus deltoides using rRNA gene sequence analyses and how these vary with tree and wood properties.Our data indicate that wood environments are dominated by anaerobic microbiomes. Methanogens are prominent in heartwood (mean 34% relative abundance) compared to sapwood environments (13%), and dominant operational taxonomic units (OTUs) were classified as the Methanobacterium sp. Members of the Firmicutes phylum comprised 39% of total sequences and were in 42% greater abundance in sapwood over heartwood niches. Tree diameter was the strongest predictor of methanogen abundance, but wood moisture content and pH were also significant predictors of taxon abundance and overall community composition.Unlike microbiomes of the soil, rhizosphere and phyllosphere, wood associated communities are shaped by unique environmental conditions and may be prominent and overlooked sources of methane emissions in temperate forest systems. [ABSTRACT FROM AUTHOR]

Abstract Surface mould growth contributes to the colour changes of outdoor exposed wood over time. Modelling mould growth can thus help visualize wooden facades' colour development, which can improve facade design and service life. However, existing wood mould models do not consider transient wetting effects that occur outdoors due to precipitation and condensation. To address this, four mould models were evaluated using laboratory experimental data that included exposure to transient wetting. First, the models (the original and the updated VTT model, the biohygrothermal model and the mould resistance design (MRD) model) were evaluated for Scots pine sapwood. For this evaluation, the transient wetting effect was implemented in the models by using hourly wood surface relative humidity (RH), calculated from electrical resistance measurements, as input. This showed that the original and the updated VTT model gave best fit to the experimental data. However, further evaluation of these two models for more wood materials showed that the updated VTT model was sensitive to the choice of material parameters. Large discrepancies occurred when varying the material parameters in the updated VTT model. Finally, different estimates of RH were tested in the original VTT model. Using wood surface RH as input gave best fit to the experimental data, and ambient air RH gave poorest fit. Overall, the results indicate that the original VTT model is fairly reliable and can be used to predict mould growth on wooden claddings exposed to transient wetting as long as the wood surface climate is used as climatic input data. Highlights • Four existing mould growth models were evaluated using experimental data. • Eight climatic conditions and eight wood materials were included in the evaluation. • The transient wetting effect was implemented in the models by using wood humidity as input data. • The original VTT model gave the most reliable estimates. [ABSTRACT FROM AUTHOR]

Highlights • On average, samples had 13.3 sapwood rings. • Older and more slowly growing trees have on average higher number of sapwood rings. • N SW is estimated by N HW and W HW with linear regression model. • Linear regression model explains 10.3% of variance. • N SW estimates are given for various combinations of N HW and W HW. Abstract We analysed sapwood characteristics in 344 pedunculate oak (Quercus robur L.) samples from the south-western part of the Pannonian Basin. The samples came from 13 sites, located in Slovenia, Croatia and Serbia. The trees had an average of 13.3 sapwood rings, with a minimum of 5 and maximum of 32. Fifteen log-log linear regression models were employed to assess the statistical relationship between sapwood and heartwood variables. The number of sapwood rings (N SW), which is usually needed in dendroarchaeological dating, is significantly related to the number of heartwood rings (N HW), heartwood width (W HW) and heartwood growth rate (G HW). Older and more slowly growing trees had a higher average number of sapwood rings. Using N HW and W HW , we employed an additional multiple regression model and calculated coefficients for N SW predictions for real-world dendroarchaeological dating from the south-western part of the Pannonian Basin. [ABSTRACT FROM AUTHOR]

