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Forests
Journal Prestige (SJR): 0.812  Citation Impact (citeScore): 2 Number of Followers: 4  Open Access journalISSN (Print) 1999-4907 Published by MDPI  [258 journals]
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- Forests, Vol. 15, Pages 1288: The Distribution Range of Populus euphratica
Oliv. (Salicaceae) Will Decrease Under Future Climate Change in
Northwestern China
Authors: Xun Lei, Mengjun Qu, Jianming Wang, Jihua Hou, Yin Wang, Guanjun Li, Meiwen Luo, Zhijun Li, Jingwen Li
First page: 1288
Abstract: Climate change has been regarded as a primary threat to biodiversity at local, regional, and global scales. Populus euphratica Oliv. is one of the main constructive species in dryland regions and has a key role in regulating ecosystem processes and services. However, there is a knowledge gap regarding the spatial distribution of habitat suitability of P. euphratica and how it will be affected by future climate change. Based on the distribution records collected from an online database and specialized literature, we applied an optimized MaxEnt model to predict the distribution range of P. euphratica in China under four climate change scenarios (SSP126, SSP245, SSP370, and SSP585) for both current and future (2090s) conditions. We found that (1) future climate change would reduce the adaptability of P. euphratica, resulting in a significant decrease in its distribution area; (2) water availability had the most important effect on P. euphratica distribution; (3) the habitat for P. euphratica would shift northwestward and contract towards lower elevations closer to rivers in the future. These findings can provide a reference for developing long-term biodiversity conservation and management strategies in arid regions.
Citation: Forests
PubDate: 2024-07-24
DOI: 10.3390/f15081288
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1289: Visual Aesthetic Quality of Qianjiangyuan
National Park Landscapes and Its Spatial Pattern Characteristics
Authors: Zhiqiang Gao, Chunjin Wu, Nan Li, Peng Wang, Jiang Li
First page: 1289
Abstract: This paper conducts a scientific assessment of aesthetic quality to provide intuitive and scientific planning strategies for national park construction. Focusing on Qianjiangyuan National Park, the study used the scenic beauty evaluation (SBE) method to subjectively assess landscape photos from 16 sample sites. Objective eye movement indicators describing visual behavior were also analyzed. A national park landscape visual quality assessment model was derived through multiple linear regressions correlating subjective evaluations with objective indicators. Spatial technologies like ArcGIS were used to analyze the visual quality and its spatial distribution. Key findings include (1) subjective evaluations showed higher SBE scores for wetland landscapes, followed by recreational, village, and forest landscapes, (2) eye movement behavior varied across landscape types, with the forest landscape having the shortest first fixation time and the lowest saccade frequency, while recreational landscapes had the lowest average saccade speed, (3) strong correlations were found between SBE and indicators such as average fixation time and saccade frequency, with fixation duration ratio being the leading factor influencing visual aesthetic quality, and (4) visual aesthetic quality was highest in the north and south areas of the park, with significant differences between sample sites in these regions compared to the central area. Among different functional zones, the ecological protection area had the highest quality, while the Suzhuang management area excelled in aesthetic quality compared to the Hetian management area.
Citation: Forests
PubDate: 2024-07-24
DOI: 10.3390/f15081289
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1290: Spatial Pattern of Forest Age in China
Estimated by the Fusion of Multiscale Information
Authors: Yixin Xu, Tao Zhou, Jingyu Zeng, Hui Luo, Yajie Zhang, Xia Liu, Qiaoyu Lin, Jingzhou Zhang
First page: 1290
Abstract: Forest age is one of most important biological factors that determines the magnitude of vegetation carbon sequestration. A spatially explicit forest age dataset is crucial for forest carbon dynamics modeling at the regional scale. However, owing to the high spatial heterogeneity in forest age, accurate high-resolution forest age data are still lacking, which causes uncertainty in carbon sink potential prediction. In this study, we obtained a 1 km resolution forest map based on the fusion of multiscale age information, i.e., the ninth (2014–2018) forest inventory statistics of China, with high accuracy at the province scale, and a field-observed dataset covering 6779 sites, with high accuracy at the site scale. Specifically, we first constructed a random forest (RF) model based on field-observed data. Utilizing this model, we then generated a spatially explicit forest age map with a 1 km resolution (random forest age map, RF map) using remotely sensed data such as tree height, elevation, meteorology, and forest distribution. This was then used as the basis for downscaling the provincial-scale forest inventory statistics of the forest ages and retrieving constrained maps of forest age (forest inventory constrained age maps, FIC map), which exhibit high statistical accuracy at both the province scale and site scale. The main results included the following: (1) RF can be used to estimate the site-scale forest age accurately (R2 = 0.89) and has the potential to predict the spatial pattern of forest age. However, (2) owing to the impacts of sampling error (e.g., field-observed sites are usually located in areas exhibiting relatively favorable environmental conditions) and the spatial mismatch among different datasets, the regional-scale forest age predicted by the RF model could be overestimated by 71.6%. (3) The results of the downscaling of the inventory statistics indicate that the average age of forests in China is 35.1 years (standard deviation of 21.9 years), with high spatial heterogeneity. Specifically, forests are older in mountainous and hilly areas, such as northeast, southwest, and northwest China, than in southern China. The spatially explicit dataset of the forest age retrieved in this study encompasses synthesized multiscale forest age information and is valuable for the research community in assessing the carbon sink potential and modeling carbon dynamics.
Citation: Forests
PubDate: 2024-07-24
DOI: 10.3390/f15081290
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1291: Environmental Impacts of Mechanized Timber
Harvesting in Eucalyptus Plantations in Brazil
Authors: Camila Porfirio Albuquerque Ferraz, Márcia Pereira da Silva Manoel, Jô Vinícius Barrozo Chaves, Luiz Henrique Freguglia Aiello, Gislene Sales da Silva, Gerson Araújo De Medeiros, Admilson Írio Ribeiro
First page: 1291
Abstract: The advancement of mechanization in forestry has increased productivity in the forestry sector, bringing positive and negative impacts that require a deeper understanding for sustainable forest management. This study aimed to apply a simplified instrument for assessing damage and environmental impacts in forest harvesting of commercial eucalyptus plantations, using a combination of methodologies. The methodology used combined interaction networks and impact assessment matrices, carrying out field surveys, transposing them to interaction networks and weighting them through assessment matrices, resulting in environmental indices (ES) for prioritizing actions. The study was conducted on a commercial eucalyptus plantation in the municipality of São Pedro, São Paulo, Brazil. The mechanized harvesting of the area consists of the structure of a module with a mobile unit consisting of a harvester and forwarder. The results indicated that wood transport presented the highest ES, both positive and negative. The most significant negative impacts (ES) were the depletion of water resources and erosion, while the positive impacts included regional development and job creation. The most notable changes, positive and negative, were observed in the physical and anthropic environment, with a lesser impact on the biotic environment.
Citation: Forests
PubDate: 2024-07-24
DOI: 10.3390/f15081291
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1292: The Impact of Future Land Use Change on
Carbon Emission and Its Optimization Strategy
Authors: Yang Sun, Junjun Zhi, Chenxu Han, Chen Xue, Wenjing Zhao, Wangbing Liu, Shanju Bao
First page: 1292
Abstract: Rapidly changing climate issues and increasingly severe carbon emissions are great challenges to the carbon peaking and carbon neutrality strategy. Analyzing the impact of future land use changes on carbon emissions can provide an important basis and reference for scientifically constructing a low-carbon and sustainable territorial spatial planning, as well as realizing the goal of the dual-carbon strategy. Based on land use data, agricultural production activity data, and energy consumption statistics, this study simulated the land use changes of the Yangtze River Delta region (YRDR) from 2030 to 2060 under the natural development (ND) scenario and sustainable development (SD) scenario by using the Patch-generating Land Use Simulation (PLUS) model and analyzed the impacts of future land use changes on carbon emissions. The results showed that: (1) The land use simulation results obtained by using the PLUS model under the sustainable development scenario were highly consistent with the actual land use with an OA value of 97.0%, a Kappa coefficient of 0.952, and a FoM coefficient of 0.403; (2) Based on the simulated land use under the SD scenario from 2030 to 2060, the quantity of construction land was effectively controlled, and the spatial distributions of cropland and forests were found to dominate in the north and south of the Yangtze River, respectively; (3) Anhui Province was the major contributor (accounted for 49.5%) to the net carbon absorption by cropland while Zhejiang Province was the major contributor (accounted for 63.3%) to the net carbon absorption by forest in the YRDR during the period 2020–2060 under the SD scenario; (4) Carbon emissions from construction land were the main source of carbon emissions from land use in the YRDR during the period 2020–2060 with proportions higher than 99% under both the ND and SD development scenarios. These findings underscore the urgent need for the government to take measures to balance the relationships between cropland and ecological protection and economic development, which provides a reference for the optimization of land use structure and policy formulation in the future.
Citation: Forests
PubDate: 2024-07-24
DOI: 10.3390/f15081292
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1293: Soil Fungal Function Centralization Enhances
the Decomposition of Fine Roots at Canopy Gap Borders
Authors: Haijun Liao, Chaonan Li, Zhoulin Han, Guorong Luo, Yulian Yang, Qinggui Wu, Aluo An, Xianwei Li, Dehui Li
First page: 1293
Abstract: Canopy gaps can result in abiotic heterogeneities and diverse niches from gap borders to centers, potentially affecting fine root decompositions mediated by soil fungal communities. Despite extensive discussions on the relationship between soil fungi and fine root decomposition, the mechanism by which gap locations regulate fine root decomposition through the soil fungal community remains elusive. Here, we conducted an in situ field decomposition experiment of Chinese Toon (Toona senensis) fine roots in a low-efficiency weeping cypress (Cupressus funebris) plantation forest across three microhabitats: gap centers, gap borders, and closed canopy areas. Soil fungal communities were determined using internal transcribed spacer (ITS) sequencing after two years of field incubation. Results showed that soil properties and nutrient content in residual roots varied across the three microhabitats, with the gap borders exhibiting the highest decomposition rates. While fungal α-diversity remained relatively consistent, taxonomic compositions differed significantly. Decomposition rates did not show significant correlations with soil properties, observed fungal ASVs, or overall community composition. However, they positively correlated with the relative abundance of saprotrophic Sordariomycetes, which in turn positively correlated with soil total nitrogen (with a highest correlation), peaking at the gap borders. Overall community variations were primarily driven by soil temperature and magnesium content in residual roots. Further analysis revealed high fungal community similarities and low dispersal limitations between the gap borders and closed canopy areas, with more phylogenetically clustered communities at the borders. These results demonstrate that the gap borders possess a high decomposition rate, likely due to the centralization of functions driven by soil fungi such as saprotrophs existing in the “microbial seed bank” or migrating from closed canopy areas. These findings highlight the key role of soil fungi, especially saprotrophic fungi, in fine root decomposition at the gap borders, stressing the importance of soil fungi-driven mechanisms in nutrient cycling, and also informing sustainable forest management practices.
Citation: Forests
PubDate: 2024-07-24
DOI: 10.3390/f15081293
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1294: Carbon (δ13C) and Nitrogen
(δ15N) Isotope Dynamics during Decomposition of Norway Spruce and
Scots Pine Litter
Authors: Mukesh K. Gautam, Björn Berg, Kwang-Sik Lee
First page: 1294
Abstract: We studied the dynamics of stable carbon (δ13C) and nitrogen (δ15N) isotopes in litter from Norway spruce (NSL) (Picea abies) and Scots pine (SPL) (Pinus silvestris) during in situ decomposition over a period of more than 4 years. Relative to initial values, δ13CNSL showed a weak enrichment (0.33‰), whereas δ13CSPL was depleted (−0.74‰) at the end of decomposition. Both litter types experienced a depletion in δ15N during decomposition; δ15NNSL decreased by −1.74‰ and δ15NSPL decreased by −1.99‰. The effect of the selective preservation of acid-unhydrolyzable residue (AUR) in lowering δ13C of the residual litter was evident only in SPL. In the NSL, only in the initial stage did C/N have a large effect on the δ13C values. In the later stages, there was a non-linear decrease in δ13CNSL with a simultaneous increase in AUR concentrations, but the effect size was large, suggesting the role of lignin in driving δ13C of residues in later stages. Depletion in 15N in the residual litters concomitant with the increase in N concentration suggests bacterial transformation of the litter over fungal components. A consistent decline in δ15N values further implies that bacterial dominance prompted this by immobilizing nitrate depleted in 15N in the residual litter.
Citation: Forests
PubDate: 2024-07-24
DOI: 10.3390/f15081294
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1295: Glycine Betaine Enhances Poplar Cultivar
(Populus deltoides × Populus euramericana) Tolerance to Confront
NaCl Stress
Authors: Feiyan Chen, Ali Movahedi, Hui Wei, Qiang Zhuge, Weibo Sun
First page: 1295
Abstract: Glycine betaine (GB) serves as a compatible solute crucial for stress tolerance across numerous plant species. Populus trichocarpa grows along coastal regions and often suffers from salt stress. In this study, we explored the effects of foliar spraying of GB on the growth, physicochemical indexes, gene expression, and stress tolerance of poplar under salt stress. To achieve this, poplar plants (Populus deltoides × Populus euramericana “Nanlin 895”) were grown under four NaCl concentrations: 0, 50, 100, and 150 mM. Additionally, they were treated with 0, 5, 15, and 25 mM GB. The degree of effect on potted poplars was observed after 8 weeks. A GB treatment of about 15 mM significantly reduced the impact of salt stress and photosynthetic pigments and caused an improvement in the activity of the antioxidant enzymes peroxidase (POD) and superoxide dismutase (SOD). Moreover, GB-treated poplars had significantly more malonaldehyde (MDA) than the control lines. This study indicated that GB treatment reduces salt stress symptoms in poplars. This research helps to develop safe levels of endogenous GB, which will make poplars more resistant to environmental stresses.
Citation: Forests
PubDate: 2024-07-25
DOI: 10.3390/f15081295
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1296: Numerical Simulation of Ablative Damage in
Gas-Assisted Laser Processing of Wood
Authors: Qingwei Liu, Lijia Ning, Chunmei Yang, Fucheng Wang, Tianxiang Liu
First page: 1296
Abstract: To reduce defects in wood laser processing, this study establishes a multi-field coupling model that reflects the coupling relationship between laser energy, auxiliary gas, and slit quality. It reveals the temperature field distribution and heat transfer during this process at a macroscopic level. Using the COMSOL Multiphysics 5.6 software to simulate laser processing with or without helium gas assistance, we show that helium-assisted laser processing positively affects the quality of wood processing. We further researched the influence of different laser powers and spot radii on ablation damage volume and gasification volume, and the results indicate that the adopted model effectively simulates the influence of laser power and auxiliary gas on laser cutting ability, accurately reflecting the impact of different process parameters on cutting depth and kerf width. The accuracy and effectiveness of this model were validated through comparison with experimental data. This research enhances process reliability and economic benefits through numerical simulation and prediction, expands theoretical research and engineering applications in the laser processing field, and optimizes and innovates wood processing technology. It provides a promising method for enhancing the added value of wood products and efficiently using wood resources.
Citation: Forests
PubDate: 2024-07-25
DOI: 10.3390/f15081296
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1297: Genome-Wide Identification of WRKY in Suaeda
australis against Salt Stress
Authors: Yinquan Qu, Ji Wang, Caihui Qu, Xiaoyun Mo, Xiumei Zhang
First page: 1297
Abstract: Suaeda australis is a typical halophyte due to its high salt tolerance. The WRKY gene family plays crucial roles in responding to salt stress, yet reports on WRKY genes in S. australis are scarce. In this study, we identified 47 WRKY genes in the S. australis genome. We then conducted comprehensive analyses, including investigations into their chromosomal locations, gene structures, phylogenetic relationships, promoter regions, conserved motifs, and expression profiles. The 47 WRKY genes were classified into three main groups (with six subfamilies). Among nine chromosomes, S. australis displayed an unequal pattern of distribution. The analysis of regulatory elements revealed that WRKY promoters were associated with light responsiveness, anaerobic induction, drought inducibility, meristem expression, and gibberellin responsiveness. Expression pattern analyses highlighted the role of several SaWRKYs, including Sau00527, Sau00681, Sau18413, Sau19293, Sau00810, Sau05901, Sau09209, Sau12457, and Sau14103. These genes exhibited higher expression levels under ST2 compared to ST1, indicating a significant response to salt stress. Higher SOD, POD, and CAT activity, as well as increased MDA and H2O2 content, were observed in ST2, in line with the expression patterns and our RTq-PCR results. Our study offers a profound understanding of the evolutionary development of S. australis WRKY members, clarifying their vital functions in responding to salt stress. Along with crucial genomic data, these findings establish a solid foundation for investigating the mechanisms of salt-stress regulation in S. australis. This research holds substantial scientific and ecological importance, offering potential contributions to the conservation of S. australis and the utilization of saline soil resources.
Citation: Forests
PubDate: 2024-07-25
DOI: 10.3390/f15081297
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1298: Effective Reduction in Natural Enemy Catches
in Pheromone Traps Intended for Monitoring Orthotomicus erosus
(Coleoptera, Curculionidae)
Authors: Milan Pernek, Tomislav Milas, Marta Kovač, Nikola Lacković, Milan Koren, Boris Hrašovec
First page: 1298
Abstract: Infestations have persisted following a sudden and intense outbreak of the bark beetle Orthotomicus erosus along the Croatian coast, necessitating a continuous battle against this pest. A recommended protective action is the utilization of pheromone traps for population surveillance. Previous monitoring efforts have recorded an exceptionally high capture rate of natural enemies using pheromone traps; these traps inadvertently prevented natural enemies from fulfilling their essential role in controlling bark beetle populations. To address and significantly diminish instances of this unintended capture, our study designed a modification to the Theysohn-type pheromone trap by integrating a metal mesh within the trapping container. An experimental setup was established in Marjan Forest Park, situated on a peninsula bordered by the sea on three sides and partly by the city of Split. For monitoring purposes, unmodified standard pheromone traps were deployed at the onset of a significant O. erosus outbreak in Croatia in 2018. Catch data from 2020 to 2022 show a marked decrease in the bark beetle population, indicating a shift toward a latent phase. In 2022, modified traps were integrated into the existing monitoring setup, consisting of 10 pairs, to evaluate whether modifications to the traps could significantly reduce the capture of the bark beetle’s natural enemies, specifically Temnoscheila caerulea, Thanasimus formicarius, and Aulonium ruficorne. The objective is to offer recommendations for forestry practices on employing pheromone traps with minimal disturbance to the ecological equilibrium. Our findings indicate that the modifications to the traps markedly decreased the capture of natural predators, particularly T. caerulea, which was the predominant predatory insect found in the traps. Simultaneously, captures of the target species, all bark beetles in the trap, were marginally reduced. This decrease in the capture rates of the target bark beetle species, O. erosus, is not considered problematic when pheromone traps are utilized primarily for monitoring purposes. The modifications to the traps significantly reduced the capture of common bark beetle predators, thereby facilitating a more balanced strategy in forest protection efforts.
Citation: Forests
PubDate: 2024-07-25
DOI: 10.3390/f15081298
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1299: Impact of Different Land Use Types on
Bacterial and Fungal Communities in a Typical Karst Depression in
Southwestern China
Authors: Cong Hu, Zhonghua Zhang, Chaofang Zhong, Gang Hu, Chaohao Xu
First page: 1299
Abstract: Understanding the land use pattern relationships regarding the composition, diversity, and abundance of soil microbial communities in a typical karst depression in southwestern China is crucial for assessing the stability of local karst ecosystems. However, these aspects in typical karst depressions within northern tropical karst seasonal rainforests in China remain limited. Therefore, we examined the differences in soil microorganism abundance, diversity, community composition, and co-occurrence networks under five land use types in a tropical karst region in southwestern China: sugarcane fields, orchards, grasslands, plantation forests, and secondary forests. The soil microbial communities of samples from these areas were analyzed using 16S rRNA gene amplification. The abundances of Acidobacteria and Ascomycota were lowest (20.66% and 66.55%, respectively) in secondary forests and highest (35.59% and 89.35%, respectively) in sugarcane fields. Differences in microbial abundance across land use types were related to soil pH and total phosphorus. PCoA and ANOSIM demonstrated significant differences in soil bacterial and fungal community structures among the five land use types. Bacterial alpha-diversity showed no significant variation among the different land uses, whereas fungal alpha-diversity exhibited significant differences. Observed Chao1, ACE, and Shannon indices indicated that secondary forests had the highest fungal alpha-diversity. Land use changes also influenced bacterial and fungal co-occurrence networks, with the networks in secondary forests, plantation forests, and orchards being more complex and stable than those in grasslands and sugarcane fields. Key taxa such as Proteobacteria, Planctomycetes, Chloroflexi, Ascomycota, and Basidiomycota were predominantly connected within the co-occurrence networks, highlighting their high functional potential. This study provides insights that can inform more effective land use planning and management strategies in karst depressions, thereby enhancing ecological sustainability and balance.
