Forests doi: 10.3390/f17050589

Authors: Mariana Sedliačiková Marek Kostúr Mária Osvaldová

Family businesses represent an important part of the wood-processing and furniture industry and may play a significant role in sustainable forest-based development. This study aims to analyze how family businesses perceive selected external determinants of the microeconomic environment, assess the role of non-economic goals in their management, and propose a strategic framework for their sustainable development. The research was conducted in Slovakia through a questionnaire survey administered between August 2024 and May 2025. The final dataset included 507 valid responses, of which 432 businesses were identified as family businesses. The data were analyzed using non-parametric statistical methods, particularly the Kruskal–Wallis test and multiple comparison analysis. The results confirmed significant differences in the perceived importance of external determinants, with customers identified as the most important factor and intermediaries as the least important. The findings also showed that non-economic goals, such as sustainability and intergenerational continuity, are relevant, although not the most prominent characteristic. Relational factors, especially trust, reputation, and long-term relationships, play a more central role. Based on these findings, a conceptual strategic framework was developed using the Ishikawa diagram. The study highlights the role of family businesses in long-term competitiveness and sustainable forest-based development.

Forests doi: 10.3390/f17050588

Authors: Bobae Lee Hong-Duck Sou Seoncheol Park Chan-Ryul Park

Urban forests (UFs) are increasingly promoted as a nature-based solution for mitigating particulate matter (PM) pollution, yet their removal performance can vary depending on surrounding emission sources and environmental conditions. Here, we quantified the particulate matter reduction efficiency (PMRE) of UFs located near roads, industrial complexes, and urban areas, together with background forests in South Korea, based on field observations during the late autumn–spring period across two consecutive years (November–May in 2021–2022 and 2022–2023). We applied vector autoregression (VAR) to examine the dynamic relationships between PMRE and meteorological and air pollutant variables across eight representative sites. The results revealed that PM mitigation dynamics were strongly particle-size-dependent and context-specific. Across all sites, ΔPM10 RE was predominantly self-driven, explaining over 90% of its own variance, whereas fine-particle dynamics showed stronger interdependence. In particular, ΔPM2.5 RE consistently acted as a key mediator, accounting for up to 70%–80% of the variation in ΔPM1.0 RE depending on source context. Industrial-complex-adjacent UFs exhibited the strongest cross-variable interactions, while urban-core UFs were largely governed by intrinsic mitigation processes. Roadside UFs showed site-specific responses associated with CO and temperature variability. Notably, PMRE responses exhibited damped oscillation patterns across all source contexts, converging toward equilibrium over time, indicating stabilization of mitigation performance following disturbance events. These findings demonstrate that urban forest air-quality benefits are highly context dependent and governed by particle-size-specific dynamics. Our results provide evidence-based guidance for designing and managing urban forests, emphasizing the need for source-specific strategies and prioritization of PM2.5-oriented mitigation, particularly in industrial and roadside environments where fine-particle interactions are strongest.

Forests doi: 10.3390/f17050587

Authors: Elena Górriz-Mifsud Marc Rovellada Ballesteros Elisa Fernández Descalzo Adolfo Miravet Laura Ojalvo Ortega Ricardo Quiroga Aida Rodríguez-García Mariola Sánchez-González

Although Non-Wood Forest Products can offer interesting economic opportunities for rural communities, little is known about their commercial harvesters. Our work aims to shed light on the labour profiles, their accessibility to new entrants, and attractiveness for future green jobs. Through in-depth interviews, we explored the five-capitals profile of commercial resin, cork, mastic foliage, chestnut, pine nut, and wild mushroom harvesters in Spain. We found either freelance harvesters or entrepreneurs with a small gang. Our data show a typical male collector, who started the activity through his social networks (Social Capital), and whose origin depends on the product and Spanish region. Some commercial female harvesters were found in mushroom, chestnut and resin harvesting. Social constructs around the masculinization of these activities may explain their limited attractiveness for women. The ratio of non-Spanish commercial harvesters correlates with the weight of migrants in the analysed regions. Only a subgroup of resin harvesters devotes most of their year to this single activity. The rest complement NWFP income with a main forestry (cork and pinenut) or non-forestry occupation (mushroom, chestnut and mastic). For the latter products, access to Natural Capital was found to be crucial for job progress, as non-landowners require administrative and/or negotiation capacities to secure harvesting permits. Human Capital differs across NWFPs, from simpler skills such as recognising marketable produce and handling easy tools (mushroom, chestnuts, pine nut ground gathering and mastic), to complex abilities needed to balance efficiency with minimising tree damage (in resin tapping, pinenut shaking, and cork extraction). Such specialised tools and machinery (Built Capital) typically act as a barrier to entry and advancement. These profiles are expected to help decision-makers to design instruments promoting and regulating commercial harvesting, and tackle their risks: local landowners in allocating harvesting rights to external collectors; regional policymakers as competent authorities in forest legislation; and state-level administration concerning cultural, fiscal and labour-permit aspects.

Forests doi: 10.3390/f17050586

Authors: Jean A. Magalhães Margarida Tomé

Stand-level canopy base height (Cbh) is a key variable controlling crown fire initiation, yet it is commonly computed as the mean of tree height to the base of the crown (hbc), which does not reflect the lower portion of the hbc distribution governing the transition from surface to crown fire. This study investigates the relationship between physically based Cbh definitions and the hbc distribution. We develop a general multi-percentile modeling framework to estimate hbc percentiles at the stand level. Using a dataset of Pinus pinaster Aiton trials in Portugal, percentile-specific models (5th to 50th) were fitted and synthesized into a nonlinear multi-percentile formulation. Results show that the height at which canopy bulk density exceeds the critical threshold does not match mean hbc, but instead corresponds to lower percentiles, typically around the 10th percentile, varying with stand structure and age. Mean-based Cbh tends to overestimate the lower canopy boundary, reflecting its inability to capture structural variability. The final model predicts hbc at any percentile and incorporates effects of stand height, basal area, tree density, and age, ensuring positive predictions and high predictive accuracy (adjusted R2 = 0.9770; RSE = 0.4073 m; PRESS R2 = 0.9769). The framework provides a consistent representation of canopy base height for fire behavior modelling.

Forests doi: 10.3390/f17050585

Authors: Yiwen Ji Lei Zhang Chuntao Li Xinchen Gu

Non-built-up green areas are essential for preserving the ecological functions of cities and fostering sustainable growth. Focusing on Shanghai, we developed a comprehensive framework of driving forces that integrates socioeconomic, natural, policy, and financial indicators. To assess the spatial-temporal changes in regional green space configurations and their underlying mechanisms between 2000 and 2020, we utilized stepwise regression alongside Geographically Weighted Regression (GWR) techniques. The results show that regional green space exhibited a clear stage-dependent evolution, with the total area decreasing from 580.56 km2 in 2000 to 506.43 km2 in 2005 and then increasing continuously to 905.70 km2 in 2020. Forest land consistently expanded and became the dominant land type, while wetland showed a “decrease–increase” pattern and grassland experienced an early decline followed by partial recovery. The primary elements driving these changes underwent substantial transformations over the study period. During the initial phase, socioeconomic variables, particularly real estate investments (β = −0.296), demonstrated pronounced adverse impacts. Conversely, post-2005, financial allocations for landscaping and policy interventions emerged as the main favorable drivers (β = 0.598). Furthermore, environmental aspects like NDVI and waterway density provided a continuous positive influence on green space enlargement. Certain socioeconomic indicators, notably population density, transitioned from exerting adverse impacts to having beneficial effects during the latter periods. The primary drivers demonstrated considerable spatial variation; socioeconomic impacts were largely localized in regions undergoing urban growth, whereas environmental and policy variables exerted broader and more consistent influences. Overall, these outcomes highlight a shift from a socioeconomic-dominated evolutionary process to one governed by a synergy of multiple factors. This offers a theoretical foundation for refining urban ecological strategies and harmonizing city expansion with ecological conservation.

Forests doi: 10.3390/f17050584

Authors: Luis Alejandro Acosta-Martínez Solhanlle Bonilla-Duarte Ulises J. Jauregui-Haza

The accelerated growth of cities has intensified interest in the ecosystem services provided by urban forests, increasingly conceptualized as socio-ecological systems (SESs). This study presents a structured narrative review combined with bibliometric analysis of research published between 2010 and 2025 to examine how urban forests are addressed in relation to ecosystem service provision and climate change adaptation. The literature search and screening process followed procedures informed by the PRISMA framework to enhance transparency in the identification and selection of relevant studies. The results reveal a marked increase in scientific production during the last decade, with approximately 70% of publications concentrated in five countries: the United States, China, Italy, Canada, and Brazil. Although research methodologies are diverse, a strong bias toward quantitative ecological models—particularly tools such as i-Tree—persists, often prioritizing carbon sequestration while overlooking social dimensions of urban forest governance. A key finding is the disconnect between objectively modeled ecosystem services and the benefits perceived by citizens, which may influence the long-term sustainability and acceptance of urban green infrastructure. In addition, emerging research highlights the importance of considering ecosystem disservices, such as allergenic pollen, infrastructure conflicts, or maintenance costs, within urban forest planning. Finally, the review identifies a significant research gap in Latin America and the Caribbean, where rapid urbanization requires context-specific socio-ecological approaches. Advancing urban forest management therefore requires transdisciplinary frameworks that integrate ecological processes, social perception, governance, and climate adaptation to support more resilient and equitable cities.

Forests doi: 10.3390/f17050583

Authors: Qiuyi Wang Zhuchao Xu Han He Xinzhou Wang Yanjun Li

Bamboo flattening technology provides an efficient approach for improving bamboo utilization, but the heterogeneous stress response and the mechanism of bamboo nodes during the flattening process remain insufficiently understood. In this study, a universal mechanical testing machine equipped with a temperature-controlled chamber was used to simulate the stress state during the flattening process. The effects of different heat treatment temperatures on the transverse mechanical response and chemical properties of different layers of bamboo internodes and nodes were systematically investigated. The results showed that at room temperature, the transverse strength of bamboo exhibited a gradient characteristic of outer layer bamboo (OB) > middle layer bamboo (MB) > inner layer bamboo (IB). Nodes showed higher transverse strength than internodes. As the temperature increased, the transverse properties of all layers significantly declined, with transverse tensile strength showing higher sensitivity. The IB exhibited the poorest thermal stability. Chemical analysis revealed the continuous degradation of cellulose and hemicellulose, while the relative lignin content and relative crystallinity of cellulose increased. This study clarifies the mechanism of heat treatment temperature on the physicochemical characteristics of different parts of bamboo, providing a scientific theoretical basis for temperature control in the industrial production of crack-free flattened bamboo boards.

Forests doi: 10.3390/f17050582

Authors: András Csótó József Csajbók Tamás Ábri Károly Pál Andrea Zabiák Kata Mihály István Attila Kocsis Erzsébet Sándor

Black locust (Robinia pseudoacacia L.) has exceptional growth capacity in nutrient-poor environments and is therefore widely used for afforestation and land reclamation on degraded soils. However, drought stress can restrict sapling growth, which undermines the success of their establishment. The effect of a product containing two endophytic strains (Trichoderma afroharzianum P. Chaverri, F.B. Rocha, Degenkolb & Druzhinina TR04 and Trichoderma simmonsii P. Chaverri, F.B. Rocha, Degenkolb & Druzhinina TR05) was studied on a black locust sapling stand under severe drought in eastern Hungary. The two-year-old saplings were root-soaked before planting in sandy soil. The growth of Trichoderma-treated plants improved by late spring. Compared to the control trees, average height increased by 25.75%, and root collar diameter was 21.96% larger. Treated plants also showed 9.1% higher chlorophyll content and 11.1% Normalized Difference Vegetation Index (NDVI). The reduced intercellular CO2 concentration, together with slightly lower stomatal conductance and increased transpiration rate, suggests tighter stomatal regulation and altered water-use dynamics under drought conditions. These responses indicate improved short-term drought acclimation rather than enhanced carbon assimilation capacity. Pre-planting inoculation with endophytic Trichoderma strains provides a sustainable method to enhance the early establishment and drought resilience of black locust, thereby increasing the efficacy of forest restoration by improving the survival of black locust on challenging degraded sites.

Forests doi: 10.3390/f17050581

Authors: Hantao Wu Zhongke Qu Yan Qu Yongbiao Ji Shaohui Zhang Huiwen Li

Soil organic carbon (SOC) is pivotal to the terrestrial carbon cycle and climate regulation, yet its spatiotemporal dynamics and future climate responses across soil layers remain insufficiently understood in mountainous ecosystems. Taking the Qinling Mountains, a typical mountainous ecological barrier in central China with a total area of approximately 38.18 × 104 km2, as the study area, we analyzed historical SOC changes (1980s–2010s) and projected its future dynamics under different scenarios using a validated Random Forest model (R2 = 0.81 for 0–20 cm, SOC20; 0.73 for 0–100 cm, SOC100), and further disentangled dominant drivers. Results showed historical mean SOC density increased, with higher storage in western/central high-elevation zones and lower values in southern/eastern low-elevation areas. Climate was the primary driver of SOC20 dynamics, while SOC100 was jointly regulated by climate, vegetation, and environmental factors, indicating weakened climatic control with increasing soil depth. Precipitation increases partially offset warming-induced SOC loss, leading to small changes in regional mean SOC density, but strong spatial heterogeneity resulted in substantial total SOC stock losses (SOC20: −1.41 to −6.59 Tg C; SOC100: −6.86 to −28.76 Tg C), with net losses in high-elevation zones and gains in low-elevation areas. SOC within the whole 1 m soil profile exhibited larger climate-driven changes than topsoil. These findings advance understanding of SOC dynamics in complex mountainous ecosystems and provide key scientific insights for regional carbon cycle assessments under climate change.

Forests doi: 10.3390/f17050580

Authors: Zhimin Feng Huiqiang Wang Ruiping Li Xiangwei Meng Liying Zhou Xiaoming Ma

Conventional Interferometric Synthetic Aperture Radar (InSAR)-based sub-canopy topography retrieval models often suffer from insufficient characterization of scattering mechanisms, strong nonlinearity, and poor parameter convergence. To address these issues, this study proposes an improved Interferometric Water Cloud Model (IWCM) that integrates Fractional Vegetation Cover (FVC) to retrieve sub-canopy topography. The proposed method accounts for both volume and ground scattering and introduces FVC as a constraint to improve the model’s physical realism. In addition, this study utilizes InSAR observations derived from TanDEM-X dual-baseline data, which enhance the information content of the measurements by providing multiple independent interferometric observations. A two-step nonlinear least squares optimization strategy is further employed to enhance the convergence of model parameter estimation. The proposed method was validated in the forested region of Genhe City, Inner Mongolia. Airborne LiDAR-derived surface elevation data were used for assessment. The results indicate that, compared with the original InSAR-derived Digital Elevation Model (DEM), the accuracy of the retrieved sub-canopy topography improves by 39.04%. Furthermore, compared with the previously proposed Normalized Difference Vegetation Index (NDVI)-based method, under their respective optimal initial extinction coefficient conditions (μ0), an additional accuracy improvement of 11.69% is achieved. These results demonstrate that the proposed method effectively reduces the influence of the forest canopy on interferometric phase observations and improves the capability of sub-canopy topography reconstruction in complex forest environments. The method also provides a new approach for dual-baseline and multi-baseline InSAR-based sub-canopy topography retrieval.

Forests doi: 10.3390/f17050579

Authors: Yonghua Zhang Chanjuan Lai Xi Liu Yunpeng Zhao Zupei Lei

Broussonetia monoica (Moraceae) is an ecologically, medicinally and economically valuable species but lacks adequate molecular resources for genetic studies. Here, we developed the first set of expressed sequence tag-derived simple sequence repeat (EST-SSR) markers for B. monoica and applied them to characterize genetic diversity and Broussonetia species relationships. Transcriptome sequencing of B. monoica generated 185,167 unigenes, from which 8921 candidate polymorphic EST-SSRs were mined. Twenty-one primer pairs (21/27, 77.78%) were successfully validated across 100 B. monoica plants. Cross-species transferability was high (14/18, 77.78%), enabling comparative analysis revealing significant genetic differentiation among the Broussonetia species (FST = 0.284). Seventeen polymorphic loci revealed moderate to high genetic diversity in six B. monoica populations, with significant population structure (FST = 0.119) and sub-structuring into three clusters. Bayesian clustering, principal coordinate analysis, and neighbor-joining trees consistently resolved three Broussonetia species boundaries (FST = 0.284). These novel EST-SSRs provide robust tools for population genetics, germplasm conservation, and molecular breeding in Broussonetia species, addressing a critical resource gap for this genus.

Forests doi: 10.3390/f17050578

Authors: Shaopeng Zhang Hongge Zhu

For researchers in the forestry field, a holistic, multi-dimensional perspective undoubtedly represents the most compelling approach for analyzing modern forestry production and development [...]

Forests doi: 10.3390/f17050577

Authors: Shuna Dong Xinbo Zhou Yufen Yu Ying Guo Yongcun Fu Jiquan Zhang

Against the background of ecological civilization construction and the transformation of state-owned forest regions after the logging ban, balancing economic development with ecological protection has become an important issue in China’s forest areas. The development of the non-timber forest-based economy plays a critical role in advancing high-quality, green economic growth in China and contributes significantly to sustainable resource utilization. This study examines data from key state-owned forests and the natural environment in the Changbai Mountain region of Jilin Province from 2013 to 2023. A comprehensive evaluation model and a coupling coordination model, based on the human–land relationship framework, are employed to assess temporal changes in economic growth quality, ecological environment carrying capacity, and their coupling coordination. The quality of non-timber forest-based economic growth exhibited an overall upward trend. Fusong County, Wangqing County, and Dunhua City consistently maintained high levels, while Helong City experienced the largest decline. The spatial distribution followed a “high center, low periphery” pattern, with the 2015 logging ban serving as a key turning point in promoting ecological transformation. The per capita ecological environment carrying capacity improved across the region, with significant increases in Dunhua, Helong, and Antu Counties. A radial decline from the central to peripheral areas was observed, with the highest values in Wangqing and Antu Counties. The coupling coordination degree between economic growth and ecological environment fluctuated between 0.4 and 0.6. In 2023, Wangqing County reached a state of intermediate coordination (index > 0.7), whereas Linjiang remained in a dysfunctional state (index < 0.5). Spatial clustering of coordination weakened over time, as indicated by Moran’s I values of 0.32, 0.21, and 0.09 in 2013, 2018, and 2023, respectively. These findings provide a quantitative foundation for promoting the coordinated development of human–land systems and guiding high-quality regional growth in forest-based economic zones.

