Wood Volume Research Articles

Understanding the Coleoptera community at the tree‐line using taxonomic and functional guild approaches

Abstract Mountain species are at the forefront of climate change disruption, and montane saproxylic Coleoptera are facing large‐ and small‐scale changes in their surroundings. Saproxylic Coleoptera are both functionally and taxonomically diverse and are the representatives of an imperilled fauna confronted with the realities of a changing landscape. Understanding the effects of elevation and other forest characteristics on saproxylic and non‐saproxylic Coleoptera is a step towards predicting the future of taxonomic and functional group biodiversity at the tree‐line and on mountains. The objective of this study was to examine the effect of elevation and other forest characteristics on the biodiversity of montane Coleoptera at the tree‐line using both taxonomic and functional feeding guild classifications. Our results suggest that abundance of saprotrophs is closely linked to the density of large trees rather than the volume of wood. Edge effects and elevation seem to drive abundance patterns of some species and also influence taxonomic and functional guild community patterns differently. Finally, we discuss the implications of climate change and land abandonment to future Coleoptera community structure.

Individual tree volume estimation with terrestrial laser scanning: Evaluating reconstructive and allometric approaches

Accurate estimates of above-ground tree biomass within forest inventories are essential for calibration and validation of biomass mapping products based on Earth observation data. Terrestrial laser scanning (TLS) enables detailed and non-destructive volume estimation of individual trees, which can be converted to biomass with wood basic density. Existing TLS-based approaches range from simple geometrical features to virtual 3D reconstruction of entire trees. Validating such approaches with weight measurements is a key step before the integration of TLS or other close-range technologies into operational applications such as forest inventories. In this study, we firstly evaluate individual tree volume estimation approaches based on 3D reconstruction through quantitative structure models (QSM) against destructive reference data of 60 trees and compare them to operational allometric scaling models (ASM). Secondly, we determine the explanatory power of TLS-derived geometric parameters regarding total wood, stem, coarse wood and fine branch volume. We observe similar accuracy in merchantable (¿7 cm) wood compartments for ASMs (NRMSE = 25 %) and QSMs (NRMSE = 29 %), with QSMs showing better results for broadleaves than conifers and generally overestimating fine branch volume. Feature selection shows that a combination of stem diameters and volume of convex hulls around tree crowns has the most potential to model the entire tree volume including branches, especially for conifers. In cases where the quality of available point clouds is insufficient for QSMs, 3D information can thus still be utilised by deriving geometric parameters. The integration of crown dimension parameters into new allometric models could substantially improve the estimation of branch wood volume.

Can models for forest attributes based on airborne laser scanning be generalized for different silvicultural management systems?

In Finland, interest in continuous cover forestry (CCF) has increased rapidly in recent years. During those years CCF has been examined from various viewpoints but not from the perspective of forest inventories. This holds especially true for applications based on remote sensing. Conversely, airborne laser scanning (ALS) data have been widely used to predict forest characteristics such as size distribution and vertical forest structure, which are closely related to the forest information needs of CCF.In this study we used the area-based approach to predict a set of stand attributes from ALS data (5 pulses per m2) in a CCF forest management experiment in Katajamäki, eastern Finland. In addition to the CCF stands, the experiment included shelterwood stands and untreated stands. The predicted attributes included volume, biomass, basal area, number of stems, mean diameter, Lorey’s height, dominant height, standing dead wood volume, parameters of the theoretical stem diameter distribution model, understory height and number of understory stems. Our main aim was to test whether the same model could be used across different management systems. The accuracy of the attributes predicted for the CCF stands was compared with the predictions for the other management systems in the same experiment. We also compared and discussed our results in relation to the even-aged stand attribute predictions that were conducted by using separate operational forest data collected from sites surrounding Katajamäki.The results showed that forest data from the different management systems could be combined into a single model of a stand attribute, i.e., ALS metrics were found to be suitable for comparing different management systems in regard to differences in forest structure. The accuracy of the predicted attributes in the CCF plots was comparable to that of the other management alternatives in the experiment. The accuracy was also comparable to that of even-aged forests.The results of this study were promising; the stand attributes of CCF-managed forests could be predicted analogously to those of other management systems. This indicates that for the purposes of forest inventories there may not be a need to stratify forest lands by management system. It should be noted, however, that the study area was relatively small, that the forest stands were harvested in the 1980 s, and that the attributes may not have been completely exhaustive for CCF.