Citation: Forests
PubDate: 2024-07-25
DOI: 10.3390/f15081299
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1300: Deciphering the Regulatory Mechanism of
PmMYB21 in Early Flowering of Prunus mume through Dap-Seq and WGCNA
Analysis
Authors: Xi Yuan, Ran He, Hui Zhang, Dongyan Liu, Donghuan Liu, Zhihong Niu, Yu Zhang, Xinli Xia
First page: 1300
Abstract: Prunus mume Siebold & Zucc (mei) is a horticulturally important fruit tree that undergoes anthesis in winter. Therefore, its flowering process is challenged by low-temperatures conditions. The transcription factor (TF) MYB21 is pivotal in regulating the flowering process, and particularly functions in petal expansion and filament elongation. However, the regulatory mechanism of PmMYB21 in mei remains unknown. To breed early-flowering cultivars, a deeper understanding of PmMYB21-regulated genes is essential. We employed DNA affinity purification sequencing (Dap-seq) to identify downstream genes bound by PmMYB21. The results revealed the promoter region is the primary binding region of PmMYB21, and the AGTTAGGTARR motif (motif1) is the predominant binding sequence type. Our analysis identified 8533 genes that are potentially bound by PmMYB21 with the motif1 sequence type, within the promoter region. These genes are involved in biological processes critical to flowering. Further refinement of candidate genes was achieved through Weighted Gene Co-expression Network Analysis (WGCNA), which identified the co-expressed genes of PmMYB21 during flowering activity. Integrating Dap-seq and WGCNA data, we narrowed down the candidate gene list to 54, with a focus on 4 MADS-box genes and 2 hormone signaling genes that are crucial to the flowering process under low-temperature conditions. This study offers valuable insights into the molecular underpinnings of PmMYB21’s role in the low-temperature flowering regulation of mei, paving the way for the development of new cultivars adapted to early blooming.
Citation: Forests
PubDate: 2024-07-25
DOI: 10.3390/f15081300
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1301: Predicting Potential Suitable Areas of
Dendrocalamus brandisii under Global Climate Change
Authors: Hang Tao, Kate Kingston, Zhihong Xu, Shahla Hosseini Bai, Lei Guo, Guanglu Liu, Chaomao Hui, Weiyi Liu
First page: 1301
Abstract: Climate change restricts and alters the distribution range of plant species. Predicting potential distribution and population dynamics is crucial to understanding species’ geographical distribution characteristics to harness their economic and ecological benefits. This study uses Dendrocalamus brandisii as the research subject, aiming to accurately reveal the impact of climate change on this plant. The findings offer important insights for developing practical conservation and utilization strategies, and guidance for future introduction and cultivation. The MaxEnt model was optimized using regularization multiplier (RM) and feature combination (FC) from the ‘Kuenm’ package in R language, coupled with ArcGIS for modeling 142 distribution points and 29 environmental factors of D. brandisii. This article explored the key environmental factors influencing the potential suitable regions for D. brandisii, and predicted trends in habitat changes under SSPs2.6 and SSPs8.5 climate scenarios for the current era, the 2050s, 2070s, and 2090s. (1) The results show that when FC = QPH and RM = 1, the AUC = 0.989, indicating that the model prediction is accurate with the lowest complexity and overfitting. The key environmental factors affecting its primary suitable distribution, determined by jackknife training gain and single-factor response curve, are the precipitation of warmest quarter (bio18), the temperature seasonality (bio4), the minimum average monthly radiation (uvb-4), and elevation (Elev), contributing 93.6% collectively. It was established that the optimal range for D. brandisii is precipitation of warmest quarter of between 657 and 999 mm, temperature seasonality from 351% to 442%, minimum average monthly radiation from 2420 to 2786 J/m2/day, at elevation from 1099 to 2217 m. (2) The current potential habitat distribution is somewhat fragmented, covering an area of 92.17 × 104 km2, mainly located in southwest, south, and southeast China, central Nepal, southern Bhutan, eastern India, northwestern Myanmar, northern Laos, and northern Vietnam. (3) In future periods, under different climate scenario models, the potential habitat of D. brandisii will change in varying degrees to become more fragmented, with its distribution center generally shifting westward. The SSP8.5 scenario is not as favorable for the growth of D. brandisii as the SSPs2.6. Central Nepal, southern Bhutan, and the southeastern coastal areas of China have the potential to become another significant cultivation region for D. brandisii. The results provide a scientific basis for the planning of priority planting locations for potential introduction of D. brandisii in consideration of its cultivation ranges.
Citation: Forests
PubDate: 2024-07-25
DOI: 10.3390/f15081301
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1302: Exposure to Waste Might Decrease Relaxation:
The Effects of Viewing an Open Dump in a Forest Environment on the
Psychological Response of Healthy Young Adults
Authors: Ernest Bielinis, Natalia Korcz, Emilia Janeczko
First page: 1302
Abstract: Forest recreation can be successfully used for psychological relaxation and can serve as a remedy for common stress-related problems. The special form of forest recreation intended for restoration is forest bathing. These activities might be disrupted by some factors, such as viewing buildings in the forest or using a computer in nature, which interrupt psychological relaxation. One factor that might interrupt psychological relaxation is the occurrence of an open dump in the forest during an outdoor experience. To test the hypothesis that an open dump might decrease psychological relaxation, a case study using a randomized, controlled crossover design was conducted. For this purpose, two groups of healthy young adults viewed a control forest or a forest with an open dump in reverse order and filled in psychological questionnaires after each stimulus. Participants wore oblique eye patches to stop their visual stimulation before the experimental stimulation, and the physical environment was monitored. The results were analyzed using the two-way repeated measures ANOVA. The measured negative psychological indicators significantly increased after viewing the forest with waste, and the five indicators of the Profile of Mood States increased: tension–anxiety, depression–dejection, anger–hostility, fatigue, and confusion. In addition, the negative aspect of the Positive and Negative Affect Schedule increased in comparison to the control and pretest. The measured positive indicators significantly decreased after viewing the forest with waste, the positive aspect of the Positive and Negative Affect Schedule decreased, and the Restorative Outcome Scale and Subjective Vitality scores decreased (in comparison to the control and pretest). The occurrence of an open dump in the forest might interrupt a normal restorative experience in the forest by reducing psychological relaxation. Nevertheless, the mechanism of these relevancies is not known, and thus, it will be further investigated. In addition, in a future study, the size of the impact of these open dumps on normal everyday experiences should be investigated. It is proposed that different mechanisms might be responsible for these reactions; however, the aim of this study is to only measure this reaction. The identified psychological reasons for these mechanisms can be assessed in further studies.
Citation: Forests
PubDate: 2024-07-25
DOI: 10.3390/f15081302
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1303: Exploring the Efficient Irrigation Period
for Larix kaempferi Seedlings in Nursery Pots in Greenhouse Conditions
Using Optical Measurements
Authors: Ukhan Jeong, Seung Hyun Han, Dohee Kim, Sohyun Kim, Eun Ju Cheong
First page: 1303
Abstract: Larix kaempferi is in high demand in Korea due to its value in timber and afforestation. However, it faces challenges in terms of propagation and the collection of physiological information for seedling production. In particular, moisture supply is crucial in seedling production. Therefore, establishing efficient irrigation regimes based on optical measurements is essential. Optical measurement methods are expected to be non-destructive, rapid, and reduce labor consumption in nursery systems. This study applied optical measurements using vegetation indices (VIs), chlorophyll fluorescence (FL) imaging, and thermal (TH) imaging to explore the efficient irrigation period for one-year-old Larix kaempferi seedlings in greenhouse conditions under drought stress and perform rehydration experiments. It was observed that all the seedlings survived without irrigation until day 4 (D4) (soil moisture content: 5.3%). Upon rehydration on D6, 83.33% of the seedlings survived until D14. According to the optical measurement results, the TH parameters, PRI (photochemical reflectance index), and Fm (maximum fluorescence in a dark-adapted state) showed sensitive stress responses in all drought treatment pots on D6. Among them, thermal imaging was found to have the highest potential for addressing limitations and being utilized in the greenhouse. The results of this study are expected to provide foundational data for the development of smart nursery systems for efficient irrigation in the future.
Citation: Forests
PubDate: 2024-07-25
DOI: 10.3390/f15081303
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1304: The Impact of Urban Forest Landscape on
Thermal Environment Based on Deep Learning: A Case of Three Main Cities in
Southeastern China
Authors: Shenye Zhang, Ziyi Wu, Zhilong Wu, Sen Lin, Xisheng Hu, Lifeng Zheng
First page: 1304
Abstract: Accelerated urbanization has exacerbated the urban heat island phenomenon, and urban forests have been recognized as an effective strategy for modulating thermal environments. Nevertheless, there remains a dearth of systematic investigations into the nonlinear associations between the detailed spatial configurations of urban forests and thermal conditions. We proposed a deep learning-based approach to extract forest data, utilizing multisource high-resolution remote sensing data with relative radiometric correction. Subsequently, we employed deep neural networks (DNNs) to quantify the linkages between urban forest landscape patterns and land surface temperature (LST) in summer and winter across Fuzhou, Xiamen, and Zhangzhou in Fujian Province, China. Our findings indicate the following: (1) Our extraction approach outperforms DeepLabv3+, FCN_8S, and SegNet in terms of extraction precision and adaptability, achieving an overall accuracy (OA) of 87.57%; furthermore, the implementation of relative radiometric correction enhances both the extraction precision and model generalizability, improving OA by 0.05%. (2) Geographic and seasonal differences influence the urban forests’ cooling effects, with more pronounced cooling in summer, particularly in Zhangzhou. (3) The significance of forest landscape composition and configuration in affecting the thermal environment varies seasonally; landscape configuration plays a more pivotal role in modulating surface temperatures across the three cities, with a more critical role in winter than in summer. (4) Seasonal and city-specific variations in forest spatial patterns influence LST. Adopting the appropriate forest structures tailored to specific seasons, cities, and scales can optimize cooling effects. These results offer quantitative insights into urban heat island dynamics and carry significant implications for urban planning strategies.
Citation: Forests
PubDate: 2024-07-25
DOI: 10.3390/f15081304
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1305: A Three-Level Model System of Biomass and
Carbon Storage for All Forest Types in China
Authors: Weisheng Zeng, Wentao Zou, Xinyun Chen, Xueyun Yang
First page: 1305
Abstract: Forest biomass and carbon storage models are crucial for inventorying, monitoring, and assessing forest resources. This study develops models specific to China’s diverse forests, offering a methodological foundation for national carbon storage estimation and a quantitative basis for national, regional, and global carbon sequestration projections. Utilizing data from 52,700 permanent plots obtained during China’s 9th national forest inventory, we calculated biomass and carbon storage per hectare for 35 tree species groups using respective individual tree biomass models and carbon factors. We then constructed a three-level volume-based model system for forest biomass and carbon storage, applying weighted regression, dummy variable modeling, and simultaneous equations with error-in-variables. This system encompasses one population of forests, three forest categories (level I), 20 forest types (level II), and 74 forest sub-types (level III). Finally, the assessment of these models was carried out with six evaluation indices, and comparative analyses with previously established biomass models of three major forest types were conducted. Determination coefficients (R2) for the population average model, and three dummy models on levels I, II, and III, exceed 0.78, 0.85, 0.92, and 0.95, respectively, with corresponding mean prediction errors (MPEs) of 0.42%, 0.34%, 0.24%, and 0.19%, and mean percent standard errors (MPSEs) of approximately 22%, 21%, 15%, and 12%. Models for 20 forest types and 74 sub-types yield R2 values above 0.87 and 0.85, with MPE values below 3% and 5%, respectively. Notably, the estimates of previous biomass models of three major forest types demonstrated considerable uncertainty, with TRE ranging from −20% to 74%. However, accuracy has improved with larger sample sizes. In total biomass and carbon storage estimations, the R2 values of dummy models for levels I, II, and III progressively increase and MPSE and MPE values decrease, whereas TRE approximates zero. The tiered model system of simultaneous equations developed herein offers a quantitative framework for precise evaluations of biomass and carbon storage on different scales. For enhanced accuracy in such estimations, applying level III models is recommended whenever feasible, especially for national estimation.
Citation: Forests
PubDate: 2024-07-25
DOI: 10.3390/f15081305
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1306: Experimental Study on the Effect of Root
Content on the Shear Strength of Root–Soil Composite with Thick and
Fine Roots of Cryptomeria japonica (Thunb. ex L.f.) D.Don
Authors: Jianping Liu, Yusha Tang, Yulin Jiang, Shixin Luo, Kai Wu, Xingxin Peng, Yucong Pan
First page: 1306
Abstract: The current research on slope protection with plants mainly focuses on herbs and shrubs. In order to investigate the difference in shear strength of root–soil composite with thick and fine roots under different root content conditions, Cryptomeria japonica (Thunb. ex L.f.) D.Don was selected as the research object, and the distribution characteristics of its roots with the increase of buried depth were studied using the longitudinal profile method. Based on the distribution range of root area ratio (RAR) in field investigation, the modified large-scale direct shear tests were executed on the root–soil composite samples with thick and fine roots of five RAR grades under four normal stress levels, and the variation rule of the shear strength of the root–soil composites with thick and fine roots under different root contents was analyzed. The influence mechanism of RAR was briefly discussed. The results show that the RAR of Cryptomeria japonica (Thunb. ex L.f.) D.Don increases first and then decreases with the increase of buried depth, and decreases with the increase of horizontal distance from the excavation point to the trunk. Both the thick and fine roots can increase the soil shear strength, but the effect of thick roots is greater than that of fine roots. The shear strengths of root–soil composites with thick and fine roots both increase first and then decrease with the increase of RAR, which means that there exists the optimal root content for the roots with the best reinforcement effect on soil, and the optimal RAR is 0.1% and 0.2%, respectively. The cohesive and internal friction angle of the root–soil composite can be improved by the roots of Cryptomeria japonica (Thunb. ex L.f.) D.Don, and the thick root is better than the fine root. Meanwhile, the enhancement effect on the cohesion is greater than that on the internal friction angle. The results are of great significance for understanding the effect of roots on soil shear strength and enriching the existing theory of slope protection with arbors.
Citation: Forests
PubDate: 2024-07-25
DOI: 10.3390/f15081306
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1307: Herbicide Uptake (Flashback) in Non-Target
Hardwood Species within South Carolina Floodplains
Authors: Stephen E. Peairs, Nilesh Timilsina
First page: 1307
Abstract: Herbicide flashback is an undesirable response that results in damage or mortality of non-target plants near chemically treated plants. In severe instances, crop trees can be injured resulting in financial loss or inability to capture management objectives. Land managers need to know the potential limitations of using triclopyr acid (50% solution in water) and what quantity can cause damage to non-target trees (trees not aimed at for control via herbicide). Three naturally regenerated (previously clearcut) bottomland hardwood sites, ranging from 14–20 years of age, received partial overstory deadening using Trycera® herbicide. Residual “leave” trees experienced indirect herbicide uptake resulting in some trees either experiencing mortality or partial mortality with top dieback/epicormic branching. An increased probability of damage occurred as tree diameter decreased and the number of treated stems around the non-target stems increased. American sycamore, green ash, and sweetgum were most susceptible to flashback. This study examines the unanticipated chemical effect of deadening adjacent stems surrounding residual leave trees in poorly drained soils.
Citation: Forests
PubDate: 2024-07-26
DOI: 10.3390/f15081307
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1308: Modeling the Effects of Spatial Distribution
on Dynamics of an Invading Melaleuca quinquenervia (Cav.) Blake Population
Authors: Yuanming Lu, Junfei Xia, Robert D. Holt, Donald L. DeAngelis
First page: 1308
Abstract: To predict the potential success of an invading non-native species, it is important to understand its dynamics and interactions with native species in the early stages of its invasion. In spatially implicit models, mathematical stability criteria are commonly used to predict whether an invading population grows in number in an early time period. But spatial context is important for real invasions as an invading population may first occur as a small number of individuals scatter spatially. The invasion dynamics are therefore not describable in terms of population level state variables. A better approach is spatially explicit individual-based modeling (IBM). We use an established spatially explicit IBM to predict the invasion of the non-native tree, Melaleuca quinquenervia (Cav.) Blake, to a native community in southern Florida. We show that the initial spatial distribution, both the spatial density of individuals and the area they cover, affects its success in growing numerically and spreading. The formation of a cluster of a sufficient number and density of individuals may be needed for the invader to locally outcompete the native species and become established. Different initial densities, identical in number and density but differing in random positions of individuals, can produce very different trajectories of the invading population through time, even affecting invasion success and failure.
Citation: Forests
PubDate: 2024-07-26
DOI: 10.3390/f15081308
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1309: Detection Model and Spectral Disease Indices
for Poplar (Populus L.) Anthracnose Based on Hyperspectral Reflectance
Authors: Zhicheng Jia, Qifeng Duan, Yue Wang, Ke Wu, Hongzhe Jiang
First page: 1309
Abstract: Poplar (Populus L.) anthracnose is an infectious disease that seriously affects the growth and yields of poplar trees, and large-scale poplar infections have led to huge economic losses in the Chinese poplar industry. To efficiently and accurately detect poplar anthracnose for improved prevention and control, this study collected hyperspectral data from the leaves of four types of poplar trees, namely healthy trees and those with black spot disease, early-stage anthracnose, and late-stage anthracnose, and constructed a poplar anthracnose detection model based on machine learning and deep learning. We then comprehensively analyzed poplar anthracnose using advanced hyperspectral-based plant disease detection methodologies. Our research focused on establishing a detection model for poplar anthracnose based on small samples, employing the Design of Experiments (DoE)-based entropy weight method to obtain the best preprocessing combination to improve the detection model’s overall performance. We also analyzed the spectral characteristics of poplar anthracnose by comparing typical feature extraction methods (principal component analysis (PCA), variable combination population analysis (VCPA), and the successive projection algorithm (SPA)) with the vegetation index (VI) method (spectral disease indices (SDIs)) for data dimensionality reduction. The results showed notable improvements in the SDI-based model, which achieved 89.86% accuracy. However, this was inferior to the model based on typical feature extraction methods. Nevertheless, it achieved 100% accuracy for early-stage anthracnose and black spot disease in a controlled environment respectively. We conclude that the SDI-based model is suitable for low-cost detection tasks and is the best poplar anthracnose detection model. These findings contribute to the timely detection of poplar growth and will greatly facilitate the forestry sector’s development.
Citation: Forests
PubDate: 2024-07-26
DOI: 10.3390/f15081309
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1310: A Mixed Broadleaf Forest Segmentation
Algorithm Based on Memory and Convolution Attention Mechanisms
Authors: Xing Tang, Zheng Li, Wenfei Zhao, Kai Xiong, Xiyu Pan, Jianjun Li
First page: 1310
Abstract: Counting the number of trees and obtaining information on tree crowns have always played important roles in the efficient and high-precision monitoring of forest resources. However, determining how to obtain the above information at a low cost and with high accuracy has always been a topic of great concern. Using deep learning methods to segment individual tree crowns in mixed broadleaf forests is a cost-effective approach to forest resource assessment. Existing crown segmentation algorithms primarily focus on discrete trees, with limited research on mixed broadleaf forests. The lack of datasets has resulted in poor segmentation performance, and occlusions in broadleaf forest images hinder accurate segmentation. To address these challenges, this study proposes a supervised segmentation method, SegcaNet, which can efficiently extract tree crowns from UAV images under natural light conditions. A dataset for dense mixed broadleaf forest crown segmentation is produced, containing 18,000 single-tree crown images and 1200 mixed broadleaf forest images. SegcaNet achieves superior segmentation results by incorporating a convolutional attention mechanism and a memory module. The experimental results indicate that SegcaNet’s mIoU values surpass those of traditional algorithms. Compared with FCN, Deeplabv3, and MemoryNetV2, SegcaNet’s mIoU is increased by 4.8%, 4.33%, and 2.13%, respectively. Additionally, it reduces instances of incorrect segmentation and over-segmentation.
Citation: Forests
PubDate: 2024-07-26
DOI: 10.3390/f15081310
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1311: The Expanding Thread of Ungulate
Browsing—A Review of Forest Ecosystem Effects and Management
Approaches in Europe
Authors: Darius Hardalau, Codrin Codrean, Daniel Iordache, Mihai Fedorca, Ovidiu Ionescu
First page: 1311
Abstract: In recent decades, ungulates have expanded in number and range in Europe. This review aims to analyze the impact of ungulate browsing in different forest ecosystems and identify the main driving factors and trends. In total, 155 studies were analyzed in preparing this review, across 19 European countries. In Europe, the main browsers are represented by roe deer (Capreolus capreolus L.), red deer (Cervus elaphus L.), moose (Alces alces L.), chamois (Rupicapra rupicapra L.), and fallow deer (Dama dama L.). Regarding browsing severity, they frequently exceeded 50%, meaning that over half of the saplings were browsed. Ungulate density was the main driving factor of browsing severity, with areas exhibiting high browsing pressure often having more than ten individuals per square kilometer. The type of silvicultural system used played a vital role in the severity of browsing, and trends in foraging for preferred tree species were identified. Fencing was the most common non-harmful protection method used, while hunting management was the most efficient method for controlling deer numbers and browsing intensity. Large carnivores were missing in most study areas, but in the areas where they were present, they played a significant role in creating a chain reaction of ecological impacts. Considering the significant impact of ungulate browsing on forest ecosystems, there is a pressing need for more research to comprehend and effectively mitigate the effects of deer presence comprehensively.