Forests doi: 10.3390/f17050575

Authors: Hadi Mahmoudi Meimand Jiaxin Chen Daniel Kneeshaw Changhui Peng

Monitoring boreal above-ground biomass (AGB) change requires approaches that are both measurement-based and spatially explicit. We integrated permanent sample plots from Quebec and Ontario with Landsat-7 spectral trajectories (1999–2023) to quantify non-fire-related AGB change after excluding wildfire-affected intervals and to evaluate whether annualized AGB change can be predicted from spectral change at the plot-interval scale. Tree height was estimated using a multilayer perceptron model (R2 = 0.83) and combined with species-specific allometry to derive plot-level AGB and interval ΔAGB. These estimates were aggregated to ecodistricts using effective sample sizes and confidence intervals. Across well-sampled ecodistricts, mean annualized ΔAGB ranged from −0.82 to +3.54 t ha−1 yr−1, with lower or negative changes mainly occurring in eastern regions. Spectral indices derived from NIR–SWIR bands showed relatively stronger associations with ΔAGB than greenness-based indices, consistent with the sensitivity of moisture- and disturbance-related metrics to canopy stress, including defoliation. An XGBoost ensemble correctly predicted the direction of change in 77% of intervals. These results provide a measurement-constrained and scalable framework for monitoring non-fire-related biomass change and supporting greenhouse-gas reporting across boreal forest landscapes.

Forests doi: 10.3390/f17050576

Authors: Xingyue Lan Zhongxuan Huang Jiaoling Wu Haotian Duan Lixin Chen Junhao Wu Jingwen Peng Kuangji Zhao Guirong Hou Xianwei Li

Accurate prediction and assessment of carbon storage are crucial in the context of global climate change. However, existing research has largely focused on large-scale regions, while studies on small-scale ecologically fragile alpine regions remain insufficient. This study focuses on Zoige County, integrating the PLUS model, InVEST model, and Random Forest model to form a composite analysis workflow. Through this workflow, we simulated the distribution of land use types in 2030 and quantified carbon storage from 1990 to 2030, subsequently analyzing their spatial distribution and driving factors. The key findings include: (1) Under the natural development scenario (NDS) and the ecological protection scenario (EPS) for 2030, the primary land use transition involved the conversion of grassland to forest and wetland. Conversely, wetland was converted into cropland under the economic development scenario (EDS). (2) Under the NDS, EDS, and EPS, carbon storage would be 8.396 × 107 t, 8.252 × 107 t, and 8.432 × 107 t, respectively. The EPS yielded the largest increase in carbon storage. (3) In all three scenarios, carbon storage showed a clustered distribution. Compared with 2020, the carbon storage hot spot areas under both NDS and EPS showed an expansion trend, whereas the cold spot areas also expanded in three scenarios. (4) The key drivers of carbon storage include slope, elevation, soil type, and mean annual temperature. This study concludes that the EPS represents the most favorable development pathway for carbon storage accumulation. This finding can provide a basis for future carbon storage dynamics and land use planning for Zoige County.

Forests doi: 10.3390/f17050574

Authors: Jiaxin Zhang Hao Li Hongwen Ma Aining Li

Poplar (Populus spp.) canker severely threatens poplar shelterbelt stability in Wuwei, Gansu. Field experiments were conducted from 2024 to 2025 to screen 16 single fungicides and 10 compound formulations via spray and smearing, using lesion inhibition and callus formation rates as core criteria, and establish a precise hierarchical control scheme. Results showed preventive agents (300-fold Bordeaux mixture, 45% lime sulfur mixture) achieved >75% control efficacy. 43% tebuconazole and 1.8% xinjunamine acetate had the strongest bacteriostatic effects, while compound systems combining fungicides, penetrants and immune inducers showed >88% efficacy. A four-grade precise control strategy was finally established, providing technical support for eco-friendly poplar canker control in arid Northwest China.

Forests doi: 10.3390/f17050573

Authors: Qinmin Lin Yingxin Wen Cunyi Tan Yifan Wu Zijie Lin Shujie Lin Zekai Ding Xinghao Tang Shijiang Cao Zhenzhen Zhang Yankong Zhu

Phoebe bournei is a rare and economically valuable tree species native to China that plays an important ecological role. In this study, we conducted a genome-wide identification of the SQUAMOSA promoter-binding protein (SBP) transcription factor family in Phoebe bournei and characterized 19 PbSBP genes distributed across 10 chromosomes. Phylogenetic analysis grouped these genes into five distinct subfamilies, each of which showed homology to SBP genes in Arabidopsis thaliana and Oryza sativa, indicating strong evolutionary conservation within the family. All identified PbSBP proteins contain the conserved SBP domain, and some members also harbor additional motifs such as the ANK domain, which may mediate protein–protein interactions. Tissue-specific expression profiling revealed that several PbSBP genes are predominantly expressed in root bark and leaves, suggesting their potential roles in defense responses and developmental regulation. Moreover, qPCR validation showed that PbSBP2, PbSBP9, and PbSBP16 were significantly upregulated under PEG-induced drought stress, implying their involvement in abiotic stress responses. This study provides a foundational understanding of the SBP gene family in P. bournei and highlights candidate genes for future genetic improvement and breeding for stress resistance.

Forests doi: 10.3390/f17050572

Authors: Aleh Marozau Sławomir Piętka Piotr Borowik Konrad Wilamowski Ewelina Bagińska

This study assessed phenotypic variation among open-pollinated half-sib families from a single relict population. Autochthonous silver fir (Abies alba Mill.) preserved in the Tisovik Reserve of Białowieża Forest represents the northeasternmost isolated relict population of the species in Europe. To secure its genetic resources and evaluate its breeding potential, a conservation plantation of open-pollinated half-sib families was established in the Hajnówka Forest District outside the natural species range. This study assessed the effects of half-sib family affiliation on the growth and phenotypic performance of almost two thousand 28–31-year-old trees representing 20 half-sib families and compared them with age-matched managed stands in the State Forests of Poland. Significant within- and among-family variation was observed for diameter at breast height (DBH) and height (H), while environmental factors had only marginal influence under the uniform site conditions of the plantation. Several half-sib families produced disproportionately high numbers of individuals with exceptional phenotypic performance, including DBH values exceeding 25 cm and height values surpassing those of managed stands. Based on a combined assessment of qualitative traits, selection differential, and 95th percentile values, 30 prototype plus trees were selected as sources of scions for establishing a future seed orchard. The outstanding growth parameters of these individuals correspond to stand ages of 40–65 years according to yield tables, despite their biological age of only 28–31 years. The results confirm the high breeding value and substantial genetic variability of the Tisovik population and demonstrate its potential for producing genetically diverse planting material adapted to lowland sites under changing climatic conditions.

Forests doi: 10.3390/f17050571

Authors: Raffaele Spinelli Natascia Magagnotti Pietro Gallo Marcello Biocca

Abandoned and semi-abandoned chestnut (Castanea sativa Mill.) orchards can be restored to production by removing invasive vegetation and pruning overgrown crowns. Both interventions stimulate a strong reaction from the old trees, which sprout abundant suckers at the root collar and along the stem. Suckers must be removed promptly to boost fruit-bearing branches. Sucker removal can be achieved with traditional manual tools (e.g., pruning saws or pole saws) or with more modern semi-mechanized methods relying on battery-powered saws. The latter are much more expensive than the former and questions arise regarding the minimum amount of work necessary to justify their purchase. This study compared the two methods, showing that the introduction of a battery-powered saw would boost work productivity by 67%, that is, from 18 to 31 trees per day. At current cost levels, that productivity margin would justify investment in a semi-mechanized system when treating at least 100 trees per year. In that case, the de-suckering cost would amount to 3.8 and 3.9 € tree−1 respectively for semi-mechanized and manual systems. Shifting from manual to semi-mechanized operation also resulted in a significant reduction in the physiological workload imposed on the workers, which would decrease by −4% to −71% depending on the circumstances. Productivity and workload variations followed the same trend, but their magnitude was highly dependent on the individual worker.

Forests doi: 10.3390/f17050570

Authors: Jifeng Deng Yueyao Li Yifan Wang Chang Sun Yanfeng Bao

In this study, natural Pinus koraiensis Siebold & Zucc. forest, Pinus sylvestris var. mongholica Litv. plantation, Quercus mongolica Fisch. ex Ledeb. plantation, Juglans mandshurica Maxim. plantation, and natural mixed coniferous–broad forests were selected in Qingyuan County. Treeless plots were set as the control check, and comparisons were then made across soil particle size composition, average particle size, standard deviation, skewness, kurtosis, single- and multifractal dimensions, and spatial distribution of soil physicochemical properties and their relationships with fractal dimensions under natural conditions. The results indicated the following: (1) The soil particle size compositions of both the topsoil and sub-topsoil in all forest stands were dominated by sand. (2) The soil particle size was characterized by excellent sorting, skewness, and a narrow peak. (3) The average particle size, single-fractal dimension, and soil physicochemical properties of the forest stands were all higher than those of the control check plots. (4) From coniferous forests to broadleaved forests and then to mixed forests, the aforementioned soil indices showed an overall increasing trend. (5) The single-fractal dimension and capacity dimension were significantly positively correlated with the volume fractions of clay and silt, as well as with soil physicochemical properties. This indicates that the contents of soil clay and silt gradually recovered under the protection of forest stands, with a better recovery effect in the topsoil. (6) Multifractal analysis showed non-uniform soil particle size distribution; thus, evaluating soil quality requires combining single- and multifractal dimensions to characterize physicochemical properties and particle size variation.

Forests doi: 10.3390/f17050569

Authors: Julia Zabala-García Guzmán Carro-Huerga Andrea Antolín-Rodríguez Víctor Marcelo Marcos Guerra Pedro A. Casquero Andrés Juan-Valdés Lucía Delgado-Salán Álvaro Rodríguez-González

The holm oak (Quercus ilex) is a keystone species in Mediterranean ecosystems due to its ecological relevance and economic value. However, its forests are experiencing increasing decline driven by poor regeneration, prolonged drought, diseases, and wood-boring insect infestations. This study evaluates the impact of Coraebus florentinus on the mechanical properties of holm oak wood. Laboratory bending tests on healthy and insect-damaged branches assessed resistance in relation to applied load, diameter, and length until maximum deflection and breakage. Results showed that C. florentinus damage (considered as a categorical variable, it was not quantified based on the presence or absence of visible symptoms and characteristic larval galleries, and we acknowledge this as a limitation of the study) altered the bending behavior of holm oak branches, mainly by reducing deformation capacity before failure. However, bending strength showed a site-dependent response, indicating that the mechanical effect of infestation may vary according to local branch characteristics and damage distribution. Infestations of C. florentinus in Q. ilex stands, whether used for timber production or pasture systems, may contribute to the loss of photosynthetically active branches and potentially affect tree productivity.

Forests doi: 10.3390/f17050568

Authors: Arzuv Allayarova Hongge Zhu

This research explores how livelihood capital endowments affect the growth of Non-Wood Forest Products (NWFPs) in rural communities in the Koyten Dag region of Turkmenistan. This study is grounded in the Sustainable Livelihoods Framework. It draws on the Capability Approach, Institutional Theory, and Human Capital Theory, which are considered to have a strong influence on NWFP development within the exclusive post-Soviet socio-ecological environment. This study also uses annual time-series data from 2001 to 2024. It applies the ARDL bounds testing method to examine the short- and long-run associations among livelihood assets and NWFP production. The results confirm strong long-run co-integration, indicating that the five capitals have a significant impact on NWFP development. Emerging as the ultimate drivers in both the short and long term, education, skills, health, and digital connectivity become especially important. Financial and social capital reflect long-term contributions, while natural capital highlights the significance of the availability of ecological resources and governance systems. The correction error term indicates a rapid rate of adjustment, suggesting that the livelihood system is robust and can return to equilibrium quickly in response to temporary shocks. This research uses the Autoregressive Distributed Lag (ARDL) method of co-integration, which is effective for small-sample analyses of long-run relationships. The empirical analysis is conducted in a systematic process, which is the unit root tests based on augmented Dickey–Fuller (ADF) and Phillips–Perron (PP) techniques, in order to establish the order of integration of variables. The Akaike Information Criterion (AIC) is used to determine the appropriate lag length for the ARDL model to achieve the best model specification. In the robustness analysis, we perform fully modified OLS (FMOLS) and dynamic OLS (DOLS) estimation. Sub-period analysis was performed to test structural breaks. The variance inflation factor (VIF) test was used to detect multicollinearity. This paper has significant theoretical and practical implications, including the need for policies that are integrative and, at the same time, enhance human capabilities, digital infrastructure, institutional quality, and resource governance. This knowledge can be used to promote the sustainable development of rural areas and as an efficient approach to the NWFP sector in Turkmenistan.

Forests doi: 10.3390/f17050567

Authors: Domena A. Agyeman Thomas O. Ochuodho Omkar Joshi

Closely related industries are often aggregated in US forest sector economic contribution analysis, yet the choice of aggregation scheme can influence results. The Impact Analysis for Planning (IMPLAN) system is the most widely applied input–output model for forest economic contribution analysis in the US. In IMPLAN, the level of industry aggregation determines which inter-industry transactions are restricted, thereby influencing the magnitude of estimated indirect and induced effects. Although IMPLAN practitioners can model individual industries to avoid aggregation bias, they must still decide whether to analyze forest industries as a single group, as traditional subsectors, or individually. This decision can alter estimated economic contributions and the conclusions drawn from them. This study evaluates how three aggregation approaches affect economic contribution estimates for the Kentucky forest sector: analyzing all forest industries as a single group, as six traditional subsectors, and individually. Direct contributions were identical across all approaches. However, indirect and induced effects differed significantly between the single-group approach and both the subsector and individual-industry approaches. These differences indicate that aggregation is not simply a reporting choice but has measurable, systematic effects on contribution estimates. Clear specification and justification of aggregation choices are therefore essential in forest economic contribution analysis.

Forests doi: 10.3390/f17050566

Authors: Ivan Milenković Ana Žugić Slobodan Milanović Jovan Dobrosavljević Milan Milenković Vanja Tadić

Phytophthora species are devastating oomycete pathogens affecting agriculture, horticulture, and natural ecosystems globally, primarily spread through the international trade of nursery stock. While synthetic fungicides remain a primary control method, there is an increasing demand for sustainable biocontrol agents. This study evaluated the inhibitory potential of essential oils from three Cupressaceae species, × Hesperotropsis leylandii (needles), Platycladus orientalis (needles), and Juniperus communis (ripe berries), against four common nursery and forest pathogens: P. cactorum, P. plurivora, P. pseudocitrophthora, and P. × cambivora. The essential oils were evaluated at concentrations of 0.1%, 0.25%, and 0.5% (v/v), while the commercial fungicide Infinito® (propamocarb + fluopicolide) served as a positive control. Results demonstrated significant dose-dependent inhibition across all treatments, with the 0.5% concentration yielding the highest efficacy. Notably, essential oil from J. communis achieved 90.2% inhibition against P. × cambivora, while Pl. orientalis essential oil reached 82.8% and 73.1% inhibition relative to the Infinito® effect against P. × cambivora and P. cactorum, respectively, underscoring the potential antimicrobial properties of these coniferous essential oils compared to the tested synthetic standard. Although the chemical analysis revealed that all investigated essential oils (× H. leylandii, Pl. orientalis, and J. communis) contained significant quantities of α-pinene (32.11, 16.01, and 32.29%, respectively), their chemical compositions differed. Namely, GC analysis revealed the presence of δ-3-carene in × H. leylandii and Pl. orientalis (18.51 and 37.98%, respectively), while cedran-8-ol was detected in significant quantity in Pl. orientalis (19.96%). Sabinene and myrcene (18.52 and 14.57%, respectively), besides α-pinene, were most abundant in J. communis essential oil. The observed differences in the evaluated activity might be due to the determined essential oils’ chemical composition.

Forests doi: 10.3390/f17050565

Authors: Didik Suprayogo Arif Firmansyah Muhammad Al-Faruqi Desca Wahyu Ramadhan Istika Nita Kurniatun Hairiah Meine van Noordwijk

Pine plantations on volcanic slopes in Indonesia are considered to be forests and are managed for wood production and slope protection. Logging practices followed by replanting may affect soil health. Existing agroforestry management contracts allow farmers to intercrop with vegetables in young plantations and grow fodder grasses in older ones. However, critical data on hydrological functions in such systems are scarce, while concerns over heavy rainfall and floods increase. We explored the relationships between soil cover, soil carbon, earthworms, soil porosity and infiltration rates in relation to slope class in second-rotation pine plantations around two years of age (intercropped) and at ten-year old pine-grass stages. Five slope classes (0%–8%, 8%–15%, 15%–25%, 25%–45%, and >45%) were compared with three measurement points each. Basic soil chemical and physical characteristics were measured for the 0–10, 10–20 and 20–30 cm layers. Remnant natural forest was available as a historical reference only on the steepest slope class. Organic soil carbon (COrg) divided by a texture-based reference level was 1.12, 0.32 and 0.49 for natural forest, young and old agroforestry on very steep slopes, respectively. Within pine-based agroforestry relative decline with slope class (1–5) was pronounced in earthworms (biomass −3.46, population −4.18) and infiltration rates (−2.35) while bulk density increased (0.49); for soil carbon (COrg), nitrogen, available phosphorus and exchangeable Mg effects in the −1.26 to −1.68 range indicated a loss of functional topsoil. Differences with age of the agroforestry systems were much smaller but included a decreasing earthworm population but an increase in mean earthworm weight and partial recovery of the COrg/CRef ratio. Pine-based agroforestry on very steep soils had only 10%–14% of the earthworm biomass and 35% of the infiltration rate of reference natural forest. Understory vegetation biomass and litter layer necromass were more than five-fold higher in the natural forest. Across all samples a higher COrg and higher earthworm biomass were associated with complementary positive changes in infiltration rates and soil porosity. Regression analysis suggests equal skill of tree cover, soil COrg, porosity, aggregate stability and earthworms to predict infiltration rates while explanatory variables were strongly correlated. Management of the pine plantations may have to achieve a closer approximation of the conditions in natural forests to effectively protect upper watersheds.

Forests doi: 10.3390/f17050564

Authors: Viacheslav I. Kharuk Il’ya A. Petrov Sergei T. Im Alexander S. Shushpanov Sergei O. Ondar Andrey M. Samdan

Changing hydrothermal regime leads to pronounced changes in growth and ranges of Siberian tree species that are mostly negative at the southern part of the trees’ habitat. Here we analyzed the response of Larix sibirica and Populus laurifolia to moisture changes in unique refugia that border the Mongolian desert in Southern Siberia. The great age of old-growth larch trees (>500 years) suggests that the refugia have existed throughout the Holocene. We aimed to (1) analyze larch and poplar growth and range response to the changing temperature and moisture regime, (2) explore the potential migration of trees into the desert, and (3) analyze Gross Primary Productivity (GPP) dynamics within the refugia and adjacent desert. We used on-ground surveys, remote sensing data, and dendroecological analysis. We found that since the warming onset (c. 1980), larch and poplar trees have increased their growth and population within and beyond the refugia (+300% for poplar and +45% for larch). Both species’ growth has been controlled by atmospheric and soil droughts (measured by the Standardized Precipitation Evapotranspiration Index (SPEI) and Self-Calibrating Palmer Drought Severity Index (scPDSI)) and by microtopography-dependent moistening. Summer winds impair trees’ growth via increased evapotranspiration. Both species were migrating to the southern sandy dunes. Although poplar is less drought-resistant than larch, it was shifting ahead of larch (5.6 m/year vs. 0.8 m/year). The mean and maximum treeline shifts were 260 and 450 m for poplar and 35 m and 70 m for larch. P. laurifolia occupied new climate-caused niches ahead of drought-resistant L. sibirica due to its higher prolificacy. We found a “desert greening” phenomenon, i.e., a significantly increasing GPP trend (R2 = 0.31) in both refugia and sandy dunes. The GPP increase correlated with tree growth increase (r2 = 0.36–0.39). The larch and poplar migration to the desert contradicts the predicted shrinkage of the tree ranges within their southern boundary. However, the projected increase in the moisture deficit by 2080–2100 may impair this phenomenon. Nevertheless, current changes in the hydrology regime are favorable for larch and poplar growth and expansion into the adjacent Mongolian desert.

