Forests

11 pages, 2774 KiB

Open AccessArticle

Biochar Promotes the Growth of Arbuscular Mycorrhizal Fungi on Taxodium ‘Zhongshanshan’ in Coastal Saline–Alkali Soils

by Xiang Peng, Jieyi Ma, Jinchi Zhang, Qi Cai, Jie Lin, Jingyi Zeng and Xin Liu

Forests 2025, 16(5), 828; https://doi.org/10.3390/f16050828 (registering DOI) - 16 May 2025

Abstract

Taxodium ‘Zhongshanshan’ serves as a primary afforestation species in coastal saline–alkali soils, yet its healthy growth is significantly constrained by excessive soil salinity and nutrient deficiencies. This study investigated the synergistic effects of arbuscular mycorrhizal fungi (AMF) with organic amendments (biochar/straw) on ameliorating [...] Read more.

Taxodium ‘Zhongshanshan’ serves as a primary afforestation species in coastal saline–alkali soils, yet its healthy growth is significantly constrained by excessive soil salinity and nutrient deficiencies. This study investigated the synergistic effects of arbuscular mycorrhizal fungi (AMF) with organic amendments (biochar/straw) on ameliorating soil amelioration and plant adaptation. Six treatments were implemented: Control (CK), Biochar (B), Straw (S), AMF (M), AMF+Biochar (M+B), and AMF+Straw (M+S), with physiological and edaphic parameters monitored over two growth cycles. The results revealed that the M+B treatment demonstrated superior performance, achieving the lowest soil pH (8.06) and electrical conductivity (0.25 mS/cm) alongside reduced Na⁺ accumulation in plant tissues (0.28–0.88 mg/g). Synergistic effects were evident in enhanced chlorophyll synthesis, soluble protein production, and antioxidant enzyme activation. Partial Least Squares Path Modeling (PLS-PM) analysis revealed that soil nitrogen availability indirectly stimulated growth through upregulation of soluble proteins (path coefficient: 0.54) and antioxidant activity (0.22), with cumulative indirect effects (0.88) outweighing direct inhibition (−0.36). These finding provide actionable insights for coastal afforestation strategies using microbial–organic material co-application. Full article

(This article belongs to the Section Forest Soil)

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21 pages, 3507 KiB

Open AccessArticle

WSSGCN: Hyperspectral Forest Image Classification via Watershed Superpixel Segmentation and Sparse Graph Convolutional Networks

by Pingfei Chen, Xuyang Li, Yong Peng, Xiangsuo Fan and Qi Li

Forests 2025, 16(5), 827; https://doi.org/10.3390/f16050827 - 15 May 2025

Abstract

Hyperspectral image classification is crucial in remote sensing but faces challenges in forest ecosystem studies due to high-dimensional data, spectral variability, and spatial heterogeneity. Watershed Superpixel Segmentation and Sparse Graph Convolutional Networks (WSSGCN), a novel framework designed for efficient forest image classification, is [...] Read more.

Hyperspectral image classification is crucial in remote sensing but faces challenges in forest ecosystem studies due to high-dimensional data, spectral variability, and spatial heterogeneity. Watershed Superpixel Segmentation and Sparse Graph Convolutional Networks (WSSGCN), a novel framework designed for efficient forest image classification, is introduced in this paper. Watershed superpixel segmentation is first used by the method to divide hyperspectral images into semantically consistent regions, reducing computational complexity while preserving terrain boundary information. On this basis, a dual-branch model is designed: a local branch with multi-scale convolutional neural networks (CNN) extracts spatial–spectral features, while a global branch constructs superpixel graphs and uses GCNs to model the global context. To enhance efficiency, a sparse tensor-based storage method is proposed for the adjacency matrix, reducing complexity from quadratic to linear. Additionally, an attention-based adaptive fusion strategy dynamically balances local and global features. Experiments on multiple datasets show that WSSGCN outperforms mainstream methods in overall accuracy (OA), average accuracy (AA), and Kappa coefficient. Notably, it achieves a 3.5% OA improvement and a 0.04 Kappa coefficient increase compared to SPEFORMER on the WHU-Hi-HongHu dataset. Practicality in resource-limited scenarios is ensured by sparse graph modeling. This work offers an efficient solution for forest monitoring, supporting applications like biodiversity assessment and deforestation tracking, and advances remote sensing-based forest ecosystem analysis. The proposed approach shows strong potential for real-world ecological conservation and forest management. Full article

(This article belongs to the Special Issue Artificial Intelligence and Machine Learning Applications in Forestry—Second Edition)

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19 pages, 1173 KiB

Open AccessArticle

Do Regional Differences in Forest Distribution Affect Residents’ Preferences for Forest Ecosystem Services?

by Young-Gyun Son, Jang-Hwan Jo and Chae-Jun Lim

Forests 2025, 16(5), 826; https://doi.org/10.3390/f16050826 - 15 May 2025

Abstract

This study investigates how residents of Jeollabuk-do, South Korea perceive and emphasize forest ecosystem services, focusing on whether the distribution of forests between the eastern mountainous areas and the western lowlands influences their preferences. We applied the Choice Experiment (CE) method to gauge [...] Read more.

This study investigates how residents of Jeollabuk-do, South Korea perceive and emphasize forest ecosystem services, focusing on whether the distribution of forests between the eastern mountainous areas and the western lowlands influences their preferences. We applied the Choice Experiment (CE) method to gauge willingness to pay (WTP) for seven key forest ecosystem services and a tax-related attribute. Between 10 and 14 August 2023, we conducted an online survey with 400 participants (out of 4177 invited). Only 20% of respondents were aged 50 or older, despite this age group making up nearly half of the region’s population. On the surface, no significant statistical differences appeared between the two areas regarding overall preferences, perhaps unsurprising, given their shared administrative framework and cultural background. However, a closer look at marginal WTP values uncovered clear regional priorities: residents in the eastern region placed a higher value on erosion control (KRW 23,559–33,109), while those in the west assigned greater priority to biodiversity improvement (KRW 30,225–43,961). Although the sheer distribution of forests may not drastically reshape general preferences, the specific forest characteristics of each area still shape what people care about most. These insights underscore the significance of tailoring forest ecosystem management policies to fit local needs, such as prioritizing erosion control in hilly regions and enhancing biodiversity in flatter areas. Full article

(This article belongs to the Special Issue Multiple-Use and Ecosystem Services of Forests—2nd Edition)

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28 pages, 20721 KiB

Open AccessArticle

Forest Carbon Storage Dynamics and Influencing Factors in Southeastern Tibet: GEE and Machine Learning Analysis

by Qingwei Fan, Yutong Jiang, Yuebin Wang and Guangpeng Fan

Forests 2025, 16(5), 825; https://doi.org/10.3390/f16050825 - 15 May 2025

Abstract

As an important ecological security barrier on the Tibetan Plateau, southeastern Tibet is crucial to maintaining regional carbon balance under climate change. This study innovatively integrates multi-source remote sensing data (Landsat 8, Sentinel-1, and GEDI) on the Google Earth Engine (GEE) platform, and [...] Read more.