Citation: Forests
PubDate: 2024-07-26
DOI: 10.3390/f15081311
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1312: Impact and Spatial Effect of Government
Environmental Policy on Forestry Eco-Efficiency—Examining
China’s National Ecological Civilization Pilot Zone Policy
Authors: Yingzheng Yan, Ziwei Zhou, Liupeng Chen, Yuanzhu Wei
First page: 1312
Abstract: Can government environmental policy harmonize environmental protection with economic output' We explore this issue from the perspective of forestry eco-efficiency, using China’s National Ecological Civilization Pilot Zone Policy (NECP), an environmental policy promulgated by the government of China, as the subject of this study. The study introduces forestry eco-efficiency as an indicator to assess the balance between economic development in the forestry sector and environmental conservation. The indicator, grounded in sustainable development theory, employs a super-efficiency SBM model that includes undesirable outputs to evaluate efficiency. Additionally, we empirically analyze the impact of NECP on forestry eco-efficiency by using the difference-in-difference (DID) model with provincial panel data from 2011 to 2020. Ultimately, we analyze the effects of spatial spillover by employing the spatial Durbin model (SDM). Our study yields the following conclusions. (1) In this paper, through hotspot clustering analysis, forestry eco-efficiency in each province is categorized into three categories: effective, semi-effective and ineffective. Our findings suggest that China’s average forestry eco-efficiency falls into the ineffective category, highlighting the need to optimize resource allocation within the sector. (2) NECP significantly enhances forestry eco-efficiency, with robust findings across various stability tests. Thus, implementing government environmental policies can have a multiplier effect on forestry, i.e., it can synergize its economic development with environmental protection. (3) In provinces with a strong ecological foundation, the NECP significantly enhances forestry eco-efficiency. However, in other provinces, the improvement is only moderate. Furthermore, while the NECP has a substantial positive impact in the eastern region, it has yet to show a discernible effect in other regions. (4) The positive impacts of NECP implementation on forestry eco-efficiency have spatial spillover effects due to demonstration effects and comparative advantages.
Citation: Forests
PubDate: 2024-07-26
DOI: 10.3390/f15081312
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1313: Analysis of the Potential Distribution of
Shoot Blight of Larch in China Based on the Optimized MaxEnt and Biomod2
Ensemble Models
Authors: Xiuyun Zhang, Wenhui Wu, Yingmei Liang
First page: 1313
Abstract: Shoot blight of larch caused by Neofusicoccum laricinum (Sawada) Y. Hattori & C. Nakash poses a significant threat to the growth and development of larch plantations and is among the most devastating diseases of forest trees. Its consecutive occurrence can cause serious damage and even death of the host plant. Analyzing the geographical distribution patterns of shoot blight of larch in China based on the optimized maximum entropy (MaxEnt) and Biomod2 ensemble (EM) models and recognizing the environmental factors limiting the spread of this disease could provide a reasonable basis for its control. The potential geographical distribution areas of shoot blight of larch were predicted using occurrence data and environmental variables. The area under the receiver operating characteristic (ROC) curve (AUC) was employed to compare the predictive performance of the optimized MaxEnt and Biomod2 ensemble models. Our results showed that both models had a prominent performance in predicting the potential distribution of shoot blight of larch, with the latter performing slightly better based on the AUC than the former. The potentially suitable areas for shoot blight of larch, as predicted by both the MaxEnt and Biomod2 ensemble models, were similarly distributed, mainly in Northern China, including Heilongjiang, Jilin, Liaoning, and Northeastern Inner Mongolia. The environmental variables significantly limiting the distribution of shoot blight of larch identified using the jackknife method and Pearson’s correlation analysis included the annual mean temperature, annual precipitation, precipitation of the wettest quarter, mean temperature of the warmest quarter, and elevation. This research offers a theoretical basis for rationally delineating potential sites invaded by shoot blight of larch, strengthening the detection and quarantine in critical areas, formulating timely effective control measures, and establishing conservation measures for larch resources.
Citation: Forests
PubDate: 2024-07-27
DOI: 10.3390/f15081313
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1314: Influence of Perceived Sensory Dimensions on
Cultural Ecosystem Benefits of National Forest Parks Based on Public
Participation: The Case of Fuzhou National Forest Park
Authors: Songjun He, Yanting Yu, Siren Lan, Yongrong Zheng, Chang Liu
First page: 1314
Abstract: The decision-making process of China’s national forest park (NFP) system typically excludes the consideration of the public’s perceived benefits. In this regard, the objective of this study was to elucidate the type of cultural ecosystem benefits (CEB) that NFP can provide and to inform the evidence-based design of forest parks by establishing its linkage to the public’s perceived sensory dimensions (PSD). A CEB evaluation scale was developed for forest parks, and a 6-day public participation GIS (PPGIS) survey was conducted in Fuzhou NFP to collect evaluations of CEB and PSD at different sites from 853 respondents. The findings revealed that the CEB furnished by NFP is comprised of three dimensions. The three dimensions of cultural ecosystem benefits (CEB) are identities, experiences, and capabilities. The impact of different PSDs on CEBs varies, as do the impacts of high and low scores on CEBs for the same PSD. It can be concluded that the creation of more serene and open spaces will result in an increase in the CEB available to the public. Furthermore, designers may wish to consider enhancing single dimensions of PSDs in order to characterize different areas, which may prove to be a more effective approach than enhancing PSDs across the board. In summary, our PPGIS survey is expected to enable community-based governance of the NFP and provide a basis for a comprehensive sustainability dialogue between people and forests.
Citation: Forests
PubDate: 2024-07-27
DOI: 10.3390/f15081314
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1315: Tree Height Estimation of Chinese Fir
Forests Based on Geographically Weighted Regression and Forest Survey Data
Authors: Xinyu Zheng, Hao Wang, Chen Dong, Xiongwei Lou, Dasheng Wu, Luming Fang, Dan Dai, Liuchang Xu, Xingyu Xue
First page: 1315
Abstract: Estimating tree height at the national to regional scale is crucial for assessing forest health and forest carbon storage and understanding forest ecosystem processes. It also aids in formulating forest management and restoration policies to mitigate global climate change. Extensive ground-survey data offer a valuable resource for estimating tree height. In tree height estimation modeling, a few comparative studies have examined the effectiveness of global-based versus local-based models, and the spatial heterogeneity of independent variable parameters remains insufficiently explored. This study utilized ~200,000 ground-survey data points covering the entire provincial region to compare the performance of the global-based Ordinary Least Squares (OLS) and Random Forest (RF) model, as well as local-based Geographically Weighted Regression (GWR) model, for predicting the average tree height of Chinese fir forests in Zhejiang Province China. The results showed that the GWR model outperformed both OLS and RF in terms of predictive accuracy, achieving an R-squared (R2) and adjusted R2 of 0.81 and MAE and RMSE of 0.93 and 1.28, respectively. The performance indicated that the local-based GWR held advantages over global-based models, especially in revealing the spatial non-stationarity of forests. Visualization of parameter estimates across independent variables revealed spatial non-stationarity in their impact effects. In mountainous areas with dense forest coverage, the parameter estimates for average age were notably higher, whereas in forests proximate to urban areas, the parameters were comparatively lower. This study demonstrates the effectiveness of large ground-survey data and GWR in tree height estimation modeling at a provincial scale.
Citation: Forests
PubDate: 2024-07-28
DOI: 10.3390/f15081315
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1316: Assessing the Flight Potential of the
Four-Eyed Fir Bark Beetle Polygraphus proximus Blandford in Natural
Conditions
Authors: Denis A. Demidko, Sergey S. Kulakov, Anton A. Efremenko, Nikita S. Babichev, Alexey P. Barchenkov, Pavel V. Mikhailov
First page: 1316
Abstract: The four-eyed fir bark beetle Polygraphus proximus Blandford (Coleoptera, Curculionidae, Scolytinae) has become an aggressive invader in Siberia’s fir forests in recent decades. However, its spread in the invaded area is not yet complete; this species is absent so far in most of the Siberian fir Abies sibirica Ledeb. range. To predict this process, appropriate models are needed, including at the local level. One of the essential parameters for modeling is the flight characteristics of imago. To evaluate its flight potential, we placed slabs (sections of the bark with a thin sapwood layer) in an area without forests or with forests with an absence of fir at the end of May. The beetles overwintered under the bark in these slabs. We also placed short fir trap logs at distances ranging from 50 to 1500 m in the four cardinal directions from the release point to attract migrating beetles. After the beetles from the slabs had completed their migration, we evaluated the number of parental pairs (male and female) of the four-eyed fir bark beetle on the trap logs (p) and their number per dm2 (pS). The sole factor that affected the colonization of host objects in our experiment was the distance from the release point. The relationship between p and pS and the distance to the release point can be accurately represented by a negative exponential curve. This experiment established a flight distance of 1500 m, with calculated values of 4919 m for p and 2965 m for pS. However, an analysis of similar experiments and studies using flight mills suggests that these values may not be extreme in an environment with few and sparse host objects. In conditions of abundant food supply, the actual flight distance of P. proximus beetles is significantly less than the theoretically possible maximum.
Citation: Forests
PubDate: 2024-07-28
DOI: 10.3390/f15081316
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1317: The Importance of the Scots Pine for the
Diversity of Forest Avifauna: The Augustów Forest as a Case Study
Authors: Dorota Zawadzka, Grzegorz Zawadzki
First page: 1317
Abstract: The Scots Pine Pinus sylvestris is the most widespread tree species in forests of lowland parts of Central and Eastern Europe. In Polish forests, stands dominated by the Scots pine cover almost 60% of the forest area. We analysed the relationship between forest birds and pine trees in an extensive forest complex in north-eastern (NE) Poland. Based on the 20-year-long study, we considered the percentage of broods established on pine trees and the percentage of Scots pine in stands on grouse leks and territory. A total number of over 20 bird species are dependent on the Scots pine trees or stands to locate their nests. Among this group, 11 bird species strongly associated with pine trees were confirmed, and they located at least 90% of broods or nests on pines. The Black Woodpecker Dryocopus martius selects the Scots pine to excavate cavities. Its cavities were regularly used by some species of secondary cavity nesters. In turn, the Common Raven Corvus corax nests were occupied by selected birds of prey. The importance of Scots pine for birds increased with the age of the trees. Old Scots pine trees were chosen by birds that built large nests, placed nests in the tree top, and excavated large cavities. Populations of pine-specialized bird species may be in danger due to the possibility of the Scots pine range moving to the north, which results from global warming. The maintenance of the Scots pine with the modification of the methods of forest regeneration should be included in the Polish forestry’s strategies and plans as a critical factor for the care of the population of rare breeding bird species.
Citation: Forests
PubDate: 2024-07-28
DOI: 10.3390/f15081317
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1318: Study on Reinforcement Measures for Wood
Composite Beams with Discontinuous Cross-Section in Web Opening
Authors: Haoxuan Wu, Wenyuan Liao, Yue Yu, Bihui Dai, Zhiqiang Chen, Hangbin Chai, Xinliang Lv
First page: 1318
Abstract: On the basis of existing experimental studies on web-opening wood composite beams, six new types of reinforcement were proposed in this study. The effects of different reinforcement measures on mechanical properties such as the load-carrying capacity, deformation capacity, internal force distribution law, and force transfer mechanism of web-opening wood composite beams were investigated. The results show that the stress distribution in the opening area is more uniform after reinforcement, and the influence of different reinforcement measures changes the damage mode of the whole beam. The setting of reinforcement measures in the opening area can effectively inhibit and slow down the generation and development of the cracks in the opening area of the web opening and reduce the negative influence of the composite beam caused by the opening. With reinforcement, the allowable and ultimate bearing capacity of wood composite beams can be increased by 3%~21% and 28%~59%; the redistribution of shear force occurs in the opening area after reinforcement, and plywood and cold-formed thin-walled section (CFTWS) help to bear 14%~76% of the value of shear force in the opening area. The most effective reinforcement measures are bolts–epoxy–CFTWS.
Citation: Forests
PubDate: 2024-07-28
DOI: 10.3390/f15081318
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1319: Observed Vertical Dispersion Patterns of
Particulate Matter in Urban Street Canyons and Dominant Influencing
Factors
Authors: Xiaoshuang Wang, Xiaoping Chen, Bojun Ma, Zhixiang Zhou, Changhui Peng
First page: 1319
Abstract: When developing strategies aimed at mitigating air pollution in densely populated urban areas, it is vital to accurately investigate the vertical distribution of airborne particulate matter (PM) and its primary influencing factors. For this study, field experiments were conducted to quantify the vertical distribution and dispersion processes of PM at five vertical heights related to trees—including at street level near vehicular emission sources (0.3 m), pedestrian breathing height (1.5 m), beneath the canopy (6 m), mid-canopy (9 m), and the top of the canopy (12 m)—within a street-facing building in Wuhan, China. Comparing the vertical dispersion patterns of PM with six particle sizes (PM1, PM2.5, PM4, PM7, PM10, and total suspended particulates—TSPs), larger particles exhibited more pronounced variations with height, notably TSPs (correlation coefficient of −0.95) and PM10 (−0.84). The findings consistently revealed a downward trend in PM concentrations across various particle sizes with increasing height, indicating a negative linear correlation between particle concentrations and altitude within the street canyon. For every 1% increase in vertical height, the PM2.5 concentration decreased by approximately 5.44%, the PM10 concentration decreased by 132.1%, and the TSP concentration decreased by 180.6%. These findings show potential for guiding building designers in developing effective strategies, such as optimal vent placement, in order to mitigate the intrusion of outdoor air pollution—particularly PM2.5—into indoor environments. Furthermore, this research provides novel insights for residents living in street-facing buildings and individuals with respiratory diseases, aiding them in the selection of residential floors to minimize health risks associated with exposure to respirable PM.
Citation: Forests
PubDate: 2024-07-29
DOI: 10.3390/f15081319
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1320: Satellite Remote Sensing Images of Crown
Segmentation and Forest Inventory Based on BlendMask
Authors: Zicheng Ji, Jie Xu, Lingxiao Yan, Jiayi Ma, Baozhe Chen, Yanfeng Zhang, Li Zhang, Pei Wang
First page: 1320
Abstract: This study proposes a low-cost method for crown segmentation and forest inventory based on satellite remote sensing images and the deep learning model BlendMask. Taking Beijing Jingyue ecoforestry as the experimental area, we combined the field survey data and satellite images, and constructed the dataset independently, for model training. The experimental results show that the F1-score of Sophora japonica, Pinus tabulaeformis, and Koelreuteria paniculata reached 87.4%, 85.7%, and 86.3%, respectively. Meanwhile, we tested for the study area with a total area of 146 ha, and 27,403 tree species were identified in nine categories, with a total crown projection area of 318,725 m2. We also fitted a biomass calculation model for oil pine (Pinus tabulaeformis) based on field measurements and assessed 205,199.69 kg of carbon for this species across the study area. Additionally, we compared the model to U-net, and the results showed that BlendMask has strong crown-segmentation capabilities. This study demonstrates that BlendMask can effectively perform crown segmentation and forest inventory in large-scale complex forest areas, showing its great potential for forest resource management.
Citation: Forests
PubDate: 2024-07-29
DOI: 10.3390/f15081320
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1321: Projecting the Impacts of Climate Change,
Soil, and Landscape on the Geographic Distribution of Ma Bamboo
(Dendrocalamus latiflorus Munro) in China
Authors: Li-Jia Chen, Yan-Qiu Xie, Tian-You He, Ling-Yan Chen, Jun-Dong Rong, Li-Guang Chen, Yu-Shan Zheng
First page: 1321
Abstract: Ma bamboo (Dendrocalamus latiflorus Munro) is a fast-growing woody grass that offers significant economic benefits, including materials for construction, furniture, biofuel, food, and handicrafts. It also provides ecological benefits like soil conservation, wildlife habitats, and carbon sequestration. However, its species distribution patterns are influenced by various factors, including climate (mainly temperature and precipitation), soil attributes, and landscape characteristics such as topography, land use, and vegetation. Understanding these impacts is essential for the sustainable management of D. latiflorus resources and fostering related economic activities. To address these challenges, we developed a comprehensive habitat suitability (CHS) model that integrates climate, soil, and landscape variables to simulate the distribution dynamics of D. latiflorus under different shared socio-economic pathway (SSP) scenarios. An ensemble model (EM) strategy was applied to each variable set to ensure robust predictions. The results show that the current potential distribution of D. latiflorus spans 28.95 × 104 km2, primarily located in South China and the Sichuan Basin. Its distribution is most influenced by the annual mean temperature (Bio1), the cation exchange capacity of soil clay particles in the 20–40 cm soil layer (CECc 20–40 cm), vegetation, and elevation. Under future climate scenarios, these habitats are projected to initially expand slightly and then contract, with a northward shift in latitude and migration to higher elevations. Additionally, the Sichuan Basin (Sichuan–Chongqing border) is identified as a climatically stable area suitable for germplasm development and conservation. To conclude, our findings shed light on how climate change impacts the geographic distribution of D. latiflorus, providing key theoretical foundations for its sustainable cultivation and conservation strategies.
Citation: Forests
PubDate: 2024-07-29
DOI: 10.3390/f15081321
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1322: Hidden Potential of the Subdominant Ant
Formica lemani Bondroit (Hymenoptera: Formicidae): The Formation of Large
Nest Complexes and Restructuring Behavioural Stereotypes
Authors: Tatiana Novgorodova, Dmitry Taranenko
First page: 1322
Abstract: The potential of subdominant ants of the Formica fusca group and their role in forests are still underestimated. Since ant behaviour is dependent on colony size, studying the functional organisation of nest complexes (NC) is most promising for a more accurate assessment of species capabilities. The study focused on the main ecological and ethological issues of the life activity of Formica lemani Bondroit within large NC (>150 nests) and beyond. After preliminary mapping of the F. lemani NC (main nests, trails, foraging trees), off-nest activity, aggressiveness, and trophobiotic relationships with aphids in and outside the NC territory were studied. Within the NC, the dynamic density, the intensity of movement on trails, and aggressiveness of F. lemani were significantly higher than beyond; the range of symbiont aphids was twice as small, with aphids on birches playing a key role in carbohydrate nutrition of F. lemani. The latter ensures accelerated restoration of trophobiotic interactions in spring and stability of the food supply until autumn. Combined with the lack of pressure from F. rufa group ants, this allowed F. lemani to maintain high population densities, and significantly increased its competitiveness, and role in plant protection against phytophages.
Citation: Forests
PubDate: 2024-07-30
DOI: 10.3390/f15081322
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1323: Effect of Planting Ground Treatments Using
Artificial Rainfall Slope Simulating Degraded Forestland on Drought Stress
Susceptibility of Pinus densiflora
Authors: Kyeongcheol Lee, Yeonggeun Song, Minsu Kim, Wooyoung Choi, Hyoseong Ju, Namin Koo
First page: 1323
Abstract: Trees in degraded forest areas are generally exposed to water stress due to harsh environmental conditions, threatening their survival. This study simulated the environmental conditions of a degraded forest area by constructing an artificial rainfall slope and observing the physiological responses of Pinus densiflora to control, mulching, and waterbag treatments. P. densiflora exhibited distinct isohydric plant characteristics of reducing net photosynthetic rate and stomatal transpiration rate through regulating stomatal conductance in response to decreased soil moisture, particularly in the control and waterbag treatments. Additionally, the trees increased photochemical quenching, such as Y(NPQ), to dissipate excess energy as heat and minimize damage to the photosynthetic apparatus. However, these adaptive mechanisms have temporal limitations, necessitating appropriate measures. Under extreme drought stress (DS45), mulching treatment showed 4.5 times and 2.2 times higher in PIabs and SFIabs than in the control, and after the recovery period (R30), waterbag and mulching treatment showed similar levels, while PIabs and SFIabs in the control were only 45% and 75% of those in the mulching and waterbag treatments, respectively. Specifically, mulching extended the physiological mechanisms supporting survival by more than a week, making it the most effective method for enhancing the planting ground in degraded forest areas. Although the waterbag treatment was less effective than mulching treatment, it still significantly contributed to forming better growth conditions compared to the control. These findings highlight the potential for mulching and waterbag treatments to enhance forest restoration efforts, suggesting future research and application could lead to more resilient reforested areas capable of withstanding climate change-induced drought conditions.
