Forests

14 pages, 828 KB

Open AccessArticle

Biomass Allocation and Allometric Equations in an Age Sequence of Chinese Pine (Pinus tabuliformis) Plantations

by Huitao Shen, Haizhou You, Xiaoya Yu, Tao Zhang, Yanxia Zhao and Xin Liu

Forests 2025, 16(12), 1760; https://doi.org/10.3390/f16121760 - 21 Nov 2025

Large-scale tree planting programs that store carbon provided by wood and non-wood products are being promoted to mitigate climate change. Assessing the biomass pool of plantations is thus an essential task in forest ecology. This study investigated biomass allocation and allometric equations for [...] Read more.

Large-scale tree planting programs that store carbon provided by wood and non-wood products are being promoted to mitigate climate change. Assessing the biomass pool of plantations is thus an essential task in forest ecology. This study investigated biomass allocation and allometric equations for above- and belowground components along an age-sequence of Pinus tabuliformis plantations (8, 18, 32, and 46 years old) in northern Hebei Province, China. The biomass of each tree component (root, stem, branch, foliage) was quantified by destructive harvesting. Allometric equations and biomass conversion and expansion factors (BCEFs) were subsequently developed for each tree component. The mean above- and belowground biomass was 5.86, 20.05, 41.26, and 135.28 kg tree⁻¹ and 1.73, 3.42, 11.39, and 27.30 kg tree⁻¹ in the 8-, 18-, 32-, and 46-year-old stands, respectively. The proportion of stem biomass to total tree biomass increased from 28.7% for the 8-year-old stand to 55.8% for 46-year-old stand. In contrast, the contributions of foliage and branch decreased along the chronosequence. The root contribution to total tree biomass also showed a declining trend with stand age. Allometric models based on diameter at breast height showed a good fit (p < 0.001) and incorporating stand age as an additional variable improved the fit of allometric equations (higher R² and lower ACI) for branch, aboveground, root, and total tree biomass. BCEFs decreased for all tree components as stand age increased. These findings indicate that changes in tree biomass allocation and allometry across stand development must be considered to improve estimates of plantation biomass and carbon stocks at regional and national scales. Full article

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

16 pages, 2754 KB

Open AccessArticle

Tree Size Inequalities Induced by Stand Age and Functional Trait Identities Control Biomass Productivity Across Stand Types of Temperate Forests in South Korea

by Yong-Ju Lee and Chang-Bae Lee

Forests 2025, 16(12), 1759; https://doi.org/10.3390/f16121759 - 21 Nov 2025

Abstract

Enhancing forest biodiversity and carbon sinks in the face of climate change is a high priority on the global agenda. The aim of our study was to explore the feasibility and potential of enhancing biodiversity and stand biomass productivity, which are strongly linked [...] Read more.

Enhancing forest biodiversity and carbon sinks in the face of climate change is a high priority on the global agenda. The aim of our study was to explore the feasibility and potential of enhancing biodiversity and stand biomass productivity, which are strongly linked to forest ecosystem functioning and services in temperate forests. Based on data from the 5th to 7th National Forest Inventory of South Korea, 1760 natural forest plots (0.16 ha) were used, of which 344 plots belonged to conifer stands, 711 plots belonged to broadleaved stands, and 705 plots belonged to mixed stands. Forest succession-related factor (i.e., stand age), and abiotic (i.e., climatic and topographic conditions, and soil properties) and biotic drivers (i.e., species diversity, functional trait diversity, functional trait identity, and stand structural diversity) were jointly included as independent variables in an integrated model to explain variations in stand biomass productivity. In order to reveal the key drivers and relationships that regulate stand biomass productivity across forest stand types, we applied a multi-model averaging approach and piecewise structural equation modelling (pSEM). As a key finding, across all forest stand types, forest stand age-induced tree size inequality (i.e., DBH STD) in all forest stand types commonly increased stand biomass productivity, showing strong positive standardized effects (β > 0.5, p < 0.001). We also found that the functional trait identities controlling stand biomass productivity within each forest stand type differed according to their functional traits of dominant species, and that these mechanisms were controlled directly or indirectly by environmental conditions. Our research suggests that appropriate forest management plans should be developed in accordance with environmental gradients to simultaneously promote biodiversity and stand biomass productivity in different forest stand types. Full article

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

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19 pages, 7553 KB

Open AccessArticle

A Dynamic Model for Estimating Forest Carbon Storage: Application in Wuyishan Forests

by Weiping Hua, Chuanmao Hua, Siheng Zhang, Tian Qiu, Xidian Jiang, Baoyin Li and Baibi Chen

Forests 2025, 16(12), 1758; https://doi.org/10.3390/f16121758 - 21 Nov 2025

Abstract

Accurate estimation of forest stand carbon storage is critical for assessing ecosystem functions and informing sustainable forest management. Most existing models depend heavily on stand age, a strategy that is often unreliable in natural forests, and they typically ignore species interactions, limiting their [...] Read more.

