Moisture Content Of Heartwood Research Articles

Stem moisture content prediction model for Larix olgensis based on beta regression.

To investigate the longitudinal variation patterns of sapwood, heartwood, bark and stem moisture content along the trunk of artificial Larix olgensis, we constructed mixed effect models of moisture content based on beta regression by combining the effects of sampling plot and sample trees. We used two sampling schemes to calibrate the model, without limiting the relative height (Scheme Ⅰ) and with a limiting height of less than 2 m (Scheme II). The results showed that sapwood and stem moisture content increased gradually along the trunk, heartwood moisture content decreased slightly and then increased along the trunk, and bark moisture content increased along the trunk and then levelled off before increasing. Relative height, height to crown base, stand area at breast height per hectare, age, and stand dominant height were main factors driving moisture content of L. olgensis. Scheme Ⅰ showed the stable prediction accuracy when randomly sampling moisture content measurements from 2-3 discs to calibrate the model, with the mean absolute percentage error (MAPE) of up to 7.2% for stem moisture content (randomly selected 2 discs), and the MAPE of up to 7.4%, 10.5% and 10.5% for sapwood, heartwood and bark moisture content (randomly selected 3 discs), respectively. Scheme Ⅱ was appropriate when sampling moisture content measurements from discs of 1.3 and 2 m height and the MAPE of sapwood, heartwood, bark and stem moisture content reached 7.8%, 11.0%, 10.4% and 7.1%, respectively. The prediction accuracies of all mixed effect beta regression models were better than the base model. The two-level mixed effect beta regression models, considering both plot effect and tree effect, would be suitable for predicting moisture content of each part of L. olgensis well.

Effects of cutting speed and feed per knife on energy requirements for processing black spruce logs with a chipper-canter

The effects of cutting speed (CS), feed per knife (FK), and temperature condition on energy requirements for processing black spruce logs by a chipper-canter were assessed. Nine groups of 15 logs were tested at three CS (20, 25, and 30 m/s) and three FK (19, 25, and 32 mm). Each log was processed under frozen (−13 °C) and unfrozen (19 °C) conditions. Mean power increased as CS and FK increased. This behavior is explained by the mechanical relationships between the parameters and the rotation and feed speeds, as well as by the increase in the volume of wood cut. The energy consumption and the specific energy consumption increased as CS increased and FK decreased. For the three electrical criteria, more energy was consumed when processing frozen logs, which is due to the greater mechanical properties of wood. A positive relationship was identified between sapwood and heartwood moisture content, basic density, grain angle, and wood volume transformed into chips, as covariates, and the three energy criteria. These results give useful information on energy requirements to adjust cutting parameters of chipper-canters for a better energy management in sawmills.

Using electrical resistivity tomography to detect wetwood and estimate moisture content in silver fir (Abies alba Mill.)

Key message Using several experimental approaches, we have demonstrated that electrical resistivity tomography (ERT) is a reliable nondestructive tool for estimating the moisture content of heartwood in situ. ERT measurements show that water pockets in heartwood (wetwood) are present in a large majority (90%) of silver fir ( Abies alba Mill.) trunks. ContextFor wood professionals, the presence of wetwood in wood logs leads to an increase in costs, especially during the drying process. Assessing these internal properties in situ with a nondestructive method will provide reliable information for improved management of respective forests.AimsThe objective of this study was to evaluate the efficiency of the electrical resistivity tomography (ERT) tool to detect wetwood in standing trees and to estimate the mean moisture content (MC) of silver fir trunks.MethodsThe study was carried out in 3 forests located in the region “Massif Central” in France. We selected 58 silver fir trees, visually healthy and without visible default. Each tree has been subject to regular ERT measurements for more than a year. At the same time, one to three cores were taken from each tree in order to measure the actual MC of the wood.Results90% of the silver fir trees showed the presence of wetwood in their heartwood. Our results showed a significant correlation between the mean heartwood MC measured on cores and the mean electrical resistivity (ER) obtained with ERT.Conclusion(i) The presence of wetwood occurs in a high proportion of the silver fir trees studied, and (ii) ERT can be used to estimate the average MC of the heartwood of standing trees. However, the data provided by ERT vary seasonally and do not allow the precise location of wetwood.

