Wood Products Research Articles

A Transcriptomic Analysis Sheds Light on the Molecular Regulation of Wood Formation in Populus trichocarpa during Drought Stress

Wood is an abundant and essential renewable resource whose production is threatened in some parts of the world by drought. A better understanding of the molecular mechanisms underlying wood formation during drought is critical to maintaining wood production under increasingly adverse environmental conditions. In this study, we investigated wood formation in black cottonwood (Populus trichocarpa) during drought stress. The morphological changes during drought stress in P. trichocarpa included the wilting and drooping of leaves, stem water loss, and a reduction in whole plant biomass. The water embolism rate indicated that the water transport in stems was blocked under drought conditions. An anatomical analysis of the xylem and cambium revealed that drought stress changed the structure of vessel cells, increased lignin accumulation, and decreased the cambium cell layers. We subsequently identified 12,438 and 9156 differentially expressed genes from stem xylem and cambium tissues under well-watered and drought conditions, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that these genes were mainly involved in hormone signal transduction and amino sugar and nucleotide sugar metabolism. To further explore the molecular mechanism of wood formation in response to drought, we analyzed the expression patterns of the genes involved in lignin, cellulose, and hemicellulose biosynthesis in xylem and the genes involved in cambial activity in the cambium. To better understand the regulatory networks governing xylem development and cambium activity in response to drought, we analyzed the MYB (138), AP2 (130), bHLH (89), and NAC (81) transcription factor families to shed light on the interactions between the TFs in these families and the genes they regulate. Identifying the key genes that regulate wood formation in P. trichocarpa during drought provides a genetic foundation for further research on the molecular regulatory networks and physiology underpinning wood formation during drought stress.

Chemical reagent for detecting tension wood in selected tree species

Reaction wood is a wood defect arising during the growth of the tree in the part of the trunk that is under tension (hardwood tree species) or compression (coniferous tree species). Beech (Fagus sylvatica L.) tension wood has different anatomical and chemical characteristics than normal (opposite) wood. The difference in density is conditioned by the percentage of the gelatinous layer (G-layer). Fibre cells in reaction beech wood have a different cell wall structure and a different chemical composition. Tension wood cannot be detected by the naked eye. It is only possible to assume its occurrence based on the macroscopic characteristics of the logs, such as a woolly surface, taper or eccentric pith, and so forth. However, these are imprecise and unreliable methods that have minimal effectiveness, especially when shortening the length of the log for cut-outs. This study aimed to create a unique chemical reagent for the detection of tension wood in logs and timber and wood products immediately. The present research can contribute to the mitigation of flaws resulting from the reaction of wood in timber production while addressing noticeable constraints in manufacturing, such as energy resources and the availability of wood raw materials. This can be achieved through the efficient identification of reaction wood in materials. The colour change is only temporary and will fade over time. After the chemical reagent has dried on the surface, the surface can be milled. The colour change extends to a depth of approx. of 3 to 5 mm.

Relationship between the acoustic emission and the strain field in finger joints of engineered wood products for construction

The use of Engineered Wood Products (EWPs) for buildings is becoming very popular because they favor decarbonization in the construction sector and improve the performance and mechanical properties of solid timber. Finger joint technology makes it possible to remove the natural defects of timber (knots, splits, decay areas, etc.), providing for clearer timber and the manufacture of larger structural elements. Nowadays, glued laminated timber (GLT) and cross laminated timber (CLT) are the most used products, suitable even for tall buildings. The finger joints —given the adhesive used and the increased friction surface due to their geometry— allow stress to be transferred efficiently between the joined lamellae, making them behave mechanically almost like a single piece of solid timber. The quality control of these products is therefore crucial. In this work, the longitudinal and transverse strain fields in samples with finger joints, measured by means of the Digital Image Correlation (DIC) technique, are compared with the acoustic emission waves released when the sample is subjected to tensile stress. It is shown that there is a very close correlation between the two, meaning that the acoustic emission technique can be considered a promising tool for the quality control of these structural joints.