Accurate estimation of forest stand carbon storage is critical for assessing ecosystem functions and informing sustainable forest management. Most existing models depend heavily on stand age, a strategy that is often unreliable in natural forests, and they typically ignore species interactions, limiting their applicability across forest types. To overcome these issues, we developed a dynamic carbon storage model based on the Richards equation that replaces stand age with a growth interval period (defined as the time difference between two successive growth stages, T_n = T₂ − T₁) and explicitly incorporates site quality and species composition. This approach enables consistent estimation for both natural and plantation forests. Using field data from six dominant tree species in Wuyishan City, Fujian Province, we calibrated and validated the model through five-fold cross-validation. It achieved high accuracy, with an efficiency coefficient (EA) above 99% and a relative mean absolute error (RMA) under 7%, effectively reflecting how site conditions and mixed-species structures influence carbon dynamics. Total forest carbon storage in the study area was estimated at 7.32 million tons. Simulations show a gradual decline in carbon accumulation over time, consistent with natural growth saturation in aging stands. Scenario analyses further identified practical zones for sustainable harvesting in major plantation types, underscoring the model’s management relevance. The model does not yet include climate variability, disturbances, or below-ground carbon pools. Adding these components in future work would strengthen its utility for regional carbon assessment and support more robust carbon-neutral forestry planning. Full article

(This article belongs to the Special Issue Forest Management Planning and Decision Support)

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27 pages, 8061 KB

Open AccessArticle

EFCW-YOLO: A High-Performance Lightweight Model for Automated Wood Surface Defect Detection

by Mingming Qin, Hongxu Li, Hao An, Xingyu Tong, Yuxiang Huang, Shihan Dong and Zhihong Liang

Forests 2025, 16(12), 1757; https://doi.org/10.3390/f16121757 - 21 Nov 2025

Abstract

Accurate and efficient wood defect detection is crucial for improving timber utilization rates in the wood processing industry. To address the limitations of existing detection models in terms of accuracy, efficiency, and generalization, this study proposes EFCW-YOLO, an improved model based on YOLOv8n. [...] Read more.

Accurate and efficient wood defect detection is crucial for improving timber utilization rates in the wood processing industry. To address the limitations of existing detection models in terms of accuracy, efficiency, and generalization, this study proposes EFCW-YOLO, an improved model based on YOLOv8n. The model incorporates four key enhancements: the Focal Modulation module for superior context modeling, the Efficient Channel Attention (ECA) mechanism for lightweight channel attention, the C2fCIB module for efficient feature extraction, and the Wise-IoU v3 loss function for robust bounding box regression. Experimental results on the self-built PlankDef-9K multi-species defect dataset demonstrate that EFCW-YOLO achieves a mean average precision (mAP50) of 90.26%, outperforming several mainstream detectors while maintaining a compact model size of 6.12 MB. Furthermore, the model exhibits strong generalization capability, as validated on a cross-domain crop pest dataset. The study concludes that EFCW-YOLO provides a high-performance, lightweight solution for automated wood surface defect detection, offering significant potential for industrial deployment to reduce waste and enhance processing efficiency. This technology holds significant practical potential for enabling precise utilization of wood resources, reducing raw material waste, and enhancing the economic benefits of the wood processing industry. Full article

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

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18 pages, 5574 KB

Open AccessArticle

Genome-Wide Identification and Expression Profiling of MYC Transcription Factor Family in Toona sinensis Under Abiotic and Hormonal Stresses

by Guoquan Zhou, Sirui Zeng, Xinru Cui, Yongling Liao, Weiwei Zhang, Feng Xu and Daoju Jiang

Forests 2025, 16(12), 1756; https://doi.org/10.3390/f16121756 - 21 Nov 2025

Abstract

Toona sinensis (Chinese toon) is a valuable forest resource widely used in gastronomy, phytotherapy, and timber production. MYC transcriptional factors are critical to a variety of biological functions. However, the MYC family remains unsystematically characterized in T. sinensis. A total of 18 [...] Read more.

Toona sinensis (Chinese toon) is a valuable forest resource widely used in gastronomy, phytotherapy, and timber production. MYC transcriptional factors are critical to a variety of biological functions. However, the MYC family remains unsystematically characterized in T. sinensis. A total of 18 TsMYC genes were identified in the T. sinensis genome and grouped into six distinct subfamilies according to phylogenetic analysis in this study. This classification was further supported by analyses of gene structure and conserved motifs. Evolutionary analysis revealed that the TsMYC gene family achieved expansion via whole-genome duplication (WGD) and segmental duplication, with these genes experiencing intense purifying selection throughout the evolutionary process. Additionally, 42 cis-acting elements were detected in the promoter regions of TsMYC genes, and the protein–protein interaction (PPI) network demonstrated that MYC2 serves as a central component in the jasmonic acid (JA) signaling pathway. Expression profiling showed that all TsMYC genes except TsMYC17 were highly expressed in leaves. TsMYC genes displayed distinct expression patterns under salt stress and various phytohormone treatments, with TsMYC17 being the only gene consistently upregulated under all conditions. Subcellular localization assays confirmed that TsMYC17 is localized in the nucleus. These findings suggest that TsMYC17 may play a key role in mediating responses to multiple hormonal signals and abiotic stresses. This research lays a foundation for future investigations into the molecular characteristics and biological roles of the TsMYC17 gene. Full article

