Search Results (189)

Forest volume is an important information for assessing the economic value and carbon sequestration capacity of forest resources and serves as a key indicator for energy flow and biodiversity. Although remote sensing technology is applied to estimate volume, optical remote sensing data have limitations in capturing forest vertical height information and may suffer from reflectance saturation. While LiDAR data can provide more detailed vertical structural information, they come with high processing costs and limited observation range. Therefore, improving the accuracy of volume estimation through multi-source data fusion has become a crucial challenge and research focus in the field of forest remote sensing. In this study, we integrated Sentinel-2 multispectral data, Resource-3 stereoscopic imagery, UAV-based LiDAR data, and field survey data to quantitatively estimate the forest volume in Saihanwula Nature Reserve, located in Inner Mongolia, China, on the southern part of Daxing’anling Mountains. The study evaluated the performance of multi-source remote sensing features by using recursive feature elimination (RFE) to select the most relevant factors and applied four machine learning models—multiple linear regression (MLR), k-nearest neighbors (kNN), random forest (RF), and gradient boosting regression tree (GBRT)—to develop volume estimation models. The evaluation metrics include the coefficient of determination (R²), root mean square error (RMSE), and relative root mean square error (rRMSE). The results show that (1) forest Canopy Height Model (CHM) data were strongly correlated with forest volume, helping to alleviate the reflectance saturation issues inherent in spectral texture data. The fusion of CHM and spectral data resulted in an improved volume estimation model with R² = 0.75 and RMSE = 8.16 m³/hm², highlighting the importance of integrating multi-source canopy height information for more accurate volume estimation. (2) Volume estimation accuracy varied across different tree species. For Betula platyphylla, we obtained R² = 0.71 and RMSE = 6.96 m³/hm²; for Quercus mongolica, R² = 0.74 and RMSE = 6.90 m³/hm²; and for Populus davidiana, R² = 0.51 and RMSE = 9.29 m³/hm². The total forest volume in the Saihanwula Reserve ranges from 50 to 110 m³/hm². (3) Among the four machine learning models, GBRT consistently outperformed others in all evaluation metrics, achieving the highest R² of 0.86, lowest RMSE of 9.69 m³/hm², and lowest rRMSE of 24.57%, suggesting its potential for forest biomass estimation. In conclusion, accurate estimation of forest volume is critical for evaluating forest management practices and timber resources. While this integrated approach shows promise, its operational application requires further external validation and uncertainty analysis to support policy-relevant decisions. The integration of multi-source remote sensing data provides valuable support for forest resource accounting, economic value assessment, and monitoring dynamic changes in forest ecosystems. Full article

Chile is among the leading global exporters of pulp and paper, supported by extensive plantations of Pinus radiata and Eucalyptus spp. This review synthesizes recent progress in the valorization of forestry biomass in Chile, including both established practices and emerging bio-based applications. It highlights advances in lignin utilization, nanocellulose production, hemicellulose processing, and tannin extraction, as well as developments in thermochemical conversion technologies, including torrefaction, pyrolysis, and gasification. Special attention is given to non-timber forest products and essential oils due to their potential bioactivity. Sustainability perspectives, including Life Cycle Assessments, national policy instruments such as the Circular Economy Roadmap and Extended Producer Responsibility (REP) Law, are integrated to provide context. Barriers to technology transfer and industrial implementation are also discussed. This work contributes to understanding how forestry biomass can support Chile’s transition toward a circular bioeconomy. Full article