ASSESSING THE IMPACT OF ENGINEERED WOOD PRODUCTS ON SUSTAINABLE CONSTRUCTION: A COMPARATIVE STUDY WITH CONVENTIONAL CONCRETE BUILDING METHODS

Renewable-sourced EWPs offer enhanced dimensional stability, durability, and mechanical properties, facilitating larger and more complex structural elements, and contributing to faster construction times and better energy performance. The research investigates the feasibility and effectiveness of Engineered Wood Products (EWPs) as sustainable building materials in the construction sector by a comparison of their cost, performance, and environmental impact against conventional concrete. The research emphasises the importance of innovative design, recycling, and waste reduction in fostering sustainable construction methods that satisfy the demands of present and future generations while conserving energy. However, there are negative environmental impacts linked to the production of concrete, such as habitat destruction, atmospheric emissions, and waste generation. The research adopted a web-based survey to gather quantitative data from construction experts. The Relative Importance Index (RII) was adopted to analyze the respondents' perceptions of the benefits of EWP and concrete negative effects. The results of the research reflect respondents' significant preference for EWPs and are consistent with their outstanding environmental qualities. In conclusion, this paper argues that EWPs possess the potential to effectively revolutionise the construction industry by minimising its carbon footprint and encouraging sustainable construction practices that are required for addressing the expectations of both the present and the future.

Notes on South-East Asian Diospyros L. (Ebenaceae, Ericales): commonly misidentified species in mainland South-East Asia

Diospyros L. is a large genus of flowering plants predominantly distributed in the tropics. It comprises over 700 species globally and around 300 are believed to occur in South-East Asia. Many species are economically important and exploited for the production of ebony wood and persimmons, yet taxonomic information on the genus is incomplete and inconsistent due to its morphological and nomenclatural complexity. Revisions of Diospyros in continental and insular South-East Asia were conducted independently by different authors, occasionally with different names used for the same species, or different species being given the same name in different countries. During our ongoing study of the genus Diospyros in Indochina (Cambodia, Laos, Thailand and Vietnam), we identified several such instances. Here, we clarify the most commonly misidentified species, including 1) D. apiculata Hiern, D. strigosa Hemsl. and D. tamiriensis Lecomte; 2) D. bejaudii Lecomte and D. retrofracta Bakh.; 3) D. dictyoneura Hiern and D. hasseltii Zoll.; 4) D. borneensis Hiern and D. fecunda H.R.Fletcher. Lectotypifications are also made for D. brachiata King & Gamble var. lanceolata H.R.Fletcher, D. fecunda, D. similis Craib and D. strigosa.

Blue carbon and the role of mangroves in carbon sequestration: Its mechanisms, estimation, human impacts and conservation strategies for economic incentives

Mangroves, tidal marshes, and seagrasses have been recognized as blue carbon coastal ecosystems as they accommodate large carbon stocks, enable long-term carbon storage, have the capacity to control greenhouse gas emissions and possess the potential to reduce the rise in atmospheric CO2 levels. In the tropical and subtropical intertidal zones, mangroves show significant productivity and rapid deposition rates. Mangroves play an important role in capturing, transforming, and storing CO2 in the atmosphere into coastal sediments for a long time, displacing organic carbon from the coastal zone to the offshores and the ocean. Mangroves also help in preventing storms, hurricanes, coastal erosion, and tidal waves. Recently, mangroves have been threatened by natural and anthropogenic activities such as urbanization, pollution, aquaculture and tourism. They are expected to hamper their essential services, such as coastal defense, breeding grounds for aquatic organisms' seafood supply, etc. Despite the importance of mangrove forests in carbon sequestration and the numerous goods and services they offer humans, wood and non-wood forest products, food, fisheries, medicines, eco-tourism, and recreation. These mangrove ecosystems are deteriorating at alarming rates, necessitating immediate intervention. Thus, the protection, restoration and conservation of this ecosystem are gaining considerable attention from researchers across the globe. This paper provides information on different mangrove adaptations, their mechanisms, roles in the ecosystem, carbon estimation, influencing factors, threats, and conservation strategies for carbon sequestration in this invaluable coastal habitat.

A comparative study on the performance of terahertz, near-infrared, and hyperspectral spectroscopy for wood identification

ABSTRACT Wood species identification is of paramount significance in wood products manufacturing and applications. In contrast to traditional wood identification methods, spectroscopy-based technology offers a rapid, cost-effective, and efficient alternative. This study focuses on five wood species as experimental materials and aims to obtain three distinct wood spectra for each: near-infrared (NIR) spectra, hyperspectral image spectral information, and terahertz (THz) spectra. These spectra underwent pre-processing techniques such as Savitzky–Golay smoothing (SG), normalization, multiple scattering correction (MSC), and standard normalized variate (SNV), followed by dimensionality reduction through principal component analysis (PCA). Subsequently, the processed data were input into a partial least squares discriminant analysis (PLS-DA) for recognition. The results demonstrate the best recognition accuracy of 99.8% for THz spectra, 98.7% for NIR spectra, and 97.3% for hyperspectral image spectral information. The THz spectra exhibited the highest recognition accuracy, particularly with the SG-preprocessed THz spectra. These preprocessed spectra effectively removed noise and smoothed the spectral curves compared to the raw spectra.