Copyright of Forest Research is the property of Forest Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Accurately estimating sapwood area is essential for modelling whole-tree or stand-scale transpiration from point-flow sap-flux observations. In this study, we tested the validity of electrical resistance tomography (ERT) to locate the sapwood–heartwood (SW/HW) interface for two ring porous (Quercus nigra L. and Quercus virginiana Mill.) and one diffuse porous (Acer rubrum L.) species. Estimates derived from the ERT analyses were compared with the SW/HW interface measured following dye perfusion testing. The ERT results revealed spatial variation in electrical resistance, with higher resistivity in the inner part of the cross sections. Regression analyses showed that ERT was able to accurately account for 97% and 80% of the variation in sapwood area (calculated as R 2) for Q. virginiana (n = 19) and Q. nigra (n = 7), respectively, and 56% of the variation in the diffuse porous species (n = 8). Root mean square error (RMSE) values for sapwood areas of the ring porous species were 11.12 cm2 (19%) and 25.98 cm2 (33%) for Q. virginiana and Q. nigra, respectively. Sapwood area estimates for diffuse wood carried greater error (RMSE = 33.52 cm2 (131%)). Model bias for all sapwood area estimates was negative, suggesting that ERT had a tendency to overestimate sapwood areas. Electrical resistance tomography proved to be a significant predictor of sapwood area in the three investigated species, although it was more reliable for ring porous wood. In addition to the results, a comprehensive code sequence for use with R statistical software is provided, so that other investigators may follow the same method. [ABSTRACT FROM AUTHOR]

Wetwood, water accumulation in the heartwood of tree trunks, is a defect of forest trees and needs to be improved for wood utilization. To understand the mechanism of wetwood formation, differences in water potential between sapwood and heartwood and their seasonal changes were investigated. The water potential of specimens sampled from tree trunks using an increment corer was measured by psychrometry at four-week intervals for 2 years in two coniferous species. A water potential gradient from sapwood to heartwood was identified that could provide a driving force of the radial water movement, and this gradient was found to fluctuate seasonally. The two species studied differed in seasonal change in water potential. The source of the water potential gradient is thought to be heartwood-accumulated potassium and water-soluble heartwood substance. The hypothesis is proposed that water movement from sapwood to heartwood during wetwood formation involves vaporous rather than liquid water and occurs over a limited season. [ABSTRACT FROM AUTHOR]

• Heterogeneous urban conditions may affect the radial patterns of sap flow in trees. • We measured sap flow at four sapwood depths of 30 trees in streets and parks. • Radial patterns of sap flow diverged between parks and streets, and individual trees. • Radial patterns of sap flow varied also in time, affected by VPD and PAR. • Tree-to-tree variation in the radial pattern was larger than temporal variation. Quantifying sap flow patterns along the sapwood radius is necessary for accurate up-scaling and estimation of tree and stand transpiration based on sap flow measurements. However, little information on radial patterns of sap flow exists in urban environments where precise estimates of tree water uptake and transpiration are important to quantify ecosystem services and plan tree management. Because of the heterogeneous conditions in urban environment, upscaling approaches specific to urban environments and species may be required to estimate whole-tree transpiration. We measured sap flow at four sapwood depths for Acer platanoides, Acer saccharinum and Tilia cordata, in two contrasting urban environments (site types): parks and streets, in Montreal, Canada. We then estimated the potential importance of tree-to-tree and temporal variation of radial patterns by comparing generalized additive models (GAM) with or without tree ID or a temporal effect, and using the models to upscale sap flow measurements conducted at the sapwood surface to tree-level daily water use estimates. The radial pattern of sap flow diverged between park and street trees, with a slightly more monotone pattern in park than street trees in the two Acer species. However, tree-to-tree variation was large even within a given species and site type, and partly associated with tree size. The radial pattern of sap flow varied in time in five of the twelve trees that were measured twice over the growing season. Sap flow in deeper layers relative to the sapwood surface correlated with vapor pressure deficit, solar radiation and the sap flow density at the sapwood surface. When comparing the two sources of uncertainty (tree-to-tree and temporal variation) in upscaling daily water use, a larger uncertainty was associated with tree-to-tree variation than with temporal variation. Thus, understanding the inter-tree variability in radial patterns of sap flow patterns should be prioritized in future studies. [ABSTRACT FROM AUTHOR]