Monoculture plantation systems face increasing challenges in sustaining ecosystem multifunctionality (EMF) under intensive management and climate change, with long-term functional trajectories remaining poorly understood. Although biodiversity–EMF relationships are well-documented in natural forests, the drivers of multifunctionality in managed plantations, particularly age-dependent dynamics, require further investigation. This study examines how stand development influences EMF in Castanopsis hystrix L. plantations, a dominant subtropical timber species in China, by assessing six ecosystem functions (carbon stocks, wood production, nutrient cycling, decomposition, symbiosis, and water regulation) of six forest ages (6, 10, 15, 25, 30, and 34 years). The results demonstrate substantial age-dependent functional enhancement, with carbon stocks and wood production increasing by 467% and 2016% in mature stand (34 year) relative to younger stand (6 year). Nutrient cycling and water regulation showed intermediate gains (6% and 23%). Structural equation modeling identified plant diversity and microbial community composition as direct primary drivers. Tree biomass profiles emerged as the strongest biological predictors of EMF (p < 0.01), exceeding abiotic factors. These findings highlight that C. hystrix plantations can achieve high multifunctionality through stand maturation facilitated by synergistic interactions between plants and microbes. Conservation of understory vegetation and soil biodiversity represents a critical strategy for sustaining EMF, providing a science-based framework for climate-resilient plantation management in subtropical regions. Full article

The aim of this study was to evaluate the suitability of eight softwood species most commonly used by Greek timber industries, including furniture manufacturers and companies producing roundwood, sawn timber, and plywood. The analysis was based on integrated Multi-Criteria Decision Analysis (MCDA), using a combined approach of the PROMETHEE method and the Analytical Hierarchy Process (AHP), taking into consideration some important criteria that affect timber quality. According to the PROMETHEE complete ranking, Aleppo pine (Pinus halepensis Mill.) achieved the best performance under the selected criteria among the examined softwood species, underlying the importance of Aleppo pine to the Greek timber industry. Our findings could be highly beneficial to the wood industry, promoting the recovery and advancement of the forest sector in general, taking into account that sustainable wood supply is lower than the total biomass available in Europe. Policymakers should prioritize the selection of conifer tree species that can strengthen Greece’s forestry sector, promote sustainable management practices, and increase the economic value derived from the country’s diverse forest resources. Full article

The objectives were to evaluate the energy potential of biomass and pellets produced from five underutilized herbaceous and woody plant species in México and Colombia; characterize pellet quality parameters; and calculate the preliminary production costs and energy requirement during the densification process. Harvest and sawmill residues were obtained for five non-timber and woody plant species. The volatile compounds, ash, and fixed carbon were evaluated, as well as the higher heating value (HHV) and pellet impact resistance (PIR); in addition, lignin, hemicellulose, and cellulose were quantified. The data were analyzed using descriptive statistics, including mean and standard deviation. The volatile compounds ranged from 65.9–77.5%, ash 2.5–17.2%, fixed carbon 5.4–19.9%, HHV 16.4–21.9 MJ kg⁻¹, and PIR (0.6–99.1%). Considerable intra- and inter-specific differences were observed for all the variables, which expanded the options for the selection of biomass sources used in bioenergy production. Biomass processing costs ranged from 675.9 to 679.3 EUR t⁻¹. Optimization of these processes is required to implement more efficient technologies that significantly reduce operating costs in biomass use in biofuel industry. The systematic study of different plant species, both introduced and native, will provide new sources of biomass to produce bioenergy, fertilizers, and other organic inputs. Full article

It is essential to emphasize the significant impacts of climate change, which are evident in the form of severe and prolonged droughts, hurricanes, snowstorms, and other climatic disturbances. These challenges are particularly pronounced in urban environments and among human populations. The situation is further aggravated by the increasing utilization of available open spaces for residential and industrial development, leading to heightened energy consumption, elevated pollution levels, and increased carbon emissions, all of which negatively affect public health. The primary objective of this review article is to provide a comprehensive evaluation of current research, with a particular focus on the innovative use of residual biomass from urban vegetation for biochar production in the United States. This research entails an exhaustive review of existing literature to assess the implementation of a carbon-negative wood biomass biochar system as a strategic approach to sustainable urban management. By transforming urban wood waste—including tree trimmings, construction debris, and storm-damaged timber—into biochar through pyrolysis, a thermochemical process that sequesters carbon while generating renewable energy, we can leverage this valuable resource. The resulting biochar offers a range of co-benefits: it enhances soil health, improves water retention, reduces stormwater runoff, and lowers greenhouse gas emissions when applied in urban green spaces, agriculture, and land restoration projects. This review highlights the advantages and potential of converting urban wood waste into biochar while exploring how municipalities can strengthen their green ecosystems. Furthermore, it aims to provide a thorough understanding of how the utilization of woody biomass biochar can contribute to mitigating urban carbon emissions across the United States. Full article

