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The document titled "Correction to: Scaling of leaf area with biomass in trees reconsidered" in the Journal of Experimental Botany addresses an error in the grant number listed for a research project. The correct grant number for the Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica, UNAM, project is now identified as IN211124, not IN210719 as previously stated. This correction ensures accuracy in the publication. [Extracted from the article]

The science of tropical dendrochronology is now emerging in regions where tree-ring dating had previously not been considered possible. Here, we combine wood anatomical microsectioning techniques and radiocarbon analysis to produce the first tree-ring chronology with verified annual periodicity for a new dendrochronological species, Neltuma alba (commonly known as "algarrobo blanco") in the tropical Andes of Bolivia. First, we generated a preliminary chronology composed of six trees using tradi tional dendrochronological methods (i.e., cross-dating). We then measured the 14C content on nine selected tree rings from two samples and compared them with the Southern Hemisphere (SH) atmospheric 14C curves, covering the period of the bomb 14C peak. We find consistent offsets of 5 and 12 years, respectively, in the calendar dates initially assigned, indicating that several tree rings were missing in the sequence. In order to identify the tree-ring boundaries of the unidentified rings we investigated further by analyzing stem wood microsections to examine anatomical characteristics. These anatomical microsections revealed the presence of very narrow terminal parenchyma defining several tree-ring boundaries within the sapwood, which was not visible in sanded samples under a stereomicroscope. Such newly identified tree rings were consistent with the offsets shown by the radiocarbon analysis and allowed us to correct the calendar dates of the initial chronology. Additional radiocarbon measurements over a new batch of rings of the corrected dated samples resulted in a perfect match between the dendrochronological calendar years and the 14C dating, which is based on good agreement between the tree-ring 14C content and the SH 14C curves. Correlations with prior season precipitation and temperature reveal a strong legacy effect of climate conditions prior to the current Neltuma alba growing season. Overall, our study highlights much potential to complement traditional dendrochronology in tree species with challenging tree-ring boundaries with wood anatomical methods and 14C analyses. Taken together, these approaches confirm that Neltuma alba can be accurately dated and thereby used in climatic and ecological studies in tropical and subtropical South America. [ABSTRACT FROM AUTHOR]

Stored water in inner tissues influences the plant water economy, which might be particularly relevant for trees facing increasing dry conditions due to climate change. We studied the water storage in the inner bark and the sapwood of Araucaria araucana (Molina) K. Koch. This species has an extremely thick inner bark and thus it can be used as a model system to assess the impact of internal water storage on plant water balance. Specifically, we analyzed the water circulation pathways in and out of the elastic water storages by using simultaneously frequency domain moisture sensors and dendrometers inserted in the inner bark and in the sapwood, and sap flow determinations during the dry season. The daily patterns of water content and expansion and contraction of the stem tissues were similar to the sap flow pattern. The whole-stem water content and diameter increased in the morning and decreased in the afternoon, contrary to the typical pattern observed in most tree species. An osmotic gradient favoring the water influx from sapwood to inner bark was observed in the morning. There were no lags in the onset of sap flow between different stem heights at the time that recharge of reservoirs occurred. Sap flow at 6 m height was higher than basal sap flow in the afternoon, when the sapwood water content started to decline followed by the water content of the inner bark. Inner bark and sapwood contributed 5–11% to total daily transpiration, allowing the maintenance of high water potentials in the dry season. Our results suggest that the stored water in the stems, the atypical dynamic of recharge and discharge of water from reservoirs and the high tissue capacitance may make an important contribution to the survival of A. araucana during drought periods by maintaining the water balance. [ABSTRACT FROM AUTHOR]

The aim of the present research was to obtain a wood material with improved service properties, by combining two industrially used processes – namely a thermo-hydro treatment (THT) and an impregnation (Imp) with a commercial biocide – through the application of both a lower preservative retention and lower modification temperature, respectively. In the study, specimens from Scots pine (Pinus sylvestris L.) sapwood were used. The properties of the wood obtained with the sequence Imp-THT were extensively studied. Impregnation was performed in a pilot scale autoclave by a vacuum-pressure-vacuum process using a copper-azole type wood preservative, whilst THT was carried out in a WTT laboratory pilot device in a water vapour medium under elevated pressure. To improve physical properties while maintaining strength properties, the THT regime 160°C/1 h was used. The properties (strength, swelling, water uptake, colour, biocide (Cu) fixation properties as well as bioresistance to rot fungus) of combined treated pine wood were compared with those of the wood obtained in the respective separate processes. [ABSTRACT FROM AUTHOR]

Hydraulic architecture refers to the different morphological structures and water transport strategies acquired during the long-term evolution of plants. In this study, Chinese fir, an important commercial forest species in southern China, was examined, and hydraulic architecture characteristics with respect to ramification rate, canopy height, and ramification direction were studied. The results showed that changes in hydraulic architecture parameters of Chinese fir had pronounced rank effects; the hydraulic conductivity and leaf-specific conductivity were in the following order: main stem＞primary lateral branches＞secondary lateral branches; leaf-specific conductivity and Huber values were higher in primary than in secondary lateral branches. Hydraulic architecture parameters at different ramification rates were significantly affected by canopy height. Hydraulic conductivity and specific conductivity of the main stem decreased significantly with increasing canopy height, and the Huber value of the main stem increased significantly with increasing canopy height. Hydraulic conductivity and specific conductivity of primary and secondary lateral branches were the highest in the middle canopy, leaf-specific conductivity of the primary lateral branches decreased significantly with increasing canopy height, and leaf-specific conductivity of secondary lateral branches was the highest in the middle canopy. With regard to different ramification directions, hydraulic conductivity, specific conductivity, and leaf-specific conductivity of primary and secondary lateral branches were generally higher in the south and west directions than in the north and east directions. Correlation analyses showed that hydraulic conductivity at different ramification rates was significantly positively（P＜0.01） correlated with the total diameter, sapwood cross-sectional area, and leaf dry weight; specific conductivity of the main stem was significantly positively（P＜0.05） correlated with these factors, whereas the specific conductivity of primary and secondary lateral branches produced a negative correlation with them. Thus, the smaller the diameter of high-level branches of Chinese fir, the lower is the water transport ability. This hydraulic grade effect is beneficial to sacrificing inferior branches in order to maintain the water supply of superior branches when Chinese fir experience drought stress, which is an important adaption to drought acquired during long-term evolution. This study is of great significance for the breeding of drought-tolerant Chinese fir and sustainable plantation management [ABSTRACT FROM AUTHOR]

Drought has serious effects on forests, especially semi-arid and arid forests, around the world. Zagros Forest in Iran has been severely affected by drought, which has led to the decline of the most common tree species, Persian oak (Quercus brantii). The objective of this study was to determine the effects of drought on the anatomical structure of Persian oak. Three healthy and three declined trees were sampled from each of two forest sites in Ilam Forest. Discs were cut at breast height, and three sapwood blocks were taken near the bark of each tree for sectioning. The anatomical characteristics measured included fiber length (FL), fiber wall thickness (FWT), number of axial parenchymal cells (NPC), ray number (RN), ray width (RW), and number of calcium oxalate crystals. Differences between healthy and declined trees were observed in the abundance of NPC and in RN, FL, and FWT, while no differences occurred in the number of oxalate crystals. The decline had uncertain effects on the FL of trees from sites A and B, which showed values of 700.5 and 837.3 μm compared with 592.7 and 919.6 μm in healthy trees. However, the decline resulted in an increase in the FWT of trees from sites A and B (9.33 and 11.53 μm) compared with healthy trees (5.23 and 9.56 μm). NPC, RN, and RW also increased in declined individuals from sites A and B (28.40 and 28.40 mm−1; 41.06 and 48.60 mm−1; 18.60 and 23.20 μm, respectively) compared with healthy trees (20.50 and 19.63 mm−2; 31.60 and 28.30 mm−2; 17.93 and 15.30 μm, respectively). Thus, drought caused measurable changes in the anatomical characteristics of declined trees compared with healthy trees. [ABSTRACT FROM AUTHOR]