The hemicelluloses, which represent an important family of polysaccharides constituting ≈ 20–30% of the plant wall are currently one of the most poorly valorized fractions of the biomass. Extracted in polymeric form, hemicelluloses could be used for innovative material applications, replacing fossil materials. Five cumulative pretreatments involving bleaching and/or steam explosion (SE) and/or alkaline extraction processes have been studied for polymeric hemicelluloses extraction from Okoumé sapwood. Morphological analysis of the cell wall of untreated and steam exploded wood was performed by optical and fluorescence microscopy after staining. Near infrared spectroscopy combined with multivariate calibration modeling were also performed for evaluating hemicellulose extraction. Hemicelluloses extracts were characterized by HPEAC/PAD ion chromatography, size exclusion chromatography (SEC), and high-performance liquid chromatography (HPLC), FTIR and HSQC NMR spectroscopy analyses. Alkali extraction of bleached wood led to high yields (≈ 19%) of high molecular weight hemicelluloses (Mw ≈ 65 kDa) while neutral SE pretreatment allowed the recovery of highly acetylated polymers with a low degree of branching. A bleaching step prior to SE increased accessibility to hemicelluloses extraction but weakened the pulp and led to the removal of micro-particles of wood during the SE. • Polymeric hemicelluloses were extracted from okoumé by cumulative treatments. • Morphological analysis of the cell wall was performed by microscopy. • Near infrared spectroscopy was performed for evaluating hemicellulose extraction. • Hemicelluloses were characterized by NMR, SEC, HPLC. [ABSTRACT FROM AUTHOR]

European larch (Larix decidua Mill.) holds significant importance as a forest tree species throughout the Alps and in certain regions of central Europe. Its extensive use as construction timber has made it a subject of substantial interest in dendroarchaeological studies aimed at understanding the long-term interactions between human societies and forests. Precise dating of felling phases, accurate estimation of the age of harvested wood, and information on the geographical origin of wood play a crucial role when it comes to characterize these interactions. In this study, we compiled a large dataset of L. decidua samples from across the European Alps to provide a robust statistical model that predicts the cambial age of L. decidua trees based on the number of heartwood rings. By extension, this model can be used to estimate the number of sapwood rings so as to approximate the felling date and to more precise date archaeological larch timber. The model requires almost complete heartwood sequences (<5 missing rings) to achieve accurate estimations. Our results also evidence that the ratio between the number of sapwood and heartwood rings varies across the Alps. At the same time, the indicator developed in this work is not suitable for a determination of wood origin, raising doubts about the effectiveness of attempts aimed at dendroprovenancing L. decidua based on sapwood. [ABSTRACT FROM AUTHOR]

Sawnwood of teak (Tectona grandis L. f.) from a Costa Rica plantation was thermally treated at different process conditions using thermo-vacuum technology. The main objectives of the study were to find the optimal combination of the process parameters, i.e. temperature (T), and duration (t), in order to minimise the colorimetric difference between sapwood and heartwood, and to evaluate the influence of the treatment on the modification pattern of physical properties of the material. The resulting mass loss (ML), hygroscopicity (H), dimensional stability (ASE), and lightness (L) were measured and compared. As expected, the temperature (T) is the main parameter influencing the extent of modification. The measured ML values turned out to be moderate even at high T values if compared with other hardwoods. The temperature range between 180 °C and 190 °C minimizes the colorimetric difference between treated sapwood and not treated heartwood.

This study examined the changes in the properties of beech wood (Fagus sylvatica L.) after intense drying. Beech wood with false red heartwood was selected as the test specimen. The test samples had dimensions of 50 mm thickness, 180 mm width, and 350 mm length. The specimens were divided into two groups, false red heartwood and sapwood. These specimens were selected with different angles of the growth rings (radial and tangential). The results showed that samples with red heartwood, in comparison to samples with sapwood content, had a remarkable effect in covering. Observation of specimens with false red heartwood and sapwood before and after drying process revealed significant differences in color changes and measured values during the covering-slicing test, but not between samples with different growth ring angles.