As an important ecological security barrier on the Tibetan Plateau, southeastern Tibet is crucial to maintaining regional carbon balance under climate change. This study innovatively integrates multi-source remote sensing data (Landsat 8, Sentinel-1, and GEDI) on the Google Earth Engine (GEE) platform, and uses machine learning to model forest carbon storage dynamics from 2019 to 2023. The fusion of multi-source data improves forest vertical structure characterization and makes up for the shortage of single optical data. By comparing machine learning algorithms, the Gradient Boosting model performs excellently (validation set R² = 0.909, RMSE = 26.608 Mg/Ha), achieving high-resolution spatiotemporal mapping. The results show significant spatial heterogeneity; the increase in carbon storage in the central and southern regions is mainly in contrast to the scattered decreases in the eastern and western regions, reflecting vegetation restoration and topographic influence. High-altitude areas are subject to climate restrictions and small changes, while low-altitude areas show significant fluctuations due to human activities. Key drivers were elevation (importance score 22.06), slope (17.00), and temperature (22.04). Land use transformation (such as forest expansion) promotes net carbon accumulation and highlights the effectiveness of regional protection policies. This study provides a scientific basis for targeted ecological management of high-altitude ecosystems. Full article

(This article belongs to the Section Forest Ecology and Management)

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21 pages, 2699 KiB

Open AccessArticle

Formulation and Numerical Verification of a New Rheological Model for Creep Behavior of Tropical Wood Species Based on Modified Variable-Order Fractional Element

by Loic Chrislin Nguedjio, Jeanne Sandrine Mabekou Takam, Benoit Blaysat, Pierre Kisito Talla and Rostand Moutou Pitti

Forests 2025, 16(5), 824; https://doi.org/10.3390/f16050824 - 15 May 2025

Abstract

This paper aims to develop a rheological model with fewer parameters that accurately describes the primary and secondary creep behavior of wood materials. The models studied are grounded in Riemann–Liouville fractional calculus theory. A comparison was conducted between the constant-order fractional Zener model [...] Read more.

This paper aims to develop a rheological model with fewer parameters that accurately describes the primary and secondary creep behavior of wood materials. The models studied are grounded in Riemann–Liouville fractional calculus theory. A comparison was conducted between the constant-order fractional Zener model and the variable-order fractional Maxwell model, with four parameters each. Using experimental creep data from four-point bending tests on two tropical wood species, along with an optimization algorithm, the variable-order fractional model demonstrated greater effectiveness. The selected fractional derivative order, modeled as a linearly increasing function of time, helped to elucidate the internal mechanisms in the wood structure during creep tests. Analyzing the parameters of this order function enabled an interpretation of their physical meanings, showing a direct link to the material’s mechanical properties. The Sobol indices have demonstrated that the slope of this function is the most influential factor in determining the model’s behavior. Furthermore, to enhance descriptive performance, this model was adjusted by incorporating stress non-linearity to account for the effects of the variation in constant loading level in wood. Consequently, this new formulation of rheological models, based on variable-order fractional derivatives, not only allows for a satisfactory simulation of the primary and secondary creep of wood but also provides deeper insights into the mechanisms driving the viscoelastic behavior of this material. Full article

(This article belongs to the Special Issue Physical–Mechanical Characteristic Analysis of Wood and Wood-Based Composites)

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20 pages, 1927 KiB

Open AccessArticle

Aboveground Biomass Models for Common Woody Species of Lowland Forest in Borana Woodland, Southern Ethiopia

by Dida Jilo, Emiru Birhane, Tewodros Tadesse and Mengesteab Hailu Ubuy

Forests 2025, 16(5), 823; https://doi.org/10.3390/f16050823 - 15 May 2025

Abstract

Aboveground biomass models are useful for assessing vegetation conditions and providing valuable information on the availability of ecosystem goods and services, including carbon stock and forest/rangeland products. This study aimed to develop aboveground biomass estimation models for the common woody species found in [...] Read more.

Aboveground biomass models are useful for assessing vegetation conditions and providing valuable information on the availability of ecosystem goods and services, including carbon stock and forest/rangeland products. This study aimed to develop aboveground biomass estimation models for the common woody species found in Borana woodland. Multispecies and species-specific models for aboveground biomass were developed using 114 destructively sampled trees representing five species. The dendrometric variables selected as predictors of the trees’ aboveground dry biomass for both multispecies and species-specific models were diameter at breast height, tree height, wood basic density (ρ), crown area (ca) and crown diameter (cd). The distribution of biomass across trees’ aboveground components was estimated using destructively sampled trees. Most tree biomass is allocated to branches, followed by the stems. The tree diameter, wood basic density, and crown diameter were significant predictors in generic and species-specific biomass models across all tree components. Incorporating wood basic density into the model significantly improved prediction accuracy, while tree height had a minimal effect on biomass estimation. The stem and twig biomasses were the highest and least predictable plant parts, respectively. Compared with the existing models, our newly developed models significantly reduced prediction errors, reinforcing the importance of location-specific models for accurate biomass estimation. Hence, this study fills the geographic and ecological gaps by developing models tailored with the unique conditions of the Borana lowland forest. The accuracy of species-specific biomass models varied among tree species, indicating the need for species-specific models that account for variations in growth architecture, ecological factors, and bioclimatic conditions. Full article

(This article belongs to the Special Issue Forest Biometrics, Inventory, and Modelling of Growth and Yield)

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26 pages, 28790 KiB

Open AccessArticle

An Ecoregional Conservation Assessment for the Northern Rockies Ecoregion and Proposed Climate Refugium in the Yaak River Watershed, USA

by Dominick A. DellaSala, Kaia Africanis, Bryant C. Baker, Matthew Rogers and Diana Six

Forests 2025, 16(5), 822; https://doi.org/10.3390/f16050822 - 15 May 2025

Abstract

The incorporation of climate refugia concepts in large-scale protection efforts (e.g., 30% protected by 2030, 50% by 2050) is needed to forestall the global extinction crisis. The 8.19 M ha Northern Rockies Ecoregion (NRE) of western Montana, northeastern Washington, and northern Idaho, USA, [...] Read more.

The incorporation of climate refugia concepts in large-scale protection efforts (e.g., 30% protected by 2030, 50% by 2050) is needed to forestall the global extinction crisis. The 8.19 M ha Northern Rockies Ecoregion (NRE) of western Montana, northeastern Washington, and northern Idaho, USA, includes the 159,822 Yaak River Watershed (YRW) in northwest Montana, a proposed climate refugium that may buffer extreme climate change effects. Climate projections show temperature increases along with reduced summer precipitation, lowered spring snowpack, and increased wildfire susceptibility across the NRE but to a lesser extent in the YRE under an intermediate emissions scenario. Overall protection levels were quite low in the NRE (2.2% in GAP 1 or 2) and even lower in the YRW (1% of national forests; the USDA Forest Service manages most of the area). Approximately 32% of forests are mature but only 2.4% and 0.25% are protected (GAP 1 or 2) within the NRE and YRW, respectively. Habitat protection levels for eight focal forest species selected to reflect conservation priorities were generally low, with only wolverine (Gulo gulo) meeting conservation targets if roadless areas were better protected. Most (~75%) Forest Service fuel reduction treatments were >1 km from structures despite congressional funds aimed at the wildland–urban interface/intermix. Increased roadless area protections would close the lower bound (30%) target for most ecosystem types and focal species but still fall short of upper targets. We recommend coupling conservation targets with strategic investments in fuel reductions aimed at the innermost buffer around structures, while reducing logging and roadbuilding in priority areas and refugia. Full article

(This article belongs to the Section Forest Biodiversity)

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28 pages, 4569 KiB

Open AccessReview

Remote Sensing of Forest Above-Ground Biomass Dynamics: A Review

by Yuzhen Zhang, Yiming Zou and Yiwen Wang

Forests 2025, 16(5), 821; https://doi.org/10.3390/f16050821 - 15 May 2025

Abstract

Recent studies have primarily focused on estimating forest above-ground biomass (AGB) at single time points, with limited attention to temporal changes. However, time-series remote sensing data offer valuable insights into biomass trends, drivers of change, and forest recovery following disturbance, deepening our understanding [...] Read more.