The Barents Shear Margin separates the Svalbard and Barents Sea from the North Atlantic. It includes one northern (Hornsund Fault Zone) and a southern (Senja Fracture Zone) margin segment in which structuring was dominated by dextral shear. These segments are separated by the Vestbakken Volcanic Province that rests in a releasing bend position between the two. During the break-up of the North Atlantic the plate tectonic configuration was characterized by sequential dextral shear, extension, contraction and inversion. This generated a complex zone of deformation that contain several structural families of over-lapping and reactivated structures Although the convolute structural pattern associated with the Barents Shear Margin has been noted, it has not yet been explained in this framework. A series of crustal-scale analogue experiments, utilizing a scaled stratified sand-silicon polymer sequence, serve to study the structural evolution of the shear margin in response to shear deformation along a pre-defined boundary representing the geometry of the Barents Shear Margin and variations in kinematic boundary conditions of subsequent deformation events, i.e. direction of extension and inversion. The observations that are of particular significance for interpretating the structural configuration of the Barents Shear Margin are: 1) The experiments reproduced the geometry and positions of the major basins and relations between structural elements (fault and fold systems) as observed along and adjacent to the Barents Shear Margin. This supports the present structural model for the shear margin. 2) Several of the structural features that were initiated during the early (dextral shear) stage became overprinted and obliterated in the subsequent stages. 3) Prominent early-stage positive structural elements (e.g. folds, push-ups) interacted with younger (e.g. inversion) structures and contributed to a complex final structural pattern. 4) All master faults, pull-part basins and extensional shear duplexes initiated during the shear stage quickly became linked in the extension stage, generating a connected basin system along the entire shear margin at the stage of maximum extension. 5) The fold pattern generated during the terminal stage (contraction/inversion became dominant in the basinal areas and was characterized by fold axes with traces striking parallel to the basin margins. These folds, however, most strongly affected the shallow intra-basinal layers. This is in general agreement with observations in previous and new reflection seismic data from the Barents Shear Margin. [ABSTRACT FROM AUTHOR]

We use output from a freely-running NEMO model simulation for the equatorial Pacific to investigate the utility of linearly removing the local influence of vertical displacements of the thermocline from variations in sea surface height. We show that the resulting time series of residual sea surface height, denoted η nlti , measures variations in near-surface heat content that are independent of the local vertical displacement of the thermocline and can arise from horizontal advection, surface heat flux and diapycnal mixing processes. We find that the variance of η nlti and its correlation with sea surface temperature, are focused on the Niño4 region. Furthermore, η nlti averaged over the Niño4 region is highly correlated with indices of Central Pacific El Niño Southern Oscillation (CP ENSO), and its variance in 21 year running windows shows a strong upward trend over the past 50 years, corresponding to the emergence of CP ENSO following the 1976/77 climate shift. We show that η nlti can be estimated from observations, using satellite altimeter data and a linear multi-mode model. The time series of η nlti , especially when estimated using the linear model, show pronounced westward propagation in the western equatorial Pacific, arguing an important role for zonal advective feedback in the dynamics of CP ENSO, in particular for cold events. We also present evidence that the role of the thermocline displacement in influencing sea surface height increased strongly after 2000 in the eastern part of the Niño4 region, at a time when CP ENSO was particularly active. Finally, the diagnostic is easy to compute and can be easily applied to mooring data or couple climate models. [ABSTRACT FROM AUTHOR]

Waterlogged archaeological wood (WAW) is a rare and precious organic material that can hold outstanding cultural values. In order to protect WAW for the next generations, this material must be accurately characterized to set its proper conservation, storage and exhibition conditions in museum environments. In this study, the mineral content found in WAW retrieved in a volcanic lake, was investigated by analysing wood ash through scanning electron microscopy coupled with energy dispersion spectroscopy (SEM-EDS). This micro-destructive approach was coupled with morphological studies carried out through optical microscopy. SEM-EDS was also performed on the WAW and on the surrounding sediment, to study the possible correlation between the mineral composition and the wood degradation state. The analysis revealed that calcium was the most abundant element in all poles with weight percentages ranging between 24 % and 42 %. This element was more represented in heartwood (HW) than sapwood (SW). In Sapwood the second most abundant element was arsenic. Sulphur, iron, and potassium were also present in all the analysed samples. Arsenic was detected also in the sediments; it was particularly concentrated in the samples taken near archaeological wood. The presence of this element can be linked to the volcanic origin of the lake, and its high concentration points to bioaccumulation processes induced by bacteria (erosion bacteria and sulphate-reducing bacteria) and biochemical processes favouring precipitation of insoluble compounds. The present work is the first investigation on mineral content in archaeological wood establishing a possible correlation with the surrounding volcanic lake sediments. [ABSTRACT FROM AUTHOR]

An optimum adhesive penetration is needed to provide satisfactory bonding strength at the veneer-veneer interface. The effect of veneer density and glue spreading rate on the phenol formaldehyde adhesive penetration plot profile was determined. An X-ray apparatus was used to visualize the adhesive penetration of the plywood. The heartwood and sapwood veneer of Cryptomeria japonica with low, medium, and high veneer densities were made into plywood. The glue spreading rate was applied from 75 g/m2 to 225 g/m2 for the heartwood plywood and up to 300 g/m2 for the sapwood plywood (plus 75 g/m2 at every level of glue spreading rate). An X-ray apparatus with a low tube voltage successfully visualized the adhesive penetration plot profile. Based on the half-width calculation, the adhesive penetration depth ranged from 0,3 - 0,9 mm. The mean half-width was 0,5 mm. The adhesive concentration increased with increasing glue spreading rate. In contrast, it also showed that using different veneer densities and increasing glue spreading rates does not affect the half-width value as the adhesive penetrates deeper. [ABSTRACT FROM AUTHOR]

The objective of the present study was the determination of the extractives, acidity and ash content of three different provenances of Cupressus semprevirens wood. The specimens were collected from the sapwood, heartwood, bark and needles of the trees. The quantitative determination of the extractions was performed with two different solvents, water and ethanol. The results showed no significant differences among the three provenances (P1, P2 and P3), except for the oldest, which also had the highest extract content, a fact that is attributed to the growth of the trees without competition. Furthermore, the needles and the bark, had, in all cases, the highest ash content, while heartwood appeared to have higher contents of extractives, compared to sapwood. [ABSTRACT FROM AUTHOR]