On the intrinsic recycling potential of carbon-based materials and products; an assessment method and outlook

In this paper we investigate the market size of all materials and products presently produced from (organic) carbon and we present a method to estimate the intrinsic recycling potential of these materials/chemicals as a function of their respective applications. The method is based on the expert assessment of a number of variables that are important within the different application categories and markets of the carbon-based materials/chemicals. Applying the method, the paper presents the recycling potential of all carbon-based products. Following, an estimation of the amount of new products that can be produced each year through recycling of discarded products is presented and the amount of carbon that needs to come from other sustainable sources to fulfil our demand for new products is calculated.We distinguish nine different categories of (organic) carbon-based materials/chemicals: plastics, textile fibres, thermoset resins, rubbers, surfactants, solvents, fine chemicals, paper/board and wood products. Within these nine categories the most important materials/chemicals types were taken into account. Fossil-based and bio-based materials/chemicals were assessed separately. For each of the materials/chemicals types, the market size in terms of mass (Mt) was calculated for the main applications in which they are applied. Next, for all materials/chemicals types in these applications, the maximum recycling potential, in case mechanical or physical recycling methods are applied, was assessed, using an expert panel. Also, inevitable leakage of materials/chemicals in the different applications was assessed. Finally, the amount of feedstock coming from recycling streams that may be made available for chemical recycling or carbon capture and utilisation technologies was derived. From this, the magnitude of carbon-based materials/chemicals that need to be replaced each year by other renewable feedstock than recycled content in terms of Mton carbon was calculated.The analysis is relevant in view of implementation of a circular economy and reuse and recycling of materials, to combat depletion of raw materials. Next, it is relevant in view of phasing out fossil-feedstock to combat climate change. Our analysis indicates that the recycling potential of carbon-based materials and products through mechanical or physical methods lies around 50%, even in a system that is fully optimised for recycling. Chemical recycling and carbon capture and utilisation may provide another 25% of the renewable-carbon feedstock needed, but they generally require far more energy and other inputs to produce new materials and chemicals than the mechanical and physical recycling methods. The remaining demand for renewable-carbon feedstock thus needs to come from either biomass or CO2 through carbon capture and utilisation technologies. Based on our findings, we argue that the composition of our present carbon-based products pool needs to be redesigned on a fundamental molecular level, towards material types that contain more oxygen. Carbon-based materials that contain more oxygen generally can be recycled more efficiently, and are also easier to produce from the alternative feedstocks biomass and CO2 through CCU.

Gluing parameters optimization and failure mechanism of cross-laminated timber prepared with Chinese fir

Cross-laminated timber (CLT) has become a popular engineered wood product, mainly prepared from imported wood in China. More extensive research is needed to improve the local production of cross-laminated timber with fast-growing coniferous wood species. Chinese fir (Cunninghamia lanceolata) and one component polyurethane (1C-PUR) adhesive were selected to prepare CLT under different process parameters. International standard methods, scanning electron microscopy (SEM), optical microscopy (LM), confocal laser scanning microscopy (CLSM), and nanoindentation (NI) were applied. The bonding performance and failure mechanism of Chinese fir CLT were investigated and clarified. The results showed that the optimal gluing parameters for preparing CLT from Chinese fir wood were 160 g/m2 of glue, 0.9 MPa of pressure, and 180 minutes of pressing time. Failure of CLT made from Chinese fir lumber was mainly due to the shear failure of the vertical layer board. Cracks often appeared in the earlywood cells near the boundary between earlywood and latewood. The impact of adhesive penetration on the mechanical properties of the wood cell wall showed that adhesive penetration increased the elastic modulus of the cell wall at earlywood and latewood cells.