Recent studies have primarily focused on estimating forest above-ground biomass (AGB) at single time points, with limited attention to temporal changes. However, time-series remote sensing data offer valuable insights into biomass trends, drivers of change, and forest recovery following disturbance, deepening our understanding of forest dynamics. This review synthesized 166 studies published between 2010 and 2024 (15 years) on forest biomass changes or dynamics monitored through remote sensing, with an emphasis on temporal datasets and both indirect (83.7%) and direct (16.3%) methods for estimating AGB changes, as well as the key drivers of these changes. A meta-analysis of AGB change estimates revealed that 81.5% of studies operated at spatial resolutions below 100 m, while only a few studies addressed coarser scales. Notably, just 11.9% of the studies used independent validation, and 8.8% of studies reported no validation at all, underscoring the need for more rigorous accuracy assessment to ensure methodological reliability and ecological relevance. This review also discusses key challenges, limitations, and future directions for improved remote sensing-based AGB change monitoring. Full article

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

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18 pages, 6378 KiB

Open AccessArticle

A Digital Replica of a Marteloscope: A Technical and Educational Tool for Smart Forestry Management

by Mattia Balestra, Enrico Tonelli, Loris Lizzi, Roberto Pierdicca, Carlo Urbinati and Alessandro Vitali

Forests 2025, 16(5), 820; https://doi.org/10.3390/f16050820 - 15 May 2025

Abstract

Rapidly evolving surveying and monitoring methods are leading the transition toward more efficient, data-driven forest management practices. Recent research highlights the potential of advanced remote sensing platforms to support “smart” forestry, enabling precise, timely, and cost-effective assessments which inform multi-function management methods and [...] Read more.

Rapidly evolving surveying and monitoring methods are leading the transition toward more efficient, data-driven forest management practices. Recent research highlights the potential of advanced remote sensing platforms to support “smart” forestry, enabling precise, timely, and cost-effective assessments which inform multi-function management methods and specialized silvicultural practices for each forest type, composition, and structure. We created a digital replica of a marteloscope, which is a forestry tool to practice silvicultural simulations for technicians and students. The selected stand is an official marteloscope included in the Integrate+ Network project coordinated by the European Forest Institute (EFI). We established a framework for data collection and processing to achieve an accurate digital replica, using a mobile laser scanner (MLS) in a European beech (Fagus sylvatica L.) forest stand. We extracted the main structural forest parameters (diameter at breast height (DBH) and total height (TH)), using the 3DFin software and we graphically returned the obtained digital replica with the CloudCompare software. We compared the MLS-derived values of DBH (1087 trees) and TH (50 trees) with those from a traditional field survey and obtained a root mean square deviation (RMSD) of 2.38 cm for DBH and 2.42 m for TH. The digital marteloscope can help to visualize and assess the effects of selective thinning options on forest structure. The implementation of these virtual reality or augmented reality applications is a useful step toward smarter forestry and could be further improved. Full article

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

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19 pages, 11465 KiB

Open AccessArticle

Scots Pine at Its Southern Range in Siberia: A Combined Drought and Fire Influence on Tree Vigor, Growth, and Regeneration

by Viacheslav I. Kharuk, Il’ya A. Petrov, Alexander S. Shushpanov, Sergei T. Im and Sergei O. Ondar

Forests 2025, 16(5), 819; https://doi.org/10.3390/f16050819 - 14 May 2025

Abstract

Climate models have predicted changes in woody plant growth, vitality, and species distribution. Those changes are expected mainly within the boundaries of species ranges. We studied the influence of changing hydrothermal and burning-rate regimes on relict pine stands at the southern edge of [...] Read more.

Climate models have predicted changes in woody plant growth, vitality, and species distribution. Those changes are expected mainly within the boundaries of species ranges. We studied the influence of changing hydrothermal and burning-rate regimes on relict pine stands at the southern edge of the Pinus sylvestris range in Siberia. We hypothesize that (1) warming has stimulated pine growth under conditions of sufficient moisture supply, and (2) increased burning rate has threatened forest viability. We found that the increase in air temperature, combined with the decrease in soil and air drought, stimulated tree growth. Since the “warming restart” around 2000, the growth index (GI) of pines has exceeded its historical value by 1.4 times. The GI strongly correlates with the GPP and NPP of pine stands (r = 0.82). Despite the increased fire rate, the GPP/NPP and EVI index of both pine stands and surrounding bush–steppes are increasing, i.e., the pine habitat is “greening” since the warming restart. These results support the prediction (by climatic scenarios SSP4.5, SSP7.0, and SSP8.5) of improvement in tree habitat in the Siberian South. Meanwhile, warming has led to a reduction in the fire-return interval (up to 3–5 y). Although the post-fire density of seedlings on burns (ca. 10,000 per ha) is potentially sufficient for pine forest recovery, repeated surface fires have eliminated the majority of the undergrowth and afforestation. In a changing climate, the preservation of relict pine forests depends on a combination of moisture supply, burning rate, and fire suppression. Full article

(This article belongs to the Section Forest Ecology and Management)

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23 pages, 1924 KiB

Open AccessArticle

Forestry Communication and Public Perception: Insights from the Czech Republic

by Marcel Riedl

Forests 2025, 16(5), 818; https://doi.org/10.3390/f16050818 - 14 May 2025

Abstract

This paper presents a structured methodology for identifying and addressing key communication challenges in the forestry sector, using the Czech Republic (CZ) as a case study. The approach integrates the CIMO model, problem tree analysis, SWOT evaluation, and a confrontation matrix to identify [...] Read more.

This paper presents a structured methodology for identifying and addressing key communication challenges in the forestry sector, using the Czech Republic (CZ) as a case study. The approach integrates the CIMO model, problem tree analysis, SWOT evaluation, and a confrontation matrix to identify critical factors influencing communication challenges and prioritize strategic responses. Findings from a representative public survey (n = 3600), participatory workshops, and expert consultations indicate that the primary challenge (C) in Czech forestry is a fragmented sector facing declining trust and minimal media presence. The proposed intervention (I) is a unified, strategic communication methodology designed to activate the mechanism (M) of shared narratives and coordinated messaging. This approach aims to achieve the desired outcomes (O): increased trust, engagement, and legitimacy. The absence of a unified, long-term communication strategy contributes significantly to public misunderstanding, erodes trust, and limits policy support. The study proposes evidence-based tools to enhance sector visibility, coherence, and public engagement. With direct payments for ecosystem services under debate in CZ, effective communication is a prerequisite for securing public and political support. The methods employed have broader relevance for forestry in other countries seeking strengthened stakeholder alignment through strategic communication. Full article

(This article belongs to the Special Issue Multiple-Use and Ecosystem Services of Forests—2nd Edition)

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24 pages, 13246 KiB

Open AccessArticle

Non-Destructive Methods for Diagnosing Surface-Fire-Damaged Pinus densiflora and Quercus variabilis

by Yeonggeun Song, Yugyeong Jung, Younggeun Lee, Wonseok Kang, Jeonghyeon Bae, Sangsub Han and Kyeongcheol Lee

Forests 2025, 16(5), 817; https://doi.org/10.3390/f16050817 - 14 May 2025

Abstract

Wildfires impact forest ecosystems, affecting tree survival and physiological responses. This study explored the effects of surface fires on Pinus densiflora and Quercus variabilis, assessing mortality, internal injuries, and canopy health. By 2024, P. densiflora had an 18.0% mortality rate, whereas Q. [...] Read more.