Plant functional traits represent adaptive strategies to the environment, linked to biophysical and biogeochemical processes and ecosystem functioning. Compilations of trait data facilitate research in multiple fields from plant ecology through to land-surface modelling. Here we present version 2 of the China Plant Trait Database, which contains information on morphometric, physical, chemical, photosynthetic and hydraulic traits from 1529 unique species in 140 sites spanning a diversity of vegetation types. Version 2 has five improvements compared to the previous version: (1) new data from a 4-km elevation transect on the edge of Tibetan Plateau, including alpine vegetation types not sampled previously; (2) inclusion of traits related to hydraulic processes, including specific sapwood conductance, the area ratio of sapwood to leaf, wood density and turgor loss point; (3) inclusion of information on soil properties to complement the existing data on climate and vegetation (4) assessments and flagging the reliability of individual trait measurements; and (5) inclusion of standardized templates for systematical field sampling and measurements. Measurement(s) plant functional traits Technology Type(s) plant functional traits Sample Characteristic - Organism Plants Sample Characteristic - Location China [ABSTRACT FROM AUTHOR]

A single Norway spruce tree (Picea abies) was manually fractionated into heartwood, sapwood, juvenile wood and branches. These fractions were chemically pulped, individually, in laboratory scale. The pulps were characterized and investigated in relation to dewatering behavior and sheet strength properties. An unbleached and unbeaten commercial kraft pulp from softwood fibers was used as a reference, and the fractionated pulps were within the same range in all tested properties. The fractionated pulps were then compared with each other, and fiber characteristics were used to explain differences in dewatering and strength. Heartwood pulp results in stronger and stiffer papers that are harder to dewater. Sapwood pulp gives more open network structures resulting in easy dewatering and high air permeance, although with lower strength properties compared to heartwood. Pulp from Juvenile wood gives s quite strong but brittle sheets, with efficient dewatering. Pulp from branches gives paper sheets with efficient dewatering, air permeance and relatively high elongation of break but lower strength. The results show that there is definitely potential for utilizing more parts of the trees for pulp and paper making, especially when tailoring the raw material origins after preferred paper properties. [ABSTRACT FROM AUTHOR]

Impregnation of an appropriate chemical compound in wood is a common technique to improve durability, fire retardant properties, strength and dimensional stability, increase hardness and UV resistance. This study investigated a compression treatment followed by dipping in Alkaline Copper Quaternary solution (ACQ) as an alternative treatment method of green (unseasoned) southern pine timber. The effects of the compression parameters on ACQ uptake were investigated. The results showed that ACQ uptake increased disproportionally from 24 to 225 L/m3 with the increase of the compression ratio from 10% to 50%. ACQ uptake increased gradually from 65 to 120 L/m3 at a compression speed between 5 and 40 mm/min and dropped to 46 L/m3 for a compression speed of 50 mm/min. Radial compression resulted in a lower uptake than 45° and tangential compression. The penetration depth of Cu was satisfactory for most of the sapwood specimens for a compression ratio greater than 30%. For the heartwood/sapwood mixed specimens, 100% Cu penetration was achieved in the sapwood portion however the heartwood portion remained unpenetrated. The compression treatment could potentially reduce the treated timber cost by reducing drying cost and processing time while achieving a satisfactory performance as specified by the Australian standard. [ABSTRACT FROM AUTHOR]

In most tree species, xylem consists of two different functional parts: sapwood and heartwood. While sapwood, as the flowpath for sap, has received more attention in isotope studies assessing water sources accessed by trees (e.g. soil water from different depths, groundwater, stream water or a mixture of these), much remains unknown about heartwood and the possible water exchange between the two functional parts. We investigated four tree species (Fagus sylvatica, Quercus petraea, Pseudotsuga menziesii and Picea abies) characterised by different xylem anatomy and timing of physiological activity to evaluate the degree of differentiation in isotopic composition of water between sapwood and heartwood on a biweekly time scale. We found that the sapwood and heartwood of all species displayed a concurrent variation in their isotopic composition throughout the growing season and on a day‐night scale suggesting that the two are not isolated compartments. While the two functional parts display a consistent difference in isotopic composition in conifers, they are characterised by more similar values in broadleaved species in broadleaved species, suggesting a higher degree of water exchange. Furthermore, we have also observed a progressive change in the isotopic composition in broadleaved species with sampling depth rather than functional parts of xylem. Our study highlights the value of accounting for radial isotopic variation, which might potentially lead to uncertainties concerning the origin of the extracted water for water uptake studies. [ABSTRACT FROM AUTHOR]

The sustainability of native forests in Sub-Saharan Africa depends on the diversification of sources to generate bioenergy, and Eucalyptus spp. wood has been highlighted. However, the determination of energy quality parameters has been a challenge to enable plantation wood to generate energy. The research assessed the ash content of radial and longitudinal samples of Eucalyptus grandis (Hill) clone with different ages and growth sites. Samples were collected in three pre-established plots in the center of Mozambique. Five trees were cut down in each plot and six discs were removed from each tree. Grinded samples with

Key message: The TreeTrace_Douglas database includes images and measurements at several stages of the processing of Douglas fir logs, from sawmill logyard to machine grading and destructive testing of boards, and is suitable for research on quality assessment and traceability. A total of 52 long logs, 156 short logs, 208 wood discs, and 346 boards were analyzed. The image data includes RGB images of log ends and board ends, RGB images and CT slices of strips, and a set of images of the boards (RGB, laser, and X-rays) obtained with an industrial board grading machine. The measurements include wood density, growth ring widths, pith and board location in the logs, heartwood and sapwood areas, mechanical properties of each board obtained by vibratory and static testing, and visual grading of the boards. Dataset is available at https://doi.org/10.15454/YUNEGL and associated metadata are available at https://metadata-afs.nancy.inra.fr/geonetwork/srv/fre/catalog.search#/metadata/d9eef6e4-f195-41f4-b6c2-2ab46adc637e. [ABSTRACT FROM AUTHOR]

The purpose of this study was to characterize and quantify the chemical constituents of heartwood and sapwood of Dalbergia oliveri extract in order to investigate the chemical components that determine the formation of heartwood's color. In this work, the types of pigments in heartwood and sapwood extract were analyzed using UV-Visible (UV) Spectrophotometer, and the main pigment components of heartwood and sapwood extract were identified and quantified using ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS). The results showed that the difference in content of the main components between heartwood and sapwood of Dalbergia oliveri was slight, and the lignin structure between heartwood and sapwood is basically identical; flavonoid pigments were found to be the primary chromophoric components of heartwood and sapwood extract. However, a total of 21 flavonoids were identified in heartwood and sapwood, of which the unique substances to heartwood were vitexin, isorhamnetin, and pelargonidin, and the content of isoliquiritigenin, formononetin, and biochanin A were 253, 37, and 583 times higher in the heartwood than in the sapwood, respectively, which could be the main pigment components affecting the significant color difference between heartwood and sapwood of Dalbergia oliveri. These results will provide a foundation for revealing the underlying mechanism of color difference between heartwood and sapwood and provide a theoretical basis for wood coloring. [ABSTRACT FROM AUTHOR]

Teak wood has chemical compounds that can be used for pharmaceutical and textile industries, in addition, this compounds are related to resistance to biodeterioration, color and modification processes. Heartwood and sapwood of T. grandis (teak), 15 years-old, were characterized by Py-CG/MS analysis and syringyl (S)/guaiacyl (G) ratio was evaluated. Heartwood and sapwood were pyrolyzed at 550 °C and 62 and 51 compounds were identified from them, respectively. The acetic acid (10%) and levoglucosan (26.65%) were the most abundant compound in the sapwood and heartwood, respectively. The high acetic acid content enhances the use of teak wood to production of artificial essences for perfumery, paints, dyes. While levoglucosan can be used in the manufacture of epoxy resins, antiparasitic and insecticides. The organic compounds identified include 2-methylanthraquinone as one of the main component responsible for the resistance of the teak wood to biological factors (fungi and termites). The syringyl (S)/guaiacyl (G) ratio of heartwood and sapwood was 0.51 and 0.50, respectively. [ABSTRACT FROM AUTHOR]

