Subjects -> FORESTS AND FORESTRY (Total: 130 journals)
    - FORESTS AND FORESTRY (129 journals)
    - LUMBER AND WOOD (1 journals)

FORESTS AND FORESTRY (129 journals)                     

Showing 1 - 12 of 12 Journals sorted alphabetically
Acta Brasiliensis     Open Access  
Advance in Forestry Research     Open Access   (Followers: 7)
Advances in Forestry Science     Open Access   (Followers: 4)
Agrociencia     Open Access  
Agroforestry Systems     Open Access   (Followers: 15)
Annals of Forest Research     Open Access  
Annals of Forest Science     Open Access   (Followers: 5)
Annals of Silvicultural Research     Open Access  
Appita Journal: Journal of the Technical Association of the Australian and New Zealand Pulp and Paper Industry     Full-text available via subscription   (Followers: 6)
Arboricultural Journal : The International Journal of Urban Forestry     Hybrid Journal   (Followers: 6)
Artvin Çoruh Üniversitesi Orman Fakültesi Dergisi / Artvin Coruh University Journal of Forestry Faculty     Open Access  
Asian Journal of Forestry     Open Access   (Followers: 1)
Asian Journal of Research in Agriculture and Forestry     Open Access   (Followers: 1)
Australian Forest Grower     Full-text available via subscription   (Followers: 2)
Australian Forestry     Hybrid Journal   (Followers: 1)
Banko Janakari     Open Access  
Bartın Orman Fakültesi Dergisi / Journal of Bartin Faculty of Forestry     Open Access  
BIOFIX Scientific Journal     Open Access  
Bosque     Open Access   (Followers: 2)
Canadian Journal of Forest Research     Hybrid Journal   (Followers: 28)
Canadian Journal of Plant Science     Full-text available via subscription   (Followers: 11)
Central European Forestry Journal     Open Access   (Followers: 1)
Ciencia forestal en México     Open Access   (Followers: 1)
Colombia Forestal     Open Access   (Followers: 1)
Current Forestry Reports     Hybrid Journal   (Followers: 1)
Current Landscape Ecology Reports     Hybrid Journal   (Followers: 2)
Dissertationes Forestales     Open Access   (Followers: 1)
East African Agricultural and Forestry Journal     Hybrid Journal   (Followers: 1)
Eurasian Journal of Forest Science     Open Access  
European Journal of Forest Engineering     Open Access  
European Journal of Forest Research     Hybrid Journal   (Followers: 7)
Expert Opinion on Environmental Biology     Hybrid Journal  
Folia Forestalia Polonica. Seria A - Forestry     Open Access  
Forest Ecology and Management     Hybrid Journal   (Followers: 61)
Forest Ecosystems     Open Access   (Followers: 5)
Forest Pathology     Hybrid Journal   (Followers: 1)
Forest Policy and Economics     Hybrid Journal   (Followers: 21)
Forest Science     Hybrid Journal   (Followers: 8)
Forest Science and Technology     Open Access   (Followers: 2)
Forest@ : Journal of Silviculture and Forest Ecology     Open Access  
Foresta Veracruzana     Open Access  
Forestry : Journal of Institute of Forestry, Nepal     Open Access  
Forestry Chronicle     Full-text available via subscription   (Followers: 9)
Forestry Letters     Open Access   (Followers: 1)
Forestry Studies     Open Access  
Forestry: An International Journal of Forest Research     Hybrid Journal   (Followers: 14)
Forests     Open Access   (Followers: 2)
Forests, Trees and Livelihoods     Partially Free   (Followers: 4)
Frontiers in Forests and Global Change     Open Access   (Followers: 2)
Ghana Journal of Forestry     Full-text available via subscription   (Followers: 2)
iForest : Biogeosciences and Forestry     Open Access   (Followers: 3)
Indian Forester     Full-text available via subscription   (Followers: 3)
Indonesian Journal of Forestry Research     Open Access   (Followers: 1)
INNOTEC : Revista del Laboratorio Tecnológico del Uruguay     Open Access  
International Forestry Review     Full-text available via subscription   (Followers: 5)
International Journal of Agriculture and Forestry     Open Access   (Followers: 6)