Wildfires impact forest ecosystems, affecting tree survival and physiological responses. This study explored the effects of surface fires on Pinus densiflora and Quercus variabilis, assessing mortality, internal injuries, and canopy health. By 2024, P. densiflora had an 18.0% mortality rate, whereas Q. variabilis exhibited no crown dieback. Morphological traits, including tree height, the bark scorch index (BSI), and bark thickness, influenced fire resistance. Despite superior stand characteristics, P. densiflora showed higher mortality due to thin bark, whereas Q. variabilis maintained xylem integrity. While sonic tomography (SoT) showed no significant differences, electrical resistance tomography (ERT) detected physiological stress, with higher ERT_R and ERT_Y area ratios correlating with mortality risk. Notably, F-W-W classified trees showed elevated resistance a year before mortality, suggesting ERT as a predictive tool. ERT_R values exceeding 15.0% were associated with a 37.5% mortality rate, whereas ERT_B values below 55.0% corresponded to 42.9% mortality. Despite fire exposure, canopy responses, including chlorophyll fluorescence and photosynthetic efficiency, remained stable, indicating that the surviving trees maintained functional integrity. This study underscores ERT’s efficacy in diagnosing fire-induced stress and predicting mortality risk. The findings highlight species-specific diagnostic criteria and inform post-fire management, supporting forest resilience through the early detection of high-risk trees and improved restoration strategies. Full article

(This article belongs to the Section Natural Hazards and Risk Management)

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18 pages, 1468 KiB

Open AccessArticle

Comparative Study of Carbon Rights Governance Among 7 Countries to Develop Carbon Rights Policy in Vietnam

by Thanh Cong Vu, Ngoc Anh Nguyen, Minkyoung Jang, Dongkuyn Park and Hoduck Kang

Forests 2025, 16(5), 816; https://doi.org/10.3390/f16050816 - 14 May 2025

Abstract

This research examines the governance of carbon rights in comparison with 7 other countries, focusing on Vietnam’s carbon markets and Reducing Emissions from Deforestation and Forest Degradation in Developing Countries implementation. Through constitutional theory and comparative analysis, the study explores carbon rights and [...] Read more.

This research examines the governance of carbon rights in comparison with 7 other countries, focusing on Vietnam’s carbon markets and Reducing Emissions from Deforestation and Forest Degradation in Developing Countries implementation. Through constitutional theory and comparative analysis, the study explores carbon rights and their governance frameworks. It utilizes surveys, in-depth interviews, and literature reviews to scrutinize governance mechanisms. A comparative analysis of Vietnam with countries such as Australia, New Zealand, Sweden, Brazil, Democratic Republic of Congo, Indonesia, and the Philippines was performed. It highlights differences in legal, institutional, and policy frameworks. Australia and New Zealand, early adopters of carbon rights policies promoting private ownership, have developed strong markets. In contrast, Indonesia and other Global South nations are still evolving their frameworks, with a focus on state-controlled systems that restrict participation and equity. The findings indicate substantial gaps in Vietnam’s carbon rights governance compared to other countries, especially in terms of legal clarity, stakeholder engagement, and policy coherence. Accordingly, this study recommends that Vietnam should adopt a robust legal framework for carbon rights, improve transparency in carbon markets, and integrate Reducing Emissions from Deforestation and Forest Degradation in Developing Countries strategies within broader environmental governance objectives. Vietnam’s carbon rights ought to be designated as national assets to ensure equitable distribution among various forest ownership groups. Benefit-sharing mechanisms could be fashioned following the successful implementation of the Payment for Forest Environmental Services policy. The research concludes that, with these enhancements, Vietnam could emerge as a key player in the global carbon market and effectively leverage Reducing Emissions from Deforestation and Forest Degradation in Developing Countries for sustainable development and climate objectives. Full article

(This article belongs to the Special Issue Advances in Forest Carbon, Water Use and Growth Under Climate Change)

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20 pages, 3595 KiB

Open AccessArticle

Enhancing Airborne Laser Scanning-Based Growing Stock Volume Models with Climate and Site-Specific Information

by Elvis Tangwa, Wiktor Tracz, Yousef Erfanifard, Miłosz Mielcarek and Krzysztof Stereńczak

Forests 2025, 16(5), 815; https://doi.org/10.3390/f16050815 - 14 May 2025

Abstract

Forests grow under dynamic conditions influenced by vegetation structure and environmental factors. However, empirical models to enhance growing stock volume GSV) estimation are commonly established based on structural information from airborne laser scanning (ALS) data, raising important questions regarding the models’ performance across [...] Read more.

Forests grow under dynamic conditions influenced by vegetation structure and environmental factors. However, empirical models to enhance growing stock volume GSV) estimation are commonly established based on structural information from airborne laser scanning (ALS) data, raising important questions regarding the models’ performance across time (temporal transferability). This study presents the integration of ALS and microclimate and site-specific data to assess the temporal transferability of GSV models at the plot level in a mixed forest located in Milicz, Poland, between 2007 (t₁) and 2015 (t₂). We compared random forest (RF), multiple linear regression (MLR), and generalized additive models (GAMs) across three modelling scenarios, ALS + site type + climate (sa), ALS only (sb), and ALS + site type (sc), and also performed internal and external validation to assess temporal transferability. Among the three modelling approaches, GAMs outperformed the MLR and RF models in internal validation, improving the R² by 6%–8% and reducing the rRMSE by 6%–12%. We found that climate was significant in GSV prediction when integrated with ALS and site conditions, with a permutation test (p ≤ 0.023) based on the rRMSE confirming climate significance. The direct contribution of climate to model performance was marginal on a broad scale. However, its influence on GSV and temporal transferability seem stronger in homogenous sites. In general, RF was the most stable in both the forward (t₁→t₂) and backward (t₂→t₁) directions in the sa scenario unlike the GAM, which was more stable in the backward direction. This study provides a framework for assessing the reliability of GSV models and addresses a critical gap in forest monitoring. Full article

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

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16 pages, 4455 KiB

Open AccessArticle

Elevational Patterns and Environmental Drivers of Dominant Bacterial Communities in Alpine Forest Soils of Mt. Taibai, China

by Zhigang Li, Xin Wei and Yanbing Qi

Forests 2025, 16(5), 814; https://doi.org/10.3390/f16050814 - 14 May 2025

Abstract

Alpine ecosystems, as one of the most representative terrestrial ecosystems, have garnered significant attention due to their susceptibility to human activities and climate change. However, the distribution patterns and driving factors of alpine soil bacterial communities remain to be further explored, especially for [...] Read more.

Alpine ecosystems, as one of the most representative terrestrial ecosystems, have garnered significant attention due to their susceptibility to human activities and climate change. However, the distribution patterns and driving factors of alpine soil bacterial communities remain to be further explored, especially for different dominant phyla. This study investigated the soil bacterial community composition, elevational patterns, and relationships between bacterial diversity and environmental factors at four elevation gradients (2406–3204 m) on Mt. Taibai, Qinling Mountains, China, using 16S rRNA sequencing. The results showed that the dominant bacterial phyla were Acidobacteria, Actinobacteria, Proteobacteria, and Chloroflexi, accounting for over 69% of the bacterial sequences in soil samples. Dominant bacterial communities exhibit distinct elevation gradient patterns in diversity and community structure. The α-diversity of Actinobacteria and Chloroflexi decreases with increasing elevation, whereas that of Proteobacteria and Acidobacteria increases. Moreover, the community structure of Actinobacteria shows greater variation across elevations than the other three dominant bacterial groups, with significant differences observed among elevations. Redundancy analysis and distance decay analysis revealed that elevation was significantly correlated with the soil bacterial community structure (p < 0.01). Different dominant bacterial communities were regulated by distinct environmental factors, providing strong evidence for understanding microbial community assembly. Therefore, the α- and β-diversity of soil bacteria on Mt. Taibai exhibit distinct elevational variations, and elevation-driven plant diversity and pH may be key factors shaping the spatial distribution of soil bacteria. Full article

(This article belongs to the Section Forest Soil)

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17 pages, 4056 KiB

Open AccessArticle

Effects of Thinning of the Infected Trees and Cultivating of the Resistant Pines on Soil Microbial Diversity and Function

by Xiaorui Zhang, Zhuo Liu, Mu Cao and Tingting Dai

Forests 2025, 16(5), 813; https://doi.org/10.3390/f16050813 - 13 May 2025

Abstract

Pine wilt disease (PWD) poses a significant threat to pine forest health, making sanitation thinning of infected trees and cultivation of disease-resistant pine stands crucial measures for forest ecosystem restoration. To date, limited studies have systematically investigated how post-sanitation planting of pine-wilt-disease-resistant Pinus [...] Read more.