Impact of sound-insulated joints in the dynamic behavior of Cross-Laminated Timber structures

Cross-Laminated Timber (CLT) has gained an increasing success and widespread diffusion among wood products. Due to the novelty of the components and the dry-assembling techniques, certain aspects of its behavior and performance remain unexplored; among these, the use of sound-insulated joints and brackets, along with their possible drawbacks on mechanical performance.In this paper the authors discuss the results of dynamic identification (ID) tests carried out on twin full-size CLT mockups (two-story), one of which was furnished with sound-insulation details based on an elastomeric interlayer. Ambient (white noise and random excitations) and forced vibration (mass shaker) tests were carried out to identify modal parameters.The paper mainly aims at: i) assessing potential differences in the overall dynamic behavior of the two mockups, likely due to the introduction of acoustic insulation, ii) detecting possible drawbacks of insulation layers on mechanical performances, iii) increasing the knowledge about dynamics of CLT structures.The results of Operational Modal Analysis (OMA) are presented and the variations in the dynamics between the mockups are discussed. The construction of finite element (FE) models and their calibration – with joint properties variations – are then presented. The outcomes revealed a drop of modal frequencies values (at least 20 %) upon the introduction of elastomeric insulation, whilst no significant alteration was observed in the mode shapes. Model updating based on the FE models demonstrated that the dynamic response and the frequency variations were mostly associated with wall-to-wall and wall-to-diaphragms joints, and hold-down connections.

Chemical investigation of methanol extracts of Swietenia mahagoni leaves and its antioxidant activity

Swietenia mahagoni is among the species of trees used by the Indonesian Government for the purpose of afforestation and timber production through Perhutani Enterprise. The common use of this species as wood products has prompted investigating the chemical properties of its leaves. Based on this background, this study aimed at investigating the methanol extracts of both 2- and 3-year old S. mahagoni leaves extractives together with its antioxidants and phenols contents. The antioxidant activity was conducted through the DPPH (1,1-diphenyl-2-picrylhydrazyl) method, while the total phenolic and flavonoid content were measured through Folin-Ciocalteu and AlCl3 methods, respectively. Additionally, 24 compounds were characterized by the GC-MS, and were grouped into phenolics, fatty acids and hydrocarbons, and terpenoids. The total phenolic and flavonoid contents in both 2 and 3 years old leaves of S. mahagoni ranged from 36.4 ± 0.84 to 42.0 ± 0.18 mg GAE/g dried extract and from 2.24 ± 0.15 to 18.55 ± 1.05mg QE/g dried extract, respectively. Also, the antioxidant values were 66.45 ± 1.85% and 77.59 ±11.23%, respectively. Based on the results, the antioxidant activity of S. mahagoni leaves was indicated as a result of the presence of α-tocopherol and α-tocopherolquinone in the leaves extracts.

Chemical and Physical Debonding-on-Demand of Poly(urethane urea) Thermoset Adhesives to Facilitate the Recycling of Engineered Wooden Products

Chemical and Physical Debonding-on-Demand of Poly(urethane urea) Thermoset Adhesives to Facilitate the Recycling of Engineered Wooden Products

Residential long-span timber floor typologies: a comprehensive performance assessment and opportunities for value adding to plantation hardwood

ABSTRACT High-performance engineered wood products (EWPs) and composite mass timber products (CMTPs) are being employed more frequently in residential projects with increasing interest in more sustainable systems that achieve long-spans. The relative performance of these systems is not readily apparent, with individual manufacturers offering proprietary products assembled from specific timber resources. In addition, the suitability of producing these long-span systems using plantation hardwoods is currently unknown. This research investigated the comparative performance of four typical EWPs and CMTPs; 1. solid slab, 2. thin-walled cassette, 3. T-sections, and 4. slab on beam. Key performance metrics of depth, mass, stiffness, vibration response, fire performance and global warming potential were assessed. The mechanical performance of two high-strength plantation hardwood varieties (Eucalyptus nitens and Eucalyptus globulus) were determined experimentally and subsequently used to re-calculate performance criteria for the previously assessed typologies. Substantial improvements over the typical softwood varieties were identified, particularly in structural efficiency, global warming potential and fire performance. This highlights the potential for value adding to plantation hardwoods by using them in high-performance long-span engineered floor products.

Variation pattern in the macromolecular (cellulose, hemicelluloses, lignin) composition of cell walls in Pinus tabulaeformis tree trunks at different ages as revealed using multiple techniques