International Journal of Agriculture, Forestry and Life Sciences     Open Access  
International Journal of Forest Engineering     Hybrid Journal   (Followers: 1)
International Journal of Forestry Research     Open Access   (Followers: 2)
Iranian Journal of Forest and Poplar Research     Open Access  
Journal of Agriculture, Forestry and the Social Sciences     Full-text available via subscription   (Followers: 5)
Journal of Biodiversity Management & Forestry     Hybrid Journal   (Followers: 4)
Journal of Bioresources and Bioproducts     Open Access  
Journal of Environmental Extension     Full-text available via subscription  
Journal of Forest and Natural Resource Management     Open Access  
Journal of Forest Economics     Hybrid Journal   (Followers: 5)
Journal of Forestry     Hybrid Journal   (Followers: 15)
Journal of Forestry Research     Hybrid Journal   (Followers: 3)
Journal of Horticulture and Forestry     Open Access   (Followers: 6)
Journal of Natural Resources Policy Research     Hybrid Journal   (Followers: 10)
Journal of Research in Forestry, Wildlife and Environment     Open Access   (Followers: 5)
Journal of Sustainable Forestry     Hybrid Journal   (Followers: 6)
Journal of Wood Chemistry and Technology     Hybrid Journal   (Followers: 6)
Journal of Wood Science     Open Access   (Followers: 3)
Jurnal Ilmu Kehutanan     Open Access  
Jurnal Penelitian Kehutanan Wallacea     Open Access  
Jurnal Penelitian Sosial dan Ekonomi Kehutanan     Open Access  
Jurnal Pertanian Terpadu     Open Access  
Jurnal Sylva Lestari     Open Access  
La Calera     Open Access  
Landscapes     Hybrid Journal   (Followers: 18)
Lesnoy Zhurnal     Open Access  
Madera y Bosques     Open Access  
Maderas. Ciencia y tecnología     Open Access  
Natural Areas Journal     Full-text available via subscription   (Followers: 10)
New Forests     Hybrid Journal   (Followers: 2)
New Zealand Journal of Forestry Science     Open Access   (Followers: 3)
Open Journal of Forestry     Open Access   (Followers: 1)
Ormancılık Araştırma Dergisi / Turkish Journal of Forestry Research     Open Access  
Parks Stewardship Forum     Open Access  
Peer Community Journal     Open Access   (Followers: 8)
Proceedings of the Forestry Academy of Sciences of Ukraine     Open Access  
Quebracho. Revista de Ciencias Forestales     Open Access  
Research Journal of Forestry     Open Access   (Followers: 2)
Revista Chapingo. Serie Ciencias Forestales y del Ambiente     Open Access  
Revista Cubana de Ciencias Forestales     Open Access  
Revista de Agricultura Neotropical     Open Access  
Revista Ecologia e Nutrição Florestal - ENFLO     Open Access   (Followers: 1)
Revista Forestal Mesoamericana Kurú     Open Access  
Revista Verde de Agroecologia e Desenvolvimento Sustentável     Open Access   (Followers: 2)
Revue forestière française     Full-text available via subscription   (Followers: 4)
Rural Sustainability Research     Open Access   (Followers: 2)
Rwanda Journal     Full-text available via subscription  
Savannah Journal of Research and Development     Open Access  
Scandinavian Journal of Forest Research     Hybrid Journal   (Followers: 7)
Science, Technology and Arts Research Journal     Open Access   (Followers: 1)
Selbyana     Open Access  
Silva Balcanica     Open Access  
Small-scale Forestry     Hybrid Journal   (Followers: 1)
Southern Forests : a Journal of Forest Science     Hybrid Journal   (Followers: 3)
Tanzania Journal of Forestry and Nature Conservation     Full-text available via subscription   (Followers: 2)
Textual : Análisis del Medio Rural Latinoamericano     Open Access  
Trees     Hybrid Journal   (Followers: 3)
Trees, Forests and People     Open Access   (Followers: 1)
Urban Forestry & Urban Greening     Hybrid Journal   (Followers: 10)
Wahana Forestra : Jurnal Kehutanan     Open Access  
Wood and Fiber Science     Full-text available via subscription   (Followers: 2)