Pine wilt disease (PWD) poses a significant threat to pine forest health, making sanitation thinning of infected trees and cultivation of disease-resistant pine stands crucial measures for forest ecosystem restoration. To date, limited studies have systematically investigated how post-sanitation planting of pine-wilt-disease-resistant Pinus species affects soil microbiome, especially regarding bacterial and fungal diversity characteristics, functional succession patterns, and community assembly processes. In this study, we performed a comparative analysis of soil microbial community characteristics and biochemical properties between experimental plots subjected to sanitation thinning and those replanted with disease-resistant pine species. The results indicated that compared to the sanitation-thinned experimental plot, the disease-resistant experimental plots (Pinus taeda experimental plot and Pinus thunbergii experimental plot) exhibited significantly higher activities of β-glucosidase (S-β-GC), N-acetyl-β-D-glucosidase (S-NAG), and soil arylsulfatase (S-ASF). Compared with the sanitation logging stands, our analysis revealed that the Pinus taeda experimental plot and Pinus thunbergii experimental plot exhibited significantly higher fungal community evenness (OTUs), greater species abundance (OTUs), and more unique fungal taxa. Furthermore, the edaphic properties—specifically soil moisture content (SMC), pH levels, and total potassium (TK)—significantly influenced the structures of soil bacterial and fungal communities. Compared to the sanitation-thinned experimental plot, wood saprotrophic fungi and ectomycorrhizal fungi exhibited increased abundance in both the P. taeda experimental plot and Pinus thunbergii experimental plot. Furthermore, the null models indicated that both the P. taeda experimental plot and P. thunbergii experimental plot enhanced the undominated processes of bacteria and fungi. In summary, our data elucidate the differences in bacterial and fungal responses between pine forests undergoing thinning due to infected trees and those cultivated for disease resistance. This deepens our understanding of microbial functions and community assembly processes within these ecosystems. Full article

(This article belongs to the Special Issue How Does Forest Management Affect Soil Dynamics?)

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18 pages, 11692 KiB

Open AccessArticle

Water Balance in an Atlantic Forest Remnant: Focus on Representative Tree Species

by Adérito C. Cau, José A. Junqueira Junior, Alejandra B. Vega, Severino J. Macôo, André F. Rodrigues, Marcela C. N. S. Terra, Li Guo and Carlos R. Mello

Forests 2025, 16(5), 812; https://doi.org/10.3390/f16050812 - 13 May 2025

Viewed by 57

Abstract

The Atlantic Forest has undergone deforestation and prolonged droughts, affecting ecosystem services. This study assesses the water balance using hydrological observations from representative tree species within a Montane Semideciduous Seasonal Forest (MF) remnant. Gross precipitation (GP), canopy interception (CI), and effective precipitation (EP [...] Read more.

The Atlantic Forest has undergone deforestation and prolonged droughts, affecting ecosystem services. This study assesses the water balance using hydrological observations from representative tree species within a Montane Semideciduous Seasonal Forest (MF) remnant. Gross precipitation (GP), canopy interception (CI), and effective precipitation (EP = Throughfall + Stemflow) were recorded daily, and soil moisture was measured down to 1.80 m every two days during the dry period of the 2023/2024 hydrological year. Additionally, aboveground biomass (AGB), fresh root biomass (BR), and soil hydrological properties in the soil profile were obtained to support the water balance results. The highest EP values were recorded in Miconia willdenowii, while the lowest were in Xylopia brasiliensis. Root zone water storage exhibited a declining trend, with the highest values in Miconia willdenowii. ET remained low, mainly in April, July, and September, with Miconia willdenowii and Copaifera langsdorffii showing the highest values, and AGB correlated with CI and ET. The dynamic of this ecosystem is apparent in the temporal variations (CVt) of soil moisture, influenced by EP and ET. The greatest variability was recorded in the surface layer (0–20 cm), stabilizing with depth, especially below 120 cm. The Temporal Stability Index (TSI) of soil water storage indicated greater stability in Blepharocalyx salicifolius. This study highlights the significance of soil water storage and ET in a tropical forest ecosystem, particularly under drought conditions, suggesting potential species that may be more effective in recovering degraded areas. Full article

(This article belongs to the Section Forest Hydrology)

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22 pages, 10437 KiB

Open AccessArticle

Forest Resilience and Vegetation Dynamics in Southwest Nigeria: Spatiotemporal Analysis and Assessment of Influencing Factors Using Geographical Detectors and Trend Models

by Ismail Adelabu and Lihong Wang

Forests 2025, 16(5), 811; https://doi.org/10.3390/f16050811 - 13 May 2025

Viewed by 76

Abstract

The Southwest Region (SWR) is one of Nigeria’s six geo-political zones and comprises six distinct states. It holds considerable significance due to its unique geographical features, economic vibrancy, pastoral heritage, and fragile natural ecosystems. These ecosystems are becoming increasingly susceptible to human activities [...] Read more.

The Southwest Region (SWR) is one of Nigeria’s six geo-political zones and comprises six distinct states. It holds considerable significance due to its unique geographical features, economic vibrancy, pastoral heritage, and fragile natural ecosystems. These ecosystems are becoming increasingly susceptible to human activities and the adverse impacts of climate change. This study analyzed the temporal and spatial variations of the Normalized Difference Vegetation Index (NDVI) in relation to key influencing factors in the SWR from 2001 to 2020. The analytical methods included Sen’s slope estimator, the Mann–Kendall trend test, and the Geographical Detector Model (GDM). The analysis revealed significant spatial variability in vegetation cover, with dense vegetation concentrated in the eastern part of the region and low vegetation coverage overall, reflected by an average NDVI value of 0.45, indicating persistent vegetation stress. Human activities, particularly land use and land cover (LULC) changes, were identified as major drivers of vegetation loss in some states such as Ekiti, Lagos, Ogun, and Ondo. Conversely, Osun and Oyo exhibited signs of vegetation recovery, suggesting the potential for restoration. The study found that topographic factors, including slope and elevation, as well as climatic variables like precipitation, influenced vegetation patterns. However, the impact of these factors was secondary to LULC dynamics. The interaction detection analysis further highlighted the cumulative effect of combined anthropogenic and environmental factors on vegetation distribution, with the interaction between LULC and topography being particularly significant. These findings provide essential insights into the biological condition of the SWR and contribute to advancing the understanding of vegetation patterns with critical implications for the sustainable management and conservation of tropical forest ecosystems. Full article

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

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13 pages, 2975 KiB

Open AccessReview

Planting Trees as a Nature-Based Solution to Mitigate Climate Change: Opportunities, Limits, and Trade-Offs

by Filippo Bussotti and Martina Pollastrini

Forests 2025, 16(5), 810; https://doi.org/10.3390/f16050810 - 13 May 2025

Viewed by 83

Abstract

Trees and forests are nature-based solutions of strategic importance for climate change mitigation. Policy and popular media are focused on the number of trees to plant, but that cannot be a definitive solution. A growing number of scientific papers address the problems concerning [...] Read more.

Trees and forests are nature-based solutions of strategic importance for climate change mitigation. Policy and popular media are focused on the number of trees to plant, but that cannot be a definitive solution. A growing number of scientific papers address the problems concerning tree plantations and forest restoration for climatic purposes. In this review, we analyze ecological limitations and trade-offs to be considered for the realization and management of these interventions. Terrestrial sinks (forests and other terrestrial natural ecosystems) can absorb only a fraction of the carbon emitted, and the establishment of new effective forests is constrained by ecological limitations. Moreover, the stimulation of tree growth due to carbon fertilization is offset by the harshening of ecological conditions due to climate change (higher temperatures beyond the optimum for photosynthesis, increasing drought, and nutritional imbalances). The increase in frequency and severity of disturbances can turn forests from sinks to sources of carbon. Finally, physiological mechanisms connected to albedo and the emission of organic volatile compounds (VOCs) reduce the efficacy of climate cooling. Although such constraints exist, the establishment of new plantations and the restoration of existing forests are still necessary but are just one of the actions to fight climate change and must not be seen as an alternative to reducing carbon emissions. Considering limitations and trade-offs in the models to estimate tree growth and carbon storage will allow us to produce more realistic plans for climate mitigation. Full article

(This article belongs to the Special Issue Forests as Nature-Based Solutions: Ecosystem Services, Multiple Benefits, and Trade-Offs)

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20 pages, 4567 KiB

Open AccessArticle

Changes in Net Primary Productivity in the Wuyi Mountains of Southern China from 2000 to 2022

by Yanrong Yang, Qianqian Li, Shuang Wang, Yirong Zhang, Weifeng Wang and Chenhui Zhang

Forests 2025, 16(5), 809; https://doi.org/10.3390/f16050809 - 13 May 2025

Viewed by 43

Abstract

Forest carbon sinks have faced significant challenges with the accelerating warming trend in the 21st century. Net primary productivity (NPP) serves as a critical indicator of the carbon cycle in forest ecosystems and is intricately influenced by both human activities and climate change. [...] Read more.