Citation: Forests
PubDate: 2024-07-30
DOI: 10.3390/f15081323
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1324: Tourism Crisis Events Affecting Intention
towards Forest-Based Health Tourism: A Structural Equation Model
Authors: Chan Xiao, Jirawan Deeprasert, Songyu Jiang
First page: 1324
Abstract: Since the beginning of the 21st century, various tourism crisis events have negatively impacted the global tourism industry. This study proposes a research model grounded in the Stimulus–Organism–Response theory to explore how external stimuli influence individuals and help identify factors influencing elderly individuals’ willingness to participate in forest-based health tourism during and after tourism crisis events, considering the global aging trend. From 20 December 2023 to 15 January 2024, we collected 429 valid questionnaires from Chinese older adult participants engaged in forest-based health tourism in Guizhou Province. Structural equation modelling (SEM) and bootstrapping techniques were employed to analyze data. The results indicate that tourism crisis events, primarily in the form of geological disasters, are significant antecedent variables influencing the willingness of Chinese older adults to engage in forest-based health tourism. Furthermore, destination image and perceived value serve as individual mediators and function as chained mediators. The results enhance our understanding of the complex relationship between tourism crisis events and the willingness of older Chinese adults to travel while also revealing deeper underlying mechanisms.
Citation: Forests
PubDate: 2024-07-30
DOI: 10.3390/f15081324
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1325: Bioluminescence Inhibition Bioassay for
Estimation of Snow Cover in Urbanised Areas within Boreal Forests of
Krasnoyarsk City
Authors: Anastasia A. Rimashevskaya, Elena Y. Muchkina, Oleg S. Sutormin, Dmitry E. Chuyashenko, Arsen R. Gareev, Svetlana A. Tikhnenko, Nadezhda V. Rimatskaya, Valentina A. Kratasyuk
First page: 1325
Abstract: It has been proposed that the level of air pollution in a city should be estimated based on the accumulation of pollutants in the snow cover of urban forests. This study presents a bioluminescence method for estimating the extent of snow cover pollution in the urbanised areas of boreal forests in Krasnoyarsk city. A bioluminescent assay involving NAD(P)H:FMN oxidoreductase (Red) and luciferase with luminous bacteria (BLuc) was employed to measure the concentrations of six heavy metals (As, Cd, Zn, Co, Hg, and Pb) in the snow cover. The tested snow samples demonstrated a correlation between the reduced activity of the enzyme system and variations in Cd concentration. Furthermore, the research indicated that the period of unfavourable meteorological conditions in Krasnoyarsk city resulted in a notable decline in the activity of the BLuc–Red enzyme system, which may be associated with elevated air pollution levels. This study underscores the potential of the bioluminescence method for monitoring environmental pollution in urban forested areas.
Citation: Forests
PubDate: 2024-07-30
DOI: 10.3390/f15081325
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1326: The Role of Leaching in Soil Carbon,
Nitrogen, and Phosphorus Distributions in Subalpine Coniferous Forests on
Gongga Mountain, Southwest China
Authors: Xiaoli He, Yaning Wang, Junbo He, Yanhong Wu
First page: 1326
Abstract: To explore the role of leaching in mountainous nutrient cycling, we investigated the altitudinal distribution of soil carbon (C), nitrogen (N), and phosphorus (P) in the subalpine coniferous forest ranging from 2628 to 3044 m on the eastern slope of Mt. Gongga. The results revealed that concentrations of C and N, as well as the atomic ratios of C:N and N:P, showed no significant difference among the sampling sites (p > 0.05) in O horizons. The concentrations of P in O horizons increased gradually with altitude. In contrast, notable variations in C, N, and P concentrations and stoichiometry were observed in the mineral horizons. Lower concentrations of C, N, and P were found in A horizons, while higher contents were present in B and C horizons compared to previous studies. Additionally, results of the random forest model indicated that C and N concentrations in the O, B, and C horizons, as well as P concentration in the B horizons, were primarily influenced by Feox concentrations. This suggested that these nutrients leached from O horizons and accumulated in B and C horizons alongside Feox. Except for C:N ratios in the O horizon, the C:N, C:P, and N:P ratios in the O, B, and C horizons were mainly affected by concentrations of Feox or Alox. These results underscored the substantial impact of leaching processes on the spatial distribution of soil C, N, and P, ultimately leading to changes in the gradient distribution of soil C:N:P stoichiometry. Specifically, the C:N ratio in the mineral horizons at the 2781 m site was significantly higher compared to other sites (p < 0.05), indicating a greater movement of C relative to N. The C:P and N:P ratios in the B horizon at the 2781 m site were notably higher than at other sampling sites (p < 0.05). Conversely, the N:P ratio in the A horizon at the 2781 m site was relatively low. Furthermore, concentrations of C and N in the B horizon at the 2781 m site were significantly higher than in other sampling points, while P concentrations were notably lower (p < 0.05). This suggested a more pronounced downward leaching of C and N compared to P at the 2781 site, indicating stronger leaching effects. Overall, this study emphasizes the significant influence of leaching processes on the spatial distributions of soil C, N, and P in subalpine coniferous forests in Southwest China.
Citation: Forests
PubDate: 2024-07-30
DOI: 10.3390/f15081326
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1327: Comparison of Algorithms and Optimal Feature
Combinations for Identifying Forest Type in Subtropical Forests Using GF-2
and UAV Multispectral Images
Authors: Guowei He, Shun Li, Chao Huang, Shi Xu, Yang Li, Zijun Jiang, Jiashuang Xu, Funian Yang, Wei Wan, Qin Zou, Mi Zhang, Yan Feng, Guoqing He
First page: 1327
Abstract: The composition and spatial distribution of tree species are pivotal for biodiversity conservation, ecosystem productivity, and carbon sequestration. However, the accurate classification of tree species in subtropical forests remains a formidable challenge due to their complex canopy structures and dense vegetation. This study addresses these challenges within the Jiangxi Lushan National Nature Reserve by leveraging high-resolution GF-2 remote sensing imagery and UAV multispectral images collected in 2018 and 2022. We extracted spectral, texture, vegetation indices, geometric, and topographic features to devise 12 classification schemes. Utilizing an object-oriented approach, we employed three machine learning algorithms—Random Forest (RF), k-Nearest Neighbor (KNN), and Classification and Regression Tree (CART)—to identify 12 forest types in these regions. Our findings indicate that all three algorithms were effective in identifying forest type in subtropical forests, and the optimal overall accuracy (OA) was more than 72%; RF outperformed KNN and CART; S12 based on feature selection was the optimal feature combination scheme; and the combination of RF and Scheme S12 (S12) yielded the highest classification accuracy, with OA and Kappa coefficients for 2018-RF-S12 of 90.33% and 0.82 and OA and Kappa coefficients for 2022-RF-S12 of 89.59% and 0.81. This study underscores the utility of combining multiple feature types and feature selection for enhanced forest type recognition, noting that topographic features significantly improved accuracy, whereas geometric features detracted from it. Altitude emerged as the most influential characteristic, alongside significant variables such as the Normalized Difference Greenness Index (NDVI) and the mean value of reflectance in the blue band of the GF-2 image (Mean_B). Species such as Masson pine, shrub, and moso bamboo were accurately classified, with the optimal F1-Scores surpassing 89.50%. Notably, a shift from single-species to mixed-species stands was observed over the study period, enhancing ecological diversity and stability. These results highlight the effectiveness of GF-2 imagery for refined, large-scale forest-type identification and dynamic diversity monitoring in complex subtropical forests.
Citation: Forests
PubDate: 2024-07-30
DOI: 10.3390/f15081327
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1328: Solid Biofuel from the Amazon: A Circular
Economy Approach to Briquette Production from Wood Waste
Authors: Mariana Vilas Boas, Antonio Jose Vinha Zanuncio, Duarte Neiva, Angélica de Cássia Oliveira Carneiro, Vinicius Resende de Castro, Benedito Rocha Vital, Paula Gabriella Surdi, Amélia Guimarães Carvalho, Vicente Toledo Machado de Morais Junior, Solange de Oliveira Araújo
First page: 1328
Abstract: The Amazon region contains numerous areas dedicated to sustainable timber extraction. This operation has low yields and generates a large amount of waste. However, this waste can be repurposed for energy generation, providing income for locals and reducing reliance on non-renewable energy sources prevalent in the region. This study aimed to assess the impact of torrefaction on various wood residues for briquette production. Wood residues from Mimosa scabrella Benth (Bracatinga), Dipteryx odorata (Aubl.) Willd. (Cumaru), and Aspidosperma populifolium A.DC. (Peroba mica) were torrefied at temperatures ranging from 180 to 220 °C for sixty minutes under a nitrogen atmosphere. Briquettes were produced using laboratory equipment with loading pressures between 7 and 14 MPa. Torrefied particle properties were evaluated based on proximate composition and calorific value tests, while briquette quality was assessed for physical and mechanical properties. The results demonstrated the briquetting potential of different wood species before and after torrefaction, with optimal outcomes achieved by torrefaction at 220 °C due to its enhancement of energy density. Briquettes showed optimal characteristics at compression pressures of 14 MPa, resulting in increased density (between 1.10 and 1.24 g·cm−3) and compression strength (between 7.20 and 21.02 MPa). The ash values were low and met the requirements. The utilization of waste for briquette production offers a significant alternative for energy generation in economically disadvantaged communities, while also enabling the replacement of non-renewable energy sources.
Citation: Forests
PubDate: 2024-07-31
DOI: 10.3390/f15081328
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1329: Changes in Water Utilization Characteristics
of Trees in Forests across a Successional Gradient in Southern China
Authors: Deqiang Gao, Qing Xu, Haijun Zuo, Wenbin Xu, Ke Diao, Beibei Zhang
First page: 1329
Abstract: Elucidating the water utilization strategy of trees during forest succession is a prerequisite for predicting the direction of forest succession. However, the water utilization characteristics of trees in forests across a successional gradient remain unclear. Here, we utilized the hydrogen and oxygen stable isotopes combined with the Bayesian mixed model (MixSIAR) to analyze the water utilization of dominant trees (Pinus massoniana, Castanea henryi, and Schima superba) in forests along a successional gradient in the Dinghushan Biosphere Reserve of China. Furthermore, we determined the primary factor affecting the water utilization of various trees based on variation partitioning analysis and a random forest model. Our results illustrated that in the early-successional forest, the water utilization ratios from shallow soil layers by P. massoniana were significantly lower than that in the mid-successional forest (51.3%–61.7% vs. 75.3%–81.4%), while its water utilization ratios from deep soil layers exhibited the opposite pattern (26.1%–30.1% vs. 9.0%–15.0%). Similarly, the ratios of water utilization from shallow soil layers by C. henryi (18.9%–29.5% vs. 32.4%–45.9%) and S. superba (10.0%–25.7% vs. 29.2%–66.4%) in the mid-successional forest were relatively lower than in the late-successional forest, whereas their water utilization ratios from deep soil layers showed the contrary tendency. Moreover, our results demonstrated that the diverse water utilization of each tree in different successional forests was mainly attributed to their distinct plant properties. Our findings highlight the increased percentage of water utilization of trees from shallow soil layers with forest succession, providing new insights for predicting the direction of forest succession under changing environments.
Citation: Forests
PubDate: 2024-07-31
DOI: 10.3390/f15081329
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1330: Responses of Soil Organic Carbon Fractions
and Stability to Forest Conversion in the Nanling Nature Reserve, China
Authors: Yifan Li, Fangfang Huang, Yuhui Huang, Wenjuan Li, Mengyun Liu
First page: 1330
Abstract: Studying the impact of typical vegetation types in forest conversion zones on soil organic carbon (SOC) structure and stability is crucial for developing terrestrial ecosystem carbon sequestration strategies. In this study, we selected three typical forest stands in the Nanling National Nature Reserve: a primary evergreen broad-leaved forest (BL), a secondary mixed coniferous and broad-leaved forest (ML), and a Chinese fir plantation (CL). Soil samples were collected to examine the SOC fractions and carbon pool management index (CPMI) in three forest stands. The influence of soil property factors on SOC fractions was also analyzed. The results showed that the transformation process from a BL to an ML or a CL changed the structure and stability of organic carbon by reducing the labile SOC fractions and increasing the recalcitrant carbon fraction in the soil. The higher lability index (LI) and CPMI of soils in the BL indicated better carbon accumulation and activity, making this treatment more advantageous for management strategies aimed at promoting natural forest renewal and ecological restoration. Correlation and RDA analysis revealed that the availability of soil P was a key factor limiting the variation in organic C fractions in the acidic soils of tropical forests in South China.
Citation: Forests
PubDate: 2024-07-31
DOI: 10.3390/f15081330
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1331: Anthropogenic Impacts on a Temperate Forest
Ecosystem, Revealed by a Late Holocene Pollen Record from an
Archaeological Site in NE China
Authors: Guangyi Bai, Keliang Zhao, Yaping Zhang, Junchi Liu, Xinying Zhou, Xiaoqiang Li
First page: 1331
Abstract: Pollen records from archaeological sites provide a direct reflection of the vegetation in the immediate vicinity, enabling an accurate depiction of anthropogenic impacts on vegetation. In this study, we applied the biomization technique to fossil pollen data to reconstruct human impact on the biome at the Chengzishan archaeological site in western Liaoning, China, and hence to explore the response of temperate forest vegetation to human activities. The results indicate that the original vegetation at Chengzishan was warm temperate coniferous and broadleaved mixed forest (TEDE). The findings suggest a shift in biome dominance over time, with cool temperate steppe (STEP) replacing TEDE as the dominant biome in response to human activities. Combined with archaeobotanical records, we conclude that the observed vegetation changes in the pollen record were closely linked to deforestation, fire use, and agricultural activities.
Citation: Forests
PubDate: 2024-07-31
DOI: 10.3390/f15081331
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1332: Individual Carbon Modeling in Eucalyptus
Stands in the Cerrado Region
Authors: Fabiana Piontekowski Ribeiro, Thais Rodrigues de Sousa, Fernanda Rodrigues da Costa Silva, Ana Caroline Pereira da Fonseca, Marcela Granato Barbosa dos Santos, Jane Ribeiro dos Santos, Douglas Rodrigues de Jesus, Clara Milena Concha Lozada, Marco Bruno Xavier Valadão, Eder Pereira Miguel, Alexsandra Duarte de Oliveira, Arminda Moreira de Carvalho, Alcides Gatto
First page: 1332
Abstract: In the context of global climate change, eucalyptus stands in the planted forest sector have become a viable alternative for reducing greenhouse gas (GHG) emissions, in addition to presenting great potential for the carbon (C) stock. Thus, the objective of this study was to quantify C stocks in different eucalyptus compartments, in addition to evaluating three mathematical models at the individual tree level. We evaluated four areas of eucalyptus stands located in the Federal District, Brazil. The data were collected from the forest inventory and rigorous cubing procedures using the following statistical models: Spurr, Schumacher–Hall, and adapted Schumacher–Hall. The highest Pearson’s linear modification coefficient, lowest root means square error percentage (RMSE%), and lowest Akaike information criterion (AIC) were used to select the best model. The C content and stock varied between the compartments and areas studied owing to age and, above all, genetic differences. Clone I224 had the highest carbon concentration per acre at 233.35 Mg ha−1 and carbon difference per compartment. The adapted Schumacher–Hall was the best model. It included data on biometric factors, such as the diameter at breast height, height, and age. The contribution of eucalyptus plantations to carbon sequestration is fundamental to socioenvironmental enhancement.
Citation: Forests
PubDate: 2024-08-01
DOI: 10.3390/f15081332
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1333: Waterlogged Archaeological Woods
Authors: Yoon Soo Kim, Adya P. Singh
First page: 1333
Abstract: Ancient wooden structures that are being continually uncovered from waterlogged environments are considered to be precious artefacts that reveal past human history and culture, as well as climatic changes that have occurred over the span of centuries [...]
Citation: Forests
PubDate: 2024-08-01
DOI: 10.3390/f15081333
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1334: Natural Factors Rather Than Anthropogenic
Factors Control the Greenness Pattern of the Stable Tropical Forests on
Hainan Island during 2000–2019
Authors: Binbin Zheng, Rui Yu
First page: 1334
Abstract: Vegetation, being a core component of ecosystems, is known to be influenced by natural and anthropogenic factors. This study used the annual mean Normalized Difference Vegetation Index (NDVI) as the vegetation greenness indicator. The variation in NDVI on Hainan Island was analyzed using the Theil–Sen median trend analysis and Mann–Kendall test during 2000–2019. The influence of natural and anthropogenic factors on the driving mechanism of the spatial pattern of NDVI was explored by the Multiscale Weighted Regression (MGWR) model. Additionally, we employed the Boosted Regression Tree (BRT) model to explore their contribution to NDVI. Then, the MGWR model was utilized to predict future greenness patterns based on precipitation and temperature data from different Shared Socioeconomic Pathway (SSP) scenarios for the period 2021–2100. The results showed that: (1) the NDVI of Hainan Island forests significantly increased from 2000 to 2019, with an average increase rate of 0.0026/year. (2) the R2 of the MGWR model was 0.93, which is more effective than the OLS model (R2 = 0.42) in explaining the spatial relationship. The spatial regression coefficients of the NDVI with temperature ranged from −10.05 to 0.8 (p < 0.05). Similarly, the coefficients of Gross Domestic Product (GDP) with the NDVI varied between −5.98 and 3.28 (p < 0.05); (3) The natural factors played the most dominant role in influencing vegetation activities as a result of the relative contributions of 83.2% of forest NDVI changes (16.8% contributed by anthropogenic activities). (4) under SSP119, SSP245, and SSP585 from 2021 to 2100, the NDVI is projected to have an overall decreasing pattern under all scenarios. This study reveals the trend of greenness change and the spatial relationship with natural and anthropogenic factors, which can guide the medium and long-term dynamic monitoring and evaluation of tropical forests on Hainan Island.
Citation: Forests
PubDate: 2024-08-01
DOI: 10.3390/f15081334
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1335: A Survey of Organic Carbon Stocks in Mineral
Soils of Eucalyptus globulus Labill. Plantations under Mediterranean
Climate Conditions
Authors: Ana Quintela, Daniela Ferreira, Sérgio Fabres, João Coutinho
First page: 1335
Abstract: The main aim of this study was to assess the amount of carbon (C) stored in the upper 30 cm layer of mineral soils in eucalypt plantations in Portugal, with a Mediterranean-type climate. Soil sampling data (2468 samples), field evaluations (soil profile description) and relevant information on the particle size distribution, climate, bedrock and reference soil group were accomplished. Bulk density per sample was assessed using pedo-transfer functions and soil C stock was estimated. The results showed an average of 41.2 t C ha−1 stored in the soil. In the northern regions of Portugal, the coldest and wettest areas of the country with better stand productivity, a higher soil organic carbon (SOC) is achieved (median SOC of 39.2 g kg−1 and soil C stock of 55 t ha−1) than in southern and inland regions, with a warmer and drier climate (median SOC of 15.2 g kg−1 and soil C stock of 28 t ha−1). The assessment of mean soil C stock per bedrock type revealed higher C stored in granites followed by conglomerates, coal shales and clay shales. Regarding soil type, the results showed a higher C stock in Cambisols, Leptosols and Fluvisols (>50 t C ha−1), whereas Regosols and Luvisols stored less, following the same trend presented for reference soil groups in Europe. Comparing the geographic distribution of the C stock in the upper layer of the mineral soils with the amount of C in eucalyptus stands (root and aboveground biomass—data from national forest inventory), the mineral soil pool can represent more than two-thirds of the total C stored in eucalyptus plantations in Portugal. Further studies should focus on the evolution of C stocks in eucalypt plantations during different stages of stand growth and under different management practices.
Citation: Forests
PubDate: 2024-08-01
DOI: 10.3390/f15081335
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1336: The Impact of Forestland Tenure Security on
Rural Household Income: Analysis of Mediating Effects Based on Labor
Migration
Authors: Xin Luo, Lishan Li, Ling Zhang, Caiwang Ning, Xiaojin Liu
First page: 1336
Abstract: Although collective forest tenure reform (CFTR) has improved the legal tenure security of forestland, its impact on increasing farmers’ income is unsustainable. This study used a multiple linear regression model to empirically analyze data from 505 farmers in Jiangxi Province, examining the impact of legal, actual, and perceived tenure security on rural household income, and incorporating migration into the framework. The findings indicate that both actual and perceived tenure security have a substantial positive impact on the total rural household income and forestry income. However, it is worth noting that legal tenure security only has a positive effect on forestry income. Furthermore, outside-of-county labor migration can serve as a mediator for the income effects of actual and perceived tenure security. However, the mediating effect of intra-county labor migration is not considerable. The study found that the increase in income due to the security of actual tenure security is significant for the group of people who own less than 50 mu of forestland. However, both actual and perceived tenure security have a significant impact on income for the group of people who own more than 50 mu of forestland. The aforementioned findings indicate that, in the ongoing extensive advancement of collective forest right reform, it is crucial to prioritize the execution of forest reform policies at the local level and enhance farmers’ awareness and comprehension of said policies. In addition, the government should enhance the monitoring system for policy implementation and intensify efforts in publicizing these policies, in order to fully utilize the benefits of CFTR.
