Forests

15 pages, 9024 KB

Open AccessArticle

The Extent of Lecanosticta acicola Spread Along the Polish Baltic Coastline

by Piotr Boroń, Klaudia Bulanda, Marzena Kaźmierczak, Bartłomiej Grad, Anna Majewska and Anna Lenart-Boroń

Forests 2025, 16(12), 1830; https://doi.org/10.3390/f16121830 (registering DOI) - 6 Dec 2025

Abstract

This paper describes a study conducted to investigate the spread of Lecanosticta acicola, the cause of brown spot needle blight (BSNB), in Pinus mugo dune forests in the Polish Baltic region. Between 2023 and 2025, 22 sites were surveyed, including coastal forests [...] Read more.

This paper describes a study conducted to investigate the spread of Lecanosticta acicola, the cause of brown spot needle blight (BSNB), in Pinus mugo dune forests in the Polish Baltic region. Between 2023 and 2025, 22 sites were surveyed, including coastal forests and some ornamental plantings. Characteristic BSNB symptoms were recorded in 21 of the 22 locations, and the pathogen’s presence was confirmed through culture isolation and species-specific PCRs. The disease was most severe in compact, monospecific P. mugo thickets, where defoliation exceeded 30%, while mixed stands with P. sylvestris or occasionally P. nigra exhibited lower infection rates. A degree of infection of P. sylvestris was observed in proximity to heavily infected P. mugo stands, confirming interspecific transmission under high inoculum pressure. We observed nearly ubiquitous occurrence of L. acicola along the coast, suggesting an advanced stage of establishment. However, the very recent detection of the pathogen at the westernmost sites indicates ongoing westward spread. These findings highlight the vulnerability of coastal P. mugo populations and underline the need for genetic diversity data that would allow us to trace the origins and pathways of L. acicola spread in the south-eastern Baltic region. The potential adaptation of the pathogen to P. sylvestris in the future would pose a serious risk for Polish forestry. Full article

(This article belongs to the Section Forest Health)

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13 pages, 1767 KB

Open AccessArticle

Soil Responses to Winch-Assisted Thinning Harvester Traffic on Steep Slopes in South Korea

by Eunjai Lee, Hyun-Min Cho, Ho-Seong Mun, Hyeon-Seung Lee, Jae-Heun Oh and Sang-Kyun Han

Forests 2025, 16(12), 1829; https://doi.org/10.3390/f16121829 (registering DOI) - 6 Dec 2025

Abstract

Background: Winch-assisted harvesting is an alternative to traditional cable yarding on steep slopes, offering improved operational efficiency and fewer limitations. Knowledge on the effects of winch-assisted harvesting on soil disturbance are limited. This study aimed to assess the effects of winch-assisted and conventional [...] Read more.

Background: Winch-assisted harvesting is an alternative to traditional cable yarding on steep slopes, offering improved operational efficiency and fewer limitations. Knowledge on the effects of winch-assisted harvesting on soil disturbance are limited. This study aimed to assess the effects of winch-assisted and conventional tracked harvester operations on soil compaction and machine slippage in a clear-cut stand with sandy loam soil. Methods: We evaluated changes in soil physical properties, in depth and extent, along machine operating corridors with and without winch-assist across slope gradients ranging from 30% to 52% and up to three machine passes. Results: The relative increase in bulk density differed between treatments. In the non-assisted corridors, the bulk density increased by 18%, 12%, and 11% at depths of 0–10, 10–20, and 20–30 cm, respectively; the winch-assisted corridors showed smaller increases of 12%, 5%, and 3% at the corresponding depths. The winch-assisted plots did not show a significant reduction in rut depth compared with the non-assisted plots, a result likely influenced by site-specific dry soil conditions. Conclusions: These results highlight the potential of winch-assisted systems to reduce horizontal soil disturbance, though their effectiveness in limiting rutting remains variable under dry conditions. Full article

(This article belongs to the Special Issue The Influence of Mechanized Timber Harvesting on Soils and Stands)

26 pages, 6085 KB

Open AccessArticle

Life-Cycle Assessment of Carbon Sink Efficiency in Urban Landscape Spatial Units: Evidence from Luhe Park, Nanjing

by Ning Zhang, Leijie Lang, Shi Cheng, Boqing Fan and Yuhao Fang

Forests 2025, 16(12), 1828; https://doi.org/10.3390/f16121828 (registering DOI) - 6 Dec 2025

Abstract

Urban green spaces are pivotal to enhancing carbon sinks and advancing carbon neutrality goals, yet the structural complexity of green space units often leads to scale mismatches and weak spatial responsiveness in current assessments. This study develops an integrated evaluation framework that combines [...] Read more.