The plant cell wall is a complex, heterogeneous structure primarily composed of cellulose, hemicelluloses, and lignin. Exploring the variations in these three macromolecules over time is crucial for understanding wood formation to enhance chemical processing and utilization. Here, we comprehensively analyzed the chemical composition of cell walls in the trunks of Pinus tabulaeformis using multiple techniques. In situ analysis showed that macromolecules accumulated gradually in the cell wall as the plant aged, and the distribution pattern of lignin was opposite that of polysaccharides, and both showed heterogenous distribution patterns. In addition, gel permeation chromatography (GPC) results revealed that the molecular weights of hemicelluloses decreased while that of lignin increased with age. Two-dimensional heteronuclear single quantum coherence nuclear magnetic resonance (2D-HSQC NMR) analysis indicated that hemicelluloses mainly comprised galactoglucomannan and arabinoglucuronoxylan, and the lignin types were mainly comprised guaiacyl (G) and p-hydroxyphenyl (H) units with three main linkage types: β-O-4, β-β, and β-5. Furthermore, the C-O bond (β-O-4) signals of lignin decreased while the C-C bonds (β-β and β-5) signals increased over time. Taken together, these findings shed light on wood formation in P. tabulaeformis and lay the foundation for enhancing the processing and use of wood and timber products.

Development of transgenic Paulownia trees expressing antimicrobial thionin genes for enhanced resistance to fungal infections using chitosan nanoparticles

There is an increasing focus on genetically altering Paulownia trees to enhance their resistance against fungal infections, given their rapid growth and quality wood production. The aim of this research was to establish a technique for incorporating two antimicrobial thionin genes, namely thionin-60 (thio-60) and thionin-63 (thio-63), into Paulownia tomentosa and Paulownia hybrid 9501 through the utilization of chitosan nanoparticles. The outcomes revealed the successful gene transfer into Paulownia trees utilizing chitosan nanoparticles. The effectiveness of thionin proteins against plant pathogens Fusarium and Aspergillus was examined, with a specific focus on Fusarium equiseti due to limited available data. In non-transgenic Paulownia species, the leaf weight inhibition percentage varied from 25 to 36 %, whereas in transgenic species, it ranged from 22 to 7 %. In general, Paulownia species expressing thio-60 displayed increased resistance to F. equiseti, while those expressing thio-63 exhibited heightened resistance to A. niger infection. The thionin proteins displayed a strong affinity for the phospholipid bilayer of the fungal cell membrane, demonstrating their capability to disrupt its structure. The transgenic plants created through this technique showed increased resistance to fungal infections. Thionin-60 demonstrated superior antifungal properties in comparison to thio-63, being more effective at disturbing the fungal cell membrane. These findings indicate that thio-60 holds potential as a novel antifungal agent and presents a promising approach for enhancing the antimicrobial traits of genetically modified Paulownia trees.

Pest categorisation of Shirahoshizo flavonotatus.

The EFSA Panel on Plant Health performed a pest categorisation of Shirahoshizo patruelis (Voss, 1937) (Coleoptera: Curculionidae), following the commodity risk assessment of bonsai plants from China consisting of Pinus parviflora grafted on P. thunbergii, in which S. patruelis was identified as a pest of possible concern to the European Union (EU). This categorisation refers to S. flavonotatus, which is the pest's current valid scientific name. It is native to China and has never been recorded in the EU. It completes from 2 to 3 generations per year. Eggs are laid in cracks and crevices of trunks and branches with bark thickness of approximately 0.6-1.2 cm. The pest overwinters as an adult or as a mature larva under the bark. Plants for planting, wood with bark and wood products provide pathways for entry. Although the weevil has been reported to carry the nematode Bursaphelenchus xylophilus, it is not considered a vector. Climatic conditions and availability of host plants in some EU countries would allow S. flavonotatus to establish and spread. Impact on Pinus spp. is anticipated. Recognising that the weevil is reported to attack both weakened and healthy trees, there is uncertainty on the magnitude of impact. Its recorded capacity to attack non-Asian Pinus species also indicates its ability to adapt and expand the range of trees it can utilise as hosts, which could include European Pinus species. Phytosanitary measures are available to reduce the likelihood of entry and spread. S. flavonotatus meets the criteria that are within the remit of EFSA to assess for this species to be regarded as a potential Union quarantine pest.

Height-diameter models for King Boris fir (Abies borisii regis Mattf.) and Scots pine (Pinus sylvestris L.) in Olympus and Pieria Mountains, Greece