Energy and quality analysis of forced convection air-energy assisted solar timber drying

Discontinuities due to weather conditions and daylight affect solar drying, so to address that, a working mechanism of air energy-assisted solar drying was developed in this study. An air-energy assisted solar dryer was used to dry timber, from a green average moisture content of 183%–11.3% in 161.5 h, where the moisture diffusion coefficient ranged from 1.28 ×10-10 m2/s to 6.41 ×10-9 m2/s. The effective solar radiation intensity during drying ranged from 221.3 to 750.3 W/m2. The overall drying efficiency was 30.7%, and the effective solar heat supply ratio was 58.5%. The specific moisture extraction rate and specific energy consumption were measured within a range of 0.32–3.0 kg/kWh and 924 - 11390 kJ/kg, respectively. The average power consumption per m3 of wood volume was 254.2 kW h/m3. The results showed that the energy-assisted solar dryer was suitable for a condition with low radiation and various weather conditions.

Beyond the Case Study: Characterizing Natural Floodplain Heterogeneity in the United States

AbstractWe use the five landscape ecology metrics of aggregation index, percentage of like adjacencies, interspersion and juxtaposition index, patch density, and Shannon's evenness index to assess spatial heterogeneity at 15 floodplains in the continental United States. Assessments are based on floodplain classes and patches delineated remotely using topography and vegetation. Floodplain reaches examined here represent diverse drainage areas, flow regimes, valley geometries, channel planforms, and biomes. We selected sites with minimal direct human alteration. Our objectives are to quantify floodplain spatial heterogeneity; evaluate whether statistically significant patterns are present; and interpret the statistical analyses with respect to the influence of lateral channel mobility and valley‐floor space available. We develop a conceptual model of the influences on lateral mobility and space available, and then test specific hypotheses derived from this conceptual model. These natural floodplains have a median aggregation index of 58.8%, median percentage of like adjacencies of 58.5%, median interspersion and juxtaposition index of 74.9%, median density of 1,241 patches/ha, and median Shannon's evenness index of 0.934 (n = 15). In other words, natural floodplains have moderate aggregation of classes, high evenness and intermixing of classes, and a wide range of patch densities. Drainage area, the ratio of floodplain/channel width, elevation, precipitation, total sinuosity, large wood volume, planform, and flow regime emerge as important variables to floodplain heterogeneity. These results highlight the influence of biotic‐abiotic interactions in shaping floodplain heterogeneity across diverse river corridors.

New Technologies for Expedited Forest Inventory Using Smartphone Applications

The forest inventory plays a crucial role in forest management planning, and it is the first step in planning actions for forest production. However, conducting an inventory can be expensive and complex. Forest inventory applications on smartphones have emerged as an alternative to traditional methods and they aim to make field data collection more accessible to non-professionals while ensuring accuracy in determining the volume of wood in a given area. This study evaluates the effectiveness of the Katam, Arboreal, and Trestima applications compared to traditional data collection methods. The study focuses on assessing the stand density and diameter of sampled trees—two key variables that are assessed in forest inventories. Two species, maritime pine (Pinus pinaster Aiton) and Eucalyptus spp. (mainly Eucalyptus globulus and Eucalyptus nitens), were used to evaluate the performance of the methods, with assessments performed in the stands of diverse dendrometric characteristics, specifically those regarding the tree age, stand density, and topographic conditions (flat or sloping terrain). For the purpose of comparison, goodness-of-fit statistics (R2, RMSE, and BIAS) were calculated, and an analysis of the diameter distribution and comparison of the mean diameter, number of trees per hectare, and basal area were performed. In general, the applications were accurate, and the average basal area did not differ significantly from the traditional method. The diameter measurements showed good accuracy. The accuracy of the applications varied depending on the terrain and forest characteristics, with the applications performing better in areas with flat terrain, as well as with older forests that were regular and had low under-cover density. In contrast, the applications performed worse in younger, irregular forests with sloping terrain, high tree density, and those with a great deal of understory vegetation. The applications still need to evolve in evaluating other important variables (such as tree height or volume) as they are currently estimated from auxiliary variables through mathematical equations.