In the spring of 2012, in reforested areas of Peloritani Mountains (Sicily, Italy) a severe dieback of Acacia melanoxylon R. Brown was observed. The main symptoms on both young and adults plants consisted of elongated cankers on the trunks and epicormic shoots, wilt of the canopy and dieback interested mostly aged trees. The woody tissues showed browning beyond the cankers. Sapwood and heartwood appeared decayed with a brown to gray-greenish discoloration. One fungal species was consistently isolated from infected woody tissues, which was morphologically attributed to Neofusiccocum sp. The sequencing of the ITS regions of a representative isolate allowed to identify (99% similarity) the species Neofusiccocum parvum (Pennycook & Samuels) Crous, Slippers and Phillips, teleomorph Botryosphaeria parva Pennycook & Samuels. The pathogenicity tests have reproduced symptoms similar to those observed in the field. N. parvum is the aetiologic agent of mortality of australian blackwood observed in Sicily and to our knowledge this is the first report of this fungus on Acacia melanoxylon. It is a generalist pathogen, cosmopolitan, present in many temperate areas, Mediterranean and subtropical. The older Peloritani Mountains populations of australian blackwood seem particularly susceptible to the pathogen, the latter favored by the lack of silvicultural interventions that generate interspecific and intraspecific competition, as well as the increase and spread of the fungus. To minimize the consequential damage is necessary to adopt sanitation measures that would lower the fungal inoculum and program substitutions of this exotic species with others that have multiple functions suited to environments (e.g., Chestnut) or encouraging the establishment and development of native species, such as the holm oak and shrub.

Conventional kiln drying of wood operates by the evaporation of water at elevated temperature. In the initial stage of drying, mobile water in the wood cell lumen evaporates. More slowly, water bound in the wood cell walls evaporates, requiring the breaking of hydrogen bonds between water molecules and cellulose and hemicellulose polymers in the cell wall. An alternative for wood kiln drying is a patented process for green wood dewatering through the molecular interaction of supercritical carbon dioxide with water of wood cell sap. When the system pressure is reduced to below the critical point, phase change from supercritical fluid to gas occurs with a consequent large change in CO2 volume. This results in the efficient, rapid, mechanical expulsion of liquid sap from wood. The end-point of this cyclical phase-change process is wood dewatered to the cell wall fibre saturation point. This paper describes dewatering over a range of green wood specimen sizes, from laboratory physical chemistry studies to pilot-plant trials. Magnetic resonance imaging and nuclear magnetic resonance spectroscopy were applied to study the fundamental mechanisms of the process, which were contrasted with similar studies of conventional thermal wood drying. In conclusion, opportunities and impediments towards the commercialisation of the green wood dewatering process are discussed.

The properties of teak wood, such as natural durability and beautiful color, are closely associated with wood extractives. In order to further understand the performance differences between teak heartwood and sapwood, we analyzed the chemical components of extractives from 12 wood samples using an ultrahigh-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS)-based metabolomics approach. In total, 691 metabolites were identified, and these were classified into 17 different categories. Clustering analysis and principal component analysis of metabolites showed that heartwood samples could be clearly separated from sapwood samples. Differential metabolite analysis revealed that the levels of primary metabolites, including carbohydrates, amino acids, lipids, and nucleotides, were significantly lower in the heartwood than in the sapwood. Conversely, many secondary metabolites, including flavonoids, phenylpropanoids, and quinones, had higher levels in the heartwood than in the sapwood. In addition, we detected 16 specifically expressed secondary metabolites in the heartwood, the presence of which may correlate with the durability and color of teak heartwood. Our study improves the understanding of differential metabolites between sapwood and heartwood of teak, and provides a reference for the study of heartwood formation.

This study investigated the effect of the heat treatment on the wettability of the surface of juvenile teak (Tectona grandis) wood assessed by drop shape analyzer. Heartwood and sapwood samples were heat-treated at 180 and 200oC. Contact angle measurements were done every 5 s for 120 s using a KRÜSS DSA100. Heartwood had lower wettability than sapwood. Heat-treatment decreased the surface wettability of both heartwood and sapwood, especially in the wood treated at 200oC. Heartwood had lower wettability than sapwood, even after heat treatment.