Forest carbon sinks have faced significant challenges with the accelerating warming trend in the 21st century. Net primary productivity (NPP) serves as a critical indicator of the carbon cycle in forest ecosystems and is intricately influenced by both human activities and climate change. This study focuses on the subtropical Southern Forests of China as the research object, using the Wuyi Mountains as a representative study area. The positive and negative contributions of ecologically oriented human activities driven by China’s forestry construction over the past few decades were investigated along with potential extreme climate factors affecting the forest NPP from an altitude gradient perspective and regional-scale forest NPP changes from a novel viewpoint. MODIS NPP, climate, and land use data, along with a vegetation type transfer matrix and statistical methods, were utilized for this purpose. The results are summarized as follows. (1) From 2000 to 2022, NPP in the Wuyi Mountains exhibited a high distribution pattern in the northeastern and southern areas and a low distribution pattern in the central region, with a weak overall increase and an average annual growth increment of only 0.11 gC·m⁻²·year⁻¹. NPP increased with altitude, with a mean growth rate of 5.0 gC·m⁻²·hm⁻¹. Notably, the growth rate of NPP was most pronounced in the altitude range below 298 m in both temporal and vertical dimensions. (2) In the context of China’s long-term Forestry Ecological Engineering Projects and Natural Forest Protection Projects, as well as climate warming, the transformation of vegetation types from relatively low NPP types to high NPP types in the Wuyi Mountains has resulted in a total NPP increase of 211.58 GgC over the past 23 years. Specifically, only the altitude range below 298 m showed negative vegetation type transformation, leading to an NPP decrease of 119.44 GgC. The expansion of urban and built-up lands below 500 m over the 23-year period reduced NPP by 147.92 GgC. (3) The climatic factors inhibiting NPP in the Wuyi Mountains were extreme nighttime high temperatures from June to September, which significantly weakened the NPP of evergreen broadleaf forests above 500 m in elevation. This inhibitory effect still resulted in a reduction of 127.36 GgC in the NPP of evergreen broadleaf forests within this altitude range, despite a cumulative increment in the area of evergreen broadleaf forests above 500 m over the past 23 years. In conclusion, the growth in NPP in the southern inland subtropical regions of China slowed after 2000, primarily due to the significant rise in nighttime extreme high temperatures and the expansion of human-built areas in the region. This study provides valuable data support for the adaptation of subtropical forests to climate change. Full article

(This article belongs to the Section Forest Ecology and Management)

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27 pages, 6791 KiB

Open AccessReview

Holocene Forest Dynamics in Western Mediterranean Islands: Rates, Periodicity, and Trends

by Fabrizio Michelangeli, Elisa De Luca, Donatella Magri, Simone De Santis, Alessandra Celant, Matthieu Ghilardi, Matteo Vacchi, Jordi Revelles, Rita Teresa Melis, Juan Ochando, José Carrión, Roberta Pini, Gabriel Servera-Vives and Federico Di Rita

Forests 2025, 16(5), 808; https://doi.org/10.3390/f16050808 - 13 May 2025

Viewed by 146

Abstract

The forest ecosystems of large Mediterranean islands are critical hubs of evolutionary diversity with unique floristic composition and distinctive vegetation patterns reflecting long-term population dynamics and ecological legacies. Mediterranean islands provide invaluable natural archives, preserving crucial insights into the resilience of past forest [...] Read more.

The forest ecosystems of large Mediterranean islands are critical hubs of evolutionary diversity with unique floristic composition and distinctive vegetation patterns reflecting long-term population dynamics and ecological legacies. Mediterranean islands provide invaluable natural archives, preserving crucial insights into the resilience of past forest ecosystems and their responses to climate variability. In this paper, we provide a comprehensive overview of the Holocene vegetation history of major western Mediterranean islands, with the twofold aim of examining the timing, extent, and rates of vegetation changes over the last few thousand years, and evaluating the influence of Rapid Climate Changes (RCCs) on forest ecosystems. The rate of change analysis allowed the identification of a distinct pattern of rapid shifts in forest composition, corresponding to periods of climate instability. These shifts align with the periodicity of Bond events, suggesting synchronicity between changes in forest ecosystems and centennial-scale climatic oscillations at a supra-regional scale. A REDFIT spectral analysis applied to palynological proxies of forest cover changes identified prominent periodicities suggesting a direct influence of solar activity and/or a relation with complex ocean–atmosphere circulation mechanisms triggered by global climate forcings. Full article

(This article belongs to the Section Forest Ecology and Management)

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11 pages, 3162 KiB

Open AccessArticle

Site Variability in Fibers, Vessels, and Ring Width of Robinia pseudoacacia L. Wood: A Case Study in Hungary

by Fath Alrhman Awad Ahmed Younis, Mátyás Báder, Miklós Bak and Róbert Németh

Forests 2025, 16(5), 807; https://doi.org/10.3390/f16050807 - 12 May 2025

Viewed by 221

Abstract

The black locust tree is a plantation-grown species that occupies a large area in Hungary. Due to variations in the growth environment of trees across different locations, the anatomical features of wood may differ. This study investigated the variability in fiber properties (fiber [...] Read more.

The black locust tree is a plantation-grown species that occupies a large area in Hungary. Due to variations in the growth environment of trees across different locations, the anatomical features of wood may differ. This study investigated the variability in fiber properties (fiber length, width, wall thickness, vessel length, and width) and growth rate of Robinia pseudoacacia L. from five counties and in three specific growing conditions. The parameters were investigated based on a sample of discs taken from the trees at breast height. The statistical analysis revealed significant differences in wood fiber and vessel dimensions, as well as ring width, between counties and growth conditions. Nearly all examined parameters showed the lowest values in Bács-Kiskun County, whereas the highest values were observed in Szabolcs-Szatmár-Bereg and Vas. Regarding the growth conditions, wood in poor growth conditions (mixed trees) and good growth conditions produced superior wood fiber properties and ring widths. Full article

(This article belongs to the Section Wood Science and Forest Products)

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20 pages, 3141 KiB

Open AccessArticle

Post-Fire Recovery of Soil Multiple Properties, Plant Diversity, and Community Structure of Boreal Forests in China

by Xiting Zhang, Danqi She, Kai Wang, Yang Yang, Xia Hu, Peng Feng, Xiufeng Yan, Vladimir Gavrikov, Huimei Wang, Shijie Han and Wenjie Wang

Forests 2025, 16(5), 806; https://doi.org/10.3390/f16050806 - 12 May 2025

Viewed by 155

Abstract

Fire is important in boreal forest ecosystems, but comprehensive recovery analysis is lacking for soil nutrients and plant traits in China boreal forests, where the strict “extinguish at sight” fire prevention policy has been implemented. Based on over 50 years of forest fire [...] Read more.