Mimosa caesalpiniifolia Benth. as an alternative for wood production in Northeast Brazil

Mimosa caesalpiniifolia is a native species from Northeast Brazil, with good soil and climate adaptation, fast growth and potential for multiple use. Because of these characteristics, it has been considered a promising species for forestry. This work aimed to evaluate the growth and productivity of Mimosa caesalpiniifolia at 75 months of age, in a homogeneous plantation located in the state of Rio Grande do Norte, Northeastern Brazil. The data were collected in a 0.05 ha plot with 84 individuals, submitted to thinning at 12 and 55 months. The variables height (H), diameter at breast height (DBH), and diameter at base (DAB) were evaluated. The productivity of the plantation was estimated in terms of total volume (m3) and stacked volume (st), number of stems and mean annual increment (MAI). On average, the individuals were 4.85 m tall, 12.05 cm in diameter at the base (DAB) and 8.42 cm DBH. Each individual presented an average of 6.07 stems. The estimated productivity was 43.88 m³ ha-1, with MAI of 7.02 m³ ha-1 year-1, and the estimated stacked wood volume was 111.89 st ha-1. The results showed the high potential of the species for the production of stakes and fence posts, as well as for the production of kindling and firewood, aiming at the use of all the biomass produced. Therefore, the planting of this species for the production of wood serves as an alternative to meet demands in the Northeast of Brazil.

Assessing the Use of Burn Ratios and Red-Edge Spectral Indices for Detecting Fire Effects in the Greater Yellowstone Ecosystem

Burn severity is commonly assessed using Burn Ratios and field measurements to provide land managers with estimates of the degree of burning in an area. However, less commonly studied is the ability of spectral indices and Burn Ratios to estimate field-measured fire effects. Past research has shown low correlations between fire effects and Landsat-derived Burn Ratios, but with the launch of the Sentinel-2 constellation, more spectral bands with finer spatial resolutions have become available. This paper explores the use of several red-edge-based indices and Burn Ratios alongside more ‘traditional’ spectral indices for predicting fire effects, measured from the Maple and Berry fires in Wyoming, USA. The fire effects include ash depth, char depth, post-fire dead lodgepole pine (Pinus contorta; PICO) density/stumps, mean basal diameter, cone density on dead post-fire trees, coarse wood percent cover/volume/mass, percent cover of ghost logs and initial regeneration of post-fire PICO/aspen density. All-possible-models regression was used to determine the best models for estimating each fire effect. Models with satisfactory R2 values were constructed for post-fire dead PICO stumps (0.663), coarse wood percent cover (0.691), coarse wood volume (0.833), coarse wood mass (0.838), ash depth (0.636) and percent cover of ghost logs (0.717). Red-edge-based indices were included in all of the satisfactory models, which shows that the red-edge bands may be useful for measuring fire effects.

Classification of waste wood categories according to the best reuse using FT-NIR spectroscopy and chemometrics

In Europe, the volume of waste wood is increasing. Waste wood can be reused, promoting circular economy and avoiding landfills. It can be used as a bioenergy feedstock reducing the use of fossil fuels, or be reused for producing new composite wood material. Only wood with hazardous substances needs to be disposed. To this aim waste wood samples were collected from a panel board company and several recycling centres in Italy and Denmark. The samples were assigned to waste wood categories and analysed by Near Infrared Spectroscopy. Principal Component Analysis was used to investigate sample variability and Soft Independent Modelling of Class Analogies (SIMCA) for classifying the samples according to the appropriate reuse: energy production, panel board production or landfill. The results are good, with a classification rate of 90% for virgin wood material and 86.7% for treated wood material. The classification of waste wood is key for turning it into a secondary resource.

Energy aspects of Eucalyptus saligna wood in a seven-year-old plantation

The objective of this study was to characterize the energy parameters of wood and energy production from a seven-year-old experimental plantation of Eucalyptus saligna. For this purpose, information was collected from an experimental planting spaced at 3.0 m x 3.0 m in Chapadão do Sul, MS, Brazil. Values were obtained for the diameter and height of the trees, which were felled and rigorously cubed to obtain the volumes of wood. Wood and plantations were characterized in relation to: proximate chemical, calorific value, wood basic density and annual production of wood and energy. Trees and planting were able to yield satisfactory estimates of energy production in relation to annual wood production. The immediate chemical composition of the wood was 82.85%, 17.07% and 0.08% for volatile materials, fixed carbon and ash, respectively. The evaluated woods can be classified as medium basic density, and can be recommended for use with energy purposes. Therefore, the evaluated E. saligna woods showed results that characterize these materials as suitable for energy use, with potential for the production of energy forests. In this way, they can meet the demands of forest biomass for this purpose.