In sum, the more sapwood, the more likely any individual tree could continue producing fruits even in the face of a drier atmosphere." now reads: "Model 2 revealed that higher VAP levels (more moist air) limited fruit production, but this was mitigated when trees had more sapwood area, particularly in Cachoeira (Fig. "Model 2 revealed that higher VAP levels (drier air) limited fruit production, but this was mitigated when trees had more sapwood area, particularly in Cachoeira (Fig. [Extracted from the article]

Poor-quality Corsican pine (Pinus nigra subsp. laricio (Poir.) Maire) and Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) wood samples were heat treated with the aim of testing the improvement of wood quality that could increase their economic value. Wood properties were measured to assess quality in treated and non-treated materials, including density, hardness, anti-swelling efficiency (ASE), modulus of elasticity (MOE), modulus of rupture (MOR), and compression strength. The results showed higher dimensional stability in heat-treated wood, yet mechanical performance in compression and bending strength were only marginally affected by loss of density. Despite having a re­latively low density after heat treatment, Corsican pine sapwood has potential in manufacturing higher-value products. In contrast, heat treatment applied to Douglas fir wood did not appear economically viable; insufficient differences were detected between the naturally desirable characteristics of this species and heat-treated samples.

In this study, the differences between sapwood and heartwood in fiber morphology on the samples prepared from Pinus pinea and Robinia pseudoacacia were investigated. For this aim, cell length, cell width, lumen width, wall thicknesses were measured. The measurements were made on sapwood and heartwood wood, separately. In the maceration process, chlorite method was used. The differences between sapwood and heartwood wood were determined with T test. According to obtained findings, cell length of sapwood wood and heartwood wood of the Pinus pinea and Robinia pseudoacacia were different significantly. But, the same differences were insignificant for cell width, wall thickness and luminal diameter.

Abstract Wood has been extensively used as a material for different applications over the years, therefore the understanding of different degradation processes in various environments is of great importance. In this study, the infrared spectroscopy, X-ray diffraction and chemometric methods were used to evaluate and compare the structure of archaeological and artificially degraded oak wood. The results clearly show that modifications in the structure of archaeological wood are related to the position of the material in the log (sapwood and heartwood), thus the extent of wood degradation. To identify the possible factors influencing these effects, the control wood samples were exposed to artificial white rot biodegradation with Coriolus (Trametes) versicolor and to alkali treatment (with NaOH solution). Due to the structural similarities between biodegraded wood and control or archaeological samples, this type of decay is likely to occur during natural ageing along with degradation produced by other environmental factors. Further, no real similarity was identified between the alkali treated wood and archaeological samples, indicating that such degradation does not affect wood under natural conditions. Graphical Abstract Unlabelled Image Highlights • Archaeological waterlogged and artificially degraded wood samples were analysed. • FT-IR spectroscopy, X-ray diffraction and chemometric methods were used to evaluate wood structure. • Structural modification of archaeological wood was related to its initial structure. • Differences between sapwood and heartwood of archaeological samples were observed. • Excessive depletion of carbohydrates was observed for sapwood archaeological sample. [ABSTRACT FROM AUTHOR]