Estimates of tree heartwood and sapwood profiles are important in the pulp industry and for dynamic vegetation models, in which they determine tree biomechanical stability and hydraulic conductivity. Several phenomenological models of stem profiles have been developed for this purpose, based on assumptions on how tree crown and foliage distributions change over time. Here, we derive estimates of tree profiles by synthesizing a simple pipe model theory of plant form with a recently developed theory of branch thinning that from simple assumptions quantifies discarded branches and leaves. This allows us to develop a new trunk model of tree profiles from breast height up to the top of the tree. We postulate that leaves that are currently on the tree are connected by sapwood pipes, while pipes that previously connected discarded leaves or branches form the heartwood. By assuming that a fixed fraction of all pipes remain on the trunk after a branching event, as the trunk is traversed from the root system to the tips, this allows us to quantify trunk heartwood and sapwood profiles. We test the trunk model performance on empirical data from five tree species across three continents. We find that the trunk model accurately describes heartwood and sapwood profiles of all tested tree species (calibration; R 2: 84–99%). Furthermore, once calibrated to a tree species, the trunk model predicts heartwood and sapwood profiles of conspecific trees in similar growing environments based only on the age and height of a tree (cross-validation/prediction; R 2: 68–98%). The fewer and often contrasting parameters needed for the trunk model make it a potentially useful complementary tool for biologists and foresters. [ABSTRACT FROM AUTHOR]

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Pressurized hot water extraction (HWE) treatment has the benefit of simultaneous extraction of hemicellulose-based carbohydrates and modification of the solid phase, but it does not drastically improve wood durability. However, removing hemicelluloses from the wood by HWE treatment creates water-filled spaces in the cell walls which could be filled with modification agent in order to improve the properties of the wood. Without drying, modification agent can be added into the saturated wood via diffusion. The esterification of wood with citric acid (CA) improves resistance to biological deterioration but increases brittleness. However, combining CA esterification with additional chemicals that form links with CA can mitigate brittleness. This study investigated esterification as a method for modifying HWE treated wood. HWE treatment with CA solution (4% w/v) was applied at 120 °C for 3 h to Scots pine (Pinus sylvestris L.) sapwood specimens. The specimens were further modified by diffusion with CA and starch derivatives followed by curing. The applied method changed the moisture properties and chemical composition of the wood. The results showed successful wood bulking. The investigated method slightly improved decay resistance to Coniophora puteana and Trametes versicolor but did not change resistance to Rhodonia placenta. [ABSTRACT FROM AUTHOR]

Relationships between tree size and water use indicate how soil water is partitioned between differently sized individuals, and hence competition for water. These relationships are rarely examined, let alone whether there is consistency in shape across populations. Competition for water among plants is often assumed to be size-symmetric, i.e. exponents (b1) of power functions (water use ∝ biomassb1) equal to 1, with all sizes using the same amount of water proportionally to their size. We tested the hypothesis that b1 actually varies greatly, and based on allometric theory, that b1 is only centered around 1 when size is quantified as basal area or sapwood area (not diameter). We also examined whether b1 varies spatially and temporally in relation to stand structure (height and density) and climate. Tree water use ∝ sizeb1 power functions were fitted for 80 species and 103 sites using the global SAPFLUXNET database. The b1 were centered around 1 when tree size was given as basal area or sapwood area, but not as diameter. The 95% confidence intervals of b1 included the theoretical predictions for the scaling of plant vascular networks. b1 changed through time within a given stand for the species with the longest time series, such that larger trees gained an advantage during warmer and wetter conditions. Spatial comparisons across the entire dataset showed that b1 correlated only weakly (R 2 < 12%) with stand structure or climate, suggesting that inter-specific variability in b1 and hence the symmetry of competition for water may be largely related to inter-specific differences in tree architecture or physiology rather than to climate or stand structure. In conclusion, size-symmetric competition for water (b1 ≈ 1) may only be assumed when size is quantified as basal area or sapwood area, and when describing a general pattern across forest types and species. There is substantial deviation in b1 between individual stands and species. [ABSTRACT FROM AUTHOR]

Sapwood area is an important parameter for estimating canopy transpiration in the forest water cycle. However, sapwood area highly varies across species and forest ecosystems and is difficult to measure directly. Therefore, species- and site-specific allometric equations are needed to estimate the sapwood area of all trees in a forest. Here, we conducted a comprehensive campaign to measure sapwood thickness and to estimate the sapwood area of 14 common tree species in a successional forest in Thailand. These data represent the first comprehensive measurements of sapwood area in south-east Asian successional forests growing under diverse environmental conditions in terms of soil moisture and canopy density. The results show that a power function can significantly explain the relationship between sapwood area and stem size, represented by diameter at breast height (DBH), in all species in both primary and secondary forests. Interestingly, a single equation could describe the sapwood area~DBH relationship in all species and forest stages, except for Dipterocarpus gracilis , an emergent, dominant species in the primary forest. The latter showed slower growth in sapwood area once the trees reached a DBH of ~30 cm. Overall, our results can benefit future studies that estimate canopy transpiration of tropical forests with similar conditions as in our study sites. [ABSTRACT FROM AUTHOR]

Khair (Acacia catechu Willd) is a deciduous tree containing dark red heartwood inside the sapwood and belongs to the family Fabaceae. It yields mainly two products Katha and cutch which have many medicinal benefits and industrial uses. Katha is an indispensable ingredient of Paan preparations in India. The present study was carried out in Ratnagiri district of Konkan region of Maharashtra state to assess the Katha yield using traditional method of extraction. The heartwood of Khair was divided into different girth classes viz up to 30 cm, 30 to 40 cm and 40 to 50 cm. The extraction of Katha was done by chipping and boiling of heartwood. The results revealed that the recovery of Katha ranged from 5.06 to 6.68 per cent with overall recovery of 5.97 per cent. The maximum recovery was reported in the girth class 40 to 50 cm while minimum in girth class up to 30 cm. The study showed that as the girth of heartwood increased the recovery of Katha was also increased. [ABSTRACT FROM AUTHOR]

The evolution of woody stems approximately 400 mya (middle Paleozoic) facilitated the expansion of plants and has likely affected carbon and water budgets across much of the terrestrial surface since that time. Stems are a carbon cost/sink and limit water transport from soil to leaves as it must pass through specialized xylem tissue. While leaf fossils have provided a wealth of quantitative data, including estimates of plant water fluxes utilizing biophysically based models, fossil-informed models integrating stem and leaf physiology are lacking. Integrated stem-leaf physiology may distinguish successors to ecological catastrophes like the end of the Late Paleozoic Ice Age (LPIA). The documented collapse of LPIA tropical forests provides an opportunity to assess the importance of woody stems as a key to understanding differences in survivorship among common plant taxa from the Carboniferous to the Permian. Here, we present an analysis of the limits to leaf water supply and plant function for Paleozoic forest plant types due to (1) cavitation-induced embolism and xylem blockage and (2) insufficient sapwood water transport capacity.—collectively defined here as sapwood dysfunction. We first present a modified ecosystem process model (Paleo-BGC+) that includes sapwood dysfunction. Paleo-BGC + is parameterized using measurements obtainable from fossil xylem and therefore applicable to both modern and ancient ecosystems. We then assess the effect of sapwood dysfunction on ecosystem processes based on previously published fossil leaf measurements and a new fossil xylem dataset for plant types present in the Late Paleozoic. Using daily meteorology from a GCM of the late Carboniferous (GENESIS v3) under a Glacial (low-CO2) and an Inter-glacial (high-CO2) scenario, we found that simulated sapwood dysfunction slowed plant water use and reduced carbon storage. This inhibition occurred particularly in plants with high maximum stomatal conductance and high stem vulnerability to embolism. Coincidentally, plants with these traits were predominantly reduced or missing from the fossil record from the Carboniferous to the Permian. Integrating stem and leaf physiology may improve the fidelity of model representations of soil-to-atmosphere water transport through plants, simulations of long-term climate phenomena like the LPIA, and ecosystem projections under future climate change.