Fire is important in boreal forest ecosystems, but comprehensive recovery analysis is lacking for soil nutrients and plant traits in China boreal forests, where the strict “extinguish at sight” fire prevention policy has been implemented. Based on over 50 years of forest fire recordings in the Daxing’anling Mts, 48 pairs of burnt and unburnt controls (1066 plots) were selected for 0–20 cm soil sampling and plant surveys. We recorded 18 plant parameters of the abundance of each tree, shrub, grass, and plant size (height, diameter, and coverage), 7 geo-topographic data parameters, and 2 fire traits (recovery year and burnt area). We measured eight soil properties (soil organic carbon, SOC; total nitrogen, TN; total phosphorus, TP; alkali-hydrolyzed P, AP; organic P, Po; inorganic P, Pi; total glomalin-related soil protein, T-GRSP; easily-extracted GRSP, EE-GRSP). Paired T-tests revealed that the most significant impact of the fire was a 25%–48% reduction in tree sizes, followed by decline in the plant diversity of arbors and shrubs but increasing plant diversity in herbs. GRSP showed an >18% increase and P_o decreased by 17% (p < 0.05). Redundancy ordination showed that the post-fire recovery years and burnt area were the most potent explainer for the variations (p < 0.05), strongly interacting with latitudes and longitudes. Plant richness and tree size were directly affected by fire traits, while the burnt area and recovery times indirectly increased the GRSP via plant richness. A fire/control ratio chronosequence found that forest community traits (tree size and diversity) and soil nutrients could be recovered to the control level after ca. 30 years. This was relatively shorter than in reports on other boreal forests. The possible reasons are the low forest quality from overharvesting in history and the low fire severity from China’s fire prevention policy. This policy reduced the human mistake-related fire incidence to <10% in the 2010s in the studied region. Chinese forest fire incidences were 3% that of the USA. The burnt area/fire averaged 5 hm² (while the USA averaged 46 hm², Russia averaged 380 hm², and Canada averaged 527 hm²). Overharvesting resulted in the forest height declining at a rate of >10 cm/year. Our finding supports forest management and the evaluation of forest succession after wildfires from a holistic view of plant–soil interactions. Full article

(This article belongs to the Section Forest Biodiversity)

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19 pages, 4638 KiB

Open AccessArticle

Genome-Wide Identification, Evolution and Expression Analysis of the G-Protein Gene Family in Poplar (Populus alba × Populus glandulosa)

by Bobo Song, Qian Liu, Zitong Zeng, Yiyang Gu, Wenxin Ye, Fangfang Fu and Meiling Ming

Forests 2025, 16(5), 805; https://doi.org/10.3390/f16050805 - 12 May 2025

Viewed by 132

Abstract

Heterotrimeric G-proteins are key signal transduction mediators involved in regulating plant growth and development, and responses to various stress in plants. G-proteins are extensively investigated in model plants, such as Arabidopsis thaliana and Oryza sativa. However, the identification and function of G-proteins in [...] Read more.

Heterotrimeric G-proteins are key signal transduction mediators involved in regulating plant growth and development, and responses to various stress in plants. G-proteins are extensively investigated in model plants, such as Arabidopsis thaliana and Oryza sativa. However, the identification and function of G-proteins in woody species, particularly Populus, remain largely unexplored. In this study, we performed a genome-wide identification and comprehensive analysis of the G-protein gene family in poplar, aiming to reveal their evolutionary history, structural diversity and potential function roles. As a result, a total of 27 G-protein genes were identified in the poplar genome, including 18 Gα, 4 Gβ and 5 Gγ subunits. Phylogenetic analysis indicated that 27 G-protein genes were divided into three subgroups. Gene structure, conserved domain and motifs indicated the conserved nature of G-protein at sequence and structure. In addition, synteny analysis revealed that whole-genome duplication events contributing to the expansion of the G-protein gene family in poplar. Cis-regulatory element analysis indicated that many G-protein genes in poplar contain hormone and stress related motifs, suggesting that G-protein genes are involved in environmental adaptation. Expression profiling analysis demonstrated that G-protein genes exhibited tissue-specific expression and stress-responsive expression patterns, highlighting their potential regulatory roles in growth and development and responses to biotic and abiotic stresses. This study provides valuable insights into the poplar G-protein gene family and lays the foundation for further functional analyses, contributing to improving stress tolerance in forestry species. Full article

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

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16 pages, 2206 KiB

Open AccessArticle

The Hybrid Retrieval of Leaf Anthocyanin Content Using Four Machine Learning Methods

by Yingying Li, Qiuxiang Yi and Yaoliang Chen

Forests 2025, 16(5), 804; https://doi.org/10.3390/f16050804 - 11 May 2025

Viewed by 207

Abstract

Leaf anthocyanins are essential for plants to resist biotic and abiotic stresses. The timely and accurate estimation of leaf anthocyanin content (L_anth) plays a vital role in supporting agriculture and forestry management. To date, numerous satisfactory results have been obtained using [...] Read more.

Leaf anthocyanins are essential for plants to resist biotic and abiotic stresses. The timely and accurate estimation of leaf anthocyanin content (L_anth) plays a vital role in supporting agriculture and forestry management. To date, numerous satisfactory results have been obtained using hybrid methods for vegetation trait estimation. However, the feasibility of the hybrid retrieval of L_anth is underexplored. In this study, four typical machine learning algorithms—an artificial neural network (ANN), a support vector machine (SVM), Gaussian process regression (GPR), and random forest (RF)—were investigated to estimate L_anth with a hybrid scheme. The results showed that satisfactory accuracy (R² > 0.57 and RMSE < 2.97 μg/cm²) was obtained with all four machine learning algorithms. Among all constructed models, GPR showed superior performance. The best GPR model utilized the first three principal components derived from the logarithmic transformation of reflectance (log(1/reflectance)) as independent variables, achieving an R² value of 0.76 and an RMSE of 2.24 μg/cm². However, compared to empirical models directly built from the in situ dataset, the hybrid scheme had reduced accuracy owing to the uncertainty between the simulated and in situ datasets. Nevertheless, the present study further verifies the potential of hybrid retrieval for L_anth and supports its future application in L_anth mapping. Full article

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

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21 pages, 7692 KiB

Open AccessArticle

The Hidden Carbon Cost of Forest Fire Management: Quantifying Greenhouse Gas Emissions from Both Vegetation Burning and Social Rescue Activities in Yajiang County, China

by Zilin Ye, Yanjun Wang, Xijin Zhao, Yugang Wang, Jing Liao, Jian Min, Xun Gong, Dongmei Wang and Zhengjun Gong

Forests 2025, 16(5), 803; https://doi.org/10.3390/f16050803 - 11 May 2025

Viewed by 137

Abstract

Quantifying greenhouse gas (GHG) emissions from forest fires is essential for climate change mitigation strategies, yet current methodologies predominantly focus on vegetation combustion, neglecting emissions from firefighting operations. This study presents a comprehensive assessment of GHG emissions from a forest fire in Yajiang [...] Read more.

Quantifying greenhouse gas (GHG) emissions from forest fires is essential for climate change mitigation strategies, yet current methodologies predominantly focus on vegetation combustion, neglecting emissions from firefighting operations. This study presents a comprehensive assessment of GHG emissions from a forest fire in Yajiang County, China, by integrating remote sensing data with ground-based measurements to quantify emissions from both vegetation combustion and emergency response activities. Analysis revealed that the fire, which affected 20,688.67 hectares, generated 63,764.59 tons of GHGs—with vegetation combustion accounting for 83.5% (53,266.29 tons) and emergency response activities contributing 16.5% (10,498.30 tons). Moderate-severity fires in evergreen forests yielded the highest emissions, while aerial operations constituted the primary source of emergency-response-related emissions. Significantly, NO_x emissions from emergency response activities exceeded those from vegetation combustion. This research advances forest fire management by establishing a holistic accounting framework that incorporates previously unquantified emission sources, thereby providing foundational data for developing environmentally optimized fire social rescue activity protocols. Full article

(This article belongs to the Special Issue Fire Ecology and Management in Forest—2nd Edition)

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22 pages, 1075 KiB

Open AccessArticle

Socio-Economic Aspects of Drought Impact on Forest Industry in China

by Lei Wang, Xinyi Wang and Wei Wang

Forests 2025, 16(5), 802; https://doi.org/10.3390/f16050802 - 11 May 2025

Viewed by 87

Abstract

Extreme drought events under the background of global warming pose a significant threat to China’s forest industry system. This study aims to analyze the impact of drought on China’s forest industry from the perspective of economics, and, through the mechanism test, to further [...] Read more.