Ecological and economic aspects оf the development of ancillary forest use

The article analyzes and defines the ecological and economic aspects of the development of secondary forest use, as they are important for the balanced use of forest resources. Secondary forest use refers to the use of forests for the purpose of obtaining additional products between the main activities of forestry, such as firewood, forest fruits, mushrooms, herbs and other non-timber resources. It is substantiated that the minimization of the impact on the forest landscape is a key aspect of the ecological efficiency of secondary forest use. It has been determined and proven that current accounting of resources involves the systematic tracking and assessment of available forest resources, which may include measuring the volume of wood, studying the condition of forest lands, determining the presence and distribution of plants, fungi and other resources, as well as assessing their growth and reproduction.

Competition-based mortality and tree losses. An essential component of net primary productivity

Even-aged stands can regenerate with many thousand seedlings per hectare before the density declines to just a few hundred trees per hectare 100 years later; management practices can lead to even lower tree numbers due to quality selection and thinning. In other words, during the development of unmanaged stands, the majority of individuals die naturally due to competition. Despite the far-reaching consequences for structural and genetic diversity, dead wood and fuel wood accumulation, we have only limited quantitative knowledge about the continuous mortality of trees and the wood volume loss over longer timespans.For this study, we used a unique set of 476 unmanaged, monospecific experimental plots of Norway spruce (Picea abies (L.) H. Karst.), silver fir (Abies alba Mill.), Scots pine (Pinus sylvestris L.), European larch (Larix decidua Mill.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)), European beech (Fagus sylvatica L.), and oak (Quercus robur L. and Quercus petraea (Matt.) Liebl.) throughout Europe to analyze the competition-based mortality of trees and its dependency on age and site conditions.First, we show that the total stem volume production, standing stock, and mortality were continuously increasing until an age of 100–150 years. The accumulated competition-caused stem volume loss at that age amounted to 500–1000 m3 ha−1.Second, the net growth of the stands (share of the growth that is accumulated in the standing stock) strongly decreased with increasing age even when the gross growth was still high. The proportion of the net growth versus gross growth continuously decreased with increasing age regardless of site quality.Third, we show a degressive decrease of the annual relative tree number mortality rates from 0.05 to 0.20 in young down to 0.01–0.02 in mature stands. For some species, we found these rates to be site dependent with different directions of the site effect. The interplay of decreasing mortality rates and increasing average volume of the dead trees resulted in unimodal mortality curves over time of the annual mortality, peaking at 3–12 m3 ha−1 yr−1 at ages of about 75–150 years.Over the whole rotation, the average annual biomass loss from mortality ranged between 0.8 and 2.1 t ha−1 yr−1 with a carbon content of 0.4–1.1 t C ha−1 yr−1. We discuss the relevance of the results for measuring, understanding, modelling, and managing forest stands. Our results reveal that the withdrawal of forest management and setting aside (previously managed) forests over a rotation time of 100–150 years means that about one third of the total production in monospecific stands would flow to the debris pool rather than being exploited for carbon sequestration and related emission savings in harvested wood products. The mortality related loss fractions of above ground biomass we quantified in this study indicate the trade-off between wood production and setting aside forest to allow deadwood accumulation and associate changes in biodiversity.

Geospatial modelling of large-wood supply to rivers: a state-of-the-art model comparison in Swiss mountain river catchments

Abstract. Different models have been used in science and practice to identify instream large-wood (LW) sources and to estimate LW supply to rivers. This contribution reviews the existing models proposed in the last 35 years and compares two of the most recent geographic information system (GIS)-based models by applying them to 40 catchments in Switzerland. Both models, which we call here the empirical GIS approach (EGA) and fuzzy-logic GIS approach (FGA), consider landslides, debris flows, bank erosion, and mobilization of instream wood as recruitment processes and compute volumetric estimates of LW supply based on three different scenarios of process frequency and magnitude. Despite being developed following similar concepts and fed with similar input data, the results from the two models differ markedly. In general, estimated supply wood volumes were larger in each of the scenarios when computed with the FGA and lower with the EGA models. Landslides were the dominant process identified by the EGA, whereas bank erosion was the predominant process according to the FGA model. These differences are discussed, and results are compared to available observations coming from a unique database. Regardless of the limitations of these models, they are useful tools for hazard assessment, the design of infrastructure, and other management strategies.