Urban green spaces are pivotal to enhancing carbon sinks and advancing carbon neutrality goals, yet the structural complexity of green space units often leads to scale mismatches and weak spatial responsiveness in current assessments. This study develops an integrated evaluation framework that combines landscape spatial unit typologies with life-cycle-based carbon flux modeling. We defined 22 landscape spatial unit types based on two-dimensional surface cover and three-dimensional vegetation structure, including waterbodies and vertical greening. A life-cycle carbon model was developed with indicators covering unit carbon sink, unit carbon emission, unit net carbon sink efficiency, and time to carbon balance. Taking Luhe Park in Nanjing as a case study, the carbon sink efficiency indicators were quantified for 108 units over a 50-year cycle. Results indicate that multilayer vegetation structures, high green coverage, and moderate-to-high planting density markedly enhance carbon sink efficiency, whereas extensive built surfaces and high impervious ratios suppress it. K-means clustering classified the spatial units into four types with emphasis on efficiency-driven, structural optimization, functional compatibility, and imbalance compensation, respectively, revealing a clear gradient tied to spatial configuration. To translate diagnosis into design, we report 95% confidence intervals of key structural factors as actionable thresholds. These ranges inform targeted interventions such as maintaining continuity and multilayer structure in high-efficiency areas, modest structural upgrades with native drought-tolerant plants, edge greening with permeable pavements in open spaces, and streamlined vertical systems linked to adjacent high-sink ground units. The framework delivers spatially explicit, life-cycle-aware evidence to support low-carbon planning and design of urban green spaces. Full article

(This article belongs to the Special Issue Optimizing Urban Green Space Ecosystem Services for Resilient and Sustainable Cities)

14 pages, 1325 KB

Open AccessArticle

A Pilot Study on Somatic Embryogenesis for Japanese Larch: Addressing Challenges and Evaluating Field Performance

by Chanhoon An, Hyunmo Choi, Young-Im Choi, So Yeon Kim, Eun Woon Noh, Kyunghwan Jang, Yeong Bon Koo and Jin Kie Yeo

Forests 2025, 16(12), 1827; https://doi.org/10.3390/f16121827 - 5 Dec 2025

Abstract

In Korea, a persistent shortage of Japanese larch (Larix kaempferi) seeds and the high costs of managing seed orchards have created a significant demand for alternative reforestation methods. This pilot study, conducted over nine years, evaluated the field performance of somatic [...] Read more.

In Korea, a persistent shortage of Japanese larch (Larix kaempferi) seeds and the high costs of managing seed orchards have created a significant demand for alternative reforestation methods. This pilot study, conducted over nine years, evaluated the field performance of somatic embryo-derived larch seedlings (emblings) across 14.4 hectares in nine different locations. The study addressed challenges with SE technology, such as limited genetic diversity and the inconsistent quality of seedlings due to year-round production. Despite these initial issues and other environmental interferences, the statistical analysis revealed age to be the sole significant fixed factor driving tree growth and root collar diameter (RCD) increase (p < 0.001 for both). Crucially, the growth rate (slope) for height and RCD was not statistically different between the embling and seed-derived groups (seedlings). Furthermore, the GLMM for survival confirmed that age was not a significant predictor (p > 0.35 for both types). Instead, site-specific factors were the primary drivers of overall survival and growth variation. The random effects analysis showed that site heterogeneity was substantial for height (

σ_{Site} = 0.8256

, indicating that somatic embryo-derived larch plantlets were more sensitive to site-specific environmental conditions than seed-derived seedlings (

σ^{2}

was 1.078 for embling survival and 0.4074 for seedling survival). We also found no significant difference in overall tree form or evidence that emblings developed dominant side branches. This research demonstrates that SE technology can produce high-quality larch emblings that are statistically equivalent to their seedling counterparts in long-term growth trajectory and RCD development. It confirms that this method offers a viable and cost-effective solution to Korea’s seed shortage without sacrificing long-term growth or survival. Full article

(This article belongs to the Section Genetics and Molecular Biology)

15 pages, 1587 KB

Open AccessArticle

Morphological Response of Urban Trees to Pruning: A Case Study of Acacia auriculiformis Across Size Classes

by Kaiheng Liu, Nancai Pei, Yanjun Sun, Jiameng Zhou, Wei Guo and Can Lai

Forests 2025, 16(12), 1826; https://doi.org/10.3390/f16121826 - 5 Dec 2025

Abstract

Pruning is a regular and essential urban tree maintenance practice aimed at sustaining overall health, ecosystem services, and public safety. However, knowledge of post-pruning recovery dynamics remains limited, which in turn hinders accurate assessments of growth and ecological functions. To address this, we [...] Read more.

Pruning is a regular and essential urban tree maintenance practice aimed at sustaining overall health, ecosystem services, and public safety. However, knowledge of post-pruning recovery dynamics remains limited, which in turn hinders accurate assessments of growth and ecological functions. To address this, we examined recovery dynamics of Acacia auriculiformis, a common urban species. Tree height and crown radius were recorded monthly for 12 months after pruning. Trees were classified into two size groups based on diameter at breast height (DBH, trunk diameter measured at 1.3 m above ground): medium (DBH < 45 cm) and large (DBH ≥ 45 cm). A generalized linear mixed model (GLMM), appropriate for repeated measures and non-normal data, was fitted using a Tweedie distribution and a log-link function to model the recovery pattern. Results showed continuous growth over time, with medium-sized trees presenting significantly higher crown radius growth than large trees (p = 0.006), while height growth did not differ (p = 0.788). The best model for height included time (AIC = −846.4), whereas crown recovery was best modelled by time and size class (AIC = −1586.6). These findings demonstrate that, in this study, medium-sized A. auriculiformis generally recover faster, especially in crown expansion. This exploratory study suggests that tree size may influence post-pruning recovery and can provide a reference for subsequent differentiated management studies. The morphological modeling further provides preliminary quantitative evidence for annual recovery dynamics in urban A. auriculiformis. Full article