Taiwania (Taiwania cryptomerioides Hayata) is an indigenous conifer species of Taiwan. Various secondary metabolites of Taiwania with diverse bioactivities have been identified, and lignans are especially abundant in the heartwood (hW). In the present study, the wood of this species was separated to cambium (Cam), sapwood (sW), transition zone (TZ) and hW and their transcriptomes were sequenced. Three pinoresinol-lariciresinol reductases (PLRs; designated TcPLR1, TcPLR2.2 and TcPLR3), which are responsible for lignan biosynthesis, were cloned and their expressions in wood tissues were detected. TcPLRs had higher expression levels in Cam and sW in RNA-seq and reverse transcriptase-polymerase chain reaction (RT-PCR) results. Liquid chromatography-mass spectrometry (LC-MS) analysis of the reaction products of TcPLRs revealed that TcPLR1 can reduce (+)-pinoresinol to lariciresinol, and both TcPLR2.2 and TcPLR3 could reduce (+)-pinoresinol to lariciresinol and secoisolariciresinol. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A study to test the suitability of a range of tree protection zone sizes. • Roots removed in circular trenches to mimic site developments. • Root pruning negatively affected the growth and physiology of Quercus virginiana. • Root pruning induced short-term water stress in mature Quercus virginiana. • Tree protection zones should be 15 times trunk diameter to adequately protect trees. Abstract A suite of best management practice documents (BMPs) providing procedures to protect trees are available around the world. An underpinning component of these texts is the provision of a tree protection zone (TPZ), the purpose of which is to define an area of ground surrounding the tree to be excluded from development activities. TPZs 12 times the trunk diameter are common in BMPs, however, the principles of the TPZ have not been extensively tested. The objective of this study was to test the suitability of TPZs by monitoring the responses of trees to different root removal treatments. Mature Quercus virginiana Mill trees (n = 18) were exposed to five root pruning treatments consisting of a circular trench around each tree. Trenches were established with radial offsets from the tree base between 3 and 15 times the trunk diameter in increments of three, plus control. Roots were severed manually, and their diameters measured to obtain a total cross-sectional area of severed roots, which were expressed as ratios of whole trunk cross-sectional areas (Ar (1)) as well as conductive sapwood areas (As (1)). Ar and As ratios were regressed against physiological (predawn leaf water potential (Ψ), stomatal conductance (g s) and chlorophyll fluorescence) and growth (trunk diameter, shoot extension and specific leaf area) responses. Ar (1) was a significant predictor of Ψ (p < 0.0001), trunk diameter growth (p ≤ 0.01), specific leaf area (p ≤ 0.001) and shoot extension (p ≤ 0.001), although model strength varied (R 2 = 0.75, 0.47, 0.57, 0.58 respectively). Significant (p ≤ 0.05) differences were observed in Ψ between control trees and all treatments except 15 ×. Growth responses were affected for one or more treatments between 3x and 9 ×. The results reveal that a TPZ defined by 12 times the trunk diameter was insufficient to adequately avoid short-term physiological perturbations in Quercus virginiana. [ABSTRACT FROM AUTHOR]

Highlights • Two species of Acer were exposed to root pruning treatments. • Root pruning negatively affected the growth and physiology. • Root pruning resulted in stomatal closure. • Allometry can be used to define root pruning thresholds that limit negative effects. Abstract Trees in the urban environment are affected by anthropogenic activities that have the potential to negatively affect tree function, health, and growth. The provision and maintenance of new underground utilities, footpaths, and street furniture all have the potential to result in conflicts with tree root systems leading to root severance. Traditional investigations into the responses of trees to root severance usually involve severing roots indiscriminately in one or more trenches, although root loss may not be fully quantified for individual trees. In the urban environment, root zone alterations may be localised and involve more discriminate methods, and practitioners must rely on experience and often anecdotal information when making decisions about root pruning. In this study, we investigate the suitability of allometric modelling as a tool to quantify root removal treatments. Two species of Acer were exposed to four different root severance treatments (trenching on one, two, three or four sides plus control). Fragments of the severed roots of all trees were excised and their diameters measured at the point of severance and used to estimate root cross-sectional area. Total root cross-sectional areas for each tree were expressed as a ratio of trunk cross-sectional areas at ground level (Ar (GL)) and at 1.4 m (Ar (BH)) as well as conductive sapwood areas in the trunk at each height (As (GL) and As (BH)). Ar and As ratios were used to explain differences in physiology (stomatal conductance and dark-adapted chlorophyll fluorescence) and growth (trunk diameter, shoot growth and specific leaf area) responses using linear regression models. Increasing root removal intensity (trenching treatments) revealed significant differences between treatment trees and control for stomatal conductance in both species (p ≤ 0.02), as well as growth responses (p <0.05). Ar (BH) was a significant predictor of stomatal conductance (p < 0.05), trunk diameter growth (p < 0.05), specific leaf area (p < 0.001) and shoot growth (p < 0.01); although model strength varied (R 2 = 0.56, 0.31, 0.16, and 0.03 respectively). This research takes the first steps towards developing a practical tool for practicing arborists who make day-to-day tree management decisions relating to roots and root care practices. [ABSTRACT FROM AUTHOR]