Forests doi: 10.3390/f17050563

Authors: Ruiying Ren Kai Zhang Liang Qi Maocheng Zhao Weijun Xie Chi Zhou Mingguang Li

With increasing demand for fine-scale ecological management under carbon neutrality frameworks, multi-temporal assessment of carbon stock change (ΔC) at the individual-plant scale has become essential for understanding plant-level carbon dynamics and supporting management decisions. However, methodologies for repeated monitoring at this scale remain fragmented, showing limited cross-temporal comparability, weak cross-scale consistency, and insufficient integration across methods. Existing approaches can be grouped into three pathways: (i) process-based methods derived from CO2 exchange measurements, (ii) state-based approaches estimating biomass and ΔC, and (iii) sensing-based approaches using structural, spectral, thermal, and fluorescence signals. These approaches offer complementary strengths, yet none simultaneously achieve high accuracy, temporal continuity, and operational scalability for multi-temporal ΔC estimation. Among these, stock-based and structural approaches form the primary estimation pathways, while flux-based and functional sensing methods provide complementary constraints. This review synthesizes and compares these approaches in terms of their theoretical basis, spatial support, temporal characteristics, and uncertainty structures. To address the lack of methodological integration, we propose a structure–function–scale framework that links heterogeneous observations across spatial and temporal domains and emphasizes cross-scale consistency as a prerequisite for reliable ΔC estimation. Within this framework, we further examine how multi-source integration can connect structural and functional observations through segmentation, co-registration, scaling, temporal alignment, and uncertainty propagation. By integrating traditional measurement logic with emerging remote sensing technologies, this review provides a unified methodological framework for ΔC estimation and identifies key directions for advancing fine-scale carbon monitoring, spatiotemporally consistent data fusion, uncertainty-aware inference, and MRV-oriented verification systems.

Forests doi: 10.3390/f17050562

Authors: Yadi Liu Ruidong Lu Purui Guo Ying Wang Yidan Shi Chunze Xie Yuanhang Wu Yu Zeng Lu Zou Ke Zhu He Li Song Sheng

Bamboo is a rapidly renewable lignocellulosic resource widely used in construction, composites, and bio-based materials. However, its practical applications are often limited by high hygroscopicity, biological degradation, and dimensional instability under humid conditions. This review synthesizes current research on bamboo structure, microbial interactions, and material modification strategies to better understand how bamboo-associated microbiomes influence both deterioration and potential material enhancement. We summarize conventional chemical and thermal modification approaches that improve hydrophobicity, durability, and mechanical stability while also discussing their technical limitations. Emerging studies on bamboo-associated microbial communities reveal complex interactions between fungi, bacteria, and lignocellulosic substrates, including enzymatic degradation, nutrient cycling, and potential bioprotective functions. Advances in multi-omics technologies have further provided insights into the functional gene pools and metabolic pathways involved in bamboo–microbe interactions. Recent conceptual developments in microbiome engineering and engineered living materials (ELMs) suggest possible future directions for integrating microbial functionality into bamboo-based materials. However, direct experimental evidence for microbial enhancement of bamboo structural performance remains limited. Future interdisciplinary research integrating material science, microbial ecology, and synthetic biology will be essential to evaluate the feasibility and safety of such biohybrid systems.

Forests doi: 10.3390/f17050561

Authors: Klement Vidholdová Vilkovská

This study investigates strategies to reduce mould growth on steamed beech wood by evaluating drying-based and fungicide-based protection approaches. The drying-based approach focused on optimising the temperature of warm-air drying parameters to control moisture content and limit mould development. The fungicide-based approach involved testing selected agents, including 3-iodo-2-propynyl butyl carbamate, boric acid, quaternary ammonium compounds, and nano-ZnO, for their effectiveness in preventing mould formation. Mould growth was assessed by macroscopic observation and classified according to standardised intensity levels. The results indicate that adjusting drying parameters alone is insufficient to prevent mould growth, whereas specific fungicide treatments provide effective surface protection. These findings offer practical guidance for minimising mould development on beech wood during drying and storage.

Forests doi: 10.3390/f17050560

Authors: Lu Susaeta Kauffman Kaetzel Tokarczyk

We estimate Oregon’s mass timber-related market value and economic contribution using two complementary valuation strategies and two IMPLAN implementations. Although mass timber includes CLT, glulam, nail-laminated timber, dowel-laminated timber, mass plywood panels, and structural composite lumber products, the empirical market-value estimates are centered primarily on CLT- and MPP-related evidence because these products have the most consistently available Oregon-specific data. Market value is inferred from production-based approaches, including facility capacity, Oregon’s share of U.S. output, and tracer-product scaling, and from demand-based approaches, including harvest routing, construction floor area, and U.S. demand allocation. These direct values are then entered into industry contribution analysis (ICA) for Oregon’s Engineered Wood Member and Truss Manufacturing sector and into analysis-by-parts (ABP) using a custom mass timber spending pattern. During 2018–2023, production-based estimates were larger and more variable than demand-based estimates, bracketing a plausible scenario range rather than providing a single point estimate. In 2022 price scenarios, all price-exposed cases scale proportionally with assumed panel prices. When identical direct values are used, ABP produces larger total employment and output effects than ICA because it routes more activity through upstream supplier industries. Output-per-worker sensitivity affects only direct employment in ABP. Forward scenarios for 2030 and 2035 indicate substantially larger total effects under ABP than ICA, but these estimates are conditional scenarios rather than forecasts. The framework provides a transparent basis for policy, investment, supplier-development, and workforce-planning discussions in an emerging industry with incomplete product-level data.

Forests doi: 10.3390/f17050559

Authors: Liu Cai Liu Shi Li Fan

Bamboo plantations are increasingly recognized as significant terrestrial carbon sinks, yet accurate estimation of biomass and carbon stocks requires species-specific, regionally validated allometric models. Bambusa emeiensis L.C.Chia & H.L.Fung (ci bamboo) is among the most ecologically and economically important clump-forming bamboo species in southwestern China, but robust multi-regional allometric models are lacking. Using destructive sampling data from 127 culms across two major production areas—Sichuan Province (n = 82) and Guizhou Province (n = 45)—we developed additive biomass and carbon storage model systems enforcing mathematical additivity via nonlinear seemingly unrelated regression (NSUR). Allometric equations used diameter at breast height (D), culm height (H), and compound variables (DH, D2H) as predictors. Regional models achieved Ra2 of 0.0879–0.8320 total relative error (TRE): −0.99% to 0.04% for biomass and Ra2 of 0.0923–0.8282 (TRE: −1.01% to 0.03%) for carbon storage; culm and total aboveground models attained Ra2 ≥ 0.52. Organ-level carbon content (40.79%–44.46%) was significantly lower than the intergovernmental panel on climate change (IPCC) default of 50% (one-sample t-test, p < 0.01 for all organs), with Sichuan values exceeding Guizhou values (independent-samples t-test, p < 0.01), indicating that use of the default would overestimate carbon stocks by 12%–22%. Cross-regional validation revealed prediction biases of up to ±19.24% when applying single-region models outside their training area, whereas the combined model held errors within ±11.36% for biomass and ±8.49% for carbon storage. External validation using 32 independent culms from Hunan, Yunnan, and Chongqing confirmed the robustness of the combined model (TRE: −6.30% to 4.27%). A key limitation is that belowground biomass was not measured. The established models provide scientifically rigorous and practically applicable tools for regional carbon accounting of B. emeiensis plantations under China’s national greenhouse gas inventory framework and for informing sustainable bamboo management planning, and demonstrate that species- and region-specific carbon fractions are essential for accurate carbon stock assessments.

Forests doi: 10.3390/f17050558

Authors: Xia Shi Xia Yuan Zhao Genovese

Urban forest fragmentation can weaken ecological connectivity and reduce the spatial continuity of cooling benefits, highlighting the need for structure-function integrated planning. Using 2020 as the baseline year, this study combined the Markov Chain-Future Land Use Simulation model, Morphological Spatial Pattern Analysis, the Minimum Cumulative Resistance model, and Kernel Density Estimation to simulate the evolution of Hangzhou’s forest-dominated ecological network under Business-as-Usual, Economic Development, and Ecological Conservation scenarios for 2030. A Random Forest model with Shapley Additive Explanations was further used to quantify the nonlinear relationship between landscape spatial context and land surface temperature. The results show that the Economic Development and Business-as-Usual scenarios intensify forest fragmentation and weaken the structural integrity of potential ecological corridors, whereas the Ecological Conservation scenario improves network stability through patch amalgamation, core area expansion, and reduced breakpoint density. Land surface temperature was strongly associated with built-up land adjacency. Built-up areas near forest patches showed a maximum relative cooling benefit of 8.04 degrees Celsius, and corridor cooling effects were most pronounced within 300 m, remaining detectable up to about 900 m under the Ecological Conservation scenario. These findings support structure-oriented planning for urban forest conservation and heat mitigation.

Forests doi: 10.3390/f17050557

Authors: Min Wu Ziheng Huang Shuang Liu Zhilong Wu Tao Hong Xisheng Hu

Quantifying vegetation dynamics has become a critical scientific imperative in the context of global ecosystem restoration initiatives targeting degraded forests. Previous studies have explored vegetation-cover change trends at different spatial scales worldwide using the Theil–Sen (TS) estimator and Mann–Kendall (MK) test, yet few have accounted for the uncertainty in resulting trends across time-series datasets of varying lengths. Taking the coastal zone of Fujian Province in Southeast China as a case study, we investigated the uncertainty of vegetation-cover change trends using normalized difference vegetation index (NDVI) datasets of different lengths (e.g., 20-year, 15-year, and 10-year) via the TS estimator and MK test. Additionally, piece-wise regression was employed to detect turning points and shifts in vegetation trends between 2001 and 2020. The results indicate significant discrepancies in trend estimation across datasets of different lengths, with consistency ratios ranging from 46.1% to 64.7% among the 20-year, 15-year, and 10-year series. The MK test is more sensitive to time-series length than the TS estimator, with areas of significant change decreasing by over 50% when transitioning from a 20-year to a 10-year dataset. The spatial distribution of trend shifts exhibits a distinct “coastal–inland” polarization pattern, with 2010 as the turning point. Eight modes of vegetation trend shifts were identified based on pre- and post-turning point dynamics. Furthermore, piece-wise regression improved trend accuracy by approximately 15%. This research advances the mechanistic understanding of spatiotemporal vegetation dynamics and supports adaptive ecosystem management strategies.

Forests doi: 10.3390/f17050556

Authors: Katché Komlanvi Akoete Kossi Adjonou Atsu K. Dogbeda Hlovor Kossi Novinyo Segla Jana Balzer Sally Janzen Vincenzo Polizzi Yvonne Walz Kouami Kokou

The degradation of forest landscapes in West Africa, particularly in Togo, threatens ecological and socio-economic sustainability. This study analyzes the spatio-temporal dynamics of land use in the central plains of Togo between 1991 and 2022, and projects its evolution for 2030 and 2050 to guide restoration strategies. The methodology integrates the interpretation of Landsat images (1991, 2005, 2022) and the analysis of indicators, including conversion rates and the anthropization index. Prospective modeling (Markov chains and neural networks) follows a trend scenario. The results reveal a sharp decline in natural forest formations: dense semi-deciduous and dense dry forests (−50.55%) and woodlands (−62.06%), converted mainly to cropland, plantations, and built-up areas. Shrub/tree savannas, the dominant class, represent a transitional stage resulting from forest degradation. The average annual deforestation rate is 0.75%. The ecological disturbance index increased from 0.24 (1991) to 0.45 (2005), and then to 0.56 (2022), reflecting increased human impact and fragmentation. Projections indicate that these trends will continue, highlighting the growing vulnerability of ecosystems and the need to integrate this dynamic into sustainable management and restoration policies.

Forests doi: 10.3390/f17050555

Authors: Qiao Gao Gang Xu Yi Hu Meiyu Liu Xuyang Lu Baoli Duan

Primary succession following glacier retreat provides a natural system for testing whether soil development simply shifts fine roots along a single acquisitive–conservative axis orinstead changes the nutrient-acquisition pathway that dominates at the community level. We hypothesized a stage-dependent sequence, from substrate-limited exploration, to transient morphological capture, and finally to rhizosphere-mediated biochemical mobilization. To test this idea, we quantified fine-root morphology, absorptive-transport partitioning, anatomy, phosphatase activity, exudation, community-scale belowground structure, and soil and rhizosphere properties across woody communities representing approximately 20, 40, and 90 years since deglaciation in the Hailuogou Glacier foreland. Across succession stages, bulk density and pH declined, whereas field capacity, soil carbon, and soil nitrogen increased, indicating rapid development of the belowground resource environment. Fine-root strategies did not fall along a single acquisitive–conservative continuum. Instead, morphological nutrient capture peaked at intermediate succession: the 40-year stage had the highest specific root length, specific root area, absorptive-to-transport root length ratio, and root nitrogen concentration. In contrast, the 90-year stage showed lower specific root length but higher dry matter content, thicker cortex, greater standing fine-root biomass, larger rhizosphere volume, higher phosphatase activity, and greater area-based carbon exudation. This late-successional syndrome coincided with stronger extracellular enzyme activity, larger dissolved organic carbon and nitrogen pools, and higher microbial biomass, despite negative net nitrogen mineralization. Species-level analyses showed that biochemical-input traits were jointly shaped by successional stage, species identity, and their interaction. Together, these results show that primary succession did not simply increase or decrease root acquisitiveness. Instead, as soils developed, it changed the nutrient-acquisition pathway that dominated, with direct implications for nutrient cycling and vegetation dynamics in rapidly developing glacier-foreland ecosystems.

Forests doi: 10.3390/f17050554

Authors: Jesse E. Gray Mandy Slate Alyson S. Ennis Courtney L. Peterson John B. Bradford Adam R. Noel Michael C. Duniway Tara B. B. Bishop Ian P. Barrett Chris T. Domschke Joel T. Humphries Nichole N. Barger

Pinyon–juniper (PJ) woodlands, one of the most extensive mature and old-growth woodland types in the Western United States, provide critical ecological, cultural, and economic benefits but face increasing threats from climate change, altered disturbance regimes, invasive species, and pests. We developed the PJ Woodland Climate Adaptation Management Menu, a decision support tool designed to guide adaptive, climate-informed management of PJ ecosystems, particularly within the Colorado Plateau ecoregion. The menu was created through an iterative, collaborative process involving literature review, integration of strategies from existing adaptation frameworks, and extensive input from scientists, land managers, and community partners during workshops and focus groups. The menu links specific, evidence-based approaches to each of six broad strategies, including soliciting community input, mitigating disturbance, enhancing and maintaining biodiversity, conserving ecotones, timing actions for optimal outcomes, and accepting climate-driven changes when appropriate. It is intended for use with the Adaptation Workbook to help managers connect local goals and climate vulnerabilities to tailored management tactics. Hypothetical scenarios demonstrate the menu’s application to contrasting PJ woodland conditions, from die-off events to old-growth maintenance. Lessons learned during development underscore the value of early stakeholder engagement, cross-sector collaboration, and balancing diverse ecological objectives. This menu offers a flexible, transferable framework to strengthen climate resilience in PJ woodlands and serves as a model that could improve adaptation planning in other dryland forest ecosystems.

Forests doi: 10.3390/f17050553

Authors: Zhimin Liu Xiao Zhao Linhao Guo Ming Chang Xuemei Wang Bo Peng Weiwen Wang

Mangroves are important coastal wetland ecosystems with high ecological service values and strong carbon sequestration capacity, serving as a crucial barrier for coastal ecological security. However, current afforestation efforts often ignore environmental suitability differences among mangrove species, while the applicability value and ecological risks of exotic species (Laguncularia racemosa and Sonneratia apetala) for restoration remain poorly understood. Five native and two exotic mangrove species along China’s coasts were selected in this study. Using the MaxEnt model, we identified key environmental factors governing their distribution, predicted their current and future suitable habitats (under the SSP245 scenario in the 2070s), and quantified niche overlap between native and exotic mangroves. The results showed that temperature-related factors (air and sea temperature) are the core climatic drivers shaping the typical mangrove distribution, followed by sea surface salinity, with precipitation contributing little. Currently, niche overlap between native and the two exotic species is low (D.overlap: 0.129–0.340), indicating certain niche differentiation. Under the SSP245 scenario in the 2070s, except for Rhizophora stylosa, other studied species appear to experience expanded suitable habitat areas and a northward latitudinal distribution shift. Compared with Sonneratia apetala, Laguncularia racemosa exhibits a more pronounced expansion of suitable habitats in the future, with its overall suitable area second only to the native Kandelia obovata, indicating its stronger adaptive potential to climate change. Clarifying niche differentiation and constructing species-specific management frameworks may facilitate biological invasion control, mangrove restoration, and species diversity improvement.

Forests doi: 10.3390/f17050552

Authors: Noor Azland Jainudin Gaddafi Ismaili Faisal Amsyar Redzuan Ahmad Fadzil Jobli Iskanda Openg Jamil Matarul Mohamad Zain Hashim Meekiong Kalu Mohd Effendi Wasli Zurina Ismaili Ahmad Nurfaidhi Rizalman Nur Syahina Yahya Mohamad Asrul Mustapha

This bibliometric study examined 179 Scopus-indexed publications on the physical and mechanical properties of medium-density fiberboard (MDF) published between 2016 and 2025. BiblioMagika® was used for performance analysis, and Biblioshiny was used for keyword co-occurrence, thematic mapping, and thematic evolution. The papers identified as the cohort for analysis had received 2830 citations in total, with an average of 15.81 citations per paper, and an average h-index of 30. The European Journal of Wood and Wood Products and BioResources were the most productive sources. Three distinct categories were identified through keyword mapping among the studies reviewed: (1) advanced composites and reinforcement, (2) adhesive and emission-related studies, and (3) circular-material strategies. Thematic evolution showed a trend away from traditional resin-performance topics toward broader sustainability-related themes, particularly bio-based adhesives and recycling-related topics. Overall, this review provides a quantitative overview of publication patterns, influential sources, and thematic development in MDF research. It also provides direction for future MDF research, focusing on durability, large-scale feasibility, life-cycle assessments, and practical implementation.