In forest science and practice, the total tree height is one of the basic morphometric attributes at the tree level and it has been closely linked with important stand attributes. In the current research, sixteen nonlinear functions for height prediction were tested in terms of their fitting ability against samples of Abies borisii regis and Pinus sylvestris trees from mountainous forests in central Greece. The fitting procedure was based on generalized nonlinear weighted regression. At the final stage, a five-quantile nonlinear height-diameter model was developed for both species through a quantile regression approach, to estimate the entire conditional distribution of tree height, enabling the evaluation of the diameter impact at various quantiles and providing a comprehensive understanding of the proposed relationship across the distribution. The results clearly showed that employing the diameter as the sole independent variable, the 3-parameter Hossfeld function and the 2-parameter Näslund function managed to explain approximately 84.0% and 81.7% of the total height variance in the case of King Boris fir and Scots pine species, respectively. Furthermore, the models exhibited low levels of error in both cases (2.310m for the fir and 3.004m for the pine), yielding unbiased predictions for both fir (−0.002m) and pine (−0.004m). Notably, all the required assumptions for homogeneity and normality of the associated residuals were achieved through the weighting procedure, while the quantile regression approach provided additional insights into the height-diameter allometry of the specific species. The proposed models can turn into valuable tools for operational forest management planning, particularly for wood production and conservation of mountainous forest ecosystems.

Kajian Alternatif Proyeksi Jaringan Jalan Hutan untuk Perencanaan Pemanenan Kayu di PT Inhutani I Labanan, Propinsi Jawa Barat

Forests are one of the natural resources that can be utilized in the form of both wood and non-wood forest products. Harvesting carried out to extract wood results in negative impacts such as soil damage and damage to standing stands. The negative impacts of wood harvesting can be reduced by planning in advance, such as creating a forest road network. The research was carried out in the mahogany room, utilization division, forest management department, while the assessment of the forest road network used the case study of PT Inhutani I Lebanan. The aim of the research is to examine the planning and selection of the best alternative forest road network for harvesting wood using multi-criteria decision making techniques. The research will be carried out in March 2023. The research stage begins with sketching the road network; assess road networks using economic, ecological and technical criteria; as well as conducting literature studies from various sources. The research results show that there are six alternative forest road networks for harvesting wood. This is based on forest road network assessment parameters that the best alternative road network in the PT Inhutani I Labanan road scheme is the 6th road network alternative. Sustainable management of forest resources can be achieved through a well-planned road network. The highest total utility value (rank 1) is found on the 6th road network which is the best alternative forest road network to be implemented at PT Inhutani Labanan I both in terms of technical aspects, ecological aspects and economic aspects.

Construction Price Index Prediction through ARMA with Inflation Effect: Case of Thailand Construction Industry

Over-budgeting due to inflation is a common phenomenon in the construction industry of both developed and developing countries. Inflation, with time changes, leaves an adverse effect on the project budget. Hence, this study aims to focus on the construction price index (CPI) behavior and inspect its correlation with inflation in Thailand’s construction industry as there has not been much work performed. The prediction of CPI was made from 2024 to 2028, relying on the data set from 2000 to 2023. The relationship between inflation and CPI categories helps in prediction by considering inflation as the independent variable and CPI (All Commodities, Lumber and Wood Products, Cement, and Iron Products) as the dependent variable that was incorporated in EViews to perform automated ARIMA forecasting. The correlation results show that out of four CPI, only Iron Products showed a significant relationship with inflation. For All Commodities, Lumber, and Wood Products, the predicted values were fluctuating, while for Cement and Iron Products, a clear seasonal pattern was observed. This prediction gives a direction to construction industry practitioners to make necessary adjustments to their budget estimation before signing the contract to overcome cost overrun obstruction.

Effects of Different Thinning Intensities on Carbon Storage in Pinus koraiensis Middle-Aged Plantations in Northeast China

Forest ecosystems are essential to the global carbon cycle because they are the biggest terrestrial carbon reserves. In the management of forests, thinning is a commonly employed strategy, impacting the respiration and biomass loss of trees, thereby modifying forest carbon dynamics. However, there is a lack of scientific research to confirm the impacts of thinning intensities on carbon storage in trees, soil layers, shrubs, and ground vegetation layers as well as its impact on wood production and growth rate. The goal of this study was to find the optimal thinning levels for increasing carbon sequestration during the growth stage of the Korean pine (Pinus koraiensis) middle-aged plantations in Northeast China. In this study, thinning intensity (0, 10, 11, 16, 18, and 22%) affected the carbon storage of trees, tree growth, volume, and, we suspected, soil layer, shrubs, and vegetation (herbs, litter, and grass) also. Specifically, after four years of thinning, the 18% treatment significantly increased total carbon storage, individual organ storage, growth, and tree volume (p < 0.05). These results give us abundant information about how thinning affects the dynamics of carbon storage, wood production, and the interactions between soil and plants in P. koraiensis plantations, contributing to multi-objective management strategies for optimizing carbon sequestration, wood production, and ecosystem health.