Effects of air-plasma treatment in enhancing the mechanical properties of oriented strand boards

In this work, through surface modification of poplar strands with a non-thermal type of plasma, we produced oriented strand board (OSB) panels with high loading capacity (fabricated with a target density of 0.7 g/cm3 and phenol-formaldehyde resin in a content of 7%). At the processing power of 4.5 kW, the plasma-induced efficient etching effect and chemical grafting contributed greatly to improving the wettability of strands surfaces, resulting in the 68.3% increase of resin coverage and the formation of consecutive bond-lines within the structures of OSB. Furthermore, the adhesive distribution within wood surface layers and adhesion efficiency were intensively analyzed by means of X-ray computed tomography imaging, the results demonstrated that the plasma-based surface modification considerably increased the penetration depth of the resin into the wood volume, making it easier to form mechanical interlocking in wood-resin interphase. Further nanoindentation analysis on the resin-infiltrated cell walls revealed the substantial reinforcement of bonding interphase after plasma modification. In bonding performance tests, the internal bond strength of plasma-modified OSB reached up to 1.22 MPa, nearly 3.6 times the value recommended by ISO 16894: OSB panels type 4. Meanwhile, the loadbearing property was improved significantly, which was not only reflected in the enhanced bending strength and elastic modulus, but was also confirmed by strain distribution along the thickness direction recorded using digital image correlation technique.

Host plant selection by Cerambycidae in two different strata in association with seasonality and physical wood characteristics in a tropical dry forest

Abstract1. There is little information on tropical dry forests regarding cerambycids and their relationship with seasonality, vertical stratification, and physical characteristics of the wood they require to develop.2. In this work, we determined whether cerambycids in a tropical dry forest of central Mexico differed in the selection of oviposition sites in two different strata throughout two seasons; the relationship between the time of exposure of branches and the emergence of cerambycids; the emergence of these insects in relation to the physical characteristics of the wood and its relationship with stratification and seasonality; and if there was a seasonal shift between strata by cerambycids. Branch segments from 81 woody plant species were cut and exposed to allow the cerambycids to oviposit; the branches were harvested in four 2‐month periods and placed in emergence chambers. For each plant species, we measured the density, decomposition rate, and offered volume of wood.3. There was a greater quantity of generalist species of stratum (15) and season (12), and we found six important habitat indicator species: three species were significantly associated with the canopy and the dry season, two species preferred the dry season but not strata, and one species preferred both strata in the dry season and the ground during the rainy season. Cerambycid species generally selected soft and ephemeral wood resources.4. Branch selection by cerambycids in Central Mexico is not random choice; it is determined by season, stratum, density, and especially by host type, decomposition, and volume. Finally, there is a greater abundance of cerambycids in the ground and a greater richness of species in the canopy.

Identification and Trend Analysis of Multistorey Timber Buildings in the SUDOE Region

The construction sector has one of the most polluting economic activities. In this context, several policies are being launched by the European Union to promote the transition to a sustainable economy, and timber construction is a safe way to contribute to it. Due to the recent development of multistorey timber buildings, the architectural and structural typologies have not been widely studied yet and with not many studies from Southern Europe. In this context, the main objective of this research is to identify and analyse the trends in the use of wood as a structural material in multistorey timber buildings (≥4 floors) in the SUDOE region, i.e., Spain, Portugal, and Southwest France. The methodology involved identifying 28 timber buildings in the SUDOE region and 101 worldwide, most of them in Europe, and sending online information request forms to different actors involved in their design and construction, collecting plans and BIM models, and performing technical study visits to the identified reference buildings. The collected information was included in open-access technical datasheets, and different indicators in terms of building uses, structural system, wood species, and wood volume, among others, were defined. The results showed that there is a tendency to construct taller timber buildings in the SUDOE region with a predominant use of local softwood species, with ratios of wood volume per built area varying between 0.3 and 0.4 m3/m2. The mass timber typology using cross-laminated timber (CLT) is mainly used for residential buildings, while post and beam are used for educational and offices buildings. In addition, a potential embodied CO2 equivalent depending on the building typology and use was also analysed.