(This article belongs to the Special Issue Urban Forests and Ecosystem Services)

14 pages, 1148 KB

Open AccessArticle

Influence of Pine, Birch, and Alder Tree Stands on Soil Properties, Organic Matter Recovery and C:N:P Stoichiometry After Fire Disturbance: A Case Study in a Temperate Forest

by Bartłomiej Woś, Justyna Likus-Cieślik, Magdalena Kopeć, Agnieszka Józefowska and Marcin Pietrzykowski

Forests 2025, 16(12), 1825; https://doi.org/10.3390/f16121825 - 5 Dec 2025

Abstract

The intensity of wildfires is projected to increase with the rising frequency of droughts due to climate change. Management practices following forest fires must include restoring the appropriate species composition. This study was performed within the wider context of the regeneration of soil [...] Read more.

The intensity of wildfires is projected to increase with the rising frequency of droughts due to climate change. Management practices following forest fires must include restoring the appropriate species composition. This study was performed within the wider context of the regeneration of soil properties, including the stock and soil organic matter (SOM) content, at the largest forest fire site in Poland (more than 9000 ha) in the Rudziniec Forest District, Upper Silesia. Research plots were established on sandy soils (Podzols and Arenosols) in pure stands of Scots pine (Pinus sylvestris L.), common birch (Betula pendula Roth), and black alder (Alnus glutinosa (L.) Gaertn.). The organic and mineral soil horizons were sampled from each research plot and control plots unaffected by the fire. The trees’ foliage was also sampled to determine the nutrient supply. Basic soil properties were determined, including the texture, pH, bulk density, organic carbon (C), macronutrient contents, soil microbial biomass, and labile C and nitrogen (N) fractions. We found that, 30 years after the fire, the post-fire soils had similar SOC stocks (34.80 Mg ha⁻¹) to the control plots (31.72 Mg ha⁻¹); however, they differed in their stocks of labile C and N fractions. The post-fire soils had a less stable C pool due to a higher stock of the fraction associated with particulate organic matter. In contrast, the N pool was more stable in the post-fire soils than in the control soils due to a lower contribution of the most labile fractions. The soils under Scots pine had the least stable SOM, which may have influenced the intensification of the podzolization process, whereas the highest biomass of soil microorganisms was observed under common birch. The soils under black alder had the highest acidity and lowest phosphorus (P) content. The C:N:P ratios in the post-fire soils and tree foliage indicated that P may have been the limiting factor in alder growth, and N for pine and birch. Our findings indicate that tree species composition is an important factor in the recovery of post-fire soil properties. However, the introduction of pure black alder stands to post-fire soils with low moisture and P availability showed little effectiveness in restoring the SOM content and N pool. Full article

(This article belongs to the Special Issue Post-Fire Recovery and Monitoring of Forest Ecosystems)

18 pages, 736 KB

Open AccessArticle

Policy Insights on the Contribution of Forest Bioenergy and Environmental Education Towards Achieving a Zero-Carbon Transition

by Nguyen Hoang Dieu Linh and Liang Lizhi

Forests 2025, 16(12), 1824; https://doi.org/10.3390/f16121824 - 5 Dec 2025

Abstract

The biggest concern for global policymakers is how to tackle the worsening global climate and rising temperatures, and they believe that CO₂ emissions are the main culprit behind this catastrophe. In this regard, the 2015 Paris Agreement was a major milestone in [...] Read more.

The biggest concern for global policymakers is how to tackle the worsening global climate and rising temperatures, and they believe that CO₂ emissions are the main culprit behind this catastrophe. In this regard, the 2015 Paris Agreement was a major milestone in binding the nations to reduce carbon emissions by 2030 and ultimately to achieve the objective of net zero emissions or carbon neutrality by 2050. In light of the Paris Agreement, the primary purpose of this analysis is to investigate the contribution of forest bioenergy and environmental education toward carbon neutrality objectives in BRICS economies. In order to empirically investigate the nexus, we employ the advanced econometric approaches (CS-ARDL, PMG-ARDL, DCCE). The findings of the analysis suggest that forest bioenergy significantly reduces CO₂ emissions, which is useful to the carbon neutrality objective. In contrast, environmental education is crucial for reducing CO₂ emissions and thus helps in achieving carbon neutrality objectives. In addition, economic growth is detrimental to the carbon neutrality objective, whereas natural resources rent is favorable. This study suggests that forest-based bioenergy and environmental awareness in climate strategies can accelerate the global transition toward a zero-carbon future. Full article

(This article belongs to the Special Issue Sustainable Wood Market: The Contribution and Challenges of Forest Products for Carbon Neutrality)

34 pages, 1007 KB

Open AccessReview

Evaluation of Biomass Softwood Composites: Structural Features and Functional Properties of Advanced Engineered Wood

by Ria Aniza, Anelie Petrissans, Mathieu Petrissans, Erlan Rosyadi, Hana Nabila Anindita, Tyas Puspita Rini, Zulaicha Dwi Hastuti, Nurdiah Rahmawati, Bralin Dwiratna, Ena Marlina, Akhmad Faruq Alhikami and I Dewa Ayu Agung Warmadewanthi

Forests 2025, 16(12), 1823; https://doi.org/10.3390/f16121823 - 5 Dec 2025

Abstract

Softwood-based composites are increasingly used in structural and nonstructural applications owing to their renewability, cost-effectiveness, and favorable strength-to-weight performance. This study applies a systematic literature review and comparative analysis, drawing on approximately 140 sources, to synthesize current knowledge on the physicochemical, mechanical, thermal, [...] Read more.