           

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Forests
Journal Prestige (SJR): 0.812
Citation Impact (citeScore): 2
Number of Followers: 2  

  This is an Open Access Journal Open Access journal
ISSN (Print) 1999-4907
Published by MDPI Homepage  [84 journals]
  • Forests, Vol. 13, Pages 966: Functional Diversity and Its Influencing
           Factors in a Subtropical Forest Community in China

    • Authors: Lin Li, Zhifeng Wen, Shiguang Wei, Juyu Lian, Wanhui Ye
      First page: 966
      Abstract: Functional diversity is considered a key link between ecosystem functions and biodiversity, and forms the basis for making community diversity conservation strategies. Here, we chose a subtropical forest community in China as the research object, which is unique in that other regions of the world at the same latitude have almost no vegetation cover. We measured 17 functional traits of 100 plant species and calculated seven different functional diversity indices, based on functional richness, evenness, and divergence. We found that most functional diversity and species diversity indices significantly differed with plant habit. There was a significant positive correlation among functional richness indices. However, functional divergence indices, multidimensional functional divergence (FDiv), and Rao’s quadratic entropy index (RaoQ) were significantly negatively correlated, and RaoQ and functional divergence indices (FDis) were uncorrelated. The correlations between three types (richness, evenness, and divergence) of functional diversity indices and three species diversity indices were different. Lineage regression results generally showed that three functional richness indices (Average distance of functional traits (MFAD), Functional volume (FRic) and Posteriori functional group richness (FGR)) were increased with three species diversity indices (species richness (S), Shannon-Wiener index (H) and Pielou index (E)). The functional evenness index (FEve) decreased with species richness (S), Shannon-Wiener index (H) and increased with species evenness (Pielou index (E)), but the change trends were small. All three types of functional diversity indices declined with altitude, although altitude had a weak influence on them. Other environmental factors affected the functional diversity of the community. Here, soil total phosphorus (TP) was the most critical environmental factor and the convex had the least effect on functional diversity in our subtropical forest community. These results will contribute to our understanding of functional diversity in subtropical forests, and provide a basis for biodiversity conservation in this region.
      Citation: Forests
      PubDate: 2022-06-21
      DOI: 10.3390/f13070966
      Issue No: Vol. 13, No. 7 (2022)
       
  • Forests, Vol. 13, Pages 967: Assessing the Genetic Identity of Tuscan
           Sweet Chestnut (Castanea sativa Mill.)

    • Authors: Marta Cavallini, Gianluca Lombardo, Giorgio Binelli, Claudio Cantini
      First page: 967
      Abstract: The sweet chestnut (Castanea sativa Mill.) is an important species of European trees, studied for both ecological and economic reasons. Its cultivation in the Italian peninsula can be linked to the Roman period and has been documented, especially in the Tuscan region, for centuries. We sampled 131 grafted trees from three separate areas to determine the genetic variability between populations and assess genetic identity for different varieties of trees, which is useful for future breeding programs and propagation efforts. Molecular analyses were performed using eight microsatellite loci. A total of 98 alleles was detected with an average of 12.3 alleles per locus. We found high levels of genetic diversity within the varieties of the same area, ranging between He = 0.682–0.745. Of the eight loci, seven were found to be at Hardy-Weinberg equilibrium. (FST values Differentiation between cultivation areas was significant between 0.052–0.147) with the two Southern Tuscan areas showing the closest relationship as also indicated by Bayesian inference of the population structure, which revealed the existence of three ancestral gene pools of origin. Demographic events were detected by a coalescent-based approximate Bayesian computation in two of the homogeneous clusters. This work is a step forward for the conservation of this iconic species, albeit at a regional level, as chestnut varieties have never received the full attention of breeders.
      Citation: Forests
      PubDate: 2022-06-21
      DOI: 10.3390/f13070967
      Issue No: Vol. 13, No. 7 (2022)
       