Owls’ responses to forest conservation in the Alps

Abstract As inhabitants of cavities, some owl species benefit from natural processes, different tree compositions and higher volumes of dead wood. We assumed that protected areas would have a positive impact on the owl community. We compared the abundance of calling owls on 22 lines in managed versus protected forests. Here, we recorded the acoustic communication of owls. The composition of the owl community did not differ between areas. However, we found the impact of forest landscape integrity index and altitude on the diversity of owls. Forests in protected areas probably need time to develop natural and heterogeneous habitat structures. The conservation priority should be to increase the integrity of the forests. Our results also confirmed that managed forests can have a high diversity of owls.

Automatically Extracting Rubber Tree Stem Shape from Point Cloud Data Acquisition Using a B-Spline Fitting Program

Natural rubber is an important and strategic raw material, used in tires, gloves, and insulating products, that is mainly obtained by cutting the bark of rubber trees. However, the complex contour curve of the rubber tree trunk is hard to fit using a tapping machine. Thus, a trunk contour curve collection would be useful for the development of tapping machines. In this study, an acquisition system based on laser-ranging technology was proposed to collect the point cloud data of rubber tree trunks, and a B-spline fitting program was compiled in Matrix Laboratory (MATLAB) to extract the trunks’ contour curves. The acquisition system is composed of power, a controller, a driver, a laser range finder, and data transmission modules. An automatic extraction experiment on the contour curves of rubber tree trunks was carried out to verify the feasibility and accuracy of using the acquisition system. The results showed that the degree of rubber tree trunk characteristic recognition reached 94.67%, which means that the successful extraction of the rubber tree trunk contour curves and the B-spline fitting program are suitable for the extraction of irregular curves of rubber tree trunks. The coefficient of variation of repeated collection was 0.04%, which indicates that changes in relative positions and acquisition directions have little influence on the extraction and the accuracy of the acquisition system, which are high and stable. Therefore, it was unnecessary to adjust the position of the acquisition device before the collecting process, which helped to improve the efficiency of acquisition considerably. The acquisition system proposed in this study is meaningful to the practical production and application of agroforestry and can not only improve the precision of the rubber tapping process by combining with an automatic rubber tapping machine but can also provide technical support for the prediction of rubber wood volume and the development of ring-cutting equipment for other fruit trees.

Comparison of four alternative survey methods in assessing dead wood at the stand level

ABSTRACT Many forestry practitioners need information on the amount of dead wood for various purposes, often at the level of individual stands. Our aim was to compare four simple dead-wood inventory methods of which systematic circular plot inventory is a well-known method, while relascope plot inventory (using the ordinary horizontal angle relascope also for downed trees), diameter class counting and total inventory are new methods. Seven surveyors tested the methods in four stands in southern Finland. All the methods produced rather accurate volume estimates. Mean percent error was the smallest (−5.7%) in total inventory and the largest (−12.4%) in diameter class counting. Precision differed significantly between the methods. Variation among individual measurements, expressed as percentage SD, was 15.9% in total inventory, 24.8% in diameter counting, 36.6% in relascope inventory and 43.0% in circular plot inventory. Diameter counting was by far the fastest method. Relascope inventory and circular plot inventory took about twice as much time, and total inventory over three times as much time as diameter counting. In conclusion, diameter class counting is a cost-effective dead-wood assessment method, if the purpose is to get an estimate of the total volume of dead wood within a forest stand with a reasonable precision.

Wood xerogel for fabrication of high-performance transparent wood

Optically transparent wood has been fabricated by structure-retaining delignification of wood and subsequent infiltration of thermo- or photocurable polymer resins but still limited by the intrinsic low mesopore volume of the delignified wood. Here we report a facile approach to fabricate strong transparent wood composites using the wood xerogel which allows solvent-free infiltration of resin monomers into the wood cell wall under ambient conditions. The wood xerogel with high specific surface area (260 m2 g–1) and high mesopore volume (0.37 cm3 g–1) is prepared by evaporative drying of delignified wood comprising fibrillated cell walls at ambient pressure. The mesoporous wood xerogel is compressible in the transverse direction and provides precise control of the microstructure, wood volume fraction, and mechanical properties for the transparent wood composites without compromising the optical transmittance. Transparent wood composites of large size and high wood volume fraction (50%) are successfully prepared, demonstrating potential scalability of the method.