Highlights • Forest structure explains evapotranspiration in seasonal streamflow model. • "Top-down" model's unconstrained store accounts for catchment memory and thresholds. • Very good performance for large forested catchments affected by fire and logging. • Regional consistency of parameters allows model use in ungauged catchments. • Rainfall estimation procedure for remote regions with high relief. Abstract Forest growth dynamics affect streamflow with changes in actual evapotranspiration (AET) during forest regeneration. Using a "top-down" model approach, we present a seasonal forest hydrology model that estimates streamflow in forested catchments containing sparse soil and climate data. Across a 1423 km2 remote study area, a rainfall interpolation procedure using available rainfall data and information on terrain was integrated into a new seasonal streamflow model, called ABCF, which uses catchment sapwood area (SA) as the emergent property that equilibrates with potential evapotranspiration (PET), and a soil storage threshold that reduces AET below PET when soil water is limiting. We produce seasonal estimates of streamflow with Nash Sutcliffe efficiencies of 0.85, 0.87, and 0.91 for three major catchments within the study area. A fundamental feature of the "top-down" model approach is the use of LiDAR data and forest inventory data to model forest structural properties that relate strongly with SA. Building on our previous work with this modelling framework, our representation of eco-hydrological properties of the forest has been refined with a more accurate procedure for estimating stand mean sapwood thickness, and hence SA , and a remotely sensed tree stocking density (N) of old-growth forests to correct the temporal evolution of N as a means to improve SA estimates. Regional consistency of model parameters shows that the "top-down" modelling framework may be used to estimate streamflow in ungauged catchments using a forest growth model. The seasonal model generalised for both water-limited and water-unlimited forest conditions has significant potential for application in water supply planning and drought security. [ABSTRACT FROM AUTHOR]

The drilling resistance test has been widely used in tree inspections and structures since its first demonstration in Germany in 1988. A high correlation to wood density allows a correspondingly clear interpretation and reliable evaluation of the profiles in terms of wood condition. Without such a correlation, it is not clear what the profiles mean. In this study, researchers compared the profiles of a non-calibrated resistance drill with pictures of the surfaces of the drilled stem cross sections in order to find out how defects are revealed. In decayed areas, the profiles mostly dropped down and the results showed that advanced stages of decomposition and voids of significant size can be detected reliably with this device. There were statistical differences between drilling amplitude among the studied species and, in the heartwood, the values of amplitudes were superior and statistically different from those obtained in the sapwood. However, the depth of the drop, or the changes in the profiles of this device, do not allow users to differentiate between various stages of deterioration. Similarly, it is not clear if all rising profile peaks are caused by locally higher wood density, as compatibilizations zones, or by technical artefacts. [ABSTRACT FROM AUTHOR]

There is increasing concern about tree mortality around the world due to climatic extremes and associated shifts in pest and pathogen dynamics. Yet, empirical studies addressing the interactive effect of biotic and abiotic stress on plants are very rare. Therefore, in this study, we examined the interaction between drought stress and a canker pathogen, Quambalaria coyrecup, on the eucalypt – Corymbia calophylla (marri), which is experiencing increasing drought stress. We hypothesized that drought stress would increase marri's susceptibility to canker disease, and cankers would have the largest negative effect on plants that are already drought stressed before pathogen inoculation. To test the hypotheses, in a glasshouse, marri saplings were exposed to drought either before or after pathogen inoculation, or were well-watered or droughted throughout the experiment either with or without inoculation. Canker development was greater in well-watered saplings than in droughted saplings, with the fastest development occurring in well-watered saplings that had experienced drought stress before inoculation. Irrespective of water treatments, marri saplings employed phenol-based localized biochemical defence against the pathogen. Drought reduced photosynthesis and growth, however, a negative effect of canker disease on saplings' physiological performance was only observed in well-watered saplings. In well-watered saplings, canker-induced loss of sapwood function contributed to reduced whole-plant hydraulic conductance, photosynthesis and growth. The results provide evidence that timing of drought stress influences host physiology, and host condition influences canker disease susceptibility through differences in induced biochemical defence mechanisms. The observations highlight the importance of explicitly incorporating abiotic and biotic stress, as well as their interactions, in future studies of tree mortality in drought-prone regions worldwide. [ABSTRACT FROM AUTHOR]