Forests doi: 10.3390/f17050550

Authors: Lucian Dinca Danut Chira Gabriel Murariu

Freezing rain is a high-impact winter weather phenomenon that acts as a major disturbance agent in forest ecosystems, causing canopy damage, stem breakage, tree mortality, and long-term changes in forest structure and functioning. Although ice storms have been studied for decades, research on freezing rain impacts on forests remains fragmented across multiple disciplines, and few studies have attempted an integrated synthesis that simultaneously combines climatological, ecological, and methodological perspectives. In this study, we present a systematic and integrative review of the scientific literature on freezing rain and forests, combining a large-scale bibliometric analysis with an in-depth qualitative synthesis. A total of 241 publications retrieved from the Scopus and Web of Science databases were analyzed following PRISMA guidelines. The bibliometric assessment examined publication trends, geographic distribution, institutional contributions, research domains, and keyword networks. The qualitative review synthesized current knowledge on freezing rain climatology, forest damage mechanisms, species-specific vulnerability, major ice storm events, detection and modeling approaches, and ecological consequences. Results reveal a strong increase in scientific output over the last two decades, dominated by research from North America and northern Europe. Ice accretion intensity emerges as the primary driver of forest damage, while species traits, crown architecture, tree size, stand structure, topography, and exposure strongly modulate damage severity. Freezing rain affects a wide range of forest types worldwide and triggers both immediate structural damage and long-term ecological effects, including altered successional dynamics and reduced forest productivity. Recent methodological advances—including passive remote sensing (e.g., optical satellite data), active remote sensing (e.g., LiDAR), experimental ice storm simulations, reanalysis datasets, and machine learning approaches—have significantly improved detection, monitoring, and forecasting capabilities. Despite these advances, major research gaps remain, particularly regarding long-term ecosystem recovery, trait-based vulnerability, socio-economic impacts, and future freezing rain regimes under climate change. This review highlights freezing rain as an increasingly important but underappreciated forest disturbance and underscores the need for interdisciplinary research and adaptive management strategies in ice-prone regions.

Forests doi: 10.3390/f17050551

Authors: Li Yi Kehao Cao Dennis W. Hess Lianpeng Zhang Xijuan Chai Kaimeng Xu Linkun Xie

Wood is a sustainable material, but hygroscopicity can affect dimensional stability and mechanical durability. Recent research has increasingly focused on combining citric acid with various polyols as eco-friendly crosslinking systems to improve wood properties. Herein, a solvent-free and catalyst-free method was used to synthesize bio-based polyesters from citric acid and mannitol. In situ curing was carried out after vacuum-pressure impregnation of fast-growing poplar wood (Populus deltoides Marshall). Morphological characterization showed that the polyester filled the cell lumen and penetrated the cell wall structure. It was confirmed by Fourier Transform Infrared (FTIR) and cross-polarization/magic angle spinning (CP/MAS) 13C nuclear magnetic resonance (NMR) analysis that the polyester formed covalent ester bonds with wood hydroxyl groups, which indicated successful chemical grafting. The dimensional stability and mechanical properties of the modified wood were greatly improved. The parallel compressive strength of the grain reached 41.5 MPa, which was 41.7% higher than that of the untreated wood. This research adopted a citric acid–mannitol polyester, providing a sustainable, economical, and scalable approach for the development of high-performance, degradable wood composites for construction/furniture applications.

Forests doi: 10.3390/f17050549

Authors: Jae-hak Song Mi-na Jang Byung-doo Lee Woong-hee Lee Seong-kyun Im Hyunseok Lee Sung-yong Kim

Recent climate change-driven warming and prolonged drought have reduced fuel moisture in forests, increasing the frequency and severity of wildfires. In particular, crown fires have become more frequent, highlighting the importance of quantifying crown fuel characteristics. However, studies on the crown fuel biomass of Pinus densiflora in South Korea remain limited. This study aimed to quantify crown fuel biomass and develop a diameter at breast height (DBH)-based allometric model across major P. densiflora distribution areas. A total of 67 sample trees were destructively sampled across seven regions. Crown fuel components were classified into needles and branch diameter classes, and their dry biomass was measured. A log-transformed allometric model was developed, and its reliability was evaluated using correction factors, confidence intervals, and prediction intervals. Branches accounted for approximately 78% of total crown fuel, while needles accounted for approximately 22%. The model demonstrated high explanatory power, with Radj2 ranging from 0.783 to 0.945. Combustible fuels (≤1.0 cm) accounted for approximately 45% of total crown fuel. The developed model can be used as an input for wildfire spread prediction and provides a basis for crown fire risk assessment and fuel mapping.

Forests doi: 10.3390/f17050548

Authors: Mosab Khalil Algidail Arbain Peter Márton Roman Kadlečík Šimon Saloň Milan Koreň

Tree detection is a core task in forest inventory and mapping, yet reliable stem identification remains difficult in dense and structurally complex forests. This study systematically reviews the literature on terrestrial laser scanning (TLS)-based tree detection to summarize methodological development, identify persistent challenges, and highlight research gaps. Records were retrieved from Scopus and Web of Science (WoS). Following PRISMA 2020, 39 articles were included and analyzed using Bibliometrix v 5.2.1 package in R Studio 2026.01.1 and qualitative content coding. The reviewed studies were published between 2011 and 2025 in 20 peer-reviewed journals and involved 169 authors from 73 institutions across 24 countries. The literature was organized into three developmental phases: foundational development (2011–2015), rapid growth (2016–2020), and refinement and integration (2021–2025). Across these phases, methods evolved from geometric fitting and clustering to voxel-based and increasingly integrated workflows. Reported performance varied markedly with scan configuration, forest structure, and algorithm design, ranging from very low detection rates to near-complete detection under favorable conditions. Overall, TLS shows strong potential for forest inventory; however, dense stands, multilayered forests, and regeneration-rich environments remain major challenges.

Forests doi: 10.3390/f17050547

Authors: Vít Šrámek Kateřina Neudertová Hellebrandová Ondřej Špulák Věra Fadrhonsová

Soil organic carbon (SOC) storage in forests is governed by complex interactions between site conditions and vegetation. This study quantifies SOC stocks across a gradient of Target Management Sets (TMS) in the Czech Republic (Central Europe) to evaluate the baseline storage capacity of distinct ecological sites and the modifying effects of dominant tree species, specifically Norway spruce and European beech. Utilizing large-scale spatial data, linear mixed-effects models, and piecewise structural equation modeling (pSEM), we analyzed SOC stratification across middle (≈400–600 m a.s.l.) and higher (≈600–800 m a.s.l.) elevational zones. The results indicate that while overall SOC stocks inherently increase with elevation due to climatic constraints, tree species dictate the vertical carbon distribution within the soil profile. Specifically, conifers (i.e., Norway spruce and Scots pine) accumulate SOC primarily in the organic layer, whereas broadleaves (mainly European beech and oak) translocate and stabilize carbon in deeper mineral horizons. The pSEM analysis revealed that beech functions as a ‘calcium pump’, increasing topsoil pH and driving calcium-mediated SOC stabilization in mineral soils. This mechanism is highly effective at middle elevations but partially overridden by abiotic limits at higher elevations. We conclude that inherent site conditions (TMS) determine total SOC capacity, whereas tree species management controls SOC stability. Although no significant differences were observed in total SOC stocks between conifers and broadleaves at the same sites (medians of total SOC ranged from approx. 5 to 16 kg·m−2, depending on the site), converting purely coniferous stands into broadleaves represents an effective strategy for long-term mineral SOC stabilization, particularly in middle-elevation sites.

Forests doi: 10.3390/f17050544

Authors: Lei Yin Jianwan Ji Yuchao Hu Xiaoxiao Zhu Haixia Chen Lei Zhang Yinpeng Zhou

Under the context of global change, forest cover, as a critical component of terrestrial ecosystems, exerts a profound influence on regional ecological security and sustainable development through its spatiotemporal evolution. Current research on forest cover change primarily focuses on pattern description and single-factor driver analysis, with insufficient in-depth exploration of the interactions among multiple factors and their associated nonlinear mechanisms. To address this gap, this study focuses on the Wumeng Mountain area, a typical ecologically fragile karst region in Southwest China. By comprehensively employing methods such as Theil–Sen Median trend analysis, land use transfer matrix, standard deviation ellipse, and spatial autocorrelation analysis, this study systematically reveals the spatiotemporal evolution characteristics of forest cover from 1985 to 2024. On this basis, an integrated eXtreme Gradient Boosting–SHapley Additive exPlanations (XGBoost-SHAP) model is introduced to construct an indicator system comprising 16 driving variables, including elevation, slope, aspect, temperature, precipitation, soil type, soil pH, soil thickness, soil organic matter, soil moisture content, GDP, population, distance from water, distance from railway, distance from grade highway, and distance from government. This model quantifies the influence intensity of each driving factor on forest change. The main findings are as follows: (1) From 1985 to 2024, the forest cover rate in the Wumeng Mountain area significantly increased from 54.7% to 60.2%, exhibiting a “high-low-high” heterogeneous spatial distribution pattern along the northeast-southwest axis; (2) Forest increase primarily originated from the conversion of cropland and grassland, with contribution rates reaching 93.58% and 5.9%, respectively, indicating an overall trend of “increase in low-value areas and decrease in high-value areas”; (3) Forest cover change is driven by both natural and anthropogenic factors, with dominant driving factors exhibiting phased replacement over time. Overall, this is manifested as long-term stable constraints exerted by natural background factors, alongside strong disturbances from anthropogenic factors such as social-economic, and transportation-related activities. Natural factors remain the primary driving force behind changes in forest cover. The core findings of this study elucidate the complex driving factors of forest change in karst mountainous areas, thereby providing scientific support for the precise management of regional forest resources, the planning of ecological restoration projects, and the implementation of sustainable development strategies.

Forests doi: 10.3390/f17050546

Authors: Wojciech Szewczyk Katarzyna Szewczyk

This study provides an operational-scale assessment of internal decay caused by Porodaedalea pini in managed Scots pine stands based on data collected during harvesting operations. Unlike previous studies relying on indirect indicators such as fruiting bodies, this work quantifies the actual proportion of logs affected by decay under real-world production conditions. Although the mean decay share was relatively low (3.29%), substantial variability among stands was observed. A moderate relationship between stand age and decay occurrence was detected; however, statistical models showed limited explanatory power, highlighting the influence of additional stand-level factors. A potential threshold around 110 years may indicate an increased risk of decay in overmature stands. These findings underline the importance of incorporating decay risk into forest management decisions while acknowledging the uncertainty associated with predicting internal decay under operational conditions. These results may support forest management decisions regarding rotation age and timber quality risk assessment.

Forests doi: 10.3390/f17050545

Authors: Lepeng Lin Gongxun Bai Tianlong Han

As a critical component of urban ecological infrastructure, urban forests play a pivotal role in regulating regional climate and mitigating the urban heat island (UHI) effect. However, existing studies have predominantly focused on single temporal snapshots or aggregate spatial scales, with limited attention to the seasonal dynamics of urban forest landscape patterns and a lack of systematic quantification of their nonlinear regulatory mechanisms. Empirical evidence from subtropical cities remains particularly scarce. In this study, Hangzhou was selected as the study area. Land Surface Temperature (LST) was retrieved using the Google Earth Engine (GEE) platform, and the Thermal Field Variance Index was employed to classify UHI intensity. Six representative forest landscape indices were selected to construct an evaluation framework. Pearson correlation analysis and the XGBoost model were further applied to quantify the relationships between landscape patterns and seasonal LST variations. The results reveal that: (1) LST in Hangzhou exhibits pronounced seasonal variability, following the order of summer > spring > autumn > winter. Areas without UHI effects dominate in spring, summer, and autumn, whereas the extent of strong UHI zones increases markedly in winter. (2) All landscape indices are significantly correlated with seasonal LST; forest ratio and forest largest patch index show negative correlations, while forest patch density, forest landscape shape index, number of patches, and landscape division index (DIVISION) are positively correlated. (3) The XGBoost model indicates that DIVISION consistently exhibits high contribution across all seasons, identifying it as a key determinant of LST variation. These findings provide a scientific basis for optimizing urban forest landscape configuration and developing effective UHI mitigation strategies.

Forests doi: 10.3390/f17050543

Authors: Anastasiia Kovalova Marcin Chodak

Microbial nutrient cycling in afforested mine soils may be affected by the plant litter quality. This study investigated how different tree species—Scots pine (Pinus sylvestris), silver birch (Betula pendula), European larch (Larix decidua), and black alder (Alnus glutinosa)—influence microbial carbon (C), nitrogen (N), and phosphorus (P) limitations in reclaimed sandy mine soils. We combined substrate-induced respiration (SIR) and ecoenzymatic stoichiometry (EES) to diagnose these metabolic constraints. The SIR analysis revealed a universal primary limitation by labile C across all tree species, with glucose addition stimulating respiration by 271%–333%, regardless of the soil organic carbon content. However, EES revealed distinct secondary nutrient constraints driven by species-specific litter quality. Alder stands exhibited severe P limitation, likely due to high P demand for symbiotic N-fixation and intense competition for P between trees and microbes. In contrast, birch stands showed stoichiometric homeostasis and a slight N deficiency. Coniferous species exhibited P limitation and low enzymatic activity, indicating a strategy focused on intensive nutrient acquisition under low-energy conditions associated with recalcitrant needle litter. These findings demonstrate that while energy limitation is a universal constraint in mine soils, tree species determine the nature and intensity of secondary nutrient limitations due to differences in litter stoichiometry.

Forests doi: 10.3390/f17050541

Authors: Shulin Chen Weixi Zhang Hengming Zhang Lulan Miao Zhongyi Pang Yanhui Peng Wenxu Zhu Keye Zhu Changjun Ding Rusheng Peng

Monoculture plantations often face challenges of soil degradation and declining ecosystem services. Intercropping is beneficial to improving soil quality; however, the long-term effects of intercropping woody plants with medicinal herbs on soil ecosystems remain unclear. This study aimed to investigate the temporal effects of different durations of poplar intercropping with Aralia elata on soil physicochemical properties, enzyme activities, and soil microbial community structure. Soil samples were collected from the 0–20 cm soil layer, with composite samples obtained by mixing four soil cores per plot. We determined soil physicochemical properties, including pH, total carbon (TC), total nitrogen (TN), and total phosphorus (TP); soil enzyme activities, including invertase, urease, phosphatase, and β-N-acetylglucosaminidase (NAG); and soil microbial community structure using high-throughput sequencing of the bacterial 16S rRNA gene and fungal ITS region. Intercropping significantly affected soil chemical properties and enzyme activities in poplar plantations. Compared with the monoculture control (Y), TN (p < 0.01) and TC (p < 0.01) contents increased significantly in the 3- and 7-year intercropping treatments. The activity of β-N-acetylglucosaminidase (NAG) was enhanced following poplar–Aralia elata intercropping. In addition, intercropping significantly changed the composition and structure of soil microbial communities. In summary, introducing Aralia elata into poplar plantations can effectively improve soil fertility and reshape soil microbial community structure. This positive effect is time-dependent and becomes more significant with a 7-year intercropping duration. Poplar–Aralia elata intercropping represents a feasible management strategy to enhance ecological sustainability and soil health in plantation ecosystems of Northeast China.

Forests doi: 10.3390/f17050542

Authors: Shaopeng Zhang Thi Yen Nhung Nguyen Hongge Zhu

This study examines the impact of Sustainable Livelihood Capital (SLC) on women’s participation in production activities in Vietnam’s mangrove areas, using a gender-focused approach to advance gender-sensitive livelihood theory. Employing binary Logit regression and cross-tabulation analysis, model robustness was confirmed via the Bayesian Information Criterion (BIC). Findings identify financial and human capital as core factors influencing participation, with access to credit emerging as the factor exhibiting the strongest correlation. Livelihood stability and practical vocational training support women’s long-term productive engagement. The study highlights the livelihood paradox and resource lock-in effects: over-reliance on mangrove income reduces participation, limiting diversification, while over-exploitation correlates positively with participation as a survival strategy, exerting short-term environmental pressure. Conversely, owning traditional assets like fishing boats negatively affects participation, showing traditional factors hinder economic restructuring. The findings of heterogeneity analysis emphasize the necessity of policy intervention. For example, women under 56 are primarily financially driven; those over 56 exhibit lower participation and face severe human capital bottlenecks, especially education. Larger households face significant financial barriers despite having abundant human capital. Married women face dual constraints from financial and traditional physical capital, while single/divorced women hold advantages in education and opportunities. Furthermore, In areas far from fishing ports, financial and human capital are core drivers. This research provides quantitative evidence on the complex, heterogeneous effects of SLC on women’s productive engagement, offering a scientific foundation for multi-dimensional, targeted policy measures to foster sustainable livelihood diversification.

Forests doi: 10.3390/f17050539

Authors: Wenhui Zheng Xin Yu Menglei Wu Jingjing Zhao Xiufang Zheng Hong Su Kaijin Kuang Fuzhong Wu

Acid rain is a severe global environmental issue, and clarifying its impacts on litter decomposition and underlying mechanisms is critical for accurately forecasting future climate change. Litter consists of components (e.g., non-structural carbohydrates, lignin, cellulose, and hemicellulose) with distinct decomposition resistance, but how acid rain affects these components to modulate overall litter decomposition across different decomposition stages remains unclear. Therefore, a microcosm experiment was conducted to determine decomposition rates of Chinese fir (Cunninghamia lanceolata) litter and its components based on litter mass loss under different simulated acid rain intensities (pH 4.5, moderate acid rain, MA; pH 3.0, severe acid rain, SA; and pH ≈ 7.0, tap water, CK) over two decomposition stages (0–5 months: initial decomposition stage; 6–16 months: late decomposition stage). Meanwhile, to analyze the factors influencing the litter decomposition rate, soil samples were collected at 5 and 16 months of decomposition for soil property analysis. Results showed that MA had no significant effect on litter decomposition in either stage. Conversely, SA led to a significant 43.7% increase in the litter decomposition rate in the initial decomposition stage, driven by its acid dissolution effect that accelerated the decomposition of cellulose and hemicellulose. However, SA significantly decreased the decomposition rate by 42.0% in the late decomposition stage by inhibiting the decomposition of lignin, cellulose, and hemicellulose, which was due to the reduced activities of soil peroxidase and xylosidase under soil acidification. Notably, neither MA nor SA significantly affected the litter decomposition rate over the entire decomposition period (0–16 months). This study indicates that acid rain’s effect on litter decomposition depends on its intensity and decomposition stage, emphasizing the necessity of distinguishing litter components and decomposition stages to explore its underlying mechanisms and precisely predict global climate change.

Forests doi: 10.3390/f17050540

Authors: Yiwen Wang Xiyu Guo Hui Zhu Fengxia Wang

Mangroves play a vital role in climate change mitigation due to their exceptional carbon sequestration capacity, as a highly productive blue carbon ecosystem. Current research on mangroves in Bamen Bay has been limited to short-term observations, lacking systematic analysis of long-term spatiotemporal dynamics and carbon storage. This study developed a decision tree method integrating SWIR1, NDVI, and NDMI, achieving high-accuracy mangrove mapping. Spatiotemporal dynamics from 2000 to 2020 were analyzed using the dynamic degree model, standard deviation ellipse, centroid model, and landscape pattern indices. Carbon storage was quantified through the InVEST model, grey prediction model, and scenario analysis. The results reveal significant mangrove expansion, with substantial net growth. Spatial aggregation strengthened despite persistent fragmentation, characterized by a shrinking standard deviation ellipse and northeastward centroid migration. Carbon storage increased considerably over the two decades. Under the baseline scenario, carbon storage would continue to grow by mid-century. Among alternative scenarios, the Green Revival scenario achieves the highest carbon storage, outperforming the baseline, while the Hard Preservation scenario achieves slightly above the baseline. The Missed Opportunity and Ecological Collapse scenarios project declines. This study provides a valuable framework for mangrove monitoring, carbon assessment, and ecological restoration, supporting regional conservation and carbon neutrality goals.