Softwood-based composites are increasingly used in structural and nonstructural applications owing to their renewability, cost-effectiveness, and favorable strength-to-weight performance. This study applies a systematic literature review and comparative analysis, drawing on approximately 140 sources, to synthesize current knowledge on the physicochemical, mechanical, thermal, and environmental characteristics of engineered wood products derived from softwood species. The intrinsic lignocellulosic composition of softwood, comprising roughly 40%–45% cellulose, 25%–30% hemicelluloses (with mannose as the predominant sugar), and 27%–30% lignin, strongly influences hydrophilicity, stiffness, and thermal behavior. Mechanical properties vary across engineered wood product classes; for example, plywood exhibits a modulus of rupture of 33.72–42.61 MPa and a modulus of elasticity of 6.96–8.55 GPa. Microstructural and spectroscopic analyses highlight the importance of fiber–matrix interactions, chemical bonding, and surface modifications in determining composite performance. Emerging advanced materials, such as scrimber, with densities of 800–1390 kg/m³, and fluorescent transparent wood, achieving optical transmittance above 70%–85%, demonstrate the expanding functional potential of softwood-based composites. Sustainability assessments indicate that coatings, flame-retardants, and adhesives may contribute to volatile organic compound emissions, emphasizing the need for lower-emission, bio-based alternatives. Overall, the findings of this systematic review show that softwood-based composites deliver robust, quantifiable performance advantages and hold strong potential to meet the rising demand for sustainable, low-carbon engineered materials. Full article

(This article belongs to the Special Issue Wood Testing, Processing and Modification)

23 pages, 8255 KB

Open AccessArticle

Identification and Evolution of Exon Junction Complex Core Genes and Expression Profiles in Moso Bamboo

by Yuhua Wang, Jun Zhang, Mengna Zhao, Xiaoyu Liu, Mingzhe Wang, Wenwen Zhong, Jiajie Yang, Tian Hua, Shengcai Xiang, Liangzhen Zhao, Yaxin Zhang and Lianfeng Gu

Forests 2025, 16(12), 1822; https://doi.org/10.3390/f16121822 - 5 Dec 2025

Abstract

The exon junction complex (EJC) is a central mediator of post-transcriptional regulation in eukaryotes. A comprehensive, systematic analysis of EJC core genes has been lacking in Phyllostachys edulis (P. edulis). Here, we identified 147 EJC core genes across 17 plant species [...] Read more.

The exon junction complex (EJC) is a central mediator of post-transcriptional regulation in eukaryotes. A comprehensive, systematic analysis of EJC core genes has been lacking in Phyllostachys edulis (P. edulis). Here, we identified 147 EJC core genes across 17 plant species spanning the major green plant lineages. Phylogenetic analyses supported each family as a monophyletic clade consistent with established taxonomic relationships. Synteny analyses indicated that segmental duplication is the principal driver of EJC core gene expansion in P. edulis (Moso bamboo). Transcriptome profiling further showed that nearly all PedEJCs were engaged during rapid shoot growth, with PedY14b-D, PedY14c-D, and PedY14d-C displaying the most pronounced expression changes. During shoots’ post-harvest senescence process, PedEIF4A3s, PedY14s, and PedMAGOs were progressively downregulated, whereas PedBTZs were upregulated, indicating distinct module-level responses among EJC subunits. Only a small subset of PedEJCs responds to phytohormones and abiotic stresses. Furthermore, cis-regulatory element composition in promoter region likely shapes PedEJCs transcriptional regulation. Collectively, these findings lay the groundwork for in-depth functional dissection of PedEJCs in Moso bamboo. Full article

(This article belongs to the Section Genetics and Molecular Biology)

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20 pages, 1095 KB

Open AccessArticle

The Problem of Enforcing Environmental Clauses in the EU–Mercosur Partnership Agreement in the Context of the Discrepancy in Deforestation Indices

by Igor Olech, Katarzyna Krupska and Katarzyna Kosior

Forests 2025, 16(12), 1821; https://doi.org/10.3390/f16121821 - 5 Dec 2025

Abstract

The EU–Mercosur Partnership Agreement (EMPA), whose ratification process started following the European Commission’s decision on 3 September 2025, is one of the EU’s most comprehensive trade agreements. From the outset, it raised serious concerns among environmental organizations about the risk of accelerating deforestation [...] Read more.