Pinus sylvestris L. is the predominant tree species used for wooden constructions in the Baltic area. Accordingly, the timber of Pinus is the most important object for investigation and dating carried out by dendrochronologists of the Baltic countries. However, the dating of historical Pinus is often challenging when the outer sapwood rings are missing in the wood samples. In Pinus, sapwood rings increase in number as the tree ages, and therefore calculating the approximate number of missing outer rings from a set range, a technique used for oak, is not possible. In Norway, a simple method for estimating the number of sapwood rings has been developed for some native species of conifers. The aim of this small-scale study was to assess the validity and the practical suitability of the Norwegian method for estimating the number of missing sapwood rings of mostly historical Pinus wood samples obtained in the southeastern part of the Baltic region. Our findings indicate that this method is not acceptable for estimating the number of missing sapwood rings for individual trees, but suggest that it may be applicable when dating tree-ring chronologies for a minimum of 20 trees, containing individuals up to 200 years old. [ABSTRACT FROM AUTHOR]

The relationships between leaf area and foliar weight with four stem dimensions (sapwood area, total stem cross-sectional area, current sapwood area, and dbh) were studied in four different stem sections such as stump height (0.3 m), breast height (1.3 m), mid bole length and base of live crown, in the most important oak species in Greece, the Hungarian oak (Quercus frainetto Ten.). Twenty three trees were destructively sampled in the university forest Taxiarchis, Chalkidiki. Simple and multiple linear regression was used for model development. In all tested models total stem cross-sectional area was consistently the most accurate estimator for leaf area and foliar weight exhibiting R² = 0.859 and R² = 0.879 respectively. Current sapwood area was the next more accurate estimator (R² = 0.726 and R² = 0.762) followed by sapwood area (R² = 0.767 and R² = 0.843). The addition of more variables such as crown length, tree age and crown ratio improved slightly the accuracy in the multiple linear models. Both leaf area and foliar weight were best described as a linear function of current sapwood area and tree age R² = 0.861 and 0.846 respectively followed by sapwood area and crown length (R²=0.808 and 0.829). These relationships were getting weaker as we move from stump height to upper stem sections. The results show that the whole sapwood area than the most recent two growth rings may be active in water conduction for Hungarian oak in the Mediterranean. [ABSTRACT FROM AUTHOR]

Nowadays, decreasing raw material for the production of pulp from wood has led to search for alternative sources. For this reason, the possibilities of using existing natural species in pulp production are being investigated. White poplar (Populus alba L.), which is a widespread naturally-grown in many parts of Turkey, has the potential to be an alternative pulp raw material. In this study, the fiber dimensions of heartwood and sapwood of white poplar were prepared for microscobic measurements. Also, the relationships between fiber dimensions measured were examined with a specific view to fiber morphology to evaluate their suitability for pulp production. The fiber length of heartwood is higher due to having more 5 year-old groups on it. The changes in the fiber diameter of the sapwood and heartwood by the ages usually showed a polynomial course. The age-related changes were increased from min to average values in the fiber wall width of the heartwood. The felting rate of heartwood indicated that a pulp with proportionally more heartwood would yield a paper with better physical properties, especially tear strength. Based on the results the muhlstep ratio of heartwood and sapwood that both woods are suitable for paper production. [ABSTRACT FROM AUTHOR]