Forests doi: 10.3390/f17050538

Authors: Junhui Zhang Guimei Cui Yue Gu Yangao Jiang

Climate change is intensifying drought stress in temperate forests, yet the mechanisms governing gradual versus threshold responses remain unclear, limiting adaptive management. This study tested whether tree morphological traits can help detect these response patterns and whether they vary with species identity, drought timescale, and stand structure. Using 2026 plot records (1022 larch, Larix principis-rupprechtii Mayr; 1004 Chinese pine, Pinus tabuliformis Carrière) from plantations across northern China, we combined random forest and generalized additive models to evaluate the height-to-diameter (H/D) ratio as a drought indicator. The H/D ratio outperforms height or diameter alone in detecting drought responses. Two distinct nonlinear strategies were identified: larch exhibited high sensitivity to spring drought with a threshold near SPEI ≈ −0.47, while Chinese pine showed resilience to short-term stress but nonlinear responses to cumulative drought (thresholds 0.07–0.12). These differences align with biomass allocation patterns, with Chinese pine maintaining lower H/D ratios. Stand structure significantly influenced responses, with strong Age × Density × Drought interactions (p < 0.001) highlighting vulnerability in young, dense stands. Overall, the H/D ratio provides a candidate early-warning indicator of drought vulnerability and may support species-specific monitoring and risk screening in young, high-density stands, although experimental validation is still needed.

Forests doi: 10.3390/f17050537

Authors: Lv Zhou Biyong Ji Binglou Xie Chenghao Zhu Qun Du

Accurate estimation of forest aboveground biomass (AGB) is pivotal for assessing forest carbon sequestration and informing global change studies. Conventional LiDAR-based AGB estimation approaches primarily rely on height and density metrics, which inadequately characterize the complex three-dimensional (3D) structure of forest canopies. This study developed and evaluated a novel method utilizing voxel-based 3D canopy structural metrics derived from airborne LiDAR (ALS) to improve AGB estimation accuracy across diverse forest types. First, voxel-based metrics (Voxel Canopy Height Model (VCHM), canopy volume, and canopy surface area) were extracted from voxelized point clouds. Their distribution patterns across five forest types (Pinus massoniana, Cunninghamia lanceolata, coniferous, broadleaf, and mixed conifer–broadleaf forests) and their correlations with AGB were systematically examined. The results revealed distinct 3D canopy architectures among forest types, with all three voxel metrics showing highly significant positive correlations with AGB; VCHM demonstrated the strongest association. We then constructed two Random Forest models: a baseline model using traditional metrics only, and an enhanced model integrating both traditional and voxel-based metrics. The 10-fold cross-validation indicated that the model incorporating voxel metrics achieved markedly higher accuracy (R2 in 0.490–0.684) than the traditional model (R2 in 0.480–0.607), representing a relative improvement of 2.1% to 32.7%. The most substantial gain occurred in structurally complex broadleaf forests. The enhanced model was subsequently applied to generate a wall-to-wall AGB map of the study region, yielding a total estimated AGB stock of 8.36 × 106 t, which exhibited a patchy spatial distribution. Pinus massoniana forests accounted for the largest proportion (57.8%) of the total stock. This study demonstrates that voxel-based 3D canopy metrics can more effectively capture forest structural heterogeneity and substantially improve the accuracy of AGB estimation models, particularly for complex forest stands. The findings provide a significant advancement toward precise, stand-scale forest biomass monitoring founded on detailed 3D structural information.

Forests doi: 10.3390/f17050536

Authors: Carmina Cruz-Huerta Tomás Martínez-Trinidad Arian Correa-Díaz José Villanueva-Díaz Laura E. Beramendi-Orosco Armando Gómez-Guerrero J. Jesús Vargas-Hernández

Tree rings record environmental conditions and can serve as long-term biomonitors of urban pollution. This study evaluated the radial growth and chemical composition of Pinus greggii wood in three urban green areas of Mexico City: San Juan de Aragón Park (SJA), Sierra de Guadalupe State Park (GUAD), and Vivero Coyoacán National Park (COY). Tree ring chemical elements were analyzed at annual resolution for the period 2002 to 2022, and their relationships with atmospheric pollutant concentrations, including nitrogen oxides (NOx), carbon monoxide (CO), ozone (O3), and particulate matter (PM), of medium size or smaller than 10 µm, including the fractions PM2.5 and PM10, were assessed using a spatial scaling approach. Elemental concentrations were determined using X-ray fluorescence (XRF). Statistical analyses included analysis of variance (ANOVA), Theil–Sen trend estimation, and Pearson correlation with lag analysis (up to 3 years). The oldest trees were recorded in COY (52 years), while the youngest were recorded in GUAD (13 years). Distinct temporal patterns in elemental concentrations were detected among sites; for instance, peak concentrations of Fe (307 ppm), Cu (11 ppm), and Zn (51 ppm) occurred in GUAD in 2021, while Pb concentrations declined during 2019–2020 across all three sites. Significant correlations (p < 0.05) were identified between Cu, Fe, Zn, and Pb and the atmospheric pollutants (NOx, PM2.5, PM10, O3). Notably, O3 showed significant positive correlations with Fe at SJA (up to r = 0.80) and GUAD (up to r = 0.46) with lags ranging from 0 to 3 years, suggesting delayed responses between atmospheric pollution and elemental deposition in tree rings. These findings highlight the sensitivity of P. greggii to urban atmospheric pollution and support its potential as a long-term biomonitoring tool, as well as its importance for informing policies aimed at improving air quality and promoting the sustainable management of urban green spaces.

Forests doi: 10.3390/f17050535

Authors: Diana Rodrigues Tiago van der Worp da Silva Paula Maia Bruna R. F. Oliveira

Wildfires are key drivers of Mediterranean forest dynamics, yet post-fire recovery and carbon cycling in coastal dune systems remain poorly understood, particularly under invasive species pressure. This study quantified how microtopography and dominant woody species shape vegetation recovery, carbon stocks, and soil CO2 efflux in a Pinus pinaster plantation burned in 2017 in coastal Portugal, during the fifth post-fire hydrological year (2021–2022). Vegetation composition, aboveground biomass, litter, soil organic matter and total organic carbon were measured across dune crests and slacks, and soil respiration was repeatedly assessed under native—Halimium halimifolium—and exotic invasive—Acacia longifolia—woody species using a closed-chamber system. Woody cover was higher on crests, whereas slacks supported greater herbaceous cover and stronger increases in soil organic matter, with litter dominating biomass and carbon pools in all microsites. A. longifolia showed marked demographic expansion and higher soil respiration than the native shrub, while mixed-effects models revealed non-linear, interacting effects of soil moisture and temperature on CO2 efflux. Overall, post-fire recovery and carbon dynamics were spatially heterogeneous and increasingly controlled by invasion, underscoring the need for microsite-specific restoration and early invasive control to safeguard carbon sequestration and native forest resilience in Mediterranean coastal dunes.

Forests doi: 10.3390/f17050534

Authors: Yanguo Ma Yude Geng

To address the challenges of over-reliance on single-source data, strong spatial heterogeneity in scenic areas, and difficulty in dynamically capturing spatial topology and heterogeneous node relationships in forestry tourism resource carrying capacity prediction, this paper constructs a carrying capacity prediction framework that integrates a multi-source data fusion algorithm with an attention mechanism and a GAT-Transformer model. This framework employs a modal-level multi-head cross-attention mechanism to conditionally weight and fuse multi-source heterogeneous data in the node and time dimensions. It adaptively allocates the contribution of each information source based on the spatiotemporal context, suppressing noise and redundant interference. A weighted spatial graph is constructed based on fusion distance, trail connectivity, and traffic similarity. Neighborhood information is aggregated through a graph attention network to characterize spatial heterogeneity. The spatially enhanced node sequence is then input into a multi-layer Transformer encoder to capture the long-term temporal dependence and periodic patterns of carrying capacity. Finally, the prediction results are output through a regression layer. Systematic experiments were conducted using two years of multi-source observation data from Wulingyuan National Forest Park. The results show that the proposed method has low prediction error and good stability, exhibiting excellent performance in temporal scale adaptation, spatial generalization, and resistance to missing data and noise. Simultaneously, the model structure is lightweight, with low inference latency, achieving a good balance between prediction accuracy, interpretability, and engineering deployment.

Forests doi: 10.3390/f17050533

Authors: Yaşar Menteş Sevgi Yilmaz Adeb Qaid

It is commonly accepted that vegetation plays an important role in climatic studies conducted at local, national, and international scales. The aim of this study is to examine the cooling effects of tree species in the cities and to reveal how they affect the microclimate in İzzetpaşa Neighborhood of Elazığ province of Turkiye. This study, which was conducted by purchasing ENVI-met 5.6.1 microclimate software, aimed to create the most appropriate microclimate scenarios in order to mitigate the urban heat island (UHI). Among the nine scenarios in which different tree species were used; the greatest cooling effect was obtained from the scenario where Acer platanoides L. was used. It was determined that the air temperature dropped by 0.8 °C compared to the base scenario and by 3.0 °C compared to the scenario in which a tree cover was not used. The lowest cooling effect was detected in the scenarios where Pinus sylvestris L. and Abies cilicica Carr. were used. In general, it was observed that there was no significant temperature decrease in the scenarios where coniferous trees were used. In scenarios where deciduous trees were used, more temperature decreases were detected compared to the coniferous trees. According to the winter simulation results of these scenarios, the daily average air temperature values vary between −0.6 and +0.1 °C compared to the base scenario. In the scenario where Acer platanoides L. was used, where the highest cooling effect was observed, the highest relative humidity rate and the lowest Tmrt value were determined. Evaluating the cooling effect of high vegetation on a species basis in reducing the UHI effect as a basis for planning in urban areas will constitute a key strategy in improving the UHI effect. It is envisaged that this study may provide a solution to help reduce the UHI in studies to be carried out in urban areas.

Forests doi: 10.3390/f17050532

Authors: Yuanzong Li Cui Zhou Junxiang Zhang Wenjun Wang Zhenyu Chen Yongfeng Luo

Accurate prediction of forest fires is crucial for enhancing regional fire prevention and control. Existing models frequently rely on static factors such as weather and terrain, while insufficiently taking into account the Fuel Moisture Content (FMC), a critical internal factor that directly determines fire behavior. Instead, proxies like the Normalized Difference Vegetation Index (NDVI) are commonly employed, which weakens the physical foundation of predictions. This study assesses the marginal contribution of integrating dynamic FMC into fire prediction models. Concentrating on California, we developed a random-forest-based model that incorporates high-resolution FMC products retrieved by our team, along with meteorological, topographic, vegetation, and anthropogenic data. Through comparative experiments and SHapley Additive exPlanations (SHAP) analysis, we evaluated model improvements and the contribution mechanisms of key drivers. The results indicated that: (1) Incorporating FMC significantly enhanced model performance, with precision and specificity increasing by 3.93% and 3.60%, respectively, and the Area Under the Curve (AUC) showing improvements, suggesting heightened sensitivity in detecting actual fire occurrences. (2) SHAP analysis disclosed nonlinear effects and threshold dynamics: temperature was the dominant positive driver (the fire risk soared above 20 °C); FMC demonstrated a negative correlation with fire risk, with 100% serving as a potential threshold; elevation presented an inverted U-shaped pattern (the peak risk occurred at 1000–1500 m); and population density exhibited a shifting influence from positive to negative. (3) The monthly risk maps for California in 2023 captured the seasonal progression of fire risk and spatial patterns consistent with historical fire points. The fire risk map for 9 September 2020 also demonstrated consistency with the spatial distribution of the actual fire points on that day. This study validates that the integration of dynamic FMC strengthens the mechanistic foundation and early-warning capacity of fire prediction models, providing scientific backing for targeted fire management.

Forests doi: 10.3390/f17050531

Authors: Mengting Zhang Mingwei Bao Xiping Cheng

Understanding the spatial distribution patterns and environmental drivers of plant communities is fundamental for biodiversity conservation and ecosystem management. Bombax ceiba is a widely distributed tree species that occurs in both humid tropical rainforests and drought-prone dry-hot valleys, representing two strongly contrasting ecological environments. However, the spatial patterns and environmental drivers of plant communities associated with B. ceiba across these habitats remain poorly understood. In this study, we investigated B. ceiba-associated plant communities in two representative habitats in Yunnan Province, Southwest China: a tropical rainforest in Mengla and a dry-hot valley in Yuanjiang. The species composition, community structure, and spatial coordinates of associated plants were recorded in replicated 20 m × 20 m plots. Spatial distribution patterns were analyzed using the pair-correlation function g(r), while environmental drivers were examined using Pearson correlation analysis and redundancy analysis (RDA). Species richness was substantially higher in the tropical rainforest (41 species from 33 families) than in the dry-hot valley (19 species from 14 families). Both communities contained a substantial proportion of tropical Asian floristic elements. Most dominant species exhibited aggregated spatial distributions at small spatial scales (0–7 m), indicating strong dispersal limitation and microhabitat heterogeneity. Spatial associations varied across scales: in the dry-hot valley, species associations alternated between positive and negative correlations at small scales (0–5 m) and shifted toward positive correlations at larger distances, whereas in the tropical rainforest negative associations were more common at small scales and positive associations increased at larger spatial scales. Environmental drivers differed markedly between habitats. In the dry-hot valley, community attributes were positively associated with slope, precipitation, and soil ammonium nitrogen, suggesting that community assembly is influenced by interactions between topography and water availability. In contrast, tropical rainforest communities were more strongly associated with soil phosphorus availability and temperature-related variables. These findings highlight distinct community assembly mechanisms in contrasting habitats and provide ecological insights for vegetation restoration in dry-hot valleys and biodiversity conservation in tropical rainforests.

Forests doi: 10.3390/f17050530

Authors: Resa Sri Rahayu Wataru Ishizuka Ayu Narita Rie Miyata Naoko H. Miki Hirokazu Kon Yuko Miyazaki

Sapling survival and growth depend on photosynthetic assimilates. Therefore, improving physiological performance during early stages may enhance subsequent performance and nursery production. This study evaluated whether exogenous oxidized glutathione (GSSG), reported to enhance photosynthesis, improves the photosynthetic, physiological, and growth-related traits of Larix gmelinii var. japonica saplings. Sixteen saplings were assigned to four treatments: GSSG, 5-aminolevulinic acid, Hyponex, and a water control. Photosynthetic, nitrogen-related, and growth traits were measured before treatment and at 3, 6, 13, and 31 days after treatment, and biomass was assessed after three months. The GSSG treatment showed no difference in the net CO2 assimilation rate (Amax) compared with the control, but exhibited a significantly earlier peak at 6 days than the other treatments. This response was supported by the stability of GSSG-treated saplings against photoinhibition (Fv/Fm) and a tendency toward greater resilience to midday light stress (ΦPSII). Enhanced photosynthetic performance was associated with reduced carbon and nitrogen fluctuations and was accompanied by numerically greater root and stem biomass in the 2024 terminal shoots. Although fertilization effects were generally weak and transient, GSSG elicited notable responses, suggesting that the immediate enhancement of photosynthesis underlies its impact. However, its antioxidant properties under stressful conditions warrant further investigation.

Forests doi: 10.3390/f17050529

Authors: Shilong Wang Shidong Ge Hui Cao Ran Wen Xueqian Wang Zhijun Liu Ang Li Junguo Shi Qiutan Ren Man Zhang

This study developed a comprehensive framework integrating ecosystem services (ESs), ecological adaptability, and ornamental value to guide tree species selection in historic cities constrained by soil salinization and subsurface heritage conservation. Taking Kaifeng, Henan Province, as a case study, we employed field surveys, i-Tree Eco, the Analytic Hierarchy Process, and K-means clustering to evaluate trees across protective, park, attached, and square green spaces. Results showed that carbon-related services dominated Kaifeng’s urban ES profile, with carbon storage (CS) and sequestration (CSE) value densities of 9.09 ¥·m−2 and 0.84 ¥·m−2·y−1, respectively. Air pollutant removal (AR) (0.21 ¥·m−2·y−1) and P (0.009 ¥·m−2·y−1) values remained comparatively low. Camphora officinarum Nees ex Wall delivered the highest annual ES value per tree (33.24 ¥·y−1). Plaza greenery outperformed other space types in overall service provision, and deciduous broadleaf species generated greater ES value than evergreen conifers. Cluster analysis identified four functional groups: stress-tolerant pioneers, balanced adapters, high-efficiency carbon sinks, and ornamental specialists—each suited to specific green space contexts. This integrated framework offers a transferable approach for evidence-based tree selection in saline historic cities, supporting nature-based solutions in urban green space (UGS) planning.

Forests doi: 10.3390/f17050528

Authors: Steffen Rust Lothar Göcke Josefine Liebisch Ana Paula Coelho-Duarte Agustina Sergio Andreas Detter Bernhard Stoinski

Tree mechanical stability is essential for forest management and urban safety. Although static pulling tests are currently the standard for non-destructive advanced risk assessments, these tests have significant methodological limitations. Large trees require high applied forces to produce measurable signals, which poses safety risks and causes equipment wear. Conversely, structurally compromised ancient, veteran, or dead trees (snags) may yield poor signal-to-noise ratios at low loads, leading to unstable model fits and unreliable safety factor extrapolations. Additionally, standard inclinometers often experience interference from motion-induced accelerations. This study introduces a high-resolution, low-noise measurement approach that resolves small basal inclinations and stem bending responses. This method uses laser-based tracking to monitor stem bending, torsion, and inclination under mechanical load. Experimental data were collected by combining traditional pulling tests with this novel system, as well as by conducting a pilot study that monitored tree movement during low-strength wind gusts. The proposed method enables more precise characterization of the initial load-response curve. Improving the signal-to-noise ratio at lower force levels allows for more robust safety extrapolations. When combined with a 3D LiDAR scan, the method can reveal deviations from the theoretical bending line in order to locate internal defects and variations in wood properties. These findings bridge a critical gap in tree risk assessment by improving the applicability of static testing to massive trees, as well as ecologically valuable yet structurally vulnerable snags and ancient and veteran trees.