The Miombo woodlands are declining in both area and value, primarily due to over-harvesting of commonly preferred species. These forests, however, still contain several other species that are potentially of commercial importance. This study aimed to address the need for improved volume and biomass estimates for the sustainable management and utilization of two of the most abundant timber species in Mozambique’s Miombo woodlands: Brachystegia spiciformis (common name: Messassa) and Julbernardia globiflora (common name: red Messassa). Non-linear models were developed to estimate the merchantable wood volume under bark, heartwood volume, and biomass. The volume and biomass models for wood and heartwood volume, which included both diameter at breast height (DBH) and tree height as predictor variables, outperformed single-predictor models. However, the performance of some ratio models using DBH as the only predictor variable surpassed that of models using two predictor variables. The developed models are recommended for adoption by forest companies to increase economic and environmental benefits as they can refine harvest planning by improving the selection of trees for harvesting. Proper tree selection enhances the rate of recovery of high-quality timber from heartwood while observing sustainable forest management practices in Miombo and increasing the proportion of carbon removed from forests, which is subsequently stored in wood products outside the forest. Full article

Ochroma lagopus Swartz is a rapidly growing plant known for its lightweight wood; it is widely utilized for timber production and ecological restoration. We investigated the effects of different numbers of drought–rehydration cycles on O. lagopus seedlings cultivated at the Xishuangbanna Tropical Botanical Garden of the Chinese Academy of Sciences. The experiment comprised three treatments: normal watering (CK, 80–85% field capacity), one drought–rehydration cycle (D1, one rewatering), and three drought–rehydration cycles (D2, three rewaterings). We characterized the effects of these treatments on seedling growth, biomass allocation, non-structural carbohydrates (NSCs), malondialdehyde (MDA), catalase (CAT) activity, peroxidase (POD) activity, superoxide dismutase (SOD) activity, proline content, and soluble protein content. The number of drought–rehydration cycles had a significant effect on the growth characteristics and physiological and biochemical properties of leaves. As the number of drought–rehydration cycles increased, the height increased significantly (by 17.17% under D2). The leaf biomass ratio, soluble sugar content, and starch content decreased (15.05%, 15.79%, and 46.92% reductions under the D2 treatment); the stem biomass ratio and root biomass ratio increased; CAT activity increased and then decreased (it was highest at 343.67 mg·g⁻¹·min⁻¹ under D1); and the POD and SOD activities, the MDA content, the soluble protein content, and the soluble sugar/starch ratio increased significantly (395.42%, 461.82%, 74.72%, 191.07%, and 59.79% higher under D2). The plasticity of growth was much greater than that of physiological and biochemical traits. In summary, O. lagopus seedlings adapted to multiple drought–rehydration cycles by increasing the accumulation of soluble proteins (likely associated with osmotic protection), activating enzymes (POD and SOD), promoting the conversion of NSCs (increasing stored carbon consumption), and allocating more biomass to plant height growth than to diameter expansion. Under climate change scenarios with intensified drought frequency, elucidating the drought resistance mechanisms of O. lagopus is critical to silvicultural practices in tropical plantation. Full article

Pollarding is an ancient agroforestry practice that greatly contributes to the sustainability of farming but is slowly becoming extinct because traditional pollards are not viable from a financial and social viewpoint. In particular, the cutting of pollards is too slow, expensive and dangerous for modern farmers to apply. This study presents the first test of mechanized pollarding, performed with two different devices: a set of shears and a disc saw. Both devices were fitted to the boom tip of a tracked excavator and were tested on poplar rows in a typical alley-cropping system. The introduction of those simple devices restored productivity and safety to pollarding as a modern practice. Tree topping incurred a cost around 1 € tree⁻¹, or 250–350 € ha⁻¹. This cost would need to be balanced against the revenue obtained from the treetops sold as biomass and the increased yields of the alley crop, prolonged for several years. Mechanization also allows cutting the treetops several metres above ground level, so that the trunks of the pollarded trees may yield valuable timber when they are eventually harvested. Full article