Citation: Forests
PubDate: 2024-08-01
DOI: 10.3390/f15081336
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1337: Forest Wildfire Detection from Images
Captured by Drones Using Window Transformer without Shift
Authors: Wei Yuan, Lei Qiao, Liu Tang
First page: 1337
Abstract: Cameras, especially those carried by drones, are the main tools used to detect wildfires in forests because cameras have much longer detection ranges than smoke sensors. Currently, deep learning is main method used for fire detection in images, and Transformer is the best algorithm. Swin Transformer restricts the computation to a fixed-size window, which reduces the amount of computation to a certain extent, but to allow pixel communication between windows, it adopts a shift window approach. Therefore, Swin Transformer requires multiple shifts to extend the receptive field to the entire image. This somewhat limits the network’s ability to capture global features at different scales. To solve this problem, instead of using the shift window method to allow pixel communication between windows, we downsample the feature map to the window size after capturing global features through a single Transformer, and we upsample the feature map to the original size and add it to the previous feature map. This way, there is no need for multiple layers of stacked window Transformers; global features are captured after each window Transformer operation. We conducted experiments on the Corsican fire dataset captured by ground cameras and on the Flame dataset captured by drone cameras. The results show that our algorithm performs the best. On the Corsican fire dataset, the mIoU, F1 score, and OA reached 79.4%, 76.6%, and 96.9%, respectively. On the Flame dataset, the mIoU, F1 score, and OA reached 84.4%, 81.6%, and 99.9%, respectively.
Citation: Forests
PubDate: 2024-08-01
DOI: 10.3390/f15081337
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1338: Effect of Forestry Carbon Offset Policy on
Sharing the Pressure of Emission Reduction: Findings from China
Authors: Rui Sun, Dayi He, Jingjing Yan
First page: 1338
Abstract: The forestry carbon offset policy has been implemented for a short time, and in order to study its optimization mechanism and pressure-sharing emission reduction effect, this paper applies the directional distance function to calculate the marginal abatement cost of each province/city based on the panel data of 30 provinces/cities in China from 2000 to 2020. Then, we utilize the synthetic control method to analyze the forestry carbon offset policy by taking Beijing, Guangdong, and Fujian as a natural experiment. Finally, placebo tests and differences-in-differences tests were used to verify the experiment’s effectiveness. The study has the following results. (1) The forestry carbon offset policy is a Pareto improvement after integrating multiple benefits. The proportion of FCS offset should be increased, and government subsidies should be reduced when carbon quotas are tightened, followed by the gradual inclusion of more industries and enterprises in the scope of mandatory emission reductions. (2) The impact of forestry carbon offset policy on sharing the abatement pressure has regional heterogeneity, which is affected mainly by geographical location, economic level, and industrial structure. It can be obtained that the forestry carbon offset policy has shared the pressure for emission reductions in Guangdong and Fujian. This study provides a theoretical basis for promoting forestry carbon offset policies and their coupling with other carbon-reduction policies.
Citation: Forests
PubDate: 2024-08-01
DOI: 10.3390/f15081338
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1339: Variety and Site Drive Salix Mixture Effects
on Soil Organic Matter Chemistry and Soil Carbon Accumulation
Authors: Joel Jensen, Petra Fransson, Christel Baum, Peter Leinweber, Kai-Uwe Eckhardt, Martin Weih
First page: 1339
Abstract: Soil organic matter (SOM) is essential for nutrient cycling and soil carbon (C) accumulation, both of which are heavily influenced by the quality and quantity of plant litter. Since SOM dynamics in relation to plant diversity are poorly understood, we investigated the effects of willow variety and mixture, and site on the soil C stocks, SOM chemical composition and thermal stability. Using pyrolysis-field ionization mass spectrometry (Py-FIMS), a method of stepwise thermal degradation in ultrahigh vacuum combined with soft ionization in a high electric field, followed by mass-spectrometric separation and detection of molecular ions, we analyzed SOM in the top 10 cm of soil from two 7-year-old experimental sites in Germany and Sweden. Monocultures and mixtures of two willow varieties (Salix spp.) belonging to different species were grown at the experimental plots. Overall, site had the strongest effect on SOM quality. The results showed significant variability across sites for willow identity and mixture effects on C accumulation and SOM chemistry. In the German site (Rostock), yearly soil C accumulation was higher (p < 0.05) for variety ‘Loden’ (1.0 Mg C ha−1 year−1) compared to ‘Tora’ (0.5 Mg C ha−1 year−1), whilst in the Swedish site (Uppsala), both varieties exhibited similar soil C accumulation rates of around 0.6 Mg C ha−1 year−1. Willow variety identity significantly affected SOM quality at both sites, while mixing had minor effects. Our findings emphasize the significance of site-specific context and variety and species identity in shaping soil C accumulation in willow plantations.
Citation: Forests
PubDate: 2024-08-01
DOI: 10.3390/f15081339
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1340: Different Responses of Terrestrial Carbon
Fluxes to Environmental Changes in Cold Temperate Forest Ecosystems
Authors: Mihang Jiang, Xinjie Liu, Liangyun Liu
First page: 1340
Abstract: As the largest carbon reservoir within terrestrial ecosystems, forest ecosystems play a major role as carbon sinks in the global carbon cycle. There are still some uncertainties regarding the responses of different carbon fluxes to environmental changes in cold temperate climate forest ecosystems. Here, 14 cold temperate forest flux sites for at least ten years were investigated, including carbon fluxes and environmental variables such as temperature, precipitation, shortwave radiation, and vapor pressure deficit. By calculating the Spearman correlation coefficient, there was a congruence between photosynthetic productivity (i.e., gross primary productivity, GPP) and carbon sequestration (i.e., net ecosystem productivity, NEP) at thirteen forest sites, and at one forest site, GPP and NEP were decoupled. Annual GPP and NEP displayed a consistent trend when temperature and precipitation had significantly opposite trends and when temperature had a significantly positive correlation with VPD. But when VPD was significantly negatively correlated with both temperature and SW in spring and when temperature was negatively correlated with both SW and VPD in summer, a decoupling of GPP and NEP occurred. The impacts of various environmental factors on the annual carbon fluxes were calculated for each year and season using the path analysis method. At forest sites with consistent trends in GPP and NEP, annual, spring, and summer temperatures had significant positive correlations with GPP and ecosystem respiration (RE). While at the decoupled forest site, environmental factors had a stronger effect on RE, which then contributed to the observed decoupling of GPP and NEP. Finally, the Partial Least Squares method was used to analyze the relative contribution of each environmental factor to annual carbon fluxes. The results revealed that temperature and summer precipitation were the key environmental factors affecting forest ecosystems. This study provides important insights into the different responses of carbon fluxes in forest ecosystems undergoing environmental changes.
Citation: Forests
PubDate: 2024-08-01
DOI: 10.3390/f15081340
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1341: Quantitative Study on the Effects of
Vegetation and Soil on Runoff and Sediment in the Loess Plateau
Authors: Gaohui Duan, Chunqian Leng, Zeyu Zhang, Cheng Zheng, Zhongming Wen
First page: 1341
Abstract: Runoff and sediment (RAS) are important indicators of soil erosion in a watershed, playing a significant role in the migration of surface material and landform development. Previous studies have extensively documented the effects of trees, shrubs, herbs, and soil on runoff and sediment during erosive rainfall; however, the precise interactions among these factors and their influence on RAS yield within the vegetation hierarchy remain unclear. Using the random forest algorithm and the structural equation model, this research aimed to quantify the interaction of numerous variables within diverse vegetation hierarchies and how they affect RAS, as well as to identify critical indicators that influence RAS. The structural equation model results show that the grass properties have a direct effect on soil properties, and the grass properties and soil properties both affect the canopy properties directly; the soil properties and canopy properties are the main factors influencing runoff and sediment directly. In addition, the grass properties could affect RAS by influencing the soil properties indirectly, and the soil properties could also affect RAS indirectly by influencing the canopy properties. Height difference (HD) between two layers of vegetation had the highest weight of 1.043 among the canopy variables, showing that HD has a substantial effect on RAS. Among the soil properties, soil bulk density and maximum field capacity have a significant impact on RAS. We conclude that canopy properties have the greatest impact on RAS. In the future, more Caragana microphylla Lam and Robinia pseudoacacia Linn plants should be planted to prevent soil erosion. This study provides a scientific basis for vegetation planting management and soil erosion control on the Loess Plateau.
Citation: Forests
PubDate: 2024-08-01
DOI: 10.3390/f15081341
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1342: Genomic Selection for Growth and Wood Traits
in Castanopsis hystrix
Authors: Weihua Zhang, Ruiyan Wei, Yuanzhen Lin
First page: 1342
Abstract: Castanopsis hystrix, a precious tree species in Southeast Asia, has the advantages of rapid growth and high-quality wood materials. However, there are problems such as its long breeding cycle and low efficiency, and being time-consuming, which greatly restricts the industrial development of C. hystrix. Performing genome selection (GS) for growth and wood traits for the early selection of superior progeny has great significance for the rapid breeding of new superior varieties of C. hystrix. We used 226 clones in the main distribution and 479 progenies within 23 half-sib families as experimental materials in this study. Genotyping datasets were obtained by high-throughput re-sequencing technology, and GS studies were conducted on the growth (tree height (H), diameter at breast height (DBH)) and wood (wood density (WD), fiber length (FL), and fiber length–width ratio (LWR)) traits. The coefficient of variation (CV) of five phenotypic traits ranged from 10.1% to 22.73%, the average CV of growth traits was 19.93%, and the average CV of wood traits was 9.72%. The Pearson correlation coefficients between the five traits were almost all significantly positive. Based on the Genomic Best Linear Unbiased Prediction (GBLUP) model, the broad-sense heritabilities of growth traits were higher than those of wood quality traits, and the different number of SNPs had little effect on the heritability estimation. GS prediction accuracy first increased and then reached a plateau at around 3K SNPs for all five traits. The broad-sense heritability of these five traits was significantly positively correlated with their GS predictive ability (r = 0.564, p < 0.001). Bayes models had better GS prediction accuracy than the GBLUP model. The 15 excellent progeny individuals were selected, and their genetic gain ranged from 0.319% to 2.671%. These 15 superior offspring individuals were 4388, 4438, 4407, 4468, 4044, 4335, 4410, 4160, 4212, 4461, 4052, 4014, 4332, 4389, and 4007, mainly from three families F5, F6, and F11. Our research lays out the technical and material foundation for the rapid breeding of new superior varieties of C. hystrix in southern China.
Citation: Forests
PubDate: 2024-08-02
DOI: 10.3390/f15081342
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1343: The Growth and Physiological Responses of
Gleditsia sinensis Lam. Seedlings with Different Phosphorus Efficiencies
to Low Phosphorus Stress
Authors: Chunyun Lu, Rong Zou, Xiurong Wang, Yang Zhao, Feng Xiao
First page: 1343
Abstract: In order to elucidate the response mechanisms of Gleditsia sinensis Lam. with different phosphorus (P) efficiencies to low P stress, this study set up low P treatment (0.01 mmol·L−1, LP) and normal P treatment (1.00 mmol·L−1, NP). The experimental materials included low P-tolerant G. sinensis families F10 and F13, and low P-sensitive G. sinensis families F21 and F29. This study aimed to investigate the effects of low P stress on the agronomic traits, nutrient content, and physiological indices of G. sinensis seedlings with different P efficiencies. The results showed that the agronomic traits, such as plant height, stem diameter, and so on, of the low P-tolerant family, were significantly higher than those of the low P-sensitive family under low P stress. Low P stress significantly increased the total root length, total root surface area, total root projected area, total root volume, and main root diameter of the tolerant family. The tolerant family exhibited significantly higher net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, and transpiration rate compared to the sensitive family. Low P stress significantly increased the activities of protective enzymes, acid phosphatase activity, and malondialdehyde content in the low P-tolerant family. The tolerant family exhibited higher P absorption efficiency and P utilization efficiency compared to the sensitive family. Low P stress significantly increased the P utilization efficiency of the tolerant family. In summary, compared to the sensitive family, the low P-tolerant G. sinensis family has stronger reactive oxygen species scavenging ability and can accumulate more osmotic regulatory substances to maintain cell osmotic potential and better protect cells; this improves P utilization efficiency and nutrient content, thereby alleviating the harm caused by low P stress and maintaining normal growth and metabolism.
Citation: Forests
PubDate: 2024-08-02
DOI: 10.3390/f15081343
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1344: Functional Characterization of PagMYB148 in
Salt Tolerance Response and Gene Expression Analysis under Abiotic Stress
Conditions in Hybrid Poplar
Authors: Su Jin Park, Hyun-A Jang, Hyoshin Lee, Hyunmo Choi
First page: 1344
Abstract: MYB transcription factors containing an R2R3 DNA-binding domain are involved in the regulation of various physiological processes, such as responses to abiotic stresses, including salt stress. In poplar, various MYB transcription factors regulate stress responses. In this study, we aimed to identify the correlation between the transcription factor MYB148 and salt stress responses in the hybrid poplar (Populus alba × P. glandulosa). We induced a mutation in the MYB-binding domain of PagMYB148 using CRISPR/Cas9-mediated editing of the PagMYB148 gene, which induced a more suppressed expression of PagMYB148 than that in the wild-type. Although salt and drought treatments enhance the expression of PagMYB148, the pagmyb148-transgenic plants exhibited more sensitive phenotypes than the wild-type plants under salt stress. After exposure to salinity stress, the chlorophyll content was lower in pagmyb148-transgenic plants than in wild-type plants, whereas the mutation increased ion leakage from cells. Additionally, the expression of genes involved in the salt stress response was higher in pagmyb148-transgenic plants than in the wild-type. After salt treatment, pagmyb148-transgenic plants exhibited an increased level of H2O2 and reduced activity of antioxidant enzymes. In summary, the MYB148 transcription factor is involved in the regulation of salt stress resistance in hybrid poplar trees. This report contributes to providing a basis for further investigating the molecular mechanisms of the poplar PagMYB148 transcription factor under abiotic stress.
Citation: Forests
PubDate: 2024-08-02
DOI: 10.3390/f15081344
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1345: A Potential Replacement to
Phenol–Formaldehyde-Based Adhesives: A Study of Plywood Panels
Manufactured with Bio-Based Wood Protein and Nanolignin Adhesives
Authors: Mario Núñez-Decap, Catherine Friz-Sánchez, Camila Opazo-Carlsson, Boris Moya-Rojas, Marcela Vidal-Vega
First page: 1345
Abstract: Plywood production relies on phenol–formaldehyde (PF), which is why bio-based wood adhesives (BBWAs) were developed as potential replacements, showing promising results in several tests performed. A control sample (PLY-C) with PF and two samples (PLY-1 and PLY-2) with BBWA were manufactured, on which physical and mechanical properties, adhesive bonding morphology, formaldehyde emissions, and accelerated UV aging were evaluated. The adhesive penetration results, into the wood cells, were according to the viscosity of each adhesive. About the mechanical properties, the sample PLY-2 presented the same MOE and tensile strength as the sample PLY-C and reached 87% of the sample PLY-C MOR in the parallel direction. On the other hand, the sample PLY-1 presented the same behavior in the Janka hardness test as the sample PLY-C. All the samples subjected to shear strength tests met the requirement, and the samples PLY-1 and PLY-2 reached 68% and 80% of the PLY-C sample, respectively. The samples manufactured with BBWA presented a decrease in formaldehyde emissions by 88% and they were less susceptible to color change than the control sample under UV aging. According to the results obtained, it is concluded that plywood manufactured with BBWA might be a considerable replacement for plywood manufactured with PF adhesives at a laboratory scale.
Citation: Forests
PubDate: 2024-08-02
DOI: 10.3390/f15081345
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1346: Land Use Evolution and Its Driving Factors
over the Past 30 Years in Luochuan County
Authors: Yuhang Xue, Wenbao Ma, Liangxu Liu, Yang Yang
First page: 1346
Abstract: Understanding the evolution of land use change and its drivers is vital in keeping the fragile balance between human activities and nature. The present study employs remote sensing data from between 1990 and 2020 during the Grain-for-Green Project (GGP) in Luochuan county, Shaanxi Province, which offers 30 years of continuous data on precipitation, temperature, population, and GDP. Here, the combined method of supervised classification with manual visual interpretation was adopted for building a high-precision spatial distribution information database, in order to explore the links existing between the change features of land use, distribution, and spatial pattern, and the interference of local socio-economic development and natural factors before and after the GGP. According to the results, during the past three decades, Luochuan county has undergone large changes in land use types, displaying distinct features and regional disparities. Geographically, the north of Luochuan county is predominantly forest and grassland, while farmland is mostly in the south of Luochuan county. In 1990, farmland dominated this county; however, after 2000, forest and grassland areas expanded. Notably, the implementation of the GGP significantly influenced changes in grassland and forest areas. With the development of modernization, Luochuan county’s land use structure has gradually equilibrated, with increased uniformity in the distribution of various land use types. Obviously, the shift in land use from 1990 to 2020 primarily correlates with mean annual temperature, annual precipitation, total population, and GDP. Furthermore, regression analysis revealed that during the initial decade of the GGP, natural factors primarily drove land use changes. However, after the GGP, the conversion rate from farmland to forest and shrubland/grassland escalated, and population growth was the continual external force driving the expansion of forest and grassland. Despite substantial economic benefits from land development and utilization in Luochuan county during the past 30 years, certain human economic activities have posed significant pressure on regional agricultural development and sustainable land resource use. Overall, this study helps our government to enhance national land management and planning through a targeted method, also providing a reference for analyzing land use change processes within same areas.
Citation: Forests
PubDate: 2024-08-02
DOI: 10.3390/f15081346
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1347: The Impact of Restoration on Epigeic
Arthropods in the Important European Forest Biotopes of the Danube Delta
Authors: Kornélia Petrovičová, Stanislav David, Vladimír Langraf
First page: 1347
Abstract: The floodplain forests of the Danube Delta are among the important European biotopes and are protected in Slovakia under Natura 2000. In order to preserve these biotopes, their restoration is underway, which also restores the original fauna. These biotopes are sensitive to environmental and ecological changes, which is also reflected in the spatial distribution of epigeic arthropods. Between the years 2020 and 2023, we investigated the impact of floodplain restoration on the population structure of epigeic arthropods in eight study areas (two control study areas and six study areas with ongoing biotope restoration). We placed five pitfall traps in a transect for each biotope. In total, we recorded 66,771 individuals belonging to 15 arthropod taxa. We found differences in the taxonomic structures between forest stands with management and forest stands without management (larger number of taxa) using spatial modelling. We also confirmed interannual changes in the taxa composition of epigeic arthropods and their abundance. Over the years of restoration, the number of individual epigeic arthropods decreased. In the years following revitalization, when succession took place, it subsequently increased. Overall, the restoration management of floodplain forests had a positive effect on epigeic arthropods, as well as on their number of individuals, which is important for the preservation of these important habitats in Europe.
Citation: Forests
PubDate: 2024-08-02
DOI: 10.3390/f15081347
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1348: Applying Specific Habitat Indicators to
Study Asteraceae Species Diversity Patterns in Mountainous Area of
Beijing, China
Authors: Lin Zhang, Shi Qi, Tianheng Zhao, Peng Li, Xiangyu Wang
First page: 1348
Abstract: The distribution pattern and influencing factors of specific species diversity play a crucial role in decision-making for biodiversity conservation. Identifying suitable regional habitat indicators to assess specific species diversity patterns is a global focus topic. A total of 112 sample plots were surveyed to investigate the relationship between Asteraceae species diversity and topography, soil nutrients, and stand factors, using a Structural Equation Model (SEM). Additionally, the Maxent model was utilized to predict the distribution pattern of Asteraceae species diversity in response to specific habitat factors. The findings revealed that soil nutrients, topography, and canopy closure had different impacts on Asteraceae species diversity, with soil nutrients showing the highest relative coefficient, followed by topography and canopy closure. The elevation and slope gradient were identified as direct and indirect influences on Asteraceae species diversity. The contribution rate of potential environmental variables on the Asteraceae species diversity was ranked as follows: STN (29.7%) > SOM (28.5%) > slope (8.5%) > Ele (8.1%). Asteraceae species diversity was found to be abundant in the locations with SOM (>27 g/kg), STN (>1.8 g/kg), Ele (165–333 m), and slopes (5–12 degrees). Soil nutrient content serves as a key indicator for assessing the abundance of Asteraceae species diversity and should be considered in biodiversity conservation.