Forests doi: 10.3390/f17050527

Authors: Kate Halstead Michael S. Watt Nicolò Camarretta Barry Gardiner Juan C. Suárez Tommaso Locatelli

Under climate change, extreme wind events are predicted to become both more common and more severe, increasing the vulnerability of plantation forests. In February 2023, ex-tropical Cyclone Gabrielle caused widespread wind damage to radiata pine (Pinus radiata D. Don) forests across the North Island of New Zealand, providing a rare opportunity to evaluate mechanistic wind-risk modelling under extreme storm conditions. This study assessed the performance of the ForestGALES model in predicting wind damage within the Rangipo genetic accelerator trial and examined the influence of stocking and cultivation on wind vulnerability. Using detailed pre-cyclone field measurements and high-resolution unmanned aerial vehicle light detection and ranging (ULS) data, ForestGALES was parameterised for the Rangipo trial and applied at both individual-tree and stand scales. Model predictions were compared with observed post-cyclone damage using balanced area under the receiver operating characteristic curve (AUC), accounting for strong class imbalance. Wind damage was observed in 16.7% of trees, of which 10.2% showed stem breakage and 6.5% overturning. Across both spatial scales, overturning was more accurately predicted than stem breakage. At the individual-tree scale, ForestGALES showed moderate predictive skill, with balanced AUC values of 0.650 ± 0.014 for overturning, 0.595 ± 0.011 for breakage, and 0.621 ± 0.008 for total damage. Model performance was stronger at the stand scale, where discrimination was highest for overturning (AUC 0.811 ± 0.122), followed by breakage (0.693 ± 0.116) and total damage (0.623 ± 0.083). Silvicultural treatments significantly influenced predicted critical wind speeds (CWS). High-stocking treatments exhibited consistently higher CWS values and therefore greater wind firmness than low-stocking treatments, while cultivation effects were smaller but significant. Simulated reductions in stocking further demonstrated increased wind vulnerability as stocking declined, highlighting thinning as a primary determinant of wind risk. These findings demonstrate that ForestGALES can reliably discriminate wind damage at operational stand scales under extreme cyclone conditions and highlight the importance of stand structure in improving plantation resilience under increasingly storm-prone climates.

Forests doi: 10.3390/f17050526

Authors: Ana Luisa Ribeiro de Faria Matheus Nathaniel Soares da Costa José Luiz Monteiro Benício de Melo Jesus Padilha Guilherme Henrique Gallo Silva Dan Gustavo Feitosa Braga Marcos Gervasio Pereira Rafael Coll Delgado

This study presents a fire risk prediction framework applied to two conservation units within the Atlantic Forest biome (AFb): Serra da Gandarela National Park (PNSG), Minas Gerais, and Campos de Palmas Wildlife Refuge (RVSCP), Paraná. Daily climate data (2001–2023), remote sensing vegetation indices Normalized Difference Vegetation Index (NDVI) and Normalized Multi Band Drought Index (NMDI), fire foci, and estimates of soil volumetric moisture were integrated to analyze the climatic and environmental drivers of fire occurrence and to develop predictive models. Sea Surface Temperature (SST) anomalies in the Niño 3.4 region revealed the influence of El Niño–Southern Oscillation (ENSO) variability on local hydrometeorological dynamics. Vegetation indices and soil moisture data reinforced this relationship, with NMDI values below 0.4 and sharp declines in volumetric moisture indicating water stress during the dry season. Kernel density maps identified clusters of fire foci during this period, confirming the strong seasonality of fire occurrence. Based on climatic predictors and environmental indicators, fire risk indices were developed for each conservation unit and validated using independent data. Model performance showed moderate explanatory capacity, with coefficients of determination ranging from 0.53 to 0.68 and high agreement between estimated and observed values. Validation stratified by ENSO phases (Neutral, El Niño, and La Niña) demonstrated stable performance across contrasting climatic regimes, indicating temporal resilience of the modeling framework. Overall, the integration of climate data, spectral indices, and soil moisture information improves the ability to anticipate fire risk in Atlantic Forest conservation units, providing a useful tool to support prevention, monitoring, and decision-making in protected areas.

Forests doi: 10.3390/f17050525

Authors: Haonan Lin Dongyang Fu Chuhong Wang Jinjun Huang Hanrui Wu Yu Huang Litian Xiong

Mangrove represent vital coastal ecosystems that contribute to shoreline stabilization, ecological balance, and environmental management. Nevertheless, the precise delineation of mangrove regions using remote sensing data is often impeded by spectral similarities with intertidal mudflats and aquatic features, alongside the irregular spatial patterns and intricate margins of mangrove stands. This research utilizes high-resolution Gaofen-6 (GF-6) satellite observations as the foundational data to develop Triplet Axial High-Resolution Network (TAHRNet), a semantic segmentation architecture derived from the High-Resolution Network with Object-Contextual Representations (HRNet-OCR) framework for mangrove identification. The model integrates a Triplet Attention module to facilitate cross-dimensional feature dependencies and an improved Multi-Head Sequential Axial Attention mechanism to capture long-range spatial context while maintaining structural consistency. Based on evaluations using the test dataset, TAHRNet yielded a Mean Intersection over Union (MIoU) of 92.01% and a Overall Accuracy of 96.38%. Relative to U-Net and SegFormer, the proposed approach showed MIoU improvements of 5.25% and 1.88%, with corresponding Accuracy gains of 2.68% and 0.94%. Further application to coastal mapping in Zhanjiang produced results that align with manual visual interpretation. These findings suggest that TAHRNet is a viable tool for mangrove extraction and can provide technical support for coastal monitoring and ecological analysis.

Forests doi: 10.3390/f17050524

Authors: Xiaomeng Kang Ling Wang Chunyan Chang Xicun Zhu Xiao Liu Chang Qiu Xianzhang Meng Danning Chen

Estimating forest aboveground biomass (AGB) in mountainous forest ecosystems remains a significant challenge due to complex terrain, the high cost and limited applicability of traditional field-based methods. To address this issue, a remote sensing-based AGB estimation framework integrating intelligent optimization and machine learning was developed for Mount Tai in eastern China. Sentinel-2 multispectral data were selected to derive 105 candidate variables, including spectral bands, vegetation indices, texture features, and topographic factors, from which 17 key variables were selected using Pearson correlation analysis for model construction. A Support Vector Machine (SVM) optimized by the Pigeon-inspired optimization (PIO) algorithm was developed to adaptively determine optimal hyperparameters, and its performance was compared with that of Random Forest (RF) and standard SVM models. Among the three models, PIO-SVM produced the highest numerical accuracy. For the training dataset, it obtained an R2 of 0.85 and an RMSE of 46.12 t/hm2. For the testing dataset, it achieved an R2 of 0.73 and an RMSE of 62.19 t/hm2, compared with 0.72 and 66.25 t/hm2 for the standard SVM model and 0.70 and 65.19 t/hm2 for the RF model. The spatial distribution of AGB derived from the optimal model shows higher AGB values in the central and northern regions characterized by dense forest cover, in close agreement with field observations. Overall, the results suggest that PIO-based parameter optimization can improve SVM performance for AGB estimation in mountainous forests. This study provides a reliable and efficient framework for regional-scale monitoring of forest biomass and carbon sink dynamics.

Forests doi: 10.3390/f17050523

Authors: Hyun-Soo Yoon Chang-Min Kang Seoung-Hwan Song Jong-Beom Jeon Joon-Hyeon Kim Hyeon-Cheol Yoon

This study aimed to detect growth stress at the individual-tree level in chestnut (Castanea crenata Sieb. et Zucc.) plantations using UAV-based RGB orthomosaic and multispectral imagery and to determine an optimal NDVI threshold for stress classification. UAV surveys were conducted over a 21 ha chestnut orchard located in Gongju, Chungcheongnam-do, Republic of Korea. NDVI was calculated and analyzed at the individual-tree level using multispectral imagery. Based on field observations, 100 healthy trees and 23 stressed trees were selected for statistical analysis. The mean NDVI value was 0.900 ± 0.012 for healthy trees and 0.816 ± 0.013 for stressed trees, showing a highly significant difference (p < 0.001). ROC analysis showed excellent classification performance with an AUC of 1.00. The optimal NDVI threshold determined using Youden’s index was 0.855. Independent validation in another chestnut plantation approximately 1 km away achieved high classification accuracy using the same threshold. These results indicate that UAV-based multispectral imagery combined with NDVI analysis provides an effective approach for early detection of growth stress and precision monitoring at the individual-tree level in chestnut plantations. This study provides a practical and efficient approach for the early detection of growth stress at the individual-tree level, enabling early intervention against potential declines in tree vitality and proactive management in chestnut orchards. The proposed NDVI threshold-based method offers a simple yet robust tool that can be readily applied in precision forestry and smart agriculture to support large-scale monitoring and informed management decisions for maintaining orchard productivity, enabling cost-effective early intervention at the individual-tree level, which is difficult to achieve using conventional ground-based surveys in complex mountainous orchards.

Forests doi: 10.3390/f17050522

Authors: Stjepan Mikac Domagoj Trlin Marko Orešković Laura Miketin Karla Agičić Igor Anić

The Muški bunar old-growth forest on Mount Psunj represents one of the rare preserved mixed ecosystems of sessile oak (Quercus petraea (Matt.) Liebl.) and European beech (Fagus sylvatica L.) in Southeastern Europe, providing an important reference for understanding natural forest dynamics. This study aimed to analyse stand structure, age distribution, growth dynamics, and disturbance regime based on repeated field surveys conducted in 1979 and 2021. The results revealed pronounced structural heterogeneity and clear interspecific differences. European beech dominates smaller- and medium-diameter classes, as well as a wider range of age classes, whereas sessile oak is primarily present in older and larger diameter classes. A very high growing stock (1155.81 m3 ha−1) indicates exceptional stand productivity, with maximum cambial ages of 295 years for oak and 253 years for beech. Basal area increment analysis showed that both species maintain substantial growth at advanced ages. However, recent decades show divergence, with increasing growth in beech and stagnation or decline in oak. Importantly, growth releases in sessile oak were not accompanied by successful regeneration, indicating a decoupling between growth response and recruitment. Stand dynamics are mainly driven by low-intensity disturbances. These findings highlight the importance of old-growth forests as reference systems and improve understanding of species-specific responses to disturbance.

Forests doi: 10.3390/f17050521

Authors: Haiyang Chen Dietrich Buck Jianwen Ding Xiaolei Guo Zhaolong Zhu

This study investigates how key milling parameters influence both cutting noise and surface quality during the machining of laminated bamboo lumber. Using a multifactorial optimal response surface methodology, the effects of fibre orientation (0–135°), spindle speed (7000–10,000 r/min), feed rate (0.5–2.0 m/min) and milling depth (0.5–2.0 mm) were quantified through 25 experimental runs. Cutting noise, measured as peak sound pressure level (SPL), ranged from 86.8 to 95.2 dB, increasing markedly with fibre angle, feed rate, and milling depth, but exhibiting a non-linear response to spindle speed. Surface roughness (Sa) varied from 2.6 to 11.7 µm and was most strongly governed by milling depth, followed by fibre orientation and feed rate, with a significant interaction between fibre orientation and spindle speed. Quadratic regression models demonstrated strong predictive performance (R2 = 0.97 for SPL; R2 = 0.85 for Sa). Based on the response surfaces, optimal low-noise, high-quality machining was achieved at moderate spindle speeds, low feed rates, and shallow milling depths. These findings provide a mechanistic basis for understanding noise–roughness coupling in bamboo machining and offer practical guidance for computer numerical control processing, tool selection, and industrial noise reduction strategies in bamboo manufacturing.

Forests doi: 10.3390/f17050520

Authors: J.T. Michel Jonathan P. Evans

Eastern deciduous forests are undergoing directional compositional shifts, marked by the progressive replacement of Quercus-dominated canopies with generalists and shade-tolerant taxa. These shifts are increasingly interpreted within a regeneration debt framework, in which canopy composition persists despite recruitment failure and regeneration mismatch in smaller size classes. We evaluated 30 years (1995–2025) of compositional and structural change in adjacent upland and cove forests on the southern Cumberland Plateau, Tennessee, using a permanent nested circular plot design to determine whether previously observed upland resistance reflects durable resilience or delayed demographic transition. Both habitats exhibited continued Quercus decline while remaining compositionally distinct. As documented in prior analyses, reductions in small-diameter stems were more pronounced in the cove forest, but now reveal demographic mismatches between canopy and regeneration layers in both habitats. Upland forests maintained a higher representation of species capable of basal sprouting and clonal growth via root suckering, indicating that vegetative regeneration buffered short-term demographic change. However, recruitment into larger size classes declined in both habitats, demonstrating that buffering facilitated by vegetative regeneration delayed but did not prevent the accumulation of regeneration debt. What appeared as differential resistance through 2014 is more accurately interpreted as temporal offset in regeneration debt accumulation.

Forests doi: 10.3390/f17050519

Authors: Rongjun Du Hongwei Jiang Shuangzhi Li Liangang Zhang Wei Zhang Chaolang Hua Huijun Guo

The administrative boundaries of ecosystems do not necessarily align with natural watershed boundaries, which is a significant reason for the current inefficiency and pronounced conflicts in ecological governance. Using the watershed as the fundamental unit, this study assessed the forest ecosystem services (FES) of the Beihai Wetland watershed in Tengchong (As of 2025). Forest vegetation was classified to the formation level, and the functional value method was employed. The results showed the following order of service values: regulating services > provisioning services > supporting services > cultural services. Biodiversity was identified as the most valuable ecosystem function. The study further revealed that factors such as stand type, stand age, and altitude influence the total FES value within the watershed. Analysis of FES per unit stand (1 ha) indicated that Lithocarpus variolosus Franch. Chun (natural forest) exhibited the highest value. Through in-depth analysis of linear correlations and spatial associations of FES per unit stand, a synergy-trade-off visualization was constructed. This revealed that natural forests in the upper watershed may exert systemic effects on nutrient cycling in the lower watershed. The results obtained at the formation level provide support for the development of watershed-based forest tending plans. Moreover, studying FES using the watershed as a unit represents a practical exploration of the “life community of mountains, rivers, forests, farmlands, lakes, grasslands, and deserts” and offers a potential reference for maintaining the ecological security and supporting the ecological protection and restoration of the Beihai watershed.

Forests doi: 10.3390/f17050518

Authors: Matevž Triplat Žiga Lukančič Vasja Kavčič

The identification of standing tree species, timber logs, and on-site assessment of their quality and value using images holds significant potential for forestry applications, including inventory management, traceability under EU regulations like the Deforestation Regulation, and market valuation amid growing demands for sustainable practices. This study addresses this by classifying images of timber logs by tree species and market value using the Orange data mining software, which leverages pre-trained convolutional neural networks (Inception v3 and SqueezeNet) to generate embeddings from a dataset of 5549 images collected at a real timber auction in Slovenia, followed by logistic regression image classification. Results show high accuracy for tree species classification (up to 92.6%), but substantially lower accuracy for market value classification (40%–55%), reflecting the greater complexity of value determination from visual features. These findings underscore the promise of deep learning for species identification while indicating the need for further methodological advancements to enhance value classification reliability, which offers the practical impact for operational forestry and bioeconomy value chains.

Forests doi: 10.3390/f17050517

Authors: Rui Hou Yantao Zhou Ying Wang Zhiquan Huang Jing Yao Quanjun Jiao Wenjiang Huang Biyao Zhang

Pine wilt disease (PWD) is a devastating biological forest disturbance, making its large-scale and high-precision remote sensing monitoring crucial for epidemic prevention and control. However, the performance of existing deep learning methods in high-resolution imagery is often limited by the confusion of spectral features among disparate ground objects and the complexity of forest boundaries. To address these challenges, this study proposes an innovative, end-to-end deep learning architecture termed MBA-Former. Built upon the robust Swin Transformer V2 backbone, the model systematically integrates two highly adaptable functional modules: (1) a front-end intelligent fusion module designed to adaptively fuse heterogeneous features, and (2) a back-end boundary refinement module that refines segmentation contours via dual-task learning. To train and evaluate the model, fine-grained manual annotations were first performed on Gaofen-2 satellite imagery acquired from multiple typical epidemic areas across northern and southern China. Information-enhanced datasets were constructed by fusing the original spectral bands, typical vegetation indices, and texture features. A comprehensive performance evaluation was then conducted, specifically targeting typical challenging scenarios characterized by complex ground object boundaries. The experimental results demonstrate that the Multi-modal Boundary-Aware Transformer (MBA-Former) significantly outperforms current state-of-the-art models. It achieved a mean Intersection over Union (mIoU) of 81.74%, an IoU of 77.58% for the most critical infected tree category, and a Boundary F1-Score of 78.62%. Compared to the best-performing baseline model, Swin-Unet, these three metrics exhibited notable improvements of 2.88%, 3.55%, and 4.46%, respectively. These findings convincingly demonstrate that MBA-Former provides a highly accurate and robust solution for the large-scale, automated remote sensing monitoring of forest diseases, offering immense value in preventing significant economic losses and preserving forest ecosystem integrity.

Forests doi: 10.3390/f17050516

Authors: Gi Beom Keum Eun-Kyung Bae Min-Jeong Kang Min-Young Park Na-Kyung Kang Eung-Jun Park

The prized wild mushroom Tricholoma matsutake maintains distinctive microbiota within its dominant zone; however, the spatial and seasonal reorganization of microbiota from taxonomic and functional perspectives remain poorly understood. High-throughput amplicon sequencing was performed in warming (March–June) and cooling (September–December) seasons to compare microbial communities among T. matsutake-dominant (present, visible mycelium) and -nondominant soils (transition, adjacent with present; control, distant from fairy ring). Fungal and bacterial community structures in T. matsutake-dominant soils were obviously distinct (ANOSIM, R > 0.6, p = 0.001), and bacterial communities exhibited clear seasonal separation. The relative abundances of Ascomycota and Mortierellomycota significantly reduced, whereas mycorrhiza-helper bacteria, including Paenibacillus, Bacillus, and Cohnella, were enriched. Functional predictions suggested that the potential expression of cofactor and vitamin biosynthesis, nutrient degradation, and inorganic nutrient metabolism pathways may be enriched in T. matsutake-dominant soil. During the fruiting period, the expression of the predicted amino acid biosynthesis pathway may be reduced, whereas that of the cofactor/carrier/vitamin biosynthesis pathway may be enriched. Our findings suggest that T. matsutake dominance could be associated with the spatial and seasonal restructuring of soil microbial communities, potentially leading to the formation of functionally interconnected microbial networks. Therefore, this study predicts hidden ecological insights that, once biochemically validated, may be used to develop important strategies for the sustainable conservation and artificial cultivation of T. matsutake.

Forests doi: 10.3390/f17040515

Authors: Eunho Choi Jiyeon Han Hyunyoung Yang

Developing countries participating in the Warsaw Framework for Reducing Emissions from Deforestation and Forest Degradation Plus (REDD+) (WFR) are eligible to receive financial incentives linked to verified reductions in greenhouse gas emissions from forest-related activities. It is necessary to strategically select priority countries among the WFR participants to achieve REDD+ cooperation and mutual benefits between recipient and donor countries. This study evaluates the mitigation potential of 71 developing countries registered under the WFR (December 2025) using two dimensions: national measurement, reporting, and verification (MRV) capacity and the need-effectiveness of official development assistance (ODA) in strengthening MRV capacity. Countries were ranked and classified into six typological groups based on MRV capacity and ODA need-effectiveness. The results show that countries with an intermediate MRV implementation capacity and high ODA need-effectiveness can transition to the MRV implementation phase through policy and financial interventions, suggesting high potential to achieve emission reductions and become priority countries for cooperation. Meanwhile, those with an intermediate MRV implementation capacity but low ODA need-effectiveness were interpreted as types where medium- to long-term cooperation possibilities can be reviewed based on improvements to MRV components. Our findings suggest a two-stage cooperation strategy that integrates short-term MRV-based engagement with long-term ODA-driven capacity-building to expand REDD+ mitigation outcomes under the WFR.