Tracing radioactive cesium in stem wood of three Japanese conifer species 3\xa0years after the Fukushima Dai-ichi Nuclear Power Plant accident

To understand the dynamics of accident-derived radioactive cesium (137Cs) in stem wood that had a substantial amount of heartwood at the time of the Fukushima Dai-ichi Nuclear Power Plant accident, the radial and vertical distributions of 137Cs activity concentration in stem wood of Japanese cedar (Cryptomeria japonica), cypress (Chamaecyparis obtusa), and larch (Larix kaempferi) were investigated. In addition, the natural distribution of stable cesium (133Cs), rubidium (85Rb), and potassium (39K) concentrations was analyzed to determine the characteristics of 137Cs distribution. Wood disks were collected from the tree stems of six cedars, three cypresses, and two larches at multiple heights in 2014, and the concentrations were measured every 2 cm in the radial direction. 137Cs distribution in stem wood differed among tree species, sampling site, and vertical position of the stem within a tree. Statistical analyses suggested that the radial distribution of 137Cs within the heartwood can be explained by the heartwood moisture content and the distance from the treetop, regardless of species, while the distribution between sapwood and heartwood was dependent on the heartwood cross-sectional area and was additionally different between larch and other species. Similarly, the heartwood/sapwood concentration ratios of stable alkali metals differed between larch and the other species. In the larch, the ratio was ca. 0.5 for all elements, but the ratio was over 1.0 and differed among elements in the other species. Consequently, the species-specific difference in the distribution of 137Cs between sapwood and heartwood was considered to be due to different activity levels of radial transport toward the heartwood. The radial variation pattern of the 137Cs/133Cs concentration ratio showed that less 137Cs was transferred to the inner heartwood compared with the 133Cs distribution pattern in many trees; however, there was also a tree in which 137Cs was excessively transferred to the inner heartwood compared with the 133Cs distribution pattern. Such patterns may result from a combination of significant foliar uptake of 137Cs and poor root uptake after the accident, in addition to the high moisture content of the heartwood.

Non-destructive detection of density and moisture content of heartwood and sapwood based on X-ray computed tomography (X-CT) technology

Density and moisture content (MC) are two of the most important wood performance indexes, which are highly correlated with many other physical and mechanical properties of wood. X-ray computed tomography (X-CT) technology was used to analyze the difference in the CT number of the heartwood and sapwood of Chinese white poplar (Populus tomentosa) and Masson pine (Pinus massoniana) under different MC. Additionally, the fitted models of CT number-density and CT number-MC were established and validated for the heartwood and sapwood of P. tomentosa and P. massoniana. The methodological improvement has been described in detail regarding the established models, which are contrasted and discussed with previous models. The results showed that the CT number-density fitted models of the heartwood and sapwood of P. tomentosa and P. massoniana adopted the linear model: $$ D = k \times H + b $$, where D is the density, H is the CT number, k is the slope, and b is the intercept. R2 values obtained in the validation models were all higher than 0.98, indicating that the CT number-density fitted models can reliably predict wood density. The CT number-MC fitted models for the heartwood and sapwood of P. tomentosa and P. massoniana adopted the logarithmic model: $$ M = \ln ((a + b \times H)^{100} ) $$, where M is the MC, H is the CT number, and a and b are the correlation coefficients in the model. R2 values obtained in the validation models were all higher than 0.95, indicating that this model is valid for the accurate prediction of wood MC. The fitted model parameters of heartwood and sapwood indicated that the X-CT technology was effective for identifying the difference in density and MC of heartwood and sapwood. Therefore, it is feasible to use non-destructive testing technology when studying density and MC of heartwood and sapwood based on X-CT technology. The study results provide reference data for the non-destructive testing of wood properties and reasonable utilization.

Mapping quantitative trait loci for growth and wood property traits in Cryptomeria japonica across multiple environments

Genomic regions which affected tree growth and wood property traits were investigated in the major plantation tree of Japan, Cryptomeria japonica, in three replicated common garden experiments planted in contrasting environments in Kyushu and Honshu, Japan. Phenotypic traits measured were stem diameter at breast height, tree height, wood strength (Young’s modulus), heartwood density, sapwood density, heartwood moisture content, and sapwood moisture content. Quantitative trait locus (QTL) analysis identified an average of 53 QTLs across the three environments. There were two QTLs which affected the same traits across all three environments. These stable QTLs were identified as being associated with sapwood density and Young’s modulus and explained 3.5–11.3% and 2.1–18.7% of the total genotypic variation, respectively. In contrast, the majority of QTLs detected were unique to only one environment, a finding which is consistent with QTL mapping studies of other forest trees, indicating a substantial contribution of environmental effects on the mapping progenies. Nonetheless, the two stable QTLs identified in this study could be important genomic regions to target for further research aimed at maximizing breeding efficiency and wood quality of C. japonica across wide environmental gradients.