The EU–Mercosur Partnership Agreement (EMPA), whose ratification process started following the European Commission’s decision on 3 September 2025, is one of the EU’s most comprehensive trade agreements. From the outset, it raised serious concerns among environmental organizations about the risk of accelerating deforestation in the Amazon, potentially exacerbated by the liberalization of trade in agricultural products. This article analyzes the problem of enforcing the environmental provisions of the agreement in the context of deforestation. We argue that the effectiveness of these clauses is fundamentally undermined by two interrelated challenges: the limitations of the legal mechanisms enshrined in the agreement and the increasing ambiguity of data used to monitor deforestation. Using statistical analysis of time series (2002–2024)—including Student’s t-test for dependent samples, Spearman rank correlation, and trend regression models—the nature and trend of increasing divergence between two major indicators of deforestation, namely the official Brazilian PRODES and the Global Forest Watch (GFW), were quantified. The results show a systematic and statistically significant discrepancy between indicators, which has structurally widened since 2015. This fundamental ambiguity of data creates a serious “enforcement gap”, allowing us to challenge the scale of the violations and may, in practice, prevent the effective application of the environmental clauses of the agreement, undermining the EU’s policy objectives related to the EUDR and the Green Deal. The article also outlines institutional options to address this enforcement gap by strengthening the transparency, consistency, and evidentiary use of deforestation data in the implementation of the agreement. Full article

(This article belongs to the Special Issue Sustainable Forestry: Linking Economics and Management)

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22 pages, 3821 KB

Open AccessArticle

Applicability of the Surface Energy Balance System (SEBS) Model for Evapotranspiration in Tropical Rubber Plantation and Its Response to Influencing Factors

by Jingjing Wang, Weiqing Lin, Qiwen Cheng, Huichun Ye, Jinlong Zhu, Zhixiang Wu, Chuan Yang and Bingsun Wu

Forests 2025, 16(12), 1820; https://doi.org/10.3390/f16121820 - 5 Dec 2025

Abstract

Evapotranspiration (ET) plays a vital role in understanding water and energy cycles in forest ecosystems, particularly in tropical regions where rubber plantations are widespread. In this study, a rubber plantation system was used. By combining meteorological data from flux towers and 30 periods [...] Read more.

Evapotranspiration (ET) plays a vital role in understanding water and energy cycles in forest ecosystems, particularly in tropical regions where rubber plantations are widespread. In this study, a rubber plantation system was used. By combining meteorological data from flux towers and 30 periods of Landsat-8 image data, we estimated the daily ET of a rubber plantation from 2022 to 2024 using the Surface Energy Balance System (SEBS) model. Additionally, the study employed the eddy covariance method to validate the accuracy of the daily average ET estimated by the SEBS model in different source areas, in order to explore the model’s applicability. Simultaneously, we examined the key drivers influencing ET in rubber plantations by analyzing meteorological factors and physiological growth indicators. The results indicated that the SEBS model exhibited the highest estimation accuracy (R² = 0.90, RMSE = 0.43 mm, RE = 15.23%) for the rubber plantation ET in the region 1.5 km away from the flux tower, and the retrieval accuracy of 30 periods of ET was higher (RMSE ≤ 1 mm, RE ≤ 46.84%), indicating that the SEBS model was well-suited for estimating ET in rubber plantations. From 2022 to 2024, the daily average and monthly cumulative ET showed a unimodal distribution, with high summer and low winter values; the average monthly accumulated ET during the wet season (102.75 mm) was found to be significantly greater than that during the dry season (50.61 mm). On the daily and monthly scales, the correlation between atmospheric pressure, temperature, and ET was the most significant. These findings enhance our understanding of rubber plantation water use patterns and support the application of remote sensing models for regional water resource management, offering valuable insights for optimizing irrigation strategies and ensuring sustainable rubber production in tropical regions. Full article

(This article belongs to the Special Issue Smart Forest Inventory, Management and Planning: Intelligent Technologies and Their Applications)

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20 pages, 4599 KB

Open AccessArticle

Improving Forest Above-Ground Biomass Estimation Using UAV LiDAR and RGB with Machine Learning Algorithm

by Xiaofang Cheng, Lai Zhou, Shaoyu Liu, Chunxin He and Yueju Teng

Forests 2025, 16(12), 1819; https://doi.org/10.3390/f16121819 - 5 Dec 2025

Abstract

Accurate estimation of individual tree Above-Ground Biomass (AGB) is essential for assessing forest carbon sequestration. This study integrates multi-source Unmanned Aerial Vehicle (UAV) remote sensing (LiDAR and RGB) with machine learning to estimate the AGB of Larix principis-rupprechtii in a natural secondary forest. [...] Read more.