Forests doi: 10.3390/f17040514

Authors: William H. Conner John W. Day Richard H. Day Jamie A. Duberstein Rachael G. Hunter Richard F. Keim G. Paul Kemp Ken W. Krauss Robert R. Lane Gary P. Shaffer Nicholas J. Stevens Scott D. Wallace Brett T. Wolfe

The once-extensive coastal forested wetlands (CFWs) of the Mississippi River Delta (MRD) are declining under the combined pressures of pervasive hydrologic change, unregulated harvesting, relative water level rise (due to the combination of geological subsidence and sea-level rise—SLR), and climate change. We synthesize here over 50 years of research conducted in the MRD to examine the history of the CFWs and their management, their ecosystem functions and services, and the nature, extent, and severity of ongoing changes. Seedling recruitment failure and increasing salinity levels are the most immediate threats to forest persistence, necessitating management that restores hydrologic function and sediment and nutrient supply to allow seedling survival and minimizes saltwater intrusion. Collectively, the evidence indicates that managed inflows can bolster accretion and sustain forest function, and long-term resilience requires hydrologic restoration at landscape scales coupled with site-level actions that secure recruitment and address local degradation trajectories. These include freshwater and sediment introduction, protection from herbivory, and, in some cases, planting. Our research findings have important implications for worldwide CFWs, and tidal freshwater ecosystems in general, which occur mainly in tropical deltas.

Forests doi: 10.3390/f17040513

Authors: Junxia Yan Jiangkun Zheng Jianfeng Zhang

Scientifically assessing the spatiotemporal evolution of regional carbon storage is of great significance for achieving the “dual carbon” goals and optimizing territorial spatial patterns. This study integrated the PLUS and InVEST models to systematically reconstruct the spatiotemporal pattern of carbon storage in Hebei Province from 2000 to 2020, simulate its evolution trajectory under different scenarios in 2030, and identify its driving mechanisms using the GeoDetector model. The main findings are as follows: (1) From 2000 to 2020, cropland was the dominant land use type in Hebei Province, and carbon storage exhibited a spatial pattern of “high in the northwest, low in the southeast.” Carbon storage increased from 16.23 × 108 t to 16.31 × 108 t, with a significantly slowed growth rate after 2010. (2) Multi-scenario simulations for 2030 indicate that under the natural development and economic priority scenarios, construction land expands significantly while cropland and grassland continue to decrease. In contrast, carbon storage shows an increasing trend under the ecological protection and cropland protection scenarios. (3) Driving factor analysis reveals that the spatial differentiation of carbon storage is primarily controlled by natural factors such as slope, elevation, and NDVI, while the explanatory power of anthropogenic factors, particularly population density, has significantly increased. The interaction between NDVI and slope exhibits a synergistic enhancement effect. This study elucidates the coupling mechanisms between land use change and carbon storage under different policy orientations, providing a scientific basis for territorial spatial optimization and the formulation of differentiated carbon neutrality pathways in Hebei Province.

Forests doi: 10.3390/f17040512

Authors: Luďka Hanincová Marta Pędzik Jiří Procházka Tomasz Rogoziński

Surface quality of machined wood-based panels plays a key role in subsequent processing and product performance; however, its formation during CNC edge milling remains insufficiently understood, particularly for materials with different structural characteristics, including recycled content. This study investigates the influence of feed per tooth, milling strategy, and material structure on surface quality during CNC edge milling of particleboards manufactured from alternative lignocellulosic resources. Six board variants were experimentally produced and machined on a five-axis CNC machining center Morbidelli m100 using a single-edge milling cutter, with feed per tooth varied at three levels and both climb and conventional milling strategies applied. Surface quality was evaluated using a non-contact 3D optical profilometer Keyence VR-6000, and roughness (Ra) and waviness (Wz) parameters were analyzed. The results showed that surface roughness increased with increasing feed per tooth for all materials, with an increase of approximately 30%–70%. Statistical analysis confirmed a significant effect of feed per tooth and material type, while milling strategy and its interaction with material were not statistically significant. Materials with higher surface heterogeneity (CVRa) showed increased roughness and greater sensitivity to feed. A statistically significant positive relationship was found between surface heterogeneity (CVRa) and roughness sensitivity (ΔRa), indicating that materials with higher surface heterogeneity (CVRa), which likely reflects variability in their internal structure, are more sensitive to changes in feed per tooth.

Forests doi: 10.3390/f17040511

Authors: Zahraa Al-Shammaa Mark Dewsbury Louise Wallis Hartwig Künzel

Quantifying moisture transport through building envelope materials is vital for durability, energy efficiency, and healthy indoor environments. Water vapour diffusion resistivity (µ-value) is a key parameter for hygrothermal modelling, moisture control, and mould risk assessment. Globally, data for solid wood species are scarce, and in Australia—despite the rising use of plantation-grown timber—critical hygrothermal properties remain undocumented. To close this gap, this study experimentally evaluated Eucalyptus nitens, a plantation-grown hardwood widely used in Australian construction. Solid-wood specimens prepared from industry-sourced boards were tested at 23 °C and 50% RH using both the wet-cup and dry-cup methods of the gravimetric technique. For wet-cup tests, µ-values ranged from 24 to 33; for dry-cup tests, µ-values ranged from 179 to 273, showing clear variability linked to differences in relative humidity. Experimental issues included surface cupping, sealing integrity, and extended equilibration time during dry-cup testing. These findings provide the first empirical µ-value dataset for E. nitens under moderate-humidity conditions, delivering essential input parameters for hygrothermal models and supporting moisture-safe, energy-efficient design strategies for the broader construction sector.

Forests doi: 10.3390/f17040510

Authors: Qiurong Liu Yutian Wu Jun Hu Dongdong Chen Wenqiang Zhao Haoxin Tan Qing Liu

Alpine treeline and shrubline ecotones are climatically sensitive transition zones where vegetation shifts strongly influence belowground microbial processes. Soil bacteria and fungi, as core component of the soil microbiome, play vital roles in nutrient cycling and plant–soil interactions within these fragile ecosystems. However, the structure and diversity of soil microbial communities across the treeline–shrubline transition remain poorly understood. Here, we investigated soil bacterial and fungal communities across treeline and shrubline ecotones in two mountain on the eastern Tibetan Plateau. We further examined how soil physicochemical properties shaped microbial community assembly. Our results demonstrated that the community composition of both bacteria and fungi differed significantly between the treeline and shrubline ecotones, while the Shannon index showed no significant variation. At the phylum level, Proteobacteria, Actinobacteriota, and Acidobacteriota dominated bacterial communities, while Ascomycota and Basidiomycota were the predominant fungal phyla. Both the network complexity of soil bacterial and fungal communities changed significantly across ecotones. Specifically, bacterial network complexity increased significantly toward the shrubline, whereas fungal network complexity declined. Bacterial community compositions were co-regulated by both environmental and vegetation factors, while fungal community compositions were only regulated by soil pH. Redundancy analysis revealed that soil organic carbon, pH, and moisture were the primary drivers of bacterial community (38.17%), whereas vegetation cover, soil organic carbon, and moisture explained the largest proportion of fungal community (44.79%). Our findings reveal the distribution patterns and underlying shift mechanisms of microbial communities between the treeline and shrubline ecotone. These insights are crucial for mountain biodiversity conservation and for improving predictions of forest responses to climate change.

Forests doi: 10.3390/f17040509

Authors: Arlis A. Navarrete Memije Carlos A. Chan-Keb Roman A. Pérez-Balan Hugo López Rosas Claudia M. Agraz-Hernández

Mangroves rank among the most productive ecosystems on Earth, yet they are increasingly threatened by climate change and the expansion of agricultural land use. Among agricultural pollutants reaching coastal environments, glyphosate-based herbicide formulations (GBHFs) are of particular concern owing to their widespread application and environmental persistence. This study evaluated the phytotoxic effects of a GBHF (commercial product Velfosato, 48% active ingredient) on Rhizophora mangle L. seedlings under controlled experimental conditions simulating the intertidal regime of the collection site. Propagules were collected from the Los Petenes Biosphere Reserve (Campeche, Mexico), established in experimental tanks containing mangrove soil, and grown until uniform seedling development was achieved. Once seedlings reached uniform development, they were exposed to nominal concentrations of 0.003, 0.03, 0.3, 3.0, and 10 mg L−1 of the formulation dissolved in interstitial water. The experiment followed a completely randomized design (three replicate tanks per treatment plus a triplicate control; n = 1170 seedlings total). All inferential tests used the tank as the experimental unit (n = 3 per treatment). Total chlorophyll concentration was significantly lower in treated seedlings than in the control across all tested concentrations (ANOVA F5,12 = 4.55, p = 0.015). Height growth rates were significantly reduced at concentrations ≥ 3 mg L−1 (F5,12 = 6.84, p = 0.003). Lenticel number increased significantly at the two highest concentrations (F5,24 = 3.63, p = 0.014). Mangrove soil exhibited significant increases in pH and decreases in redox potential across the concentration gradient (p < 0.001 and p = 0.001, respectively). These findings indicate that sublethal exposure to a GBHF is associated with alterations in key ecophysiological processes and soil physicochemical conditions in R. mangle seedlings under controlled conditions, highlighting the sensitivity of early developmental stages to GBHF exposure.

Forests doi: 10.3390/f17040508

Authors: Hugo Orlando Paredes Rodríguez Wilfredo Ramiro Franco Elio Sanoja

The neotropical genus Inga (Fabaceae) is a fast-growing tree component of tropical forests which plays crucial ecological and functional roles. However, its diversity patterns and the specific environmental drivers that structure its distribution in Andean landscapes remain insufficiently documented. This study aimed to quantify the diversity and distribution of Inga species in the province of Imbabura (4785 km2), northern Ecuador, while evaluating the influence of key environmental determinants. By integrating 52 field records along 321 km of exploration and 22 herbarium records (QCNE, MO, AAU, F, HUTN), the study analyzes the role of topographic variables (12.5 m resolution) and climate data (1 km2 resolution). Seventeen species were recorded, almost tripling previous regional findings. The results demonstrate that species richness and occurrence are strongly structured by altitude, temperature, and soil properties as primary environmental drivers. Ten species showed narrow altitudinal ranges and limited thermal tolerance (<2 °C), indicating high habitat specialization, while I. densiflora and I. insignis exhibited broader niches. Edaphically, most species were associated with sandy loam soils, particularly Mollisols and Inceptisols developed from volcanic material. These findings indicate that climatic gradients and edaphic conditions act as the main environmental filters shaping Inga assemblages in heterogeneous montane landscapes. The observed high level of specialization suggests significant vulnerability to land-use change and highlights the need for habitat-specific conservation strategies in Andean forests.

Forests doi: 10.3390/f17040507

Authors: Chan Zhang Xuhui Wang Yang Xu Runze Liu Lijing Yu Ming Wei Chenghao Li

Drought stress critically impacts plant growth and productivity. The bZIP transcription factor family is crucial for abiotic stress responses, yet its role in larch drought tolerance remains unclear. This study identified 19 bZIP genes in Larix kaempferi (Lamb.) Carr. and characterized LkbZIP4. Bioinformatics analysis classified it into the A subgroup. Subcellular localization and yeast two-hybrid assays confirmed that it is a nucleus-localized transactivator. Expression pattern analysis revealed that LkbZIP4 was highly specifically expressed in roots and was significantly induced by drought stress. A series of transgenic overexpression lines was successfully established through Agrobacterium tumefaciens-mediated method, using embryogenic callus of hybrid larch (L. kaempferi × L. gmelinii). Under 7% PEG-induced drought stress, LkbZIP4-overexpressing transgenic calli displayed enhanced drought tolerance relative to wild-type. This was evidenced by better growth, higher biomass, and reduced membrane damage, indicated by lower malondialdehyde content and relative electrolyte leakage. Meanwhile, these transgenic calli accumulated higher levels of osmoregulatory substances, including proline and soluble sugars, along with enhanced activities of antioxidant enzymes including superoxide dismutase and peroxidase. Our results indicate that LkbZIP4 functions to promote drought tolerance in larch, likely through the enhancement of osmotic adjustment and oxidative defense mechanisms.

Forests doi: 10.3390/f17040506

Authors: Miloš Ilić Mirjana Ćuk Dragana Vukov

We investigated bryophyte communities in mature beech forests (Fagus sylvatica L.) and Austrian pine plantations (Pinus nigra J.F. Arnold) on Fruška Gora Mountain (northern Serbia) to examine how stand structure and edaphic conditions influence trait composition and functional diversity. Environmental predictors included soil pH, soil temperature, herbaceous cover, and shrub density, while collinear structural variables were summarized using principal component analysis into a composite structural–moisture gradient. Community–environment relationships were analyzed using redundancy analysis (RDA) with restricted permutations, trait–environment coupling using RLQ and fourth-corner analysis, and functional diversity using Rao’s quadratic entropy (RaoQ). The RDA indicated significant effects of all predictors. RLQ revealed a structured multivariate coupling between bryophyte traits and environmental gradients. Functional diversity was higher in beech forests than in pine plantations, increasing with shrub density and decreasing along the structural–moisture gradient. Overall, plantation stands supported functionally more homogeneous bryophyte assemblages, highlighting the importance of stand structural complexity for maintaining forest-floor bryophytes’ functional diversity.

Forests doi: 10.3390/f17040505

Authors: Efrén Hernández-Alvarez Bayron Alexander Ruiz-Blandon José Antonio Hernández-Moreno Rosario Marilu Bernaola-Paucar Julian Leonardo Mantari Mallqui Carlos Emérico Nieto Ramos Luis Armando Nieto Ramos Eduardo Salcedo-Pérez

Tropical forests differ widely in floristic composition, stand structure, standing volume, and carbon storage, yet comparative evidence across contrasting tropical forest types remains limited. This study examined whether variation in standing volume and carbon stocks among contrasting tropical forests was more closely associated with structural attributes or with diversity-related patterns. Two tropical wet forests in Colombia and one tropical semi-deciduous forest in Mexico were evaluated using 40 circular plots of 500 m2 established within a 100 ha reference area in each forest, where all trees with DBH > 10 cm were measured. Floristic composition, ecological dominance, diversity, dendrometric attributes, standing volume, biomass, and carbon stocks were estimated using a common analytical framework. The two wet forests showed higher effective diversity, broader taxonomic dominance, greater basal area, mean height, standing volume, biomass, and carbon stocks than the tropical semi-deciduous forest. In contrast, the semi-deciduous forest showed stronger dominance concentrated in fewer taxa, especially Euphorbiaceae, a pattern that may reflect the ecological suitability of this family under more seasonal and water-limited conditions. At the family level, standing volume, biomass, and carbon were distributed more evenly among dominant families in the wet forests, whereas they were more concentrated in fewer lineages in the semi-deciduous forest. Basal area showed the strongest association with standing volume, total biomass, and total carbon, followed by mean height and mean DBH. Overall, the results indicate that, under the conditions evaluated, structural organization was more closely associated with standing volume and carbon storage than diversity alone, while diversity acted as a complementary correlate.

Forests doi: 10.3390/f17040504

Authors: George Rogers

Pinus clausa var. clausa (Chapm. ex Engelm.) Vasey ex Sarg., sand pine, is the dominant tree of biorich but ecologically compromised Southeast Florida scrub. Scrub habitats and P. clausa have dwindled due to habitat reduction and fragmentation, regional development, and fire suppression. The purpose of the present article was to seek correlates of P. clausa establishment under present unnatural development-impacted conditions using 428 field measurements at four sites to determine spatial positioning preferences relative to vegetation edges, then adding 120 measurements at a single site aimed at evaluating several potential predictors of P. clausa establishment. Potential establishment predictors were adjacency to other woody plants, depth to hard sand horizon, seed tree distance and direction, light-intensity, soil-core color, soil pH and soil surface firmness. Comparing frequency distributions of juvenile P. clausa locations with frequency distributions of random spots within the same perimeters, juvenile pines tended toward adjacency to other woody plants (chi2 p < 0.0001), toward shallow hard horizons (Kolmogorov–Smirnov p = 0.0006), toward soft soil surfaces (K–S p = 0.007), and toward proximity to seed trees (K–S p = 0.004). Additionally, juvenile P. clausa were often clustered under groves of Quercus geminata Small with comparatively thin canopies. Bayesian logistic regression showed adjacency to woody plants as a strong predictor of P. clausa establishment. When alongside other plants, P. clausa establishment was mostly on the north or east side of neighboring plant edges. Overall conclusions were that juvenile Pinus clausa in SE Florida scrub fragments is sensitive to positioning relative to other woody plants, and is associated with soil surface softness, soil depth to hard horizon, and light levels, except as seedlings.

Forests doi: 10.3390/f17040503

Authors: Xiaoxiao Min Mohd Johari Mohd Yusof Luxin Fan Sreetheran Maruthaveeran

Vegetation carbon stock is a key component of the terrestrial carbon cycle and supports climate-change mitigation and carbon-neutrality strategies. While field inventories provide accurate references, they are constrained by cost and limited scalability, motivating the rapid adoption of remote sensing for large-scale spatial estimation and mapping. However, the literature lacks a consolidated bibliometric and critical synthesis focused on above-ground vegetation carbon stock estimation. Therefore, this review aims to provide a quantitative overview of publication trends, synthesise methodological developments, and identify key research gaps in remote-sensing-based above-ground vegetation carbon stock estimation. A total of 1825 Web of Science records (2015–2024) were retrieved, of which 763 were included for bibliometric mapping using VOSviewer version 1.6.20 and CiteSpace version 6.3.R2, complemented by a critical review of 32 high-quality studies. Results indicate a shift from passive optical and single-index approaches toward active sensing and multi-sensor, multi-platform integration, alongside broad uptake of machine learning and an emerging dominance of deep learning for nonlinear modelling and feature learning. Research attention is expanding beyond forests to non-forest ecosystems, yet challenges persist in spatial resolution, validation data availability, and cross-biome generalizability. This review summarizes methodological trajectories and identifies priorities for robust, transferable above-ground carbon estimation.

Forests doi: 10.3390/f17040502

Authors: Dongxia Luo Kun Cheng Yanbin Wang Ting Xie Ruiqiang Yang

Despite recent advances in polycyclic aromatic hydrocarbon (PAH) research on the Tibetan Plateau (TP), studies investigating the transport potential and accumulation dynamics of these contaminants in the Hengduan Mountains, especially in forest soils which are important sinks for atmospheric PAHs, remain scarce. In the present study, soil and lichen samples (partially located under the forest canopy) were concurrently collected from 62 sampling sites across the Hengduan Mountains to characterize the occurrence, spatial distribution patterns, and underlying controlling factors of PAHs. The total concentrations of the 16 US EPA priority PAHs (∑16PAHs) in soils and lichens ranged from 59.8 to 1163 ng/g and 174 to 3362 ng/g, respectively—values consistently higher than those reported in corresponding matrices from the northern and northwestern TP. Further, concentrations of PAHs in both soil and lichen under the forest canopy are significantly higher than those on the leeward slope without forest. Compositional fractionation of PAHs along the longitudinal and latitudinal gradients of sampling locations indicates significant modulation of PAH distribution by both the Indian monsoon and East Asian monsoon, a pattern further corroborated by air mass backward trajectory analysis. Our results confirm that PAHs can be transported to the southeastern TP slope via long-range atmospheric transport (LRAT). Notably, the combined effects of mountain cold-trapping and forest filtering jointly govern the deposition and spatial distribution of PAHs in this region.