  • Forests, Vol. 13, Pages 968: First Report of Dutch Elm Disease Caused by
           Ophiostoma novo-ulmi in South Korea

    • Authors: Dong-Hyeon Lee, Youngwoo Nam, Michael J. Wingfield, Hyungcheol Park
      First page: 968
      Abstract: During a routine survey conducted in July 2021, several dead and dying Ulmus macrocarpa trees were observed in an urban forest located in the Gyeonggi Province of South Korea. The trees had symptoms of wilt with yellowing and browning of leaves, and, in most cases, the trunks of dying trees were infested by bark beetles. Isolations were made from small pieces of wood taken from dying trees, and beetles were collected from the infested stems. Fungal isolates and the beetles were identified using DNA sequence-based phylogenies and morphology, respectively. The results revealed that the fungus was Ophiostoma novo-ulmi, the causal agent of Dutch elm disease, and the associated bark beetle was Scolytus jacobsoni. This study provides the first record of Dutch elm disease in South Korea and suggests that a nationwide survey for the disease should be undertaken.
      Citation: Forests
      PubDate: 2022-06-21
      DOI: 10.3390/f13070968
      Issue No: Vol. 13, No. 7 (2022)
       
  • Forests, Vol. 13, Pages 969: About Tree Height Measurement: Theoretical
           and Practical Issues for Uncertainty Quantification and Mapping

    • Authors: Samuele De Petris, Filippo Sarvia, Enrico Borgogno-Mondino
      First page: 969
      Abstract: Forest height is a fundamental parameter in forestry. Tree height is widely used to assess a site’s productivity both in forest ecology research and forest management. Thus, a precise height measure represents a necessary step for the estimation of carbon storage at the local, national, and global scales. In this context, error in height measurement necessarily affects the accuracy of related estimates. Ordinarily, forest height is surveyed by ground sampling adopting hypsometers. The latter suffers from many errors mainly related to the correct tree apex identification (not always well visible in dense stands) and to the measurement process itself. In this work, a statistically based operative method for estimating height measurement uncertainty (σH) was proposed using the variance propagation law. Some simulations were performed involving several combinations of terrain slope, tree height, and survey distances by modelling the σH behaviour and its sensitivity to such parameters. Results proved that σH could vary between 0.5 m and up to 20 m (worst case). Sensitivity analysis shows that terrain slopes and distance poorly affect σH, while angles are the main drivers of height uncertainty. Finally, to give a practical example of such deductions, tree height uncertainty was mapped at the global scale using Google Earth Engine and summarized per forest biomes. Results proved that tropical biomes have higher uncertainty (from 1 m to 4 m) while shrublands and tundra have the lowest (under 1 m).
      Citation: Forests
      PubDate: 2022-06-21
      DOI: 10.3390/f13070969
      Issue No: Vol. 13, No. 7 (2022)
       
  • Forests, Vol. 13, Pages 970: Tracheidogram’s Classification as a New
           Potential Proxy in High-Resolution Dendroclimatic Reconstructions

    • Authors: Mikhail S. Zharkov, Jian-Guo Huang, Bao Yang, Elena A. Babushkina, Liliana V. Belokopytova, Eugene A. Vaganov, Dina F. Zhirnova, Victor A. Ilyin, Margarita I. Popkova, Vladimir V. Shishov
      First page: 970
      Abstract: Quantitative wood anatomy (QWA) is widely used to resolve a fundamental problem of tree responses to past, ongoing and forecasted climate changes. Potentially, QWA data can be considered as a new proxy source for long-term climate reconstruction with higher temporal resolution than traditional dendroclimatic data. In this paper, we considered a tracheidogram as a set of two interconnected variables describing the dynamics of seasonal variability in the radial cell size and cell wall thickness in conifer trees. We used 1386 cell profiles (tracheidograms) obtained for seven Scots pine (Pinus sylvestris) trees growing in the cold semiarid conditions of Southern Siberia over the years 1813–2018. We developed a “deviation tracheidogram” approach for adequately describing the traits of tree-ring formation in different climate conditions over a long-term time span. Based on the NbClust approach and K-means method, the deviation tracheidograms were reliably split into four clusters (classes) with clear bio-ecological interpretations (from the most favorable growth conditions to worse ones) over the years 1813–2018. It has been shown that the obtained classes of tracheidograms can be directly associated with different levels of water deficit, for both the current and previous growing seasons. The tracheidogram cluster reconstruction shows that the entire 19th century was characterized by considerable water deficit, which has not been revealed by the climate-sensitive tree-ring chronology of the study site. Therefore, the proposed research offers new perspectives for better understanding how tree radial growth responds to changing seasonal climate and a new independent proxy for developing long-term detailed climatic reconstructions through the detailed analysis of long-term archives of QWA data for different conifer species and various forest ecosystems in future research.
      Citation: Forests
      PubDate: 2022-06-21
      DOI: 10.3390/f13070970
      Issue No: Vol. 13, No. 7 (2022)
       