The enhanced use of wood residues from the timber industry contributes to mitigating the global climate crisis. Currently, bark, a by-product of the timber industry, is primarily burned for thermal energy generation. However, with the growing demand for lignocellulosic products and the emphasis on extending life cycles, it would be more beneficial to prioritize substantial uses of bark over thermal utilization. Although numerous methods for substantial bark utilization have been explored, a significant untapped potential remains. The extractives obtained through water extraction, for instance, can be applied to various further uses like biopolymers or medical applications. This study investigates the impact of hot water extraction on the mechanical and physical properties of bark-based panels, with the aim of extending the life cycle of tree bark and its valorization in bio-based composites. The findings demonstrate that hot water extraction can enhance the bending properties (modulus of rupture, modulus of elasticity) of bark-based panels. Additionally, the extractives obtained from the process have potential applications in the pharmaceutical and adhesive industries. The study also includes an LCIA that highlights the differences between the three scenarios addressed in this research, namely energy generation from bark-based biomass, extraction of bark, and use of extracted bark residues in the production of bark-based particleboard. Full article

Chinese fir (Cunninghamia lanceolata) is an important fast-growing tree species for timber production and ecological protection in China. Yet, its tissue culture for seedling propagation is hampered by low proliferation and poor quality. Light quality is vital for seedling proliferation and growth, but the regulatory mechanisms remain poorly understood. In this study, a transcriptome and metabolome were integrated to explore light quality’s effects on adventitious shoot proliferation of tissue-cultured Chinese fir seedlings. The seedlings were grown under red, green, blue, and composite light-emitting diode conditions, with white light as the control. Results showed that blue and blue-dominant composite light enhanced proliferation by promoting auxin and cytokinin and increased biomass. Red light promoted shoot height, leaf area, and carotenoid content due to elevated gibberellin and reduced auxins and cytokinin levels but inhibited proliferation due to hormonal imbalances. Green light increased abscisic acid levels and suppressed growth. Transcriptome and metabolome analyses identified key pathways including plant hormone signal transduction, photosynthesis, and flavonoid and carotenoid biosynthesis. Weighted gene co-expression network analysis (WGCNA) identified four key genes regulated by light quality that further modulated hormone biosynthesis and signaling transduction. This research provided insights for optimizing Chinese fir seedling proliferation and growth, contributing to sustainable plantation management. Full article

Forest management can be implemented for various demands, including biomass or energy production, biodiversity conservation, carbon sequestration, and ecosystem services, all related to forest utilisation and sustainability. However, these demands can conflict, with biomass production potentially hindering biodiversity conservation, and a focus on climate mitigation or ecosystem services possibly limiting wood production. The aim of the present study was to review the literature related to these conflicts and identify best practices for balancing demands in the context of policies and management tools in the European Union (EU). We found that while EU policies promote sustainability, there is insufficient integration between the biodiversity, carbon storage, and biomass production objectives. We additionally found that by integrating datasets and models, such as by interconnecting models for carbon dynamics, biodiversity, and biomass production, predictions and hence workarounds for addressing these competing demands can be more accurate. Based on these findings, we recommend adopting a more holistic approach in forest management strategies, considering both ecological and socio-economic factors for long-term sustainability. This review provides insights for policymakers, forest managers, and other stakeholders, for navigating the trade-offs between different forest ecosystem services, and for supporting informed decision-making in the development of effective forest policies. Full article

The amended European Union (EU) Renewable Energy Directive—in aiming to increase the share of renewable energy in overall energy consumption—promotes an increased demand for wood, while the EU’s updated Land Use, Land-Use Change, and Forestry (LULUCF) Regulation sets ambitious, binding national targets for the increase in net greenhouse gas removals that could restrict the supply of wood. Additionally, the ongoing war in Ukraine has directly affected the availability of woody biomass in Europe through the EU’s import ban on timber and timber products from Russia and Belarus. This paper provides an in-depth comparative analysis of sources and uses of woody biomass in four European regions in light of these recent climate and energy policies and geopolitical developments. The analysis indicates significantly underestimated reported removals in three of the four European regions studied. Further, projections suggest policy incoherence between current climate and energy objectives until 2030 in all four regions, as fellings increase at a faster rate than net annual increment in all four regions, decreasing the forest carbon sink and thus making it all but impossible to reach the 2030 target of the LULUCF regulation. However, between 2030 and 2040, energy-related fellings could decrease in regions north and west, while they could continue to grow in regions east and south, albeit at a lower rate. Full article