Forests doi: 10.3390/f17040501

Authors: Mei Zhang Li Ma Yiru Wang Ji Luo Minghong Peng Dingdi Jize Cuicui Jiao Ping Huang Yuanjie Deng

As a crucial national ecological barrier, China’s Southern Collective Forest Region (SCFR) plays an essential role in maintaining regional ecological security and promoting sustainable development. Understanding the mechanisms driving the evolution of its ecosystem service value (ESV) is of great significance. Based on county-level data from 2000 to 2023, this study integrated the equivalent factor method, spatial autocorrelation analysis, the XGBoost-SHAP model, geographically and temporally weighted regression (GTWR), and partial least squares structural equation modeling (PLS-SEM) to examine the spatio-temporal evolution patterns and driving mechanisms of ESV in the SCFR. The results showed that ESV in the SCFR exhibited an overall downward trend, with a cumulative loss of 1973.77 × 108 CNY. This was primarily due to marked reductions in hydrological and climate regulation services. The spatial distribution of ESV exhibited a significant heterogeneity—higher in the southwestern and southeastern mountainous regions, and lower in the northern plains and coastal zones, with the center of gravity shifting first to the northeast and then to the southwest. Local spatial autocorrelation revealed relatively stable “High–High” and “Low–Low” clustering characteristics, where high-value clusters were consistently distributed in core forest zones, while low-value clusters overlapped highly with urban agglomerations. Socio-economic factors exerted a significantly stronger influence on ESV than natural factors. Population density (POP), land use intensity (LUI), and gross domestic product (GDP) were identified as the dominant drivers, exhibiting distinct non-linear threshold effects and significant spatio-temporal heterogeneity. PLS-SEM analysis further quantified LUI as the dominant direct inhibitory pathway on ESV, highlighting urbanization’s indirect negative effect mediated through intensified LUI. Meanwhile, terrain effects were confirmed to positively influence ESV indirectly by constraining LUI and modulating local climate. The analytical framework of “threshold identification–spatio-temporal heterogeneity–causal pathway analysis” proposed in this study elucidated the complex driving mechanisms of ESV evolution, providing valuable guidance for ecological restoration evaluation and differentiated environmental governance.

Forests doi: 10.3390/f17040500

Authors: Sung-Min Choi

This study investigates the structural misalignment between official wage benchmarks and actual market wages in the Republic of Korea to establish an independent, forestry-specific wage system essential for labor sustainability. Historically, the Republic of Korea forestry project costs have relied on construction industry benchmarks, leading to a “diverging hypothesis” where official rates fail to reflect the specialized risks and technical skills required in forest operations. To address this, a comprehensive wage survey was conducted in 2025 across 13 specialized forestry occupations. Utilizing a sampling frame of 7555 sites, 1044 units were selected via stratified sampling with square-root proportional allocation, ensuring a relative standard error (RSE) of 2.5%. The findings reveal that market wages consistently exceed construction benchmarks by 4.5% to 41.0%. The most significant disparities were observed in leadership and mechanized roles, reflecting substantial “risk–responsibility” and “skill premiums”. Furthermore, the study identifies a structural shift toward risk-transfer strategies, such as stumpage sales, in response to the Serious Accidents Punishment Act (SAPA). These results underscore the urgent need for a specialized wage framework to ensure safety and long-term resilience. Ultimately, such institutional refinement is a prerequisite for securing the high-quality human capital necessary for a sustainable circular bioeconomy.

Forests doi: 10.3390/f17040499

Authors: Klaudia Strękowska Jakub Borkowski

Forests worldwide are increasingly affected by climate-driven stressors and large-scale disturbances that impair tree physiology, disrupt water and carbon balance, and increase mortality risk. In this context, successful natural and artificial regeneration is essential for maintaining forest continuity, carbon storage, and biodiversity. However, regeneration outcomes depend not only on site conditions but also on biotic pressures, especially browsing by cervids in temperate and boreal forests. The aim of this review was to identify and synthesize evidence on how silvicultural methods can reduce browsing damage in forest regeneration and to assess how these methods influence the underlying drivers of cervid pressure through stand structure and forage availability. We examine mechanisms operating at two spatial scales: at the microscale, regeneration type, planting density, structural heterogeneity, planting stock, and how species mixture influences browsing probability and intensity; at the macroscale, how cutting systems and the spatial and temporal arrangement of harvests shape foraging landscapes by concentrating or dispersing browse resources and edge habitats. The reviewed evidence shows that dense, structurally diverse natural regeneration can dilute browsing pressure, whereas uniform artificial regeneration may increase repeated damage, and that species composition and mixture patterns can either protect or expose palatable species. We conclude that integrating microscale regeneration design with landscape-level harvest planning can strengthen stand resilience, reduce dependence on fencing, and support climate-adaptive forest development. To the best of our knowledge, no previous review has synthesized this evidence across both micro- and macroscale silvicultural contexts. Although most of the studies included in this review originate from Europe, we believe that the knowledge presented here is relevant to the majority of boreal and temperate forests worldwide.

Forests doi: 10.3390/f17040498

Authors: Yanqun Liu Jingxue Wang Wenchao Chen Mao Xu Yu Zhang Luca Patruno Weilin Li

Shelterbelts are increasingly used to mitigate strong wind damage, but the complex canopy structures create challenges for numerical studies of windbreak effectiveness, such as the trade-off between computational cost and accuracy of results. To address these challenges and accurately investigate the downstream wind fields, most conventional studies represent shelterbelts as rectangular porous media with a uniformly distributed aerodynamic resistance coefficient. However, due to the vertical variation in canopy diameter and the irregular distribution of leaf density, the aerodynamic resistance of natural shelterbelts becomes nonuniform accordingly. To quantify the discrepancies arising from this simplification, this study first proposes a non-destructive approach to calculate canopy porosity profiles, which are further used to derive aerodynamic resistance at different heights. Then, by comparing the results obtained from the conventional and proposed approaches in Large-Eddy Simulations, the discrepancies caused by ignoring the vertical variation in canopy structures are analyzed. Finally, these discrepancies are further investigated for double-row shelterbelts. The results show that ignoring the vertical variation in canopy diameter leads to significant differences in windbreak effectiveness, especially for the downstream velocity and pressure fields at the top and middle heights of the canopy. The proposed approach provides a computationally efficient and more accurate representation of near-surface wind fields downstream of shelterbelts, thereby contributing to the accurate prediction of local wind fields for meteorological services.

Forests doi: 10.3390/f17040497

Authors: Adnan Amin Mozaniel Santana de Oliveira

Generally, forest trees with medicinal value present diverse chemotypes considered key determinants of efficacy, safety, and commercial valuation. Such heterogeneity varies among tissues, genotypes, and seasons, and stress exposure. This review summarizes how regulatory controls and genome architecture affect the stability and synthesis of secondary metabolites in woody medicinally important taxa. Detailed haplotypic and chromosomal analyses have recently identified diverse and repeatable architectural drivers. Among these, LTR/transposon-mediated revamping, neofunctionalization, biosynthetic gene clusters, and tandem duplication play a special role in reshaping pathway capacity. The enzymatic regulation of these drivers translates this “capacity” into harvest-pertinent chemistry by employing conserved TF modules, hormone crosstalk, and emergent chromatin/epigenetic layers. Nevertheless, major parameters pertaining to the tissue-specific storage, transport, and compartmentalization of these chemotypes are contextualized with certain limitations. In this review, the integration of GWAS/eQTL/TWAS with multi-tissue is explained in addition to the replacement of a single reference with pangenome/haplotype frameworks, and explicit modeling of G × E further strengthen genotype-to-chemotype mapping. Therefore, in this review we summarize practical workflows for chemotype discovery utilizing staged validation models of heterologous reconstitution, isotope/spatial evidence, and chemistry. These findings were supported by data on saponins, alkaloids, iridoids, and defense response. Such an integration links mechanistic understanding to authentication, standardization, and sustainable utilization strategies in woody medicinal trees.

Forests doi: 10.3390/f17040496

Authors: Naara Ferreira da Silva Pia Parolin Layon Oreste Demarchi Lilian Cristine Camillo Aline Lopes Maria Teresa Fernandez Piedade

Floodplain forests in central Amazonia are structured along a marked flooding gradient that influences species distribution, performance, and survival. This study evaluated the demographic structure, survival, and growth responses of two co-occurring tree species across contrasting várzea environments differing in inundation regimes. Field surveys quantified seedlings, juveniles, and adults in low- and high-floodplain forests, while a field experiment assessed survival and growth under conditions with and without interspecific interaction. Repeated-measures ANOVA revealed that temporal variation and forest type significantly affected growth parameters, with species-specific responses to flooding intensity. In the field experiment, mortality of Crateva tapia L. differed significantly among treatments (χ2 = 24.96, p < 0.001), with the highest mortality observed in high-várzea (up to 75% under interspecific interaction), while Hura crepitans L. showed 100% survival across all treatments. Non-parametric analyses detected no significant treatment effects on selected morphological traits. The results support the stress-gradient hypothesis, suggesting that plant–plant interactions may shift along the flooding gradient, with facilitative processes becoming more relevant under higher stress conditions. Overall, differential flood tolerance appears to be a key driver of habitat preference and population structure in these Amazonian wetlands.

Forests doi: 10.3390/f17040495

Authors: Wenqi Gao Shengting Wang Shouxia Wu Shangke Yuan Yujia Zhang Leping He Tuo Han

The northeastern margin of the Qinghai–Tibet Plateau is an ecologically fragile region that faces severe habitat fragmentation, which directly threatens regional biodiversity conservation and ecological security. To address this challenge, this study constructed a hierarchical “source-corridor-node” ecological network for the Gannan Tibetan Autonomous Prefecture by integrating Morphological Spatial Pattern Analysis (MSPA), the Minimum Cumulative Resistance (MCR) model, landscape connectivity assessment, and gravity modeling. The key results are as follows: (1) The Gannan Yellow River Water Source Replenishment Area contains 11 core ecological source regions, which are predominantly located in the southeastern regions of Diebu County and Zhouqu County, covering a total area of 4237.81 km2; (2) Ecological resistance analysis identifies high-resistance zones concentrated in anthropogenically active river valleys and urban belts (e.g., Hezuo urban area, Awanzang Town, and the G213 corridor). Low-resistance zones are predominantly situated in protected ecological enclaves (e.g., Zhagana Geopark and Gahai Wetland Reserve); (3) A total of 55 ecological corridors were identified, with a total length of 4355.77 km. Among these, 26 were classified as key ecological corridors, primarily distributed in Diebu and Zhouqu counties in the eastern part of Gannan Prefecture. These areas feature relatively concentrated ecological sources, and the key corridors play a critical role in connecting isolated ecological patches and maintaining regional ecological connectivity. (4) Across the entire territory of Gannan Prefecture, a total of 81 first-level ecological nodes and 53 second-level ecological nodes were delineated. As the core hub of the regional ecological network in Gannan Prefecture, Diebu County encompasses 60 First-level and 41 Second-level ecological nodes, respectively. The hierarchical “source-corridor-node” ecological network constructed in this study effectively enhances the overall landscape connectivity of the area. This progressive analytical framework—integrating source identification, corridor extraction, and node diagnosis—provides a scientific basis for biodiversity conservation, territorial ecological restoration, and sustainable development in high-altitude ecologically fragile zones.

Forests doi: 10.3390/f17040494

Authors: Norman Moreno-García Roberto Moreno Juan Ramón Molina Beatriz López Bermúdez Leonardo Durán-Garate

This study evaluates the financial profitability and carbon sequestration in mixed native forests of the Roble-Raulí-Coigüe and evergreen types in the southern macrozone of Chile, integrating both ecosystem services into forest management decision-making. The Faustmann model and dynamic programming were applied to determine the optimal rotation periods and Land Expectation Value (LEV) under two scenarios: exclusive timber production and combined timber and carbon production. The results indicate that mixed forests consistently outperform monocultures in terms of profitability, especially in 25%–75% mix configurations and moderate densities (2000 trees/ha). The observed range of 25%–75% across different tree species is determined by the interplay of two critical factors: the average annual growth rate (AAGR) of biomass and the opportunity cost of the forest rotation. In fast-growing species, the upper limit (75%) reflects an optimisation towards early carbon sequestration, whilst in slow-growing species, the ratio shifts towards the lower limit (25%) to compensate for longer rotation periods and associated biotic risks. This range acts as an efficiency frontier that balances biological productivity with the stability of the accumulated carbon stock. The inclusion of the economic value of carbon increased the LEV and extended the optimal rotation periods, confirming the relevance of integrating ecosystem services into forest planning. These findings suggest that mixed native forests represent a competitive and sustainable alternative to monocultures, contributing to climate change mitigation and income diversification for forest owners.

Forests doi: 10.3390/f17040493

Authors: Martynas Dėlkus Algirdas Ivanauskas Marija Žižytė-Eidetienė Deividas Valiūnas

‘Candidatus Phytoplasma rubi’ (elm yellows group, 16SrV-E phytoplasma subgroup) is the causal agent of rubus stunt disease, a disorder affecting economically important plants—raspberries and blackberries. Although this phytoplasma has been extensively studied in cultivated Rubus crops, its occurrence and molecular identity in wild Rubus species populations in North-Eastern Europe remain poorly documented. In this study, phytoplasmas associated with symptomatic wild Rubus idaeus L. and Rubus nessensis Hall plants were investigated in natural forest ecosystems of the Curonian Spit, Lithuania. A total of 65 symptomatic plants were surveyed, and phytoplasma infection was detected in 30 samples by nested PCR targeting the 16S rRNA gene. Positive samples were characterized using a multilocus molecular approach based on sequence analysis of the additional cpn60 and secA genes. All strains showed high nucleotide sequence similarity across the analysed loci and consistently clustered with reference strains of ‘Candidatus Phytoplasma rubi’. Virtual RFLP profiles derived from the 16S rRNA and cpn60 genes were nearly identical to those of established 16SrV-E phytoplasma subgroup reference strains and clearly distinct from other 16SrV phytoplasma subgroups. These results provide not only the first detailed multilocus molecular characterization of ‘Candidatus Phytoplasma rubi’-related strains infecting wild Rubus species in Lithuania but also represent the first report of this phytoplasma in naturally occurring R. idaeus and R. nessensis plants in the country, thereby extending the known geographical occurrence of this pathogen and documenting its presence in wild Rubus hosts from unmanaged forest habitats in the Eastern Baltic region of Northern Europe.

Forests doi: 10.3390/f17040492

Authors: Royson Donate Dsouza Tiina Belt Stefania Fortino

Fungal decay fundamentally alters moisture transport in wood through complex bio-physical coupling mechanisms that remain poorly understood. Brown-rot fungi such as Coniophora puteana (Schumach.: Fr.) P. Karst. degrade wood through chelator-mediated Fenton (CMF) chemistry, producing hydroxyl radicals that depolymerise cellulose and hemicellulose before significant mass loss. This diffusion-dependent process requires elevated moisture content and leads to structural degradation. However, existing models fail to capture the interaction between boundary-driven fungal colonization, decay-induced property changes, and multi-phase multi-Fickian moisture redistribution, particularly the separate evolution of bound- and free-water phases during decay. Here, we present a transport-response bio-hygrothermal finite element model that couples boundary-driven Monod-type fungal colonization kinetics with multi-phase moisture transport (free water, bound water, vapor) in decaying wood. Although fungal biomass evolution is simulated via a reaction–diffusion equation, decay progression is not derived from biomass–substrate interaction but prescribed independently as an experimentally informed input. The model incorporates decay-modified sorption isotherms, permeability evolution, and boundary-driven biomass influx, along with associated moisture transport, into the governing equations. The model is validated against low-field nuclear magnetic resonance (LF-NMR) measurements of C. puteana decay in Scots pine over 35 days. The model successfully reproduces the experimentally observed moisture evolution: a peak free-water content of 50%–70% during weeks 1–2, followed by a progressive decline, while bound water remains remarkably constant despite advancing decay. Monte Carlo uncertainty quantification demonstrates hierarchical parameter control: bound water is governed solely by thermodynamic factors, while free water responds to interacting biological and physical processes. Time-resolved correlation analysis shows a fundamental transition from colonization-dominated (weeks 1–2) to transport-dominated (weeks 3–5) moisture control, quantitatively explaining the experimentally observed shift from accumulation to depletion. This transport-response framework for analyzing moisture behavior under externally defined decay progression establishes quantitative parameter hierarchies that may inform the development of future substrate-coupled bio-hygrothermal models.

Forests doi: 10.3390/f17040491

Authors: Haoju Fan Jiajie Yu

C3H-type zinc finger proteins play essential roles in plant responses to abiotic stresses, as well as in the regulation of growth, development, and signal transduction. Birch (Betula platyphylla Suk.), an ecologically adaptable tree species widely distributed in northern regions, has not yet been systematically characterized for its C3H gene family. In this study, a total of 15 BpC3Hs were identified from a genome-wide analysis of birch. Their physiochemical properties, gene structures, conserved motifs and domains were systematically analyzed. Promoter analysis identified cis-acting elements associated with stress responses, hormone signaling, and developmental regulation. Transcriptome data further showed that most BpC3Hs were responsive to salt, drought, high/low-temperature stresses, and light/dark treatment, and showed differential expression patterns in tension wood and opposite wood. Additionally, they displayed stage-specific expression patterns during male inflorescence development. This study lays a foundation for future functional characterization of the C3H gene family in birch and its application in molecular breeding for stress resistance.

Forests doi: 10.3390/f17040490

Authors: Shuyi Yang Haiqian Yu Niall Farrelly Brian Tobin

Sitka spruce (Picea sitchensis (Bong.) Carr.) is among the most commercially important tree species in European and North American forestry, and genetic improvement programmes are therefore essential for promoting its productivity and sustainability. This research emphasises the significance of the breeding programmes. The primary objective of this study was to provide more reliable information on family selection for the improvement programme of Sitka spruce by accounting for competition and environmental heterogeneity effects. Analyses in the present study were carried out on historical inventory data of height (HT) and diameter at breast height (DBH) from a half-sib progeny trial of Sitka spruce in Ireland. Tree measurement data were collected at ages 6, 12, 15 and 20 years. A mixed linear model incorporating spatial and competition terms was applied to estimate genetic parameters of the Sitka spruce population. The direct genetic effects of each family on its own phenotypes and the competition effect on its neighbour’s phenotype were examined over time. The study demonstrated an analytical approach for assessing both genetic as well as environmental aspects of competition in a Sitka spruce progeny trial. The combined model integrating competition and spatial terms (model CS) improved model fit compared with the basic model, which only included the random effects of genetic and experimental design factors (model B), with an AIC difference of up to 3609 between them. Residual error obtained from model CS was usually smaller than from model B, with the greatest reduction of 85%. Furthermore, model CS generally improved the estimation of heritability for growth traits, by up to 241, when compared with model B. In addition, genetic differences in competitive ability among families were also observed. Families with favourable combinations of direct genetic and competitive breeding values were suggested for selection in subsequent cycles of the breeding programme, i.e., families with relatively high direct genetic breeding value but low and consistent competitive breeding value over time. This work develops a practical framework to inform future family selection for Sitka spruce improvement programmes.