Short rotation teak wood is susceptible to biodeterioration, particularly to termite attack. The objective of this work was to investigate the effect of chemical and thermal treatment on resistance of sapwood, transition wood, and heartwood of short rotation teak against Asian and European subterranean termites. In a second time, the "non biocidal" aspect of different treatments was evaluated using "choice" and "non-choice" screening termite tests. Furfurylation (FA), thermal treatment (HT), and combination of chemical and thermal treatment using glycerol-maleic anhydride (GMA) were performed on sapwood, heartwood, and their transition fractions (50:50, sapwood:heartwood). On one side, the wood samples were exposed to Asian subterranean termite (Macrotermes gilvus) under field test, in Indonesia. On the other side, the wood samples were also tested against the attack of European subterranean termite (Reticulitermes flavipes) under non-choice and choice screening test, in laboratory. From field tests, the results show that heartwood exhibited a lower mass loss compared to sapwood due to its extractive content. FA and GMA at 220 °C treatments performed in better termite resistance after field test according to their mass losses. Results from the choice and no-choice tests show that chemical and thermal modifications improved termite resistance due to their low mass loss. No surviving termites were observed after the non-choice test on chemically and thermally modified wood. The high termite survival rate in the choice test confirmed the hypothesis that chemical and thermal modification treatments were non-biocidal to termites compared to borax control samples. The FA and GMA treatment could be considered as eco-friendly modification methods to protect the short rotation teak wood and wood in general against subterranean termites. [Display omitted] • Furfurylation, thermal treatment, and combination of glycerol-maleic anhydride and thermal treatment were performed on fast-growing teak twood. • Termite's durability of modified or unmodified sapwood and heartwood samples was evaluated by laboratory and field tests. • Heat treated and glycerol-maleic anhydride treated at 150°C presented no significant termite's resistance. • Furfurylated and glycerol-maleic anhydride treated at 220°C samples presented full resistance to termites. • Choice tests proved the non-biocidal aspect of furfurylation and glycerol-maleic anhydride treatment at 220°C. [ABSTRACT FROM AUTHOR]

Radial chromatic aberration (∆E) in xylem is a significant phenotypic characteristic for distinguishing sapwood from heartwood. Investigating its relationship with metabolites is critical to the formation of color differences in wood. In this study, chromatic aberration of the inner heartwood (IH), outer heartwood (OH), transition zone (TZ), inner sapwood (IS), and outer sapwood (OS) were quantified utilizing the CIE color space system, and the secondary metabolite profiles of Toona fargesii wood were identified. The findings showed a radial variation in the wood color of T. fargesii. The chromatic aberration was largest in the OS vs. IH for 22.51 and smallest in OH vs. TZ for 4.92. A total of 646 metabolites from 8 categories were obtained from wood, including flavonoids, phenolic acids, terpenoids, et al. The OS vs. IH had the highest number of differential metabolites with 395, whereas the OH vs. TZ had the fewest differential metabolites with 184. The metabolites were mostly enriched in metabolic pathways and the biosynthesis of flavonoids. The 75 % metabolites in the flavonoid biosynthesis pathway were abundant in HW tissues and gradually decreased from IH to OS. There were 39 shared differential metabolites among six comparison groups, of which flavonoids accounted for 31 %. There were clear radial differences in the flavonoid metabolites, with a generally decreasing trend from IH to OS tissue. The relative content of the flavonoids exhibited negative and positive correlations with L* and a*, respectively. Especially the largest correlation coefficients for 93 % between 2-hydroxynaringenin, aromadendrin and L* showed their importance in chromatic aberration. This study demonstrated the radial variation pattern of chromatic aberration and metabolic profiles. It also identified the key metabolites that affect wood color in T. fargesii , which offered valuable insights into the formation of the chromatic aberration in wood. [Display omitted] • The chromatic aberration of wood in radial direction increased with spatial position of tissues. • A total of 646 metabolites from 8 categories were obtained from various tissues of wood. • The flavonoids enriched in HW tissues and gradually decreased in the radial direction. • Flavonoids content exhibited negative and positive correlations with color index (L* and a*). [ABSTRACT FROM AUTHOR]

• Norway spruce had 64%, 30%, and 6% of PaLAR3 genotypes AA, AB, and BB, respectively. • Two H. parviporum strains caused significantly variable necrosis responses. • The two mycovirus strains tested significantly reduced lesion width in Norway spruce. • The two mycovirus strains in H. parviporum reduced fungal growth in sapwood up to 41% Heterobasidion parviporum is a destructive forest pathogen causing root and stem rot of Norway spruce (Picea abies) in northern hemisphere. Previous research has suggested that a gene form of PaLAR3 that encodes for the leucoanthocyanidin reductase enzyme, may increase resistance to H. parviporum in Norway spruce, whether heterozygous or homozygous. Our experiment was initially focused on testing this assertion with materials from the Finnish Norway spruce breeding program, comprising 52 full-sib families. Additionally, we investigated the influence of mycoviruses on the growth of H. parviporum. The frequencies of the three PaLAR3 genotypes AA, AB, and BB were 64%, 30%, and 6%, respectively. We found no significant differences in the necrotic response to H. parviporum between the homozygous (BB) and heterozygous (AB) genotypes vs. the homozygous (AA) genotype across the two fungal strains tested, suggesting the gene is rather ineffective as a marker for overall H. parviporum resistance. The two H. parviporum strains used in the study showed significantly different necrosis responses from the control. Mycovirus infection in H. parviporum strains led to a significant reduction in lesion width in phloem and sapwood. Furthermore, the growth of the fungus was notably restricted when hyphae hosted mycoviruses, indicating a high potential of mycoviruses to reduce fungal growth and necrosis development. [ABSTRACT FROM AUTHOR]