Extreme drought events under the background of global warming pose a significant threat to China’s forest industry system. This study aims to analyze the impact of drought on China’s forest industry from the perspective of economics, and, through the mechanism test, to further study the communication path of drought to the forest industry. The study finds: (1) drought has been increasing in China in the last 50 years. (2) Drought has a significant restraining effect on the Chinese forest industry. Moreover, inland areas are more vulnerable to drought than coastal areas. (3) Drought will lead to an increase in the occurrence area of forest pests and diseases, forming a compound eco-economic loss effect, thus inhibiting the development of the forest industry. (4) Drought can drive an increase in irrigation facilities. Efficient irrigation may mitigate biological damages caused by drought, so as to resist part of the economic losses. (5) Drought may cause labor to migrate from the forest sector to non-forest sectors, leading to lower production in the forest industry. Labor transfer effects caused by drought are more obvious in the areas where the income gap is relatively big between rural and urban regions, e.g., in inland areas. Full article

(This article belongs to the Special Issue Managing Forests for Multiple Ecosystem Services Under Changing Climate)

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19 pages, 1642 KiB

Open AccessArticle

Sustainable Management of Bursera bipinnata: Relationship Between Environmental and Physiological Parameters and Resin Extraction

by Fredy Martínez-Galván, Julio César Buendía-Espinoza, Elisa del Carmen Martínez-Ochoa, Selene del Carmen Arrazate-Jiménez and Rosa María García-Núñez

Forests 2025, 16(5), 801; https://doi.org/10.3390/f16050801 - 10 May 2025

Viewed by 192

Abstract

Copal is a non-timber forest product of historical, cultural, and industrial significance in Mexico. The use of unsustainable harvesting methods and a lack of understanding of the factors influencing their production have led to a decline in natural populations of resin-producing species. This [...] Read more.

Copal is a non-timber forest product of historical, cultural, and industrial significance in Mexico. The use of unsustainable harvesting methods and a lack of understanding of the factors influencing their production have led to a decline in natural populations of resin-producing species. This study aimed to identify the dendrometric, edaphoclimatic, physiological, and resin extraction method variables with the greatest influence on resin yield in Bursera bipinnata using correlation analysis and multiple linear regression. The research was conducted in the Los Sauces micro-watershed, Morelos, Mexico, with a randomly selected sample of 70 trees. Nineteen explanatory variables were categorized into dendrometric, edaphoclimatic, physiological, and extraction method parameters. Variables significantly correlated with resin yield were diameter at breast height, crown diameter, crown volume, altitude, resin tapping faces on the stem, resin tapping faces on branches, total resin tapping faces, resin tapping face height, total resin tapping area, and the Normalized Difference Moisture Index (NDMI) in October. The regression model revealed that resin yield increased significantly with total tapping area (

β = 0.649

) but decreased with greater incision length (

β = - 0.308

) and higher NDMI values in October (

β = - 0.205

), explaining 43.8% of the variation in resin yield. Results highlight the importance of tissue damage intensity, tree physiological status, and water availability as determinants of resin production. The model provides practical guidelines for optimizing extraction techniques, enabling sustainable harvesting that maintains tree vitality and supports long-term productivity in resin-harvesting communities. Full article

(This article belongs to the Topic Climate Change and Environmental Sustainability, 4th Edition)

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17 pages, 646 KiB

Open AccessArticle

Innovative Peat-Free Organic Substrates and Fertilizers Influence Growth Dynamics and Root Morphology of Fagus sylvatica L. and Quercus robur L. Seedlings One Year After Planting

by Odunayo James Rotowa, Stanisław Małek, Dawid Kupka, Maciej Pach and Jacek Banach

Forests 2025, 16(5), 800; https://doi.org/10.3390/f16050800 - 10 May 2025

Viewed by 175

Abstract

This study evaluated the effects of six innovative peat-free substrate formulations, combined with either a conventional solid fertilizer or a novel liquid fertilizer developed by the research team, on the early growth and root morphology of Fagus sylvatica L. and Quercus robur L. [...] Read more.

This study evaluated the effects of six innovative peat-free substrate formulations, combined with either a conventional solid fertilizer or a novel liquid fertilizer developed by the research team, on the early growth and root morphology of Fagus sylvatica L. and Quercus robur L. seedlings. Treatments were analyzed through two-way ANOVA and species-specific linear regression models. Following one year of field growth, survival rates remained high across all treatments. While R22 (a peat-free substrate with liquid fertilizer) exhibited the highest mean values for seedling height and diameter, only height showed statistically significant variation among treatments (p < 0.05), with no significant differences observed for diameter increment. It was further, revealed that seedlings treated with peat-free substrates and liquid fertilizers exhibited adequate survival, with several combinations especially R22 showing comparable performance to traditional peat-based media with solid fertilizer. Root morphological traits, particularly fine root length (≤0.50 mm) were strong predictors of above-ground growth in F. sylvatica, but less so in Q. robur, which relied more on total root length. The results highlight species-specific root–shoot coordination strategies, with beech exhibiting above-ground growth pattern and oak a gravitropic one. The findings concluded that R22 substrates confirmed exceptional performance with enhanced root growth comparable to peat after one year of forest planting, indicating strong potential for future development without the environmental concerns associated with peat use. Full article

(This article belongs to the Special Issue Growth and Stand Dynamics of Unmanaged and Managed Forests Under Global Change)

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22 pages, 19585 KiB

Open AccessArticle

Effects of Plant Communities in Urban Green Spaces on Microclimate and Thermal Comfort

by Wenjie Li, Pinwei Pan, Dongming Fang and Chao Guo

Forests 2025, 16(5), 799; https://doi.org/10.3390/f16050799 - 10 May 2025

Viewed by 192

Abstract

Urban green spaces are crucial for regulating microclimates and enhancing human comfort. The study, conducted at Jiyang College of Zhejiang A&F University, investigates the effects of plant communities with diverse canopy structures on campus microclimates and thermal comfort in summer and winter. Data [...] Read more.

Urban green spaces are crucial for regulating microclimates and enhancing human comfort. The study, conducted at Jiyang College of Zhejiang A&F University, investigates the effects of plant communities with diverse canopy structures on campus microclimates and thermal comfort in summer and winter. Data on air temperature (AT), relative humidity (RH), wind speed (WS), and light intensity (LI) were collected over three consecutive sunny days in both summer and winter. Concurrently, plant community structural characteristics, including three-dimensional green biomass (3DGB), canopy density (CD), and sky-view factor (SVF), were measured and analyzed. Quantitative relationships between these plant characteristics and microclimate/thermal comfort indices were evaluated using statistical analyses. The results indicate that, in summer, plant communities produced significant cooling (daily average AT reduced by 2.3 °C) and humidifying effects, and decreased the daily maximum thermal humidity index (THI) by 1 °C compared to control areas without vegetation. In winter, the moderation of temperature and humidity was present but less pronounced, and no statistically significant temperature difference was observed. Communities with larger 3DGB, higher CD, and lower SVF provided more effective shading and improved microclimatic regulation. A regression analysis identified AT as the primary factor influencing outdoor thermal comfort across both seasons. Planting configurations such as “Tree-Shrub-Herb” and “Tree-Small Tree”, as well as the use of broad-crowned shade trees, were shown to be effective in optimizing microclimate and outdoor comfort. Overall, enhancing the vegetation structure may address outdoor thermal comfort requirements in campus environments throughout the year. Full article

(This article belongs to the Section Urban Forestry)

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