  • Forests, Vol. 13, Pages 971: Analysis of the NAC Gene Family in Salix and
           the Identification of SpsNAC005 Gene Contributing to Salt and Drought
           Tolerance

    • Authors: Haifeng Yang, Lijiao Fan, Xingwang Yu, Xinqian Zhang, Pu Hao, Dongshan Wei, Guosheng Zhang
      First page: 971
      Abstract: The NAC gene family is of great value for plant stress resistance and development. In this study, five NAC genes with a typical NAM domain were isolated from Salix psammophila, which is a stress-resistant willow endemic to western China. Two hundred sixty-two NAC genes from Salix psammophila, Salix purpurea, and Arabidopsis were used to construct the phylogenetic tree to examine the phylogenetic relationship. Five NAC genes in Salix psammophila were the focus of bioinformatics analysis and conserved structural domain analysis. The SpsNAC005 gene was overexpressed in Populus hopeiensis, and the transgenic lines were subjected to salt and simulated drought stress to analyze their phenotype changes and tolerance to stress. The results showed that transgenic poplar height and leaf area increased by 29.73% and 76.36%, respectively, compared with those of wild-type plants. Under stress treatment, the height growth rates and ground diameter growth rates of the transgenic lines were significantly higher than those of the wild-type, whereas their fresh weight and dry weight were decreased compared to those of the wild-type. The SOD activities, POD activities, and Pro contents of the transgenic plants were significantly increased, and the accumulation of MDA was significantly lower than that in the wild-type, and the transgenic lines showed clear tolerance to salt and drought. The expressions of the SOS1, MPK6, HKT1, and P5CS1 genes were downregulated in the transgenic lines. The expression of the PRODH1 gene was downregulated in the transgenic lines. These results indicate that overexpression of the SpsNAC005 gene in transgenic plants can promote plant growth and development and improve tolerance to salt and drought.
      Citation: Forests
      PubDate: 2022-06-21
      DOI: 10.3390/f13070971
      Issue No: Vol. 13, No. 7 (2022)
       
  • Forests, Vol. 13, Pages 972: Optimal Survey Design for Forest Carbon
           Monitoring in Remote Regions Using Multi-Objective Mathematical
           Programming

    • Authors: Sándor F. Tóth, Kiva L. Oken, Christine C. Stawitz, Hans-Erik Andersen
      First page: 972
      Abstract: Cost-effective monitoring of forest carbon resources is critical to the development of national policies and enforcement of international agreements aimed at reducing carbon emissions and mitigating the impacts of climate change. While carbon monitoring systems are often based on national forest inventories (NFI) utilizing a large sample of field plots, in remote regions the lack of transportation infrastructure often requires heavier reliance on remote sensing technologies, such as airborne lidar. The challenge motivating our research is that the efficacy of estimating carbon with lidar varies across the various carbon pools within forest ecosystems. Lidar measurements are typically highly correlated with aboveground tree carbon but are less strongly correlated with other carbon pools, such as down woody materials (DWM) and soil. Field measurements are essential to both (1) estimate soil and DWM carbon directly and (2) develop regression models to estimate tree carbon indirectly using lidar. With limited budgets and time, however, decision makers must find an optimal way to combine field measurements with lidar to minimize standard errors in carbon estimates for the various pools. We introduce a multi-objective binary programming formulation that quantifies the tradeoffs behind the competing objectives of minimizing standard errors for tree carbon, DWM carbon, and soil carbon. Using NFI and airborne lidar data from a remote boreal forest region of interior Alaska, we demonstrate the operational feasibility of the method and suggest that it is generalizable to other carbon sampling projects because of its generic mathematical structure.
      Citation: Forests
      PubDate: 2022-06-22
      DOI: 10.3390/f13070972
      Issue No: Vol. 13, No. 7 (2022)
       