Accurate estimation of individual tree Above-Ground Biomass (AGB) is essential for assessing forest carbon sequestration. This study integrates multi-source Unmanned Aerial Vehicle (UAV) remote sensing (LiDAR and RGB) with machine learning to estimate the AGB of Larix principis-rupprechtii in a natural secondary forest. We applied an instance segmentation approach to identify individual trees and extract structural and spectral features, which were subsequently optimized before model training. Our results demonstrate that models utilizing combined multi-source features significantly outperformed those relying on a single data source. The Extreme Gradient Boosting (XGBoost) algorithm achieved the best performance, with an R² of 0.770 using the combined feature set. SHapley Additive exPlanations (SHAP) interpretation revealed that structural attributes—particularly tree height and crown volume—were the most influential predictors, underscoring their greater importance over spectral information. This study presents an effective and interpretable framework for accurate tree-level AGB estimation, supporting scalable monitoring of regional forest carbon dynamics. Full article

(This article belongs to the Special Issue Remote Sensing-Based Methods for Forest Aboveground Biomass Estimation)

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21 pages, 3827 KB

Open AccessArticle

Detection of Printing Defects on Wood-Derived Paper Products Using an Improved YOLOv8n

by Mingyang Zhang, Shuai Li, Jun Zhang, Xiaopeng Bai, Kun Wang and Hongxia Yuan

Forests 2025, 16(12), 1818; https://doi.org/10.3390/f16121818 - 5 Dec 2025

Abstract

Paper-based printing materials originate from the wood-based value chain–wood–pulp–paper–printing—and their yield reflects the utilization efficiency of pulp and paper resources. In roll-to-roll printing production, small printing defects (e.g., missing prints, smudges, cracks) often cause rework and scrap, thereby increasing the consumption of wood-derived [...] Read more.

Paper-based printing materials originate from the wood-based value chain–wood–pulp–paper–printing—and their yield reflects the utilization efficiency of pulp and paper resources. In roll-to-roll printing production, small printing defects (e.g., missing prints, smudges, cracks) often cause rework and scrap, thereby increasing the consumption of wood-derived materials. To improve resource efficiency, this study proposes a lightweight, improved YOLOv8n model for real-time small-defect detection. The Efficient IoU (EIoU) loss is introduced in the bounding box regression stage to improve localization accuracy, and a Squeeze-and-Excitation (SE) channel attention mechanism is embedded in the feature fusion stage to strengthen feature representation for small printing defects. Evaluations conducted on datasets collected from real production lines demonstrate that, with 3.02 M parameters and 8.1 GFLOPs, the model achieves mAP@0.5 = 94.1%, Precision = 95.1%, Recall = 94.3%, and an inference speed of 100.2 FPS, outperforming the baseline model. The proposed method contributes to reducing rework and material waste, supporting the efficient utilization of wood resources and the sustainable development of the paper-based packaging industry. Full article

(This article belongs to the Special Issue Harvesting, Processing and Management of Specialty Forest Products and Biomass)

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29 pages, 3250 KB

Open AccessArticle

Determinants of the Global Timber Trade Network Evolution a Stochastic Actor-Oriented Model Analysis

by Yingying Zhou, Yage Zhang, Wenqi Zhao, Baodong Cheng, Guangyuan Qin and Fengting Wang

Forests 2025, 16(12), 1817; https://doi.org/10.3390/f16121817 - 5 Dec 2025

Abstract

Against the backdrop of accelerating restructuring in the global economy and trade landscape, understanding the evolutionary mechanisms of timber trade networks has become increasingly crucial. Utilizing cross-national timber trade data from 2000 to 2024, this study applies a Stochastic Actor-Oriented Model to analyze [...] Read more.

Against the backdrop of accelerating restructuring in the global economy and trade landscape, understanding the evolutionary mechanisms of timber trade networks has become increasingly crucial. Utilizing cross-national timber trade data from 2000 to 2024, this study applies a Stochastic Actor-Oriented Model to analyze the dynamic evolution of the timber trade network by incorporating multidimensional factors, including trade costs, resource costs, network structure, and trade structure. The findings reveal that: (1) Endogenous network mechanisms—particularly the triadic closure effect—play a dominant role in the formation of trade relationships; (2) resource-rich countries exhibit an export expansion with import restriction phenomenon, actively expanding exports while restricting imports to safeguard resource sovereignty; (3) timber price alone insufficiently reshapes trade ties, whereas sustainable forest management significantly drives network dynamics; and (4) net exporters favor developed economies via market screening. Economic development asymmetrically moderates trade—boosting exports in net exporters while curbing imports in net importers. This study moves beyond traditional economic perspectives, uncovering the profound effects of structural embeddedness and strategic behavior in timber trade, and the findings extend the theoretical framework for resource-based product commerce and provide empirical foundations for formulating equitable and sustainable forestry trade policies. Full article

(This article belongs to the Section Forest Economics, Policy, and Social Science)

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17 pages, 5510 KB

Open AccessArticle

Identifying Environmental Constraints on Pinus brutia Regeneration Using Remote Sensing: Toward a Screening Framework for Sustainable Forest Management

by Gordana Kaplan and Alper Ahmet Özbey

Forests 2025, 16(12), 1816; https://doi.org/10.3390/f16121816 - 5 Dec 2025

Abstract

Regeneration of Pinus brutia (Turkish red pine) after clear-cutting is showing failures in some low-elevation Mediterranean stands, raising questions about long-used silvicultural prescriptions. Because site limitations arise from the combined effects of climate, terrain, and surface thermal conditions that vary over short distances, [...] Read more.