Citation: Forests
PubDate: 2024-08-02
DOI: 10.3390/f15081348
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1349: Safeguarding Local Communities for REDD+
Implementation in Ghana
Authors: Jewel Andoh, Edward Martey, Elizabeth Asantewaa Obeng, Kwame Antwi Oduro, Pone Salimath, Yohan Lee
First page: 1349
Abstract: In this study, we primarily assess the relationship between social safeguards and the living standards of local communities in different ecological zones of Ghana, relying on data from the seventh round of the Ghana Living Standard Survey (GLSS 7) and publicly available policy documents from the Ghana Statistical Service and the Forestry Commission of Ghana, respectively. This research aims to assist policymakers and stakeholders to make informed and appropriate decisions when developing social safeguards for emission reduction projects. The GLSS 7 covers 14,009 households, comprising 59,864 individuals in 892 enumeration areas or communities across the 10 regions of Ghana, now divided into 16. The data were collected using a stratified random sampling technique. Principal component analysis was employed to develop a living condition index, after which we generated a second construct based on the number of factors affecting living conditions. The results showed that access to sharecropping, literacy, extension services, financial institutions, a mobile phone network, and markets have significant positive relationships with the living conditions of local communities in Ghana. In addition, 78% of the social safeguards described in Ghana’s REDD+ strategy, Forest and Wildlife Policy, Benefits Sharing Mechanism, and Forest Plantation Development Strategy are aligned with the determinants of local communities’ living conditions. The findings suggest a need to enforce the Benefit Sharing Mechanism, better forest governance, and tenancy reforms in order to prevent the overexploitation of landowners and avoid elite capture. Furthermore, farmers must be linked to financial institutions in order to obtain credits. Additionally, we must seek to provide local communities with better access to markets and mobile phone networks in a way that allows them to carry out their livelihood activities effectively and efficiently. These measures help to reduce the risk of REDD+ actions and ensure sustainability.
Citation: Forests
PubDate: 2024-08-02
DOI: 10.3390/f15081349
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1350: The Demand of Forest Bathing in Northern
Italy’s Regions: An Assessment of the Economic Value
Authors: Francesca Visintin, Ivana Bassi, Vanessa Deotto, Luca Iseppi
First page: 1350
Abstract: The study aims to evaluate the demand for forest bathing in northern Italy’s regions, underlining the willingness to pay and the potential tourists’ habits and flows on attending alpine contexts. Several studies have analyzed the psychophysical benefits of forest bathing, and there is a growing interest in assessing its economic value for tourism purposes. The sample’s answers have been analyzed employing a stratified sampling methodology considering three different macro areas (northwest regions, northeast regions, and the Friuli Venezia Giulia region). After analyzing the sample’s attitudes, the research approached the estimation section by calculating the flow as the number of potential forest bathing hikes per year and the willingness to pay through the contingent valuation method. The main results indicate that forest bathing activity in northern Italy has a considerable monetary value, and it is generally compared with positive feelings, particularly concerning well-being and fascination factors.
Citation: Forests
PubDate: 2024-08-02
DOI: 10.3390/f15081350
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1351: Nitrogen Application Promotes Drought
Resistance of Toona sinensis Seedlings
Authors: Xiaochi Yu, Runhua He, Fei Yi, Ying Liu, Peng Zhang, Junhui Wang, Wenjun Ma
First page: 1351
Abstract: A factorial design consisting of four N treatments (no N fertilization, 0.70, 0.14, and 0.28 mol N·plant−1) combined with two water conditions, drought (D = 25 ± 5% soil moisture content) and well-watered (W = 65 ± 5% soil moisture content), was used. Overall, the gas exchange parameters, chlorophyll, and growth of T. sinensis seedlings were significantly inhibited under drought conditions, while all of them showed improvement with N fertilizer, particularly at 0.14~0.28 mol N·plant−1. Under drought conditions, the root length and root surface area of T. sinensis increased; N application positively influenced the above root morphological changes. The activities of antioxidant enzymes such as superoxide dismutase (SOD; EC1.15.1.1) and peroxidase (POD; EC1.11.1.7) and the contents of osmotic adjustment substances such as soluble sugar and proline increased upon drought stress, but decreased under N application conditions. Overall, T. sinensis responds to drought stress through the synergistic action of drought resistance and drought tolerance mechanisms. N application enhances photosynthesis and improves root morphology, compensating for the need for osmotic regulation and reactive oxygen species scavenging.
Citation: Forests
PubDate: 2024-08-02
DOI: 10.3390/f15081351
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1352: Change Characteristics of Soil Erodibility
during Natural Restoration in an Earthquake Landslide of Southwestern
China
Authors: Jiangkun Zheng, Junxia Yan, Qiyang Chen, Wangyang Hu, Peng Zhao, Guirong Hou, Yong Wang
First page: 1352
Abstract: Landslides caused by earthquakes bring about dramatic changes in soil erodibility. In order to understand the change characteristics of soil erodibility during a vegetation restoration period after the 5.12 Wenchuan earthquake, a non-landslide area, landslide area, and transition area in Leigu Town, Beichuan County were selected as research areas. Field soil sampling, geostatistics, and spatial interpolation were used to explore the spatiotemporal changes in soil physicochemical properties and soil erodibility during a natural restoration in 2013 (5 years after the earthquake) and in 2022 (14 years after the earthquake). The results showed that the comprehensive soil erodibility index (CSEI) was mainly composed of five soil factors, which were soil pH, soil total nitrogen (TN), mean weight diameter of soil aggregates (MWD), fractal dimension of soil water stable aggregates (D), and soil erodibility (Kepic). The CSEI of the landslide area was slightly lower than that of the non-landslide area. The CSEI was gradually increasing during the process of natural restoration after earthquake. From 2013 to 2022, the increase rates of the CSEI were 6.9%, 10.0%, and 41.5% for the landslide area, non-landslide area, and transition area, respectively. Along attitude segments, the spatial distribution of soil erodibility in 2022 is more uniform than that in 2013. The higher value of CSEI was located in the upper part of research areas. The spatial distribution of the CSEI in 2013 and 2022 appeared as a moderate autocorrelation. The variable ranges of CSEI in 2013 and 2022 were about 20 m. In the early stage of vegetation restoration, soil and water conservation engineering was recommended in the landslide area.
Citation: Forests
PubDate: 2024-08-02
DOI: 10.3390/f15081352
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1353: Evolvement of Spatio-Temporal Pattern and
Driving Forces Analysis of Ancient Trees Based on the Geographically
Weighted Regression Model in Guangzhou and Foshan, China
Authors: Xu, Xu, Liu, Liu, Du, Yi, Zhou, Lin, Li
First page: 1353
Abstract: Ancient trees play an important ecosystem service role in high-density cities, revealing the zonal distribution characteristics of vegetation under climate influence. The ancient trees in Guangzhou and Foshan in 2018 and 2023 were taken as study objects to explore the evolution of their spatio-temporal patterns and to analyze the spatial differentiation characteristics of their driving factors using the geographical weighted regression (GWR) model. The results showed the following: (1) The ancient trees in Guangzhou and Foshan were composed of typical subtropical evergreen broad-leaved forest communities, mainly represented by broad-leaved species of evergreen dicotyledonous plants. The dominant species mainly included Litchi chinensis, Ficus microcarpa, Canarium pimela, Ficus virens, and Dimocarpus longan. However, there was a significant difference between Guangzhou and Foshan. (2) The number of ancient trees in Guangzhou showed negative growth, while Foshan saw a significant increase. However, species diversity in both areas increased, with the highest diversity in the northeast, higher diversity in the south-central part, and lower diversity in the western and northwestern parts. (3) The maximum kernel density of ancient trees in Guangzhou and Foshan differed 22-fold, indicating a spatial distribution pattern of multiple clusters. (4) The GWR model effectively explained the driving factors of the heterogeneity of the spatial distribution of ancient trees. The results showed that artificial disturbance was the most important factor affecting the spatial distribution of ancient trees in high-density urban agglomerations in the same vegetation zone. The study clarified the characteristics of the spatial distribution and species diversity of ancient trees in the region, revealed the driving factors for the evolution of the spatial pattern of ancient trees in highly urbanized areas, and provided guidelines for policies and measures for enhancing biodiversity and conserving germplasm resources in the region.
Citation: Forests
PubDate: 2024-08-02
DOI: 10.3390/f15081353
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1354: Can Ecological Protection Affect
High-Quality Forestry Development'—A Case Study of China
Authors: Longbo Ma, Jixiang Fan, Qian Wang, Rong Zhao
First page: 1354
Abstract: As the global ecological environment faces serious challenges, ecological protection has attracted global attention. As a basic industry of the national economy, China’s total forestry output value is 8.04 trillion RMB in 2022. This study aims to assess the impact of ecological protection on high-quality forestry development and find its mechanism by using provincial panel data from 2010 to 2021 in China. The variables of environmental regulation and urbanization level were introduced. The benchmark regression model, mediation effect model and threshold effect model were employed for empirical analysis. The results show that: (1) The estimated ecological protection coefficient is 0.146. The ecological protection level significantly promotes high-quality forestry development; (2) The effect is more significant in the western region and the area with higher forest coverage. The estimated coefficients are 1.392 and 0.745. It is less affected by the marginal effect of the ecological protection level in the east; (3) The estimated environmental regulation coefficient is −0.021. Ecological protection promotes high-quality forestry development by reducing environmental regulations; (4) The impact increases with the level of urbanization. The p-value of the double threshold is 0.073. Therefore, policy recommendations are proposed to strengthen ecological protection and promote high-quality forestry development.
Citation: Forests
PubDate: 2024-08-02
DOI: 10.3390/f15081354
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1355: Factors Driving Unexpected Drought-Induced
Nothofagus dombeyi Mortality in a Valdivian Temperate Rainforest,
Argentina
Authors: María Laura Suarez, Yamila Sasal, Loreta Facciano
First page: 1355
Abstract: Understanding the drivers of drought-induced tree mortality remains a significant scientific challenge. Here, we investigated an unexpected mortality event of Nothofagus dombeyi (Mirb.) Oerst. following the 2014–15 drought in a Valdivian rainforest, Argentina. Our focus was on long-term growth trend differences between vital and dead trees, and how the mixing of species in tree neighbourhoods drives tree growth during drought. The inter-annual variation of basal area increments of vital and 2014–15-dead N. dombeyi trees showed a similar pattern through the 1930–2015 period, while the climate–growth relationships indicated that precipitation during the growing season promoted growth in both vitality classes, regardless of whether they were in the wettest location. For the period 1990–2015, both vitality classes showed similar estimated growth regardless of competition level, whereas species mingling in the neighbourhood significantly affected the dead tree growth. Network analysis revealed that drought performance covaried positively with a neighbourhood dominated by species functionally different from the focal species only in vital trees. These findings suggest a nuanced response of N. dombeyi to drought, shaped by multifaceted interactions at both the individual tree and neighbourhood levels. This research underscores that species-specific relationships under different mixtures imply different tree responses within a stand, and add complexity to understanding drought response at the individual level.
Citation: Forests
PubDate: 2024-08-02
DOI: 10.3390/f15081355
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1356: Mapping Forest Growing Stock and Its Current
Annual Increment Using Random Forest and Remote Sensing Data in Northeast
Italy
Authors: Luca Cadez, Antonio Tomao, Francesca Giannetti, Gherardo Chirici, Giorgio Alberti
First page: 1356
Abstract: The role of forests in providing multiple goods and services has been recognized worldwide. In such a context, reliable spatial predictions of forest attributes such as tree volume and current increment are fundamental for conducting forest monitoring, improving restoration programs, and supporting decision-making processes. This article presents the methodology and the results of the wall-to-wall spatialization of the growing stock volume and the current annual increment measured in 273 plots of data of the Italian National Forest Inventory over an area of more than 3260 km2 in the Friuli Venezia Giulia region (Northeast Italy). To this aim, a random forest model was tested using as predictors 4 spectral indices from Sentinel-2, a high-resolution Canopy Height Model derived from LiDAR, and geo-morphological data. According to the Leave One Out cross-validation procedure, the model for the growing stock shows an R2 and an RMSE% of 0.67 and 41%, respectively. Instead, an R2 of 0.47 and an RMSE% of 57% were obtained for the current annual increment. The validation with an independent dataset further improved the models’ performances, yielding significantly higher R2 values of 0.84 and 0.83 for volume and for increment, respectively. Our results underline a relatively higher importance of LiDAR-derived metrics compared to other covariates in estimating both attributes, as they were even twice as important as vegetation indices for growing stock. Therefore, these metrics are promising for the development of a national LiDAR-based model.
Citation: Forests
PubDate: 2024-08-03
DOI: 10.3390/f15081356
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1357: Understanding Tree Mortality Patterns: A
Comprehensive Review of Remote Sensing and Meteorological Ground-Based
Studies
Authors: Filippos Eliades, Dimitrios Sarris, Felix Bachofer, Silas Michaelides, Diofantos Hadjimitsis
First page: 1357
Abstract: Land degradation, desertification and tree mortality related to global climate change have been in the spotlight of remote sensing research in recent decades since extreme climatic events could affect the composition, structure, and biogeography of forests. However, the complexity of tree mortality processes requires a holistic approach. Herein, we present the first global assessment and a historical perspective of forest tree mortality by reviewing both remote sensing and meteorological ground-based studies. We compiled 254 papers on tree mortality that make use of remotely sensed products, meteorological ground-based monitoring, and climatic drivers, focusing on their spatial and temporal patterns and the methods applied while highlighting research gaps. Our core results indicate that international publications on tree mortality are on the increase, with the main hotspots being North America (39%) and Europe (26%). Wetness indicators appear as the barometer in explaining tree mortality at a local scale, while vegetation indicators derived from multispectral optical sensors are promising for large-scale assessments. We observed that almost all of the studies we reviewed were based on less than 25 years of data and were at the local scale. Longer timeframes and regional scale investigations that will include multiple tree species analysis could have a significant impact on future research.
Citation: Forests
PubDate: 2024-08-03
DOI: 10.3390/f15081357
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1358: Native and TMT Chestnut Extractives as
Hydrophobic and Photostabylizing Additives for Wood Surfaces
Authors: Paola Cetera, Wolfgang Gindl-Altmutter, Maurizio D’Auria, Hrvoje Turkulin, Luigi Todaro
First page: 1358
Abstract: Wood extractives have proven strong anti-oxidative properties which may be used to mitigate surface deterioration caused by photolytic effects and free radical formations. An interesting challenge regarding wood extractives is understanding how they behave in terms of treating natural wood surfaces to reduce anti-oxidative processes that arise from exposure to the main environmental factors. In this study, the possible efficacy of chestnut (Castanea sativa Mill.) extractives derived from native (CH) and thermally modified wood (TMT CH), as a means of protecting against UV exposure in poplar (Populus spp.) and spruce (Picea abies Karst.) wood, was evaluated. Chestnut wood was first thermally modified at 180 °C for 3 h, and the extractives were obtained by the accelerated solvent extraction technique (ASE) and subsequently used to treat wood surfaces. Samples were immersed in extractive solutions and exposed to artificial UV-weathering exposure, then contact angle and colour stability were monitored during the process. An FTIR analysis of the photo-degradation process of poplar and spruce surfaces was also executed. Extractives of TMT chestnut changed the total colour variation in both poplar and spruce wood. A much darker colour compared to the extractives of native wood was observed and an increase in ∆E* from 9.75 to 30.76 and 6.24 to 22.97 in poplar and spruce was calculated. The stability of the colour depended both on the surface wood and the type of extractive. The initial contact angle remained almost unchanged in the poplar wood surface and only slightly increased in spruce regardless of whether they were treated with extractives from native or TMT chestnut wood. A strong reduction in contact angle after the accelerated UV exposure test was observed, especially in spruce treated with CH extractives. FTIR analysis confirmed the lower levels of chemical degradation of surfaces observed by colorimetry, where TMT CH extractives formed more stable chemical bonds than native extractives. The comparative analysis in this study clarified the complex relationships between the effects of high-temperature modification of wood and the potential protective role of TMT extractives on some wood surfaces.
Citation: Forests
PubDate: 2024-08-03
DOI: 10.3390/f15081358
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1359: Tidal Freshwater Forested Wetlands in the
Mobile-Tensaw River Delta along the Northern Gulf of Mexico
Authors: Andrew Balder, Christopher J. Anderson, Nedret Billor
First page: 1359
Abstract: Tidal freshwater forested wetlands (TFFWs) typically occur at the interface between upriver non-tidal forests and downstream tidal marshes. Due to their location, these forests are susceptible to estuarine and riverine influences, notably periodic saltwater intrusion events. The Mobile-Tensaw (MT) River Delta, one of the largest river deltas in the United States, features TFFWs that are understudied but threatened by sea level rise and human impacts. We surveyed 47 TFFW stands across a tidal gradient previously determined using nine stations to collect continuous water level and salinity data. Forest data were collected from 400 m2 circular plots of canopy and midstory species composition, canopy tree diameter and basal area, stem density, and tree condition. Multivariate hierarchical clustering identified five distinct canopy communities (p = 0.001): Mixed Forest, Swamp Tupelo, Water Tupelo, Bald Cypress, and Bald Cypress and Mixed Tupelo. Environmental factors, such as river distance (p = 0.001) and plot elevation (p = 0.06), were related to community composition. Similar to other TFFWs along the northern Gulf of Mexico, forests closest to Mobile Bay exhibited lower basal areas, species density, diversity, and a higher proportion of visually stressed individual canopy trees compared to those in the upper tidal reach. Results indicate a strong tidal influence on forest composition, structure, and community-level responses.
Citation: Forests
PubDate: 2024-08-03
DOI: 10.3390/f15081359
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1360: How Is It Covered'—A Global
Perspective on Teaching Themes and Perceived Gaps and Availability of
Resources in University Forestry Education
Authors: Konsta Wilenius, Mika Rekola, Anne Nevgi, Niclas Sandström
First page: 1360
Abstract: Forest education has evolved significantly in recent decades due to global phenomena such as climate change and globalization, which are transforming the skill sets and competencies that should be provided by university-level education on forests. This evolution has placed pressure on educational institutions to adapt and meet these emerging needs. Previous research has identified gaps in the coverage of specific teaching topics within forest education, yet assessing the global state of education has been challenging because of the absence of comparable data. To address this gap, the Global Forest Education Project was initiated in 2020. The project developed a survey aimed at evaluating the state of forest education across all levels worldwide. In this study, we used data from this survey and conducted an analysis focusing on the perceived adequacy of teaching content and the availability of educational resources at the university level. The study revealed global concerns regarding the comprehensive coverage of the various teaching themes. Although there was some variation in coverage across different regions, the trends appeared to be consistent globally. The perceived availability of resources for education varied significantly by region, including factors that likely impede the ability of educational programs to modernize and meet new educational requirements. These findings indicate that there is a need to reevaluate and improve the coverage of many of the teaching themes in forest education. Moreover, it is evident that education providers in certain regions require increased funding to ensure sufficient resources to address these needs efficiently.
Citation: Forests
PubDate: 2024-08-03
DOI: 10.3390/f15081360
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1361: Current and Future Insect Threats to Oaks of
the Midwest, Great Lakes, and Northeastern United States and Canada
Authors: Amanda J. Stump, Katie Bershing, Tara L. Bal, Carsten Külheim
First page: 1361
Abstract: Increasing temperatures, prolonged drought, the increased severity and intensity of storms, and other effects of climate change are being felt globally, and long-lived forest tree species may struggle in their current ranges. Oaks (Quercus spp.) have evolved a range of adaptations to dry and hot conditions and are believed to be a “climate change winner” by increasing their suitable habitat. However, a mixture of life history traits and increasing susceptibility to herbivores and xylovores as well as secondary pathogen infections still put oaks at risk of decline. Oak species found in the Midwestern, Great Lakes, and Northeastern United States and Canada are important keystone species with high ecological and economical importance. They are also vulnerable to existing, new, and emerging threats that have the potential to cause mortality across entire stands quickly. Current examples of insect threats include the Lymantria dispar (spongy moth), Agrilus bilineatus (twolined chestnut borer), and Nitidulidae (sap beetles) as disease vectors. Examples of emerging insects of concern include Cynipidae (oak gall wasps) and Enaphalodes rufulus (red oak borer). This study describes these insects, explains their mechanisms of action and the effects on oaks, and explores mitigation strategies for each.