In plantations, nutrient extraction is likely to be higher with shorter rotations. This is because thinner stems have a higher proportion of nutrient-rich bark, and sapwood contains more nutrients than hardwood. Annual willow plantations may extract even more nutrients than long rotation forests. In short rotation forest systems, the diameter of the harvested stems may affect the amount of nutrients exported with the wood. The present study investigated the effect of stem diameter distribution on nutrient extraction and nutrient use efficiency (UE). Two Salix clones were planted at low or high densities, and irrigated or left rainfed. Stems were harvested annually, and three years after planting, N, P, K, and Ca concentrations in small, medium, and big stems were determined, as well as the proportion of each stem diameter class at harvest. N extraction was the highest, followed by Ca, K, and P extraction. Nutrient extraction and nitrogen use efficiency were influenced by the proportion of small, medium, and big stems. The clones showed differences in nutrient concentration and stem diameter distribution, and irrigation increased the proportion of large stems and nitrogen concentration. Although the NUE and PUE were not linearly related to yield, they were related to the distribution of stem diameter and nutrient concentration. Higher yield resulted in higher CaUE and KUE, but the extraction of these nutrients during harvest was fine-tuned by stem diameter distribution and tissue concentration. This highlights the significance of stem diameter distribution in assessing the nutrient costs of wood production for bioenergy. [Display omitted] • In annual willow coppice nutrient extraction is N>Ca>K>P. • Nutrient extraction is related to the proportion of small, medium and large stems. • Clones differ in stem diameter distribution and nutrient concentration. • Irrigation increases the proportion and N concentration of large stems. • It is possible to increase nutrient use efficiency through silvicultural practices. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the dependencies between mechanical properties of modified wood and its color. Within its scope, quantitative changes in color and chemical composition (mass loss, total carbon content, content of extractives and main components of wood), as well as mechanical properties (compressive strength along the grain, strength and modulus of elasticity in longitudinal tension tests, compression across the grain and impact resistance) of the modified Scots pine sapwood, were determined. Modifications were conducted in the atmosphere of superheated steam (time—4 h, temperature of 130, 160, 190, 220 °C). Thermal modification of wood results in an increase in the modulus of elasticity, a reduction of elasticity, longitudinal tensile strength and compressive strength perpendicular to grain. It was found that color parameters ∆E, ∆L and ∆a are linear functions of the modification temperature. The existence of functional dependencies between mass loss, longitudinal tensile strength, radial modulus of elasticity and parameters of ∆E and ∆L makes it possible to determine these properties of modified wood based on color. In turn, chemical analysis indicated that an increase in the temperature of wood modification caused a decrease of holocellulose and hemicelluloses contents, especially in wood samples modified at 220 °C. [ABSTRACT FROM AUTHOR]

Transpiration is fundamental to the understanding of the ecophysiology of planted forests in arid ecosystems, and it is one of the most uncertain components in the ecosystem water balance. The objective of this study was to quantify differences in whole-tree transpiration estimates obtained with a heat ratio probe in a secondary Qinghai spruce (Picea crassifolia) forest. To do this, we analyzed the sap flux density values obtained with sensors installed in (1) holes drilled in the preceding growing season (treatment) and (2) holes drilled in the current year (control). The study was conducted in a catchment in the Qilian Mountains of western China. The results showed that an incomplete diameter at breast height (DBH) range contributed to 28.5% of the overestimation of the sapwood area when the DBH > 10 cm and 22.6% of the underestimation of the sapwood area when the DBH < 5 cm. At daily scales, there were significant differences in both the quantity and magnitude of the sap flux density between the treatment and control groups. Furthermore, a linear regression function (R2 = 0.96, p < 0.001), which was almost parallel to the 1:1 reference line, was obtained for the sap flux density correction for the treatment group, and the daily sap flux density and whole-tree transpiration were underestimated by 36.8 and 37.5%, respectively, at the half-hour scale. This study illustrates uncertainties and a correction function for sap flow estimations in young Qinghai spruce trees when using heat ratio sensors with minimal damage over multiple growing seasons. [ABSTRACT FROM AUTHOR]

Pathogenic diseases frequently occur in drought‐stressed trees. However, their contribution to the process of drought‐induced mortality is poorly understood. We combined drought and stem inoculation treatments to study the physiological processes leading to drought‐induced mortality in Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) saplings infected with Heterobasidion annosum s.s. We analysed the saplings' water status, gas exchange, nonstructural carbohydrates (NSCs) and defence responses, and how they related to mortality. Saplings were followed for two growing seasons, including an artificially induced 3‐month dormancy period. The combined drought and pathogen treatment significantly increased spruce mortality; however, no interaction between these stressors was observed in pine, although individually each stressor caused mortality. Our results suggest that pathogen infection decreased carbon reserves in spruce, reducing the capacity of saplings to cope with drought, resulting in increased mortality rates. Defoliation, relative water content and the starch concentration of needles were predictors of mortality in both species under drought and pathogen infection. Infection and drought stress create conflicting needs for carbon to compartmentalize the pathogen and to avoid turgor loss, respectively. Heterobasidion annosum reduces the functional sapwood area and shifts NSC allocation patterns, reducing the capacity of trees to cope with drought. Summary Statement: Interrelated decreases in carbon and water pools drive drought‐ and pathogen‐induced mortality mechanisms in Picea abies infected by the pathogen Heterobasidion annosum. The pathogen reduces the functional sapwood area and induces a defence response, reducing available carbon to face drought impacts. [ABSTRACT FROM AUTHOR]

The formulation of a Finnish isolate of the saprotrophic wood-rotting fungus Phlebiopsis gigantea into the biocontrol agent (BCA) Rotstop, which is used to prevent infection of Norway spruce stumps by aerial basidiospores of H. annosum, has led to its application to more than 200,000 ha of forest in Scandinavia and North Europe. The success of this treatment opens the possibility of introducing the Rotstop strain into Britain for use on Sitka spruce stumps, which at present (2022) are lacking adequate prophylactic treatment. However, Rotstop is probably non-native to Britain and to North America (the ancestral home of this spruce), and we do not know if this xylem-decaying BCA can invade standing trees. In this paper, we describe a trial into this issue conducted for the U.K. Forestry Commission in Denmark, in a country where both Rotstop and Sitka spruce have been naturalised. It was preliminary to further stump treatment trials, and is relevant to long-term issues surrounding stump treatment in Britain. Inoculations into 44-year-old standing Sitka spruce with 20 mm wooden Scots pine plugs pre-colonised with Rotstop resulted in decay of the S1, S2, S3 and middle lamellae of sapwood above and below the wounds after 11–18 months. In contrast, infection of sapwood occurred in only one of 39 wounds on the same trees challenged with oidial spore inoculants adpressed to undamaged xylem sapwood during the same period. While the results suggest that release of Rotstop into the productive stands of Sitka spruce in Britain would be unlikely to cause long-term commercial losses to wounded trees, the work highlights issues relating to the assessment of risk associated with the introduction of non-native BCAs within the forest environment. [ABSTRACT FROM AUTHOR]

During inventories of lesser-known timber species in eastern Gabon, a new Dialium morphospecies was discovered. To discriminate it from the two other 2–5 leaflets Dialium species, 25 leaf traits were measured on 45 trees (16 Dialium pachyphyllum, 14 Dialium lopense, 15 Dialium sp. nov.). Nine wood chemical traits, as well as infrared spectra, were also examined on harvestable trees (four Dialium pachyphyllum and four Dialium sp. nov.). This study revealed seven discriminant leaf traits that allowed to create a field identification key. Nine significant differences (five in sapwood and four in heartwood) in terms of wood composition were highlighted. The use of the PLS-DA technique on FT-IR wood spectra allowed to accurately identify the new morphospecies. These results provide strong support for describing a new species in this genus. Implications for sustainable management of its populations are also discussed. [ABSTRACT FROM AUTHOR]