Regeneration of Pinus brutia (Turkish red pine) after clear-cutting is showing failures in some low-elevation Mediterranean stands, raising questions about long-used silvicultural prescriptions. Because site limitations arise from the combined effects of climate, terrain, and surface thermal conditions that vary over short distances, diagnosing where problems may occur is challenging at operational scales. In this study, we first evaluate the study area (Antalya, Türkiye, 0–400 m elevation band) using open, long-term climatic indicators, along with terrain and surface thermal remote sensing variables, to describe recent environmental conditions relevant to germination and early seedling survival. We then build a transparent environmental-analog screening product that summarizes the degraded reference site as an environmental signature and computes pixel-wise similarity across the landscape at 100 m resolution. The resulting map reports three actionable tiers (≥95th, 90–95th, 85–90th percentiles), delineating compact clusters of very-high analogs surrounded by broader high/elevated belts. Interpreted strictly as a screening layer (not a predictive model), it supports compartment-scale triage: ≥95th areas are first candidates for field checks and adjusted prescriptions, while lower tiers guide targeted site preparation and monitoring. The novelty and importance are practical: widely available Earth observation data are converted into a reproducible, auditable tool that reduces dependence on complex predictive models and large calibration samples, while still requiring careful local interpretation and ground-truthing to inform P. brutia regeneration planning. Full article

(This article belongs to the Special Issue Advances in Remote Sensing and GIS Utilization in Monitoring of Forest Ecosystems)

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11 pages, 5828 KB

Open AccessArticle

Challenges in Young Siberian Forest Height Estimation from Winter TerraSAR-X/TanDEM-X PolInSAR Observations

by Tumen Chimitdorzhiev, Irina Kirbizhekova and Aleksey Dmitriev

Forests 2025, 16(12), 1815; https://doi.org/10.3390/f16121815 - 4 Dec 2025

Abstract

Accurate estimation of young forest height is essential for assessing the carbon sequestration potential of vast Siberian boreal forests recovering from wildfires. Satellite radar interferometry, particularly PolInSAR, is a promising tool for this task. However, its application in winter conditions and over sparse [...] Read more.

Accurate estimation of young forest height is essential for assessing the carbon sequestration potential of vast Siberian boreal forests recovering from wildfires. Satellite radar interferometry, particularly PolInSAR, is a promising tool for this task. However, its application in winter conditions and over sparse young forests remains underexplored. This study proposes a novel method for estimating the height of sparse young pine (Pinus sylvestris) stands using fully polarimetric bistatic TerraSAR-X/TanDEM-X data acquired in winter. The method is based on an analysis of the multimodal distribution of the unwrapped interferometric phase of the surface scattering component, which was isolated via PolInSAR decomposition. We hypothesize that the phase centers correspond to the snow-covered ground (located between tree groups) and the rough surface formed by the upper layer of branches and needles (of the tree groups). The results demonstrate that the difference between the dominant modes of the surface scattering phase distribution correlates with the height of young trees. However, the measurable height difference is limited by the interferometric height of ambiguity. Furthermore, a temporal analysis of the phase and meteorological data revealed a strong correlation between sudden phase shifts and daytime temperature rises around 0 °C. This is interpreted as the formation of a layered snowpack structure with a dense ice crust. This study confirms the potential of X-band PolInSAR for monitoring the structure of young Siberian forests in winter but also highlights a significant limitation: the critical impact of snowpack metamorphism, particularly melt-freeze cycles, on the interferometric phase. The proposed method is only applicable to certain forest regeneration stages where tree height does not exceed the ambiguity limit and snow conditions are stable. Full article

(This article belongs to the Special Issue Post-Fire Recovery and Monitoring of Forest Ecosystems)

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27 pages, 6095 KB

Open AccessArticle

Cumulative and Lagged Drought Effects Shape Start and End of Season on the Mongolian Plateau

by Yilin Liu, Yu Wang, Maolin Li, Qi Shi, Xinyu Yang, Bowen Chi, Ji Long, Qiang Yu, Buyanbaatar Avirmed, Orgilbold Myangan, Ganbold Bayanmunkh and Dambadarjaa Naranbat

Forests 2025, 16(12), 1814; https://doi.org/10.3390/f16121814 - 4 Dec 2025

Abstract

Dryland phenology is tightly constrained by water availability, yet the temporal depth of drought influence remains poorly resolved at regional scales. We analyzed the start and end of season across the Mongolian Plateau using 500 m MODIS kNDVI for 2001–2020 and a phenology-anchored [...] Read more.