Citation: Forests
PubDate: 2024-08-04
DOI: 10.3390/f15081361
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1362: Flame-Retardant Coating on Wood Surface by
Natural Biomass Polyelectrolyte via a Layer-by-Layer Self-Assembly
Approach
Authors: Mengyun Weng, Yanchun Fu, Wei Xu
First page: 1362
Abstract: In this study, environmentally friendly and low-cost biomass materials were selected as wood flame retardants. Three polyelectrolyte flame-retardant coatings made from chitosan (CS), tea polyphenols (TP), soybean isolate protein (SPI), and banana peel powder (BBP) were constructed on wood surfaces by layer-by-layer (LBL) self-assembly. The results of SEM-EDS and FT-IR analyses confirmed the successful deposition of CS-TP, CS-SPI, and CS-BPP on the wood surface, and the content of N element increased. The TG results showed that the initial decomposition temperature and the maximum thermal decomposition temperature of the coated wood specimens decreased, while the char residue increased significantly. This is due to the earlier pyrolysis of CS-TP, CS-SPI, and CS-BBP. This shows that the three polyelectrolyte flame-retardant coatings can improve the thermal stability of wood. The combustion behavior of the wood specimen was observed by exposure to combustion; the coated wood could self-extinguish within a certain period of time after ignition, and the flame-retardant performance was improved to a certain extent. SEM and EDS characterization analyses of the carbon residue after combustion showed that the coated wood charcoal layer was denser, which could effectively block heat and combustible gas.
Citation: Forests
PubDate: 2024-08-04
DOI: 10.3390/f15081362
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1363: Spatial and Temporal Variations of
Vegetation Phenology and Its Response to Land Surface Temperature in the
Yangtze River Delta Urban Agglomeration
Authors: Yi Yang, Lei Yao, Xuecheng Fu, Ruihua Shen, Xu Wang, Yingying Liu
First page: 1363
Abstract: In the Yangtze River Delta urban agglomeration, which is the region with the highest urbanization intensity in China, the development of cities leads to changes in land surface temperature (LST), while vegetation phenology varies with LST. To investigate the spatial and temporal changes in vegetation phenology and its response to LST in the study area, this study reconstructed the time series of the enhanced vegetation index (EVI) based on the MODIS EVI product and extracted the vegetation phenology indicators in the study area from 2002 to 2020, including the start of the growing season (SOS), the end of the growing season (EOS), and the growing season length (GSL), and analyzed the temporal–spatial patterns of vegetation phenology and LST in the study area, as well as the correlation between them. The results show that (1) SOS was advanced, EOS was postponed, and GSL was extended in the study area from 2002 to 2020, and there were obvious differences in the vegetation phenology indicators under different land covers and cities; (2) LST was higher in the southeast than in the northwest of the study area from 2002 to 2020, with an increasing trend; and (3) there are differences in the response of vegetation phenology to LST across land covers and cities, and SOS responds differently to LST at different times of the year. EOS shows a significant postponement trend with the annual mean LST increase. Overall, we found differences in vegetation phenology and its response to LST under different land covers and cities, which is important for scholars to understand the response of vegetation phenology to urbanization.
Citation: Forests
PubDate: 2024-08-04
DOI: 10.3390/f15081363
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1364: Fungal–Plant Interactions: Latest
Advances and Prospects
Authors: Ying-Ning Zou, Xian-An Xie, Qiang-Sheng Wu
First page: 1364
Abstract: During the evolution of higher plants, many microorganisms evolve alongside them, creating a synergistic plant–microbe world [...]
Citation: Forests
PubDate: 2024-08-05
DOI: 10.3390/f15081364
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1365: Prediction of Bonding Strength of
Heat-Treated Wood Based on an Improved Harris Hawk Algorithm Optimized BP
Neural Network Model (IHHO-BP)
Authors: Yan He, Wei Wang, Ying Cao, Qinghai Wang, Meng Li
First page: 1365
Abstract: In this study, we proposed an improved Harris Hawks Optimization (IHHO) algorithm based on the Sobol sequence, Whale Optimization Algorithm (WOA), and t-distribution perturbation. The improved IHHO algorithm was then used to optimize the BP neural network, resulting in the IHHO-BP model. This model was employed to predict the bonding strength of heat-treated wood under varying conditions of temperature, time, feed rate, cutting speed, and grit size. To validate the effectiveness and accuracy of the proposed model, it was compared with the original BP neural network model, WOA-BP, and HHO-BP benchmark models. The results showed that the IHHO-BP model reduced the Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and Mean Absolute Percentage Error (MAPE) by at least 51.16%, 40.38%, and 51.93%, respectively, while increasing the coefficient of determination (R2) by at least 10.85%. This indicates significant model optimization, enhanced generalization capability, and higher prediction accuracy, better meeting practical engineering needs. Predicting the bonding strength of heat-treated wood using this model can reduce production costs and consumption, thereby significantly improving production efficiency.
Citation: Forests
PubDate: 2024-08-05
DOI: 10.3390/f15081365
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1366: Evaluation of Tolerance and Selection of
Heat-Tolerant Woody Plants against Heat Stress
Authors: Dong Jin Park, Seong Hyeon Yong, Do Hyun Kim, Kwan Been Park, Seung A. Cha, Ji-Hyun Lee, Seon A. Kim, Myung Suk Choi
First page: 1366
Abstract: Heat-tolerant species have become increasingly important because of climate change; however, a selection system for woody plants is not well established. This study was conducted to establish a selection system for heat-tolerant woody plant species and to select heat-tolerant species. After selecting heat-tolerant woody plants and applying heat stress to 27 species, the electrolyte leakage index (ELI) was measured. The ELI of the heat-tolerant species was lower than that of the non heat-tolerant species, and they survived well after heat stress treatment. For the preselected species, the degree of cell death was measured by Evans blue staining method, and the heat stress recovery ability was measured by a 3,3′-diaminobenzidine (DAB) staining method. The species showed less cell death even after heat treatment, and oxidative stress was low after recovery from heat stress. Traditional screening methods are mainly performed through field screening; however, this is difficult because it requires many samples and considerable time. The results of this study are relatively rapid, reproducible, and highly sensitive, so it is judged to be a method that can complement the existing traditional method as a heat-tolerant plant selection system. The results of this study can be widely used for the selection and breeding of heat-tolerant plants in preparation for climate change.
Citation: Forests
PubDate: 2024-08-05
DOI: 10.3390/f15081366
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1367: Seasonal Variations in Hydraulic Regulation
of Whole-Tree Transpiration in Mongolian Pine Plantations: Insights from
Semiarid Deserts in Northern China
Authors: Jifeng Deng, Longyan Wan, Yanfeng Bao, Minghan Yu, Qingbin Jia
First page: 1367
Abstract: Seasonal precipitation variance significantly alters soil water content, potentially inducing water stress and affecting plant transpiration in semiarid deserts. This study explored the effects of environmental variables and hydraulic conductance on whole-tree transpiration (ET) in Mongolian pines (Pinus sylvestris var. mongolica) across different forest stages in the semiarid deserts of Northern China. We measured ET using sap flow in mature (MMP), half-mature (HMP), and young (YMP) Mongolian pine plantations. Measurements included soil-leaf water potential difference (ΔΨ), atmospheric conditions, and soil moisture contents on sunny days, both in dry and wet periods. Seasonally variable rainfall distinctly affected soil moisture; during the dry periods, both stomatal and hydraulic conductance influenced ET, whereas stomatal conductance primarily regulated it during the wet periods. Discrepancies between predicted and measured ET were noticed: compared to the predicted ET, the measured ET was lower during dry periods while higher during wet periods. Hydraulic conductance (KT) increased with tree height (H) and ΔΨ. The KT values in the dry period were lower than those in the wet period, indicating that the hydraulic resistance in the dry period was higher. The hydraulic compensation occurred and was observed between 11:00 and 13:00, aligned with increased hydraulic resistance during dry periods. Decreasing hydraulic conductance intensified leaf water stress in dry periods, especially when photosynthetically active radiation (PAR) and vapor pressure deficit (VPD) were heightened, potentially increasing stomatal sensitivity to drought, promoting water conservation and plant survival. A linear relationship between predawn and midday leaf water potentials was noticed, indicating extreme anisohydric behavior across forest stages during dry and wet periods. Although stomatal and hydraulic conductance influenced ET during the dry period, MMP and YMP were more susceptible to drought conditions. Understanding these dynamics could help evaluate semiarid desert ecological functions for water conservation amidst uneven seasonal precipitation in Northern China.
Citation: Forests
PubDate: 2024-08-06
DOI: 10.3390/f15081367
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1368: Interference Effect of Tree Spacing on
Natural Volatile Organic Compound Concentrations Measured Using Passive
Samplers
Authors: Doyun Song, Jae Hyoung Cho, SangTae Lee, Sujin Park, Geonwoo Kim
First page: 1368
Abstract: Research highlights: The increasing rates of mental health disorders during the COVID-19 pandemic have popularized the notion of access to natural environments as a solution, leading to a surge in demand for urban green spaces. The concentration of natural volatile organic compounds (NVOCs) in forests, resulting from plant metabolism, plays a crucial role in forest-based healing and ecosystem health. Background and objectives: This study aimed to investigate how tree spacing influences NVOC concentrations within forest ecosystems using passive samplers, thereby enhancing the understanding of optimal forest management practices to promote human health benefits. Methods: We employed passive samplers to investigate tree spacing effects on NVOC concentrations. We placed passive samplers among trees in the study area to measure NVOC concentrations in individual trees and analyzed the relationship between NVOC concentration and tree spacing and structure. Results: A multiple regression analysis using distance decay models showed that a tree spacing of 2.7–3 m had a significant impact on NVOC concentrations. These findings provide a better understanding of how tree structure, tree spacing, and microclimate within the forest influence NVOC concentration. Conclusion: These findings have important implications for forest management and the design of forest landscapes to promote human health and well-being by considering the spatial distribution of NVOC concentrations.
Citation: Forests
PubDate: 2024-08-06
DOI: 10.3390/f15081368
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1369: Mechanical Resistance to Penetration for
Improved Diagnosis of Soil Compaction at Grazing and Forest Sites
Authors: Luis Eduardo Akiyoshi Sanches Suzuki, Dalvan José Reinert, Clenio Nailto Pillon, José Miguel Reichert
First page: 1369
Abstract: Penetrometers and penetrographers are widely used to measure soil resistance to penetration, but the results are associated with other soil properties (such as bulk density, water content, and particle size distribution). Thus, for an adequate interpretation of results, site-specific studies are necessary to identify which properties are more related to soil resistance. We aimed to measure the resistance to penetration of a Typic Paleudalf under distinct soil uses and to identify soil properties that influence soil resistance. The soil uses in this study included anthropized forest (composed of tree and shrub species), pasture (5-year-old pasture), Eucalyptus 20 (a 20-year-old Eucalyptus saligna stand), and Eucalyptus 4.5 (a 4.5-year-old Eucalyptus saligna under the second rotation). Soil resistance to penetration was measured with an impact penetrometer, and the data were correlated with other physical and mechanical properties of soil, such as the particle size, soil moisture, air permeability, saturated hydraulic conductivity, porosity, bulk density, precompression stress, and compressibility index. We observed that a resistance of 1.3 MPa matches with other soil property values corresponding to soil compaction, and values greater than 1.3 MPa were verified at depths of 0–8 cm for pasture and 8–30 cm for Eucalyptus 4.5. Analyzing all soil uses together, the correlation was significant (p < 0.05) with gravel (r = 0.34), silt (r = −0.32), clay (r = 0.26), gravimetric moisture (r = −0.27), macroporosity (r = 0.24), and soil bulk density at the end of the compressibility test (r = 0.27). The penetrometer is useful for evaluating the physical conditions of soil, but we highlight that soil resistance is influenced by factors such as particle size and soil moisture, as examples. We recommend using a set of soil properties for a better interpretation of penetration resistance data and to support decision-making regarding soil management.
Citation: Forests
PubDate: 2024-08-06
DOI: 10.3390/f15081369
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1370: Effects of Heat Treatment on the Chemical
Composition and Microstructure of Cupressus funebris Endl. Wood
Authors: Jianhua Lyu, Jialei Wang, Ming Chen
First page: 1370
Abstract: The effects of heat treatment on Cupressus funebris Endl. wood were examined under different combinations of temperature, time, and pressure. The chemical composition, crystallinity, and microstructure of heat-treated wood flour and specimens were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Vacuum heat treatment led to changes in the functional groups and microstructure of C. funebris wood, and the relative lignin content decreased with increasing treatment temperature, which was significant at lower negative pressures. Cellulose crystallinity showed a change rule of first increasing and then decreasing throughout the heat treatment range, and the relative crystallinity ranged from 102.46% to 116.39%. The cellulose treated at 120 °C for 5 h at 0.02 MPa had the highest crystallinity of 44.65%. These results indicate that although heat treatment can improve cellulose crystallinity, very high temperatures can lead to decreased crystallinity. The morphology and structure of the cell wall remained stable throughout the heat treatment range; however, at elevated temperatures, slight deformation occurred, along with rupture of the intercellular layer.
Citation: Forests
PubDate: 2024-08-06
DOI: 10.3390/f15081370
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1371: Constructing and Validating Estimation
Models for Individual-Tree Aboveground Biomass of Salix suchowensis in
China
Authors: Wei Fu, Chaoyue Niu, Chuanjing Hu, Peiling Zhang, Yingnan Chen
First page: 1371
Abstract: Biomass serves as a crucial indicator of plant productivity, and the development of biomass models has become an efficient way for estimating tree biomass production rapidly and accurately. This study aimed to develop a rapid and accurate model to estimate the individual aboveground biomass of Salix suchowensis. Growth parameters, including plant height (PH), ground diameter (GD), number of first branches (NFB), number of second branches (NSB) and aboveground fresh biomass weight (FW), were measured from 892 destructive sample trees. Correlation analysis indicated that GD had higher positive correlations with FW than PH, NFB and NSB. According to the biological features and field observations of S. suchowensis, the samples were classified into three categories: single-stemmed type, first-branched type and second-branched type. Based on the field measurement data, regression models were constructed separately between FW and each growth trait (PH, GD, NFB and NSB) using linear and nonlinear regression functions (linear, exponential and power). Then, multiple power regression and multiple linear regression were conducted to estimate the fresh biomass of three types of S. suchowensis. For the single-stemmed plant type, model M1 with GD as the single parameter had the highest adj R2, outperforming the other models. Among the 16 constructed biomass-estimating equations for the first-branched plant type, model M32 FW = 0.010371 × PH1.15862 × GD1.250581 × NFB0.190707 was found to have the best fit, with the highest coefficient of determination (adj R2 = 0.6627) and lowest Akaike Information Criterion (AIC = 5997.3081). When it comes to the second-branched plant type, the best-fitting equation was proved to be the multiple power model M43 with PH, GD, NFB and NSB as parameters, which had the highest adj R2 value and best-fitting effect. The stability and reliability of the models were confirmed by the F-test, repeated k-fold cross-validation and paired-sample t-tests. The models developed in this study could provide efficient tools for accurately estimating the total aboveground biomass for S. suchowensis at individual tree levels. The results of this study could also be useful for optimizing the economic productivity of shrub willow plantations.
Citation: Forests
PubDate: 2024-08-06
DOI: 10.3390/f15081371
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1372: Reduction and Reuse of Forestry and
Agricultural Bio-Waste through Innovative Green Utilization Approaches: A
Review
Authors: Jianhui Guo, Yi Zhang, Jianjun Fang, Ziwei Ma, Cheng Li, Mengyao Yan, Naxin Qiao, Yang Liu, Mingming Bian
First page: 1372
Abstract: Biomass waste, which is biodegradable and vastly underutilized, is generated in huge quantities worldwide. Forestry and agricultural biomass wastes are notable for their wide availability, high yield, biodegradability, and recyclability. The accumulation of these wastes not only occupies valuable land but causes serious environmental pollution, which can ultimately harm human health. Therefore, leveraging scientific technology to convert forestry and agricultural bio-waste into bioenergy and other valuable products is crucial. In this paper, common forestry and agricultural bio-waste such as straw, rice husks, livestock manure, tree branches, sawdust, and bioenergy (bioethanol, biogas, biodiesel, biohydrogen) were selected as keywords, with the theme of green and efficient utilization. This paper provides a comprehensive review of the sources of biomass waste, existing recycling technologies, and the potential of forestry and agricultural bio-waste as material additives and for conversion to biomass energy and other derivatives, along with future recycling prospects.
Citation: Forests
PubDate: 2024-08-06
DOI: 10.3390/f15081372
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1373: Thermal–Acoustic Interaction Effects
on Physiological and Psychological Measures in Urban Forests: A Laboratory
Study
Authors: Ye Chen, Taoyu Li, Shaoyou Chen, Hangqing Chen, Yuxiang Lan
First page: 1373
Abstract: The environment in which people live is a complex system influenced by multiple factors interacting with each other, and therefore, it is crucial to deeply explore the influences of various factors on environmental perception. Among the numerous factors affecting the experience of urban forests visits, the thermal–acoustic environment stands out prominently. This study focuses on urban forests located in subtropical regions, with specific research conducted in the Xihu Park in Fuzhou, China. The study explores the thermal–acoustic interaction in urban forest environments. A total of 150 participants evaluated the perception of sound, thermal sensation, and overall perception through laboratory experiments, with 36 of them having their objective physiological indicators monitored. Different levels of sound and temperature were selected for the experiments, with three levels for each type of sound. Our results show that increasing temperature enhanced the perceived loudness of sound, especially when the environment was quiet. Sound type and loudness had a significant impact on thermal sensation, but no interaction was observed with temperature. Moreover, we found that certain sounds could improve overall comfort, and the effect was most evident at moderate loudness. Temperature had a significant influence on both comfort and annoyance, with increasing temperature leading to higher annoyance. These findings provide important insights into how the interplay between sound and heat affects human perception and emotional state, providing scientific guidance for the design of more human-centered environments.
Citation: Forests
PubDate: 2024-08-06
DOI: 10.3390/f15081373
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1374: Assessment of Trees’ Structural
Defects via Hybrid Deep Learning Methods Used in Unmanned Aerial Vehicle
(UAV) Observations
Authors: Qiwen Qiu, Denvid Lau
First page: 1374
Abstract: Trees’ structural defects are responsible for the reduction in forest product quality and the accident of tree collapse under extreme environmental conditions. Although the manual view inspection for assessing tree health condition is reliable, it is inefficient in discriminating, locating, and quantifying the defects with various features (i.e., crack and hole). There is a general need for investigation of efficient ways to assess these defects to enhance the sustainability of trees. In this study, the deep learning algorithms of lightweight You Only Look Once (YOLO) and encoder-decoder network named DeepLabv3+ are combined in unmanned aerial vehicle (UAV) observations to evaluate trees’ structural defects. Experimentally, we found that the state-of-the-art detector YOLOv7-tiny offers real-time (i.e., 50–60 fps) and long-range sensing (i.e., 5 m) of tree defects but has limited capacity to acquire the patterns of defects at the millimeter scale. To address this limitation, we further utilized DeepLabv3+ cascaded with different network architectures of ResNet18, ResNet50, Xception, and MobileNetv2 to obtain the actual morphology of defects through close-range and pixel-wise image semantic segmentation. Moreover, the proposed hybrid scheme YOLOv7-tiny_DeepLabv3+_UAV assesses tree’s defect size with an averaged accuracy of 92.62% (±6%).
Citation: Forests
PubDate: 2024-08-06
DOI: 10.3390/f15081374
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1375: YOLOTree-Individual Tree Spatial Positioning
and Crown Volume Calculation Using UAV-RGB Imagery and LiDAR Data
Authors: Taige Luo, Shuyu Rao, Wenjun Ma, Qingyang Song, Zhaodong Cao, Huacheng Zhang, Junru Xie, Xudong Wen, Wei Gao, Qiao Chen, Jiayan Yun, Dongyang Wu
First page: 1375
Abstract: Individual tree canopy extraction plays an important role in downstream studies such as plant phenotyping, panoptic segmentation and growth monitoring. Canopy volume calculation is an essential part of these studies. However, existing volume calculation methods based on LiDAR or based on UAV-RGB imagery cannot balance accuracy and real-time performance. Thus, we propose a two-step individual tree volumetric modeling method: first, we use RGB remote sensing images to obtain the crown volume information, and then we use spatially aligned point cloud data to obtain the height information to automate the calculation of the crown volume. After introducing the point cloud information, our method outperforms the RGB image-only based method in 62.5% of the volumetric accuracy. The AbsoluteError of tree crown volume is decreased by 8.304. Compared with the traditional 2.5D volume calculation method using cloud point data only, the proposed method is decreased by 93.306. Our method also achieves fast extraction of vegetation over a large area. Moreover, the proposed YOLOTree model is more comprehensive than the existing YOLO series in tree detection, with 0.81% improvement in precision, and ranks second in the whole series for mAP50-95 metrics. We sample and open-source the TreeLD dataset to contribute to research migration.