Microcrack Propagation in Red and Black Heartwoods of Cryptomeria japonica During Drying

Microcrack behaviors in black and red heartwoods of Cryptomeria japonica were compared in this study. Black and red heartwoods have extremely different green moisture contents but similar wood structure. Small heartwood samples were prepared from these two types of green wood. Moisture contents of black and red heartwood were 201.5% and 51.3%, respectively. The samples were dried at 50 °C in a controlled-environment chamber with a relative humidity below 5%. The propagation of microcracks was continuously observed using a confocal laser scanning microscope while the samples dried. The electrical resistivity of the surface was also measured to assess surface moisture content. Results showed that the transformation of the microcracks was similar between black and red heartwoods. However, the appearance of microcracks in the black heartwood was delayed, whereas the microcracks appeared in red heartwood immediately after drying. These suggested that in-situ observation is essential for distinguishing when microcracks emerged. It was also suggested the green moisture content of heartwood has a major effect on the occurrence of microcracks. Drying conditions must be adjusted to account for the moisture content of green heartwood, even for specimens of the same species that have the same anatomical structure.

Application of the wood properties of large-diameter Sugi (Cryptomeria japonica) logs to sorting logs and sawing patterns

The purposes of this study were to accumulate fundamental data on wood properties within large Sugi logs and to take applicable variations in wood properties into consideration for sorting logs and sawing patterns. The characteristics of basic density, moisture content, growth ring width, and microfibril angle (MFA) were measured and the relationship with log and lumber quality was examined. It was considered reasonable to estimate the lumber moisture content based on the moisture content of heartwood rather than that of whole logs, especially when producing large-sized lumber. The MFA reached a constant value before the 15th ring, and within a distance of 10 cm or less from the pith. Since the E fr of lumber correlated with that of the log affected by MFA, it would be possible to produce lumber with a higher E fr from the outer position of the log, based on selecting a log above the E fr . Since the MFA would also affect the lumber warp, a sawing pattern avoiding the area around the pith or enlarging the rough sawn size when a large warp was expected could be effective in improving the lumber quality. To improve the lumber quality, not only one but also multiple wood properties must be applied to the sawing pattern.

Radial distribution patterns of the green moisture content in trunks of 46-year-old red cypress (Chamaecyparis formosensis)

Understanding the green moisture content and wood density is important for effective forest management. Radial distribution patterns in the green moisture content (MC) and basic density (BD) in stems of red cypress (Chamaecyparis formosensis) were investigated in 69 plantation trees that were 46 years old. An increment core was collected from each sample tree at breast height (1.3 m). Five radial positions were defined: pith piece (Pith), inner heartwood (IHW), outer heartwood (OHW), intermediate wood (TSH), and sapwood (SW). Results showed that the average MC was highly dependent on the individual tree. Average values of the MC obtained from the TSH were significantly lower than those for the other positions. The MC of heartwood was higher than that of SW. Distribution patterns of the MC in the radial direction varied among trees. Radial variations in MC and BD were greater than in between-tree variations. Six types of radial distribution patterns of MC were detected for sample trees. MC values increased with decreasing BD (except for the TSH). Positive correlations were found between adjacent sampling positions in both MC and BD.

The relationship between site and tree characteristics and the presence of wet heartwood in black spruce in the boreal forest of Quebec, Canada

Wet heartwood in black spruce (Picea mariana (Mill.) BSP) causes considerable problems during the drying process. Forest companies try to avoid harvesting stands with wet heartwood, but no relationship has been yet established between the incidence of wet heartwood and tree or site characteristics. To characterize areas containing a significant proportion of black spruce affected by wet heartwood, a total of 635 black spruce trees were sampled in eighteen 400 m2 study plots under management in the central boreal forest of Quebec. A total of 18 study sites were analysed and classified as wet, intermediate, or dry, based on the proportion of individuals with wet heartwood. Thirteen of the study sites were classified as wet, two as intermediate, and three as dry. The average age calculated for trees on wet sites was significantly (p = 0.0001) higher than that of the other two classes, whereas growth rate was significantly lower on wet sites. No difference was noted in the average height or diameter of the individuals from all three classes. The wet sites contained organic soil, whereas Podzols characterized two of the three dry study sites. An additional sampling of black spruce (n = 509) revealed a significant relationship between the groundwater level and heartwood moisture content classification (i.e., dry, intermediate, or wet). Trees in the dry heartwood class grew on sites with the lowest groundwater levels (p = 0.002) compared with trees in the wet or intermediate classes.

スギ心材含水率の遺伝的改良への横打撃共振法の適用

高効率かつ非破壊的な測定により生立木の心材含水率を推定できる横打撃共振法を，37クローン（約1000個体）で構成されるスギクローン検定林での研究に適用した。2000年と2001年の2度行った，横打撃によって励起された樹幹の振動の共振周波数（f）測定の再現性は極めて高かった。1/fと測定部位の樹幹直径（d）の関係はクローンの特徴とできた。この検定林から15クローン（103個体）を伐採して心材含水率を調べた。1/dfによって心材含水率を推定する事が可能であったが，その推定精度は十分高いものではなかった。ところが1/dfのクローン平均値の順位と心材含水率のクローン平均値の順位はおおむね一致していた。よって，横打撃共振法はクローンの順位づけ，さらにはクローンの選抜に適当な方法であり，スギの心材含水率の遺伝的改良にとって有効な方法であると結論した。