Dryland phenology is tightly constrained by water availability, yet the temporal depth of drought influence remains poorly resolved at regional scales. We analyzed the start and end of season across the Mongolian Plateau using 500 m MODIS kNDVI for 2001–2020 and a phenology-anchored framework that linked multi-timescale SPEI directly to the month of each phenological event. By varying accumulation windows and testing month-wise lags up to twelve months, we mapped pixel-level optimal timescales and sensitivities. Phenology exhibits a clear north–south gradient with weak long-term shifts relative to large interannual variability. Drought acts through two pathways. Multi-month winter–spring moisture deficits delay spring green-up, with the strongest SOS sensitivity to antecedent drought about six to nine months prior. Summer–autumn dryness advances dormancy, and EOS is governed mainly by near-term moisture over the previous one to two months. Responses differ among ecoregions, with deserts and desert steppes the most sensitive and forests and alpine meadows less responsive. These asymmetric timescales imply that prolonged deficits can postpone spring emergence into the following year, whereas short deficits truncate the current season, offsetting warming-driven extensions of growing-season length. Incorporating phenology-anchored, multi-timescale drought indicators can improve model forecasts of dryland carbon–water dynamics and inform monitoring and adaptation in the most water-limited ecoregions. Full article

(This article belongs to the Section Forest Inventory, Modeling and Remote Sensing)

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17 pages, 952 KB

Open AccessArticle

The Legislative Framework and Community Expectations of Ecosystem Services in Estonian Forest Management

by Kertu Kikkas and Paavo Kaimre

Forests 2025, 16(12), 1813; https://doi.org/10.3390/f16121813 - 3 Dec 2025

Abstract

The study examines the extent to which the concept of ecosystem services is reflected in Estonian forestry legislation and how local communities and interest groups perceive and prioritise these services. Using a three-step methodology, the analysis combined (1) a content analysis of key [...] Read more.

The study examines the extent to which the concept of ecosystem services is reflected in Estonian forestry legislation and how local communities and interest groups perceive and prioritise these services. Using a three-step methodology, the analysis combined (1) a content analysis of key legal acts—including the Forest Act, Nature Conservation Act, and related regulations; (2) a qualitative review of 26 forest management proposals submitted by communities to the State Forest Management Centre between 2021 and 2024; and (3) a comparative synthesis of legislative and community perspectives in order to identify their main areas of convergence and divergence. The findings reveal that provisioning services, particularly timber production, are most explicitly regulated, while regulating and cultural services appear mainly through indirect references. Community expectations, however, emphasise regulating (44%) and cultural (30%) services—especially habitat conservation, recreation, and landscape aesthetics—over provisioning benefits (26%). This discrepancy highlights a structural imbalance between legal framework and societal values. The study concludes that a more systematic integration of ecosystem services into forest management practice and regulations is required to achieve a balanced approach that accounts for ecological, social, and economic dimensions. Full article

(This article belongs to the Section Forest Economics, Policy, and Social Science)

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19 pages, 13853 KB

Open AccessArticle

Establishment of an In Vitro Culture and Genetic Transformation System of Callus in Japanese Apricot (Prunus mume Sieb. et Zucc.)

by Yin Wu, Pengyu Zhou, Ximeng Lin, Chengdong Ma, Siqi Guo, Zhaojun Ni, Faisal Hayat, Xiao Huang and Zhihong Gao

Forests 2025, 16(12), 1812; https://doi.org/10.3390/f16121812 - 3 Dec 2025

Abstract

Japanese apricot (Prunus mume Sieb. et Zucc.) is a dicotyledonous plant from the Rosaceae family that originated in China. Functional genomic studies in Japanese apricot are essential to elucidate the molecular mechanisms underlying key agronomic traits and to accelerate crop improvement. However, [...] Read more.

Japanese apricot (Prunus mume Sieb. et Zucc.) is a dicotyledonous plant from the Rosaceae family that originated in China. Functional genomic studies in Japanese apricot are essential to elucidate the molecular mechanisms underlying key agronomic traits and to accelerate crop improvement. However, the lack of an efficient genetic transformation system has hindered gene function analysis and impeded molecular breeding efforts. Agrobacterium rhizogenes-mediated transformation has emerged as a robust tool for functional gene validation and studying root-specific processes across diverse plant species, due to its simple protocol and rapid turnaround time. Notably, Agrobacterium-mediated transformation remains notoriously recalcitrant in Rosaceae species, particularly in Japanese apricot. Through screening of ten Japanese apricot varieties, we identified ‘Muguamei’ (MGM) as the optimal cultivar for tissue culture. Using its genotype, we established an Agrobacterium rhizogenes-mediated transformation system for Japanese apricot via an in vitro approach. The binary vector incorporated the RUBY reporter for visual selection and eYGFPuv for fluorescent validation of transformation events. Furthermore, CRISPR/Cas9-mediated knockout of PmPDS in ‘Muguamei’ calli generated albino phenotypes, confirming successful genome editing. Through optimization of antibiotics, the study achieved an 80% explant survival rate using Woody Plant Medium (WPM) supplemented with 6-BA (0.5 mg/L) and TDZ (0.05 mg/L). For in vitro micropropagation, we found that ‘Muguamei’ exhibited optimal shoot growth in the presence of 6-BA (0.06 mg/L) and TDZ (0.1 mg/L), and up to 8 bud proliferation lines could be reached under 4.0 mg/L 6-BA. During the rooting of micro shoots, ½MS medium performed better and reached the optimum root length (35.70 ± 4.56 mm) and number (6.00 ± 1.00) under IAA (0.5 mg/L) and IBA (0.4 mg/L). Leaf explants were cultured on WPM supplemented with TDZ (4.0 mg/L) and NAA (0.2 mg/L). 50 mg/L kanamycin concentrations were the suitable screening concentration. Full article

(This article belongs to the Section Genetics and Molecular Biology)

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