(This article belongs to the Special Issue Recent Advances in Tree Genetics and Genomics)

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19 pages, 1709 KB

Open AccessArticle

Valuing Improved Firefighting Access for Wildfire Damage Prevention in Mediterranean Forests

by Abdullah Emin Akay, Neşat Erkan, Ebru Bilici, Zennure Ucar and Coşkun Okan Güney

Forests 2025, 16(12), 1755; https://doi.org/10.3390/f16121755 - 21 Nov 2025

Abstract

To effectively combat wildfires, ground teams must reach the fire site via road network within critical response time. However, low-standard forest roads can reduce firetruck speeds and delay fire response times. This study aimed to investigate how improving road standards affects firefighting access [...] Read more.

To effectively combat wildfires, ground teams must reach the fire site via road network within critical response time. However, low-standard forest roads can reduce firetruck speeds and delay fire response times. This study aimed to investigate how improving road standards affects firefighting access within critical response time and contributes to reducing timber losses. This study was conducted in Antalya, the city most affected by wildfires in Türkiye. In the study, highly fire-prone forests were first identified based on a fire probability map of Antalya, developed through a GIS-based MCDA model incorporating the Fuzzy-AHP method. Then, the highly fire-prone forests and their corresponding timber volume were determined. Finally, the economic value of timber saved from fire and the present net value of total road costs were determined. As a result of improving forest roads, the forest areas that could be reached in time increased by 11.04%, making an additional 81,867.53 hectare of highly fire-prone forests accessible. The amount and economic value of timber products saved in this area were 971,195.55 m³ and €37,689,301, respectively. The cost of improved roads was €37,386,622 while the resulting positive net economic value of €302,679 indicates that investing in forest roads improvements is a viable option. Full article

(This article belongs to the Special Issue Advanced Methods and Technologies for Forest Wildfire Prevention)

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12 pages, 2778 KB

Open AccessArticle

Morphological Anatomy, Developmental Characteristics of the Reproductive System in Arhopalus rusticus (Coleoptera: Cerambycidae) and Their Impacts on the Transmission Potential of Bursaphelenchus xylophilus (Aphelenchida: Parasitaphelenchidae)

by Mengxiao Wang, Guangjuan Ren, Jing Wang, Kai Zhong, Zongtao Chang, Dongqin Li, Anbao Ma, Yongyun Qu, Lei Shi, Beining Duan, Haiwei Wu and Xinwei Zhang

Forests 2025, 16(12), 1754; https://doi.org/10.3390/f16121754 - 21 Nov 2025

Abstract

In recent years, opinions have diverged on whether the oviposition pathway of Arhopalus rusticus (Linnaeus, 1758) (Coleoptera: Cerambycidae) can transmit Bursaphelenchus xylophilus (Steiner & Buhrer, 1934) (Aphelenchidae: Nematoda). Based on biological observations and biochemical index calculations, this study assessed the development degree of [...] Read more.

In recent years, opinions have diverged on whether the oviposition pathway of Arhopalus rusticus (Linnaeus, 1758) (Coleoptera: Cerambycidae) can transmit Bursaphelenchus xylophilus (Steiner & Buhrer, 1934) (Aphelenchidae: Nematoda). Based on biological observations and biochemical index calculations, this study assessed the development degree of the internal reproductive system (morphological soluble total sugar and protein content) and external genital morphology of A. rusticus before and after gnawing pine needles. The study results indicate that A. rusticus developed and matured immediately after eclosion in natural conditions, and it could mate and spawn directly. However, gnawing on pine needles has no significant impact on the development of the reproductive system of both male and female A. rusticus, indicating that this behavior is not a prerequisite for reproductive maturity. Furthermore, through dissection and behavioral observations, it has been determined that the degree of ossification in the ovipositor of A. rusticus is lower than that in the ovipositor of Monochamus alternatus (Hope, 1843) (Coleoptera: Cerambycidae), and its egg-laying method involves only depositing eggs on the surface of a bark, thus confirming that the reproductive behavior of A. rusticus does not facilitate the transmission of B. xylophilus. Full article

(This article belongs to the Special Issue Biological Control and Management of Tree Diseases and Insect Pests in Forests)

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Forests, Volume 16, Issue 12 (December 2025) – 7 articles

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