Moisture Distribution in Stems of Acacia mangium, A. auriculiformis and Hybrid Acacia Trees

Distribution of the moisture content across stem wood at breast height in Acacia mangium, A. auriculiformis, and hybrid Acacia trees grown in 3 Asian countries was evaluated. Moisture contents of the stems of A. mangium and hybrid Acacia were extremely high not only in sapwood but also in heartwood in most cases. Highest moisture content found in the inner heartwood was 253% for both A. mangium and hybrid Acacia. In sapwood, the moisture contents were 149% and 154%, respectively. Most trees of these 2 species had “wet-heartwood” which refers to the higher moisture content of heartwood compared to the surrounding sapwood. Stem wood of A. auriculiformis generally showed a slightly lower moisture content than that of A. mangium and hybrid Acacia. However, the highest moisture content found in the inner heartwood was 146% in A. auriculiformis. The large amount of water in stem wood, especially in the heartwood of these Acacia species hampers drying which is necessary for the production of sawn timber and processing to panel products. Several factors such as characteristics of clones or provenance of seeds, and amount of precipitation at plantation sites could be involved in the large fluctuations in the moisture contents of the stems of these Acacia trees. Further studies should be carried out to determine the conditions necessary for lowering the moisture content of stem wood in order to optimize the utilization of these plantation species.

S�cheresse � coeur du Douglas et aptitude au d�roulage : recherche de proc�d�s alternatifs d'�tuvage. I. R�partition de l'eau dans le bois vert et r�humidification sous autoclave

Heart dryness of Douglas fir and ability to rotary cutting: Research of alternative boiling processes. I. Moisture content distribution inside green wood and water impregnation with an autoclave. The analysis of the moisture content varia- tions along Douglas fir increment cores, fresh cut logs and peeled veneers allowed to confirm the low level of moisture content inside Douglas fir heartwood. Whatever the tree and the inside ring location may be, the heartwood moisture content is about 30% vs. 80 to 150% for sapwood. Several hygrothermic treatments (conventional boiling, hot/cold baths, vacuum/pressure cycles) have been applied to 12 cm long bolts in view to measure the moisture content increasing. Only the treatments involving vacuum and pressu re appeared efficient. The heartwood moisture content after such treatments ranged from 50% to 150%. The higher M.C. were obtained inside earlywood. wood / Douglas / rotary cutting / heartwood / boiling proces

Non-destructive study on heartwood moisture content of standing Japanese cedars, Cryptomeria japonica, by lateral impact vibration method. —Comparison between several cultivars of Cryptomeria japonica planted at Tatsunokuchi Green Shower, Okayama Prefecture—

Non-destructive study on heartwood moisture content of standing Japanese cedars, <I>Cryptomeria japonica</I>, by lateral impact vibration method. &#8212;Comparison between several cultivars of <I>Cryptomeria japonica</I> planted at Tatsunokuchi Green Shower, Okayama Prefecture&#8212;

Anatomical, Chemical, and Ecological Factors Affecting Tree Species Choice in Dendrochemistry Studies

AbstractRecently, element concentrations in tree rings have been used to monitor metal contamination, fertilization, and the effects of acid precipitation on soils. This has stimulated interest in which tree species may be suitable for use in studies of long‐term trends in environmental chemistry. Potential radial translocation of elements across ring boundaries can be a confounding factor in assessing environmental change. Thus, the selection of species which minimizes radial translocation of elements can be critical to the success of dendrochemical research. Criteria for the selection of species with characteristics favorable for dendrochemical analysis are categorized into (i) habitat‐based factors, (ii) xylem‐based factors, and (Hi) element‐based factors. Species with a wide geographic range and ecological amplitude provide an advantage in calibration and better controls on the effects of soil chemistry on element concentrations. The most important xylem‐based criteria are heartwood moisture content, permeability, and the nature of the sapwood‐heartwood transition. The element of experimental interest is important in determining which tree species will be suitable because all elements are not equally mobile or detectable in the xylem. Ideally, the tree species selected for dendrochemical study will be long‐lived, grow on a wide range of sites over a large geographic distribution, have a distinct heartwood with a low number of rings in the sapwood, a low heartwood moisture content, and have low radial permeability. Recommended temperate zone North American species include white oak (Quercus alba L.), post oak (Q. stellata Wangenh.), eastern redcedar (Juniperus virginiana L.), old‐growth Douglas‐fir [Pseudotsuga menziesii (Mirb.) Franco] and big sagebrush (Artemisia tridentata Nutt.). In addition, species such as bristlecone pine (Pinus aristata Engelm. syn. longaeva), old‐growth redwood [Sequoia sempervirens (D. Don) Endl.], and giant sequoia [S. gigantea (Lindl.) Deene] may be suitable for local purposes.