Citation: Forests
PubDate: 2024-08-06
DOI: 10.3390/f15081375
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1376: Long-Term Planting of Taxodium Hybrid
‘Zhongshanshan’ Can Effectively Enhance the Soil Aggregate
Stability in Saline–Alkali Coastal Areas
Authors: Xiaoshu Niu, Xin Liu, Tao Li, Jie Lin, Shenghua Qin, Fulin Jing, Xiang Zhang, Jinchi Zhang, Jiang Jiang
First page: 1376
Abstract: Not enough research has been conducted on the mechanisms influencing the stability of soil aggregates in coastal saline–alkaline soil and the dynamic changes in aggregates in the succession process of coastal saline–alkaline soil brought on by longer planting times. In this study, soil aggregate composition, stability, and influencing factors of 0–20 cm, 20–40 cm, and 40–60 cm soil layers in different planting time stages were analyzed in the reclaimed land at the initial stage of afforestation and the Taxodium hybrid ‘Zhongshanshan’ plantation with planting times of 6, 10, 17, and 21 years. The results show that, with the increase in planting time, the aggregate stability of the plantation increased significantly. In the 0–20 cm soil layer, the geometric mean diameter (GMD) and aggregate size >0.25 mm (R0.25) increased by 81.15% and 89.80%, respectively, when the planting time was 21 years, compared with the reclaimed land. The structural equation (SEM) showed that planting time had a direct positive effect (path coefficient 0.315) on aggregate stability. However, soil sucrase (0.407) and β-glucosidase (0.229) indirectly improved the stability of aggregates by affecting soil organic carbon. In summary, the establishment of Taxodium hybrid ‘Zhongshanshan’ plants on coastal saline–alkali land is beneficial for stabilizing soil aggregates, improving soil structure, and boosting soil quality. Long-term planting of Taxodium hybrid ‘Zhongshanshan’ can be an effective measure for ecological restoration in this region.
Citation: Forests
PubDate: 2024-08-06
DOI: 10.3390/f15081376
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1377: Genetic Diversity and Population Structural
Analysis Reveal the Unique Genetic Composition of Populus tomentosa Elite
Trees
Authors: Bo Kong, Lexun Ma, Jiahua Du, Pingdong Zhang
First page: 1377
Abstract: Genetic diversity analysis provides the scientific basis for the preservation, evaluation, and utilization of the germplasm resources of tree species. We explored the genetic diversity and structure of Populus tomentosa elite trees in North China using 13 nuclear microsatellite markers. We compared nine groups of accessions including 20 originating from Beijing (BJ), 122 from Hebei (HB), 20 from Shandong (SD), 113 from Henan (HN), 270 from Shanxi (SX), 54 from Shaanxi (SAX), 8 from Gansu (GS), 10 from Anhui (AH), and 6 from Jiangsu (JS). All of the studied primer pairs were polymorphic and generated 125 alleles. Analyses of molecular variance revealed that 79%, 14%, and 8% of the total variation was due to variations within the individual, among individuals, and among populations, respectively. Based on principal coordinate and STRUCTURE cluster analyses, individuals distributed in the southern region (HN, SAX, AH, and JS) were roughly classified into one group, while those distributed in the northeastern region (BJ, HB, and SD) and northwestern regions (SX) were separately divided into one group each. Moreover, the northwestern region included two-thirds of the SX trees, and the remainder were in the northeast region. By analyzing genetic diversity and structure within populations, individuals with different genetic backgrounds were screened for constituent training populations (TRS), including broad allelic variation for related traits. This ensures that the genomic prediction model can accurately capture genetic effects and provide reliable predictions across a broad spectrum of genetic backgrounds. Therefore, our results will benefit genome breeding technology.
Citation: Forests
PubDate: 2024-08-07
DOI: 10.3390/f15081377
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1378: Increased Saprotrophic Activity and
Phosphate Leaching Following Forest Soil Decomposition without Root Access
Authors: Karolina Tahovská, Michal Choma, Petr Čapek, Eva Kaštovská, Jiří Kaňa, Jiří Kopáček
First page: 1378
Abstract: By incubating the soil without living roots in situ at two spruce forest sites, we simulated the effects of tree dieback and interrupted mycorrhizal associations following forest disturbance on the soil microbiome and phosphorus leaching. We observed the retreat of ectomycorrhizal fungi and increased proportion of saprotrophs without changes in community richness and the Shannon diversity index. This was accompanied by a pronounced decomposition of organic matter, associated with an increased activity of carbon-mining hydrolases and acid phosphatase. The nonexistent phosphorus uptake and immobilization by ectomycorrhizal associations led to its substantial increase in the soil, in the labile fractions, such as microbial biomass and water-soluble reactive phosphorus, but also in the fraction bound to organometallics (extractable by oxalate), and caused considerable phosphate leaching, as estimated using ion-exchange resin traps. The results show that the retreat of the root-specific environment, characterized by the input of available carbon and effective nutrient uptake and by the specific microbiome, has profound effects on phosphorus dynamics and loss. Furthermore, we suggest that ectomycorrhiza plays an equally important role in controlling phosphorus-mining from organic matter and subsequent immobilization and/or leaching from soils concurrently to its known role in nitrogen cycling and immobilization in spruce forests.
Citation: Forests
PubDate: 2024-08-07
DOI: 10.3390/f15081378
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1379: Detection of Viruses in Special Stands of
Common Ash Reveals Insights into the Virome of Fraxinus excelsior
Authors: Marius Rehanek, Rim Al Kubrusli, Kira Köpke, Susanne von Bargen, Carmen Büttner
First page: 1379
Abstract: Plant diseases are mostly multicausal with several factors influencing the health status of affected hosts. Common ash (Fraxinus excelsior), a significant tree species of European forests, is currently mostly endangered by ash dieback, caused by the invasive fungus Hymenoscyphus fraxineus. However, contributing factors, including pathogenic viruses, are poorly understood. Here, we report the results of a virus screening conducted on selected special stands of F. excelsior. Over three consecutive years, ash trees from different origins were tested, including leaf material from mature seed trees, young trees and ash seedlings from the natural regeneration. Using RT-PCR, we screened for five viruses, including the generalist species ArMV (Nepovirus arabis) and CLRV (Nepovirus avii), as well as newly discovered viruses in ash, including the emaravirus ASaV (Emaravirus fraxini), the idaeovirus PrLBaV (Idaeovirus ligustri), and cytorhabdoviruses. The results revealed a high virus diversity in common ash. An association of ASaV detection with specific leaf symptoms, including shoestring, chlorotic ringspots, and vein yellowing, was documented. An analyses of relevant gene products of cytorhabdoviruses obtained from ashes of different sites revealed sequence diversities and two distinct phylogenetic groups present in ash populations. Signatures of novel viruses from different families have been identified by high-throughput sequencing. Together, our results provide insights into the virus diversity and distribution of viruses in ash and expand our knowledge about the virome of this endangered tree species.
Citation: Forests
PubDate: 2024-08-07
DOI: 10.3390/f15081379
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1380: Utilizing Deep Learning and Spatial Analysis
for Accurate Forest Fire Occurrence Forecasting in the Central Region of
China
Authors: Youbao Guo, Quansheng Hai, Sainbuyan Bayarsaikhan
First page: 1380
Abstract: Forest fires in central China pose significant threats to ecosystem health, public safety, and economic stability. This study employs advanced Geographic Information System (GIS) technology and Convolutional Neural Network (CNN) models to comprehensively analyze the factors driving the occurrence of these fire events. A predictive model for forest fire occurrences has been developed, complemented by targeted zoning management strategies. The key findings are as follows: (i) Spatial analysis reveals substantial clustering and spatial autocorrelation of fire points, indicating high-density areas of forest fire occurrence, primarily in Hunan and Jiangxi provinces, as well as the northeastern region. This underscores the need for tailored fire prevention and management approaches. (ii) The forest fire prediction model for the central region demonstrates exceptional accuracy, reliability, and predictive power. It achieves outstanding performance metrics in both training and validation sets, with an accuracy of 86.00%, precision of 88.00%, recall of 87.00%, F1 score of 87.50%, and an AUC value of 90.50%. (iii) Throughout the year, the occurrence of forest fires in central China varies by location and season. Low-occurrence periods are observed in summer and winter, particularly in Hunan and Hubei provinces, due to moderate weather conditions, agricultural practices, and reduced outdoor activities. However, spring and autumn also present localized risks due to uneven rainfall and dry climates. This study provides valuable insights into the dynamics of forest fire occurrences in central China, offering a solid framework for proactive fire management and policy formulation to effectively mitigate the impacts of these events.
Citation: Forests
PubDate: 2024-08-07
DOI: 10.3390/f15081380
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1381: Disentangling the Spatiotemporal Dynamics,
Drivers, and Recovery of NPP in Co-Seismic Landslides: A Case Study of the
2017 Jiuzhaigou Earthquake, China
Authors: Yuying Duan, Xiangjun Pei, Jing Luo, Xiaochao Zhang, Luguang Luo
First page: 1381
Abstract: The 2017 Jiuzhaigou earthquake, registering a magnitude of 7.0, triggered a series of devastating geohazards, including landslides, collapses, and mudslides within the Jiuzhaigou World Natural Heritage Site. These destructive events obliterated extensive tracts of vegetation, severely compromising carbon storage in the terrestrial ecosystems. Net Primary Productivity (NPP) reflects the capacity of vegetation to absorb carbon dioxide. Accurately assessing changes in NPP is crucial for unveiling the recovery of terrestrial ecosystem carbon storage after the earthquake. To this end, we designed this study using the Moderate Resolution Imaging Spectroradiometer (MODIS) Net Primary Productivity datasets. The findings are as follows. NPP in the co-seismic landslide areas remained stable between 525 and 575 g C/m2 before the earthquake and decreased to 533 g C/m2 after the earthquake. This decline continued, reaching 483 g C/m2 due to extreme rainfall events in 2018, 2019, and 2020. Recovery commenced in 2021, and by 2022, NPP had rebounded to 544 g C/m2. The study of NPP recovery rate revealed that, five years after the earthquake, only 18.88% of the co-seismic landslide areas exhibited an NPP exceeding the pre-earthquake state. However, 17.14% of these areas had an NPP recovery rate of less than 10%, indicating that recovery has barely begun in most areas. The factor detector revealed that temperature, precipitation, and elevation significantly influenced NPP recovery. Meanwhile, the interaction detector highlighted that lithology, slope, and aspect also played crucial roles when interacting with other factors. Therefore, the recovery of NPP is not determined by a single factor, but rather by the interactions among various factors. The ecosystem resilience study demonstrated that the current recovery of NPP primarily stems from the restoration of grassland ecosystems. Overall, while the potential for NPP recovery in co-seismic landslide areas is optimistic, it will require a considerable amount of time to return to the pre-earthquake state.
Citation: Forests
PubDate: 2024-08-07
DOI: 10.3390/f15081381
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1382: Effects of Mixing Hippophae rhamnoides and
Pinus tabuliformis on Ecosystem Carbon, Nitrogen, and Phosphorus
Sequestration and Storage Capacity in the Loess Hilly Region, China
Authors: Wenwei Yu, Rumeng Jiang, Xiaolan Wei, Xinlong Luan, Yueyan Chen, Baohong Ma, Xu Wu, Yaobin Niu, Yunming Chen
First page: 1382
Abstract: Mixed forests created by incorporating nitrogen-fixing tree species offer enhanced ecological advantages compared with forests consisting of only one type of tree species. These benefits include habitat rehabilitation and the promotion of biodiversity. Nevertheless, the impact of introducing nitrogen-fixing tree species on ecosystem carbon (C), nitrogen (N), and phosphorus (P) sequestration and storage capacity in the Loess Plateau of China remains inadequately explored. To examine changes in the sequestration and storage capacity of ecosystem C, N, and P, the mixed plantations of P. tabulaeformis and H. rhamnoides (HrPt) were selected as the research object, and the pure plantations of H. rhamnoides (Hr) and P. tabulaeformis (Pt) were selected as the control. The results indicated that in comparison to the pure forest, the ecosystem in HrPt significantly increased C and N stocks but decreased P stocks. In addition, C, N, and P stocks in the soil layer accounted for more than 60% of the C, N, and P stocks in the pure and mixed forest ecosystems compared with the vegetation layer. Moreover, HrPt significantly improved ecosystem C and N sequestration rates relative to the pure forest but decreased P sequestration rates. Furthermore, the soil physicochemical properties can be inferred from the redundancy analysis showing 66.79% and 0.06% in Hr, 44.84% and 0.06% in Pt, as well as 44.28% and 0.04% in HrPt, respectively. In conclusion, compared with the pure forest, the introduction of N-fixing tree species was more conducive to the accumulation of C and N. The results offer substantial significance for the scientific guidance of vegetation restoration in degraded landscapes and the stewardship of mixed forests in the Loess Hilly Region, providing essential data for nutrient storage in ecosystems.
Citation: Forests
PubDate: 2024-08-07
DOI: 10.3390/f15081382
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1383: Inter- and Intra-Specific Variation in Leaf
Functional Traits at Different Maturity Levels in a Tropical Monsoon
Forest
Authors: Miaolan Wu, Yue Liu, Zhihang He, Xiaojuan Gu, Yaohong Yu, Yuzhu Tao, Qing Zhou, Qifeng Mo
First page: 1383
Abstract: Plant functional traits are an important indicator for the comprehensive evaluation of community stability and resilience. Therefore, exploring the variations and relationships among leaf functional traits at different maturity levels during forest restoration can deepen the understanding of plant adaptation strategies and community assembly. In this study, we measured the leaf area (LA), specific leaf area (SLA), photosynthetic pigments, non-structural carbohydrates (NSCs), leaf nitrogen content (LNC), and leaf phosphorus content (LPC) of dominant tree species in three communities with different maturity levels (defined by species composition, biodiversity and spatial structure) in a monsoon forest located in the northern margin of the tropics in China, and explored the variation and relationships among different leaf traits at individual, species, and community scales. The results showed that maturity levels significantly affected leaf functional traits. With the increase in maturity levels, SLA increased, and leaf SS and NSCs decreased, while other leaf functional traits did not show a consistent pattern. In different communities, NSCs, Chl (a:b), SS:St or Car had a trade-off or synergistic relationship with leaf economic spectrum. Additionally, the LPC, LNC, and starch were the key traits in response to selection pressure at maturity levels, inter-specific and intra-specific scales, respectively, and the trait–trait relationships were stronger or more extreme as the scale was narrowed. Therefore, when evaluating the development and succession of tropical monsoon forest communities, the selection of leaf functional characteristics and the determination of the research scale should be comprehensively and systematically considered.
Citation: Forests
PubDate: 2024-08-07
DOI: 10.3390/f15081383
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1384: Spatial–Temporal Changes in the
Distribution of Populus euphratica Oliv. Forests in the Tarim Basin and
Analysis of Influencing Factors from 1990 to 2020
Authors: Xuefei Guo, Lijun Zhu, Zhikun Yang, Chaobin Yang, Zhijun Li
First page: 1384
Abstract: Understanding the spatiotemporal evolution patterns of Populus euphratica Oliv. (P. euphratica) forests in the Tarim Basin (TB) and their influencing factors is crucial for regional ecological security and high-quality development. However, there is currently a lack of large-area, long-term systematic monitoring. This study utilized multi-source medium and high-resolution remote sensing images from the Landsat series and Sentinel-2, applying a Random Forest classification model to obtain distribution data of P. euphratica forests and shrublands in 14 areas of the TB from 1990 to 2020. We analyzed the effects of river distance, water transfer, and farmland on their distribution. Results indicated that both P. euphratica forests and shrublands decreased during the first 20 years and increased during the last 10 years. Within 1.5 km of river water transfer zones, P. euphratica forests more frequently converted to shrublands, while both forests and shrublands showed recovery in low-frequency water transfer areas. Farmland encroachment was most significant beyond 3 km from rivers. To effectively protect P. euphratica forests, we recommend intermittent low-frequency water transfers within 3 km of rivers and stricter management of agricultural expansion beyond 3 km. These measures will help maintain a balanced ecosystem and promote the long-term sustainability of P. euphratica forests.
Citation: Forests
PubDate: 2024-08-07
DOI: 10.3390/f15081384
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1385: Homogeneous Selection Mediated by Nitrate
Nitrogen Regulates Fungal Dynamics in Subalpine Forest Soils Subjected to
Simulated Restoration
Authors: Haijun Liao, Dehui Li, Chaonan Li
First page: 1385
Abstract: Subalpine forests provide crucial ecosystem services and are increasingly threatened by human alterations like bare-cut slopes from highway construction. External soil spray seeding (ESSS) is often employed to restore these slopes, but the cement it introduces can negatively affect soil fungi, which are vital for the ecological sustainability of restored slopes. Despite previous extensive discussions about ESSS-restored slopes, fungal dynamics and their underlying ecological mechanisms during ESSS-based restorations still remain elusive. Here, we conducted a 196-day simulation experiment using natural soils from a subalpine forest ecosystem. By using nuclear ribosomal internal transcribed spacer (ITS) sequencing, we revealed soil fungal dynamics and their ecological mechanisms during simulated ESSS-based restorations. Results showed a decline in fungal α-diversity and significant shifts in community structures from the initial day to day 46, followed by relative stabilities. These dynamics were mainly characterized by ectomycorrhizal, plant pathogenic, and saprotrophic fungi, with ectomycorrhizal fungi being depleted, while saprotrophic and pathogenic fungi showed enrichment over time. Shifts in nitrate nitrogen (NO− 3−N) content primarily regulated these dynamics via mediating homogeneous selections. High NO− 3−N levels at later stages (days 46 to 196, especially day 46) might exclude those poorly adapted fungal species, resulting in great diversity loss and community shifts. Despite reduced homogeneous selections and NO− 3−N levels after day 46, fungal communities did not show a recovery but continued to undergo changes compared to their initial states, suggesting the less resilient of fungi during ESSS-based restorations. This study highlights the need to manage soil NO− 3−N levels for fungal communities during ESSS-based restorations. It provides novel insights for maintaining the ecological sustainability of ESSS-restored slopes and seeking new restoration strategies for cut slopes caused by infrastructure in subalpine forests.
Citation: Forests
PubDate: 2024-08-07
DOI: 10.3390/f15081385
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1386: Xylogenesis Responses to a Mediterranean
Climate in Holm Oak (Quercus ilex L.)
Authors: Iqra Liyaqat, Angela Balzano, Francesco Niccoli, Jerzy Piotr Kabala, Maks Merela, Giovanna Battipaglia
First page: 1386
Abstract: Quercus ilex L., an evergreen oak species typical of the western and central Mediterranean basin, is facing decline and dieback episodes due to the increase in the severity and frequency of heat waves and drought events. Studying xylogenesis (the wood formation process) is crucial for understanding how trees respond with their secondary growth to environmental conditions and stress events. This study aimed to characterize the wood formation dynamics of Quercus ilex and their relationship with the meteorological conditions in an area experiencing prolonged drought periods. Cambial activity and xylem cell production were monitored during the 2019 and 2020 growing seasons in a Q. ilex forest located at the Vesuvius National Park (southern Italy). The results highlighted the significant roles of temperature and solar radiation in stimulating xylogenesis. Indeed, the correlation tests revealed that temperature and solar radiation positively influenced growth and cell development, while precipitation had an inhibitory effect on secondary wall formation. The earlier cell maturation in 2020 compared to 2019 underscored the impact of global warming trends. Overall, the trees studied demonstrated good health, growth and adaptability to local environmental fluctuations. This research provides novel insights into the intra-annual growth dynamics of this key Mediterranean species and its adaptation strategies to climatic variability, which will be crucial for forest management in the context of climate change.
Citation: Forests
PubDate: 2024-08-08
DOI: 10.3390/f15081386
Issue No: Vol. 15, No. 8 (2024)
- Forests, Vol. 15, Pages 1387: Influence of Salt Concentration and
Treatment Cycles on Nail-Holding Power in Dimension Lumber
Authors: Jia Lei, Jingkang Lin, Zhiyuan Chen, Shuke Jia, Youying Zi, Zeli Que
First page: 1387
Abstract: To rigorously analyze the effects of high-salt environments on dimension lumber and provide scientific and reliable data to facilitate the advancement of light-frame construction in such environments, this study subjected dimension lumber to salt solution treatment. The study investigated the trend of nail-holding power variations across the radial, tangential, and cross-sections of spruce–pine–fir (SPF) dimension lumber under varying salt concentrations and treatment durations. The experimental results exhibited a significant influence of salt on the nail-holding power across all sections of the SPF dimension lumber. As the concentration of salt solution increased, the holding power gradually decreased across all directions, exhibiting considerable differences across salinity gradients. Specifically, the radial and tangential sections exhibited a 15%–20% higher nail-holding power compared to the cross-section. An increase in the salt solution concentration above 3% corresponded to an approximate 1% decrement in nail-holding power per section for every 0.5% rise in concentration. Additionally, prolonged salt treatment initially resulted in an increase, followed by a subsequent decrease in nail-holding power, demonstrating a consistent pattern across all variations. Post hoc analyses confirmed that the differences between individual salt concentrations, including between 3.5%, 4%, and 4.5%, were statistically significant. These findings provide valuable data for understanding the degradation of timber connectors in high-salt environments, contributing to the development of more durable and resilient wood-frame buildings in such conditions.
Citation: Forests
PubDate: 2024-08-08
DOI: 10.3390/f15081387
Issue No: Vol. 15, No. 8 (2024)