Mapping potential fire intensity is a fundamental tool for fire management planning. Despite the wide use of Fire Radiative Power (FRP) as an indicator of expected fire intensity and fire emissions, very few studies have spatially analyzed the role of remotely sensed proxies of vegetation productivity to explain FRP. The current study aimed at modeling and mapping the relationships between aboveground biomass and Moderate Resolution Imaging Spectroradiometer (MODIS) maximum FRP, at 1 km pixel, in 2011–2020, for each of 46 fuel regions in the entirety of Mexico. Maximum FRP–biomass relationships supported a novel hypothesis of varying constraints of fire intensity. In lower-productivity areas, such as semiarid shrub- and grass-dominated ecosystems, fine fuel loads limited fire occurrence and FRP was positively related to biomass. In the more productive areas, such as temperate or tropical forests, a humped relationship of FRP against biomass was observed, suggesting an intermediate-productivity hypothesis of maximum fire intensity within those regions. In those areas, the highest fire intensity was observed in the intermediate biomass areas, where surface (timber understory) and crown fuel availability, together with higher wind penetration, can result in crown fires. On the contrary, within the most productive areas, the lowest intensity occurred, likely due to weather and fuel (timber litter) limitations. Full article

Loblolly pine plantations have long been cultivated primarily for timber production due to their rapid growth and economic value. However, these forests are now increasingly acknowledged for their important role in mitigating climate change. Their dense canopies and fast growth rates enable them to absorb and store substantial amounts of atmospheric carbon dioxide. By integrating sustainable management practices, these plantations can maximize both timber yield and carbon sequestration, contributing to global efforts to reduce greenhouse gas emissions. Balancing timber production with vital ecosystem services, such as carbon storage, demands carefully tailored management strategies. This study examined how the timing of thinning—specifically early thinning at 17 years and late thinning at 32 years—impacts biomass accumulation, carbon storage capacity, and carbon sequestration rates in loblolly pine plantations located in northern Iran. Two thinning intensities were evaluated: normal thinning (removal of 15% basal area) and heavy thinning (removal of 35% basal area). The results demonstrated that thinning significantly improved biomass, sequestration rates and carbon storage compared to unthinned stands. Early thinning proved more effective than late thinning in enhancing these metrics. Additionally, heavy thinning had a greater impact than normal thinning on increasing biomass, carbon storage, and sequestration rates. In early heavy-thinned stands, carbon storage reached 95.8 Mg C/ha, which was 63.0% higher than the 58.8 Mg C/ha observed in unthinned 32-year-old stands. In comparison, early normal thinning increased carbon storage by 41.3%. In late heavy-thinned stands, carbon storage reached 199.4 Mg C/ha, which was 29.0% higher than in unthinned stands of the same age (154.6 Mg C/ha at 52 years). In contrast, late normal thinning increased carbon storage by 13.3%. Similarly, carbon sequestration rates in unthinned stands were 1.84 Mg C/ha/yr at 32 years and 2.97 Mg C/ha/yr at 52 years. In comparison, 32-year-old stands subjected to normal and heavy thinning had sequestration rates of 2.60 and 2.99 Mg C/ha/yr, respectively, while 54-year-old normally and heavily thinned stands reached 3.37 and 3.83 Mg C/ha/yr, respectively. The highest carbon storage was concentrated in the stems for 52–58% of the total. Greater thinning intensity increased the proportion of carbon stored in stems while decreasing the contribution from foliage. These results indicate that heavy early thinning is the most effective strategy for maximizing both timber production and carbon sequestration in loblolly pine plantations. Full article