The course of the bark beetle-vectored fungus, Leptographium terebrantis S. J. Barras and T. J. Perry, in stemwood growth loss of declining pines in the southeastern United States was assessed in a 13-year-old loblolly pine (Pinus taeda L.) plantation near Eufaula, Alabama, U.S.A. Using stem inoculation as a surrogate for root infection, we hypothesized that L. terebrantis infection impairs sapwood function and thus limits the tree leaf area (AL), new root production, and stemwood growth. Sterile toothpicks colonized by L. terebrantis at varying inoculum densities was used to elicit host growth responses. In the third year after inoculation, the root pathogen reduced the foliage moisture content, whole-tree leaf area (AL), the ratio of AL to tree sapwood area (AS), and stemwood growth in trees receiving the high inoculation treatment relative to those receiving the low or medium inoculation treatments, or the wound or control treatments after seven months of water deficit. The absence of a similar response to water deficit among trees that were noninoculated, wounded, or inoculated at the low or medium densities suggests that, in the loblolly pine–L. terebrantis pathosystem at our study site, the physiological stress caused by water deficit and the high inoculum density was required for the pathogen to elicit a stemwood growth loss. Thus, in loblolly pine forests of the southeastern United States, where climate and soil conditions yield prolonged periods of physiological stress, the presence of L. terebrantis has the potential to reduce stand volume and widen the gap between the predicted and actual stemwood production. [ABSTRACT FROM AUTHOR]

This paper compares the parallel-to-grain compressive strengths of wood sample specimens with defects with those of the associated timber log samples. The Chinese fir (Cunninghamia lanceolata) was examined using the static test method. We analyzed the effects of sampling position along the radial direction of the log sample and the age of timber on the parallel-to-grain compressive strength. We then developed time-dependent strength models of the heartwood (HW) and sapwood (SW). These models can be used to evaluate the strength of an aged timber member, using only the service duration, without taking material samples. The degradation of compressive strength over time was then analyzed using an existing multivariate time-dependent model that includes the stress level. The failure strength of the HW was found to be close to that of the SW when at low stress levels. The estimates of the compressive strength of timber members based on these models were better than those recommended by the Chinese National Standard. [ABSTRACT FROM AUTHOR]

Summary: An essential stage in woody plant ontogeny (heartwood (HW) formation) determines tree resistance to weather conditions, wood quality (moisture, colour, resistance to biodegradation), and regulates the proportion of functionally active sapwood (SW) in the total trunk biomass. In this study, the patterns of HW formation depending on tree age and cambial age within the same tree were studied in the North-West of Russia in Scots pine in a lingonberry pine forest. It is shown that HW either repeats the trunk profile or shows a maximum proportion on average at the height of 1.5 m. Models using the square root transformation and logarithm transformation have been proposed to predict the number of annual rings in HW depending on the cambial age. Multiple regression is proposed to predict the radial width in HW. Validation of the developed models on random trees gave a good result. HW formation begins at the age of 17–18 years and continues at the rate of 0.3 rings per year for 20–30-year-old trees, 0.4–0.5 rings per year for 70–80-year-old trees, and about 0.7 rings per year for 180-year-old trees. The lifespan of xylem parenchyma cells ranged from 10–15 years in 20-year-old trees to 70 years in 180-year-old trees. At the age of the previous felling (70–80 years) the HW area in the trunk biomass is about 20%, and in 180-year-old pine forests, it increases to 50%. These data can be used to assess the role of old-growth forests in carbon sequestration. [ABSTRACT FROM AUTHOR]

High pressure (20 MPa), cyclic, supercritical carbon dioxide (scCO2) treatments can reduce the moisture content of green Pinus radiata sapwood from 150–200% to 35–40%. Such treatments can be used as a dewatering pre-treatment before the kiln-drying of timber. Kiln-drying can utilise various temperature and humidity schedules, targeting around 10% moisture content, with a final stress-relieving steam-conditioning step. After scCO2 treatment and kiln-drying of samples, kiln brown stain was evaluated using the CIE L*a*b* colour space while drying stress was assessed by stress-cup measurements. The most significant results of scCO2 pre-treatment of Pinus radiata sapwood followed by kiln-drying plus steam-conditioning were as follows: Drying from green (36 h from a moisture content (MC) of 164%) using a conventional temperature schedule (90 °C/60 °C) took 2–5 times longer than kiln-drying scCO2 pre-treated boards (37.5% MC) to a target of 10% MC. Colour measurements proved that kiln brown stain does not occur. The use of a steam-conditioning step in reducing internal drying stresses was important irrespective of whether or not there was a scCO2 pre-treatment step. Over all drying schedule combinations, internal drying stress of both green and scCO2 pre-treated timber was similar after kiln-drying plus steam-conditioning. However, using only 90 °C/60 °C schedule data, with steam-conditioning, drying stresses were lower using kiln-drying without the scCO2 pre-treatment. This was surprising since the scCO2 step reduced the moisture content to around 37.5% without significant moisture gradients and so a secondary kiln-drying to 10% moisture content could have been expected to yield lower internal stress levels by preventing large moisture gradients to develop during drying. This result confirms the efficacy of the steam-conditioning step following standard kiln-drying. The colour data demonstrating the prevention of kiln brown stain using kiln-drying schedules offers a path to increasing timber quality for interior applications. [ABSTRACT FROM AUTHOR]

Gnathotrichus materiarius (Fitch, 1858) is an alien ambrosia beetle from North America, that has been spreading across Europe since the 1930s. The species infests coniferous trees, excavating galleries in sapwood. However, to date very few studies have predicted changes in ambrosia beetle habitat suitability under changing climate conditions. To fill that gap in the current knowledge, we used the MaxEnt algorithm to estimate areas potentially suitable for this species in Europe, both under current climate conditions and those forecasted for the years 2050 and 2070. Our analyses showed areas where the species has not been reported, though the climatic conditions are suitable. Models for the forecasted conditions predicted an increase in suitable habitats. Due to the wide range of host trees, the species is likely to spread through the Balkans, the Black Sea and Caucasus region, Baltic countries, the Scandinavian Peninsula, and Ukraine. As a technical pest of coniferous sapwood, it can cause financial losses due to deterioration in quality of timber harvested in such regions. Our results will be helpful for the development of a climate-change-integrated management strategy to mitigate potential adverse effects. [ABSTRACT FROM AUTHOR]

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Abstract Taiwania (Taiwania cryptomerioides Hayata) has long been regarded as a living fossil from the Tertiary period of Mesozoic Era for its distinguished yellowish-red color with purplish-pink streaks presented in its heartwood. With this elegant appearance that matches the color “red” for good fortune in the Taiwanese culture, Taiwania is supposed to be a popular wood in Taiwan where it is a native species of. Extractives contribute to the properties of wood. It is a fascinating subject to investigate extractives biosynthesis in the process of heartwood formation. Up to date, there is no phytochemistry study of Taiwania sapwood. In this study, three new sesquiterpenoids, Taiwania A (1), Taiwania B (2), and Taiwania C (3), together with 75 known compounds in the Taiwania sapwood. The structures of extractives were determined by analysis of spectroscopic data and comparison with the literatures. This study supported secondary reaction lignans could be found in sapwood that confirmed our previous research on the Taiwania-type of heartwood formation.

The objective of this study was to investigate the extractive content of three fast growing Acacia hybrid clones (Clone 16, 25, and 44) wood in three radial directions (SW = sapwood; OHW = outer heartwood; IHW = inner heartwood); total phenolic, flavonoid, flavanol contents (colorimetric assay); and antioxidant activity (1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay). Extractions were done with three different solvents in successive (n-hexane = H; methanol = M; hot water = W), yielded 0,69 % – 1,70 %; 1,51 % – 10,86 %; and 0,51 % – 1,16 % of extractive contents, respectively. The total phenolic content (TPC) from TPC-H, TPC-M, and TPC-W ranged between 3,68 mg of gallic acid equivalent (GAE)/g – 10,41 mg GAE/g; 76,83 mg GAE/g – 448,35 mg GAE/g; and 43,28 mg GAE/g – 198,92 mg GAE/g, respectively; the total flavonoid content (TFC) from TFC-H, TFC-M, and TFC-W between 4,23 mg of quercetin equivalent (QE)/g – 41,51 mg QE/g; 29,55 mg QE/g – 133,71 mg QE/g; and 7,70 mg QE/g – 29,37 mg QE/g, respectively; total flavanol content (TVC) from TVC-H, TVC-M, and TVC-W ranged between 28,74 mg of catechin equivalent (CE)/g – 66,90 mg CE/g; 83,39 mg CE/g – 247,18 mg CE/g; and 7,08 mg CE/g – 29,21 mg CE/g, respectively. Furthermore, the antioxidant activity was found to be significantly affected by the radial factor with the strongest activity exhibited by inner heartwood extract with an IC50 value of 255,77 μg/ml (gallic acid IC50 showed a value of 39,00 μg/ml). Among clones, clone 16 was determined to have the highest extractive, total flavonoid as well as flavanol contents. Thus, clone 16 was hypothesized to be more resistance against heart rot disease.

Background and Aims Despite the critical role of woody tissues in determining net carbon exchange of terrestrial ecosystems, relatively little is known regarding the drivers of sapwood and bark respiration. Methods Using one of the most comprehensive wood respiration datasets to date (82 species from Australian rainforest, savanna and temperate forest), we quantified relationships between tissue respiration rates (R d) measured in vitro (i.e. 'respiration potential') and physical properties of bark and sapwood, and nitrogen concentration (N mass) of leaves, sapwood and bark. Key Results Across all sites, tissue density and thickness explained similar, and in some cases more, variation in bark and sapwood R d than did N mass. Higher density bark and sapwood tissues had lower R d for a given N mass than lower density tissues. R d– N mass slopes were less steep in thicker compared with thinner-barked species and less steep in sapwood than in bark. Including the interactive effects of N mass, density and thickness significantly increased the explanatory power for bark and sapwood respiration in branches. Among these models, N mass contributed more to explanatory power in trunks than in branches, and in sapwood than in bark. Our findings were largely consistent across sites, which varied in their climate, soils and dominant vegetation type, suggesting generality in the observed trait relationships. Compared with a global compilation of leaf, stem and root data, Australian species showed generally lower R d and N mass, and less steep R d– N mass relationships. Conclusions To the best of our knowledge, this is the first study to report control of respiration–nitrogen relationships by physical properties of tissues, and one of few to report respiration–nitrogen relationships in bark and sapwood. Together, our findings indicate a potential path towards improving current estimates of autotrophic respiration by integrating variation across distinct plant tissues. [ABSTRACT FROM AUTHOR]

The Electric Resistance Tomograph (ERT) is a customized tree specific novel German-technology which was developed to monitor and estimate the tree growth development by looking into the inner structure of the tree to analyse the growth and health status. This technique contributes to detect and study the internal assembly of a tree for the mapping of decay, hollowness, and also to distinguish the sapwood and heartwood demarcation, this way of discovering the internal growth at an early stage, mainly for the timber trees which are economically important can help to regulate thereafter to check whether the growth is not hindered. This paper highlights the device operational methods, electric resistance testing of trees and its applications, also reviewed the various successful application of this equipment in various tree species through-out the world to estimate non-destructively for accurate quantification of standing trees. The performance of this instrument has created breakthrough among various studies and methodologies to spot the internal condition in a standing tree with less invasive ways. [ABSTRACT FROM AUTHOR]

Thermo-hydro-mechanical (THM)-densified timber is rarely used in construction, although its mechanical properties are in many cases excellent. The main reason for its rare use is set-recovery, which reduces the degree of densification over time so that the mechanical properties deteriorate. Our knowledge of the long-term creep of densified timber is insufficient and a full understanding of its long-term behaviour is still lacking. The purpose of this study was to examine the behaviour under long-term loading of Scots pine sapwood densified in an open system at 170–200 °C. The influence of the THM densification process on the creep properties was studied on (1) unmodified specimens, (2) THM-densified specimens, (3) THM-densified specimens that had been further thermally treated, and (4) low-molecular-weight phenol-formaldehyde resin-impregnated and THM-densified specimens. All specimens were loaded at 20 ± 2 °C and 65 ± 5% relative humidity for 14 days under 3-point bending at 35% of the short-term ultimate load, and the bending deformation was registered. The THM densification doubled the density, causing a significant increase in the modulus of rupture but no change in the modulus of elasticity, and reduced the equilibrium moisture content and creep compliance. Post-thermal modification and resin impregnation improved the dimensional stability and further reduced the creep compliance in bending. The results demonstrate that THM densification combined with resin-impregnation or thermal modification reduces the creep of Scots pine timber under a long-term bending load in a constant climate. [ABSTRACT FROM AUTHOR]

This paper presents differences in the drying behavior of red oak and yellow-poplar sapwood, heartwood, and bark and their relationship with selected physical characteristics. Drying experiments were performed on samples of sapwood, heartwood, and bark of respective species at 105 °C under nitrogen conditions. In addition, physical characteristics such as green moisture content, specific gravity, volumetric shrinkage, shrinkage of the cell wall, total porosity, pore volume occupied by water, and specific pore volume were calculated. The results showed that the volumetric and cellular shrinkages of sapwood were greater than those of heartwood for both species. For red oak, the specific gravity of sapwood and heartwood was not significantly different. Additionally, the total porosity of heartwood was lower than that of sapwood in red oak. The results also indicated that yellow-poplar dried faster than red oak. Among all three components, bark dried faster than sapwood and heartwood in both species. The activation energy for sapwood drying was less than for heartwood drying. [ABSTRACT FROM AUTHOR]

Leptographium terebrantis is an opportunistic root pathogen that has been implicated as a contributing factor of Pinus taeda decline and mortality over the past several decades in central parts of Alabama and Georgia, USA. We assessed the potential of L. terebrantis to initiate crown thinning in young P. taeda trees and hypothesized that L. terebrantis infestation will impose moisture stress on foliage, induce premature senescence, and cause loss of foliage biomass. The study was undertaken in a naturally regenerated 5–7‐year‐old P. taeda stand at Andalusia, Alabama in a completely randomized design using artificial inoculations of L. terebrantis colonized toothpicks. After four years of infestation, the pathogen caused sapwood occlusions and loss of sapwood function but failed to impose moisture stress on needles to induce premature senescence and loss of biomass. The new sapwood formed around the occluded area was devoid of pathogen infestation. The new growth was approximately twice the size of occluded tissue and compensated for the loss of old sapwood function to sustain tree growth. Results demonstrated that young P. taeda trees can tolerate L. terebrantis infection when stand conditions sustain the formation of new sapwood. [ABSTRACT FROM AUTHOR]