  • Forests, Vol. 13, Pages 973: Ecological Strategy Spectra for Communities
           of Different Successional Stages in the Tropical Lowland Rainforest of
           Hainan Island

    • Authors: Chen Chen, Yabo Wen, Tengyue Ji, Hongxia Zhao, Runguo Zang, Xinghui Lu
      First page: 973
      Abstract: Plant ecological strategies are shaped by long-term adaptation to the environment and are beneficial to plant survival and reproduction. Research is ongoing to better understand how plants best allocate resources for growth, survival and reproduction, as well as how ecological strategies may shift in plant communities over the course of succession. In this study, 12 forest dynamics plots in three different successional stages were selected for study in the tropical lowland rainforest ecosystem of Hainan Island. For each plot, using Grime’s competitor, a stress-tolerator, the ruderal (CSR) scheme and using the CSR ratio tool “StrateFy”, an ecological strategy spectrum was constructed using functional trait data obtained by collecting leaf samples from all woody species. The ecological strategy spectra were compared across successional stages to reveal successional dynamics. The results showed: (1) The ecological strategy spectra varied among forest communities belonging to three different successional stages. (2) The community-weighted mean CSR (CWM-CSR) strategies shifted with succession: CWM-S values decreased, while the CWM-C and CWM-R values increased. Overall, shifts in plant functional traits occurred slowly and steadily with succession showing complex and diverse trade-offs and leading to variation among the ecological strategy spectra of different successional stages.
      Citation: Forests
      PubDate: 2022-06-22
      DOI: 10.3390/f13070973
      Issue No: Vol. 13, No. 7 (2022)
       
  • Forests, Vol. 13, Pages 974: Discovery of Rickettsia and Rickettsiella
           Intracellular Bacteria in Emerald Ash Borer Agrilus planipennis by
           Metagenomic Study of Larval Gut Microbiome in European Russia

    • Authors: Maxim V. Vecherskii, Marina J. Orlova-Bienkowskaja, Tatyana A. Kuznetsova, Andrzej O. Bieńkowski
      First page: 974
      Abstract: Emerald ash borer Agrilus planipennis (Coleoptera: Buprestidae) is a quarantine pest posing a threat to ash trees all over Europe. This wood-boring beetle native to Asia is quickly spreading in North America and European Russia, and approaching the European Union and the Middle East. It is important to study microorganisms associated with this pest, because the knowledge of its “natural enemies” and “natural allies” could be potentially used for the control of the pest. All previously published information about the A. planipennis microbiome was obtained in North America and China. We present the first study on procaryotes associated with A. planipennis in Europe. Alive larvae were sampled from under the bark of Fraxinus pennsylvanica in the Moscow Oblast and the gut microbiome was studied using metagenomic methods. Next-generation Illumina-based amplicon sequencing of the v3-v4 region 16S-RNA gene was performed. In total, 439 operational taxonomic units from 39 families and five phyla were detected. The dominant families in our samples were Pseudomonadaceae, Erwiniaceae and Enterobacteriaceae, in accordance with the published information on the larval gut microbiome in North America and China. We detected intracellular bacteria in A. planipennis for the first time, namely Rickettsia (Rickettsiaceae) and Rickettsiella (Diplorickettsiaceae). Representatives of the genus Rickettsia are known to be in mutualistic symbiosis with some phytophagous insects, while Rickettsiella bacteria are pathogenic to many arthropods. The finding of Rickettsia and Rickettsiella opens perspectives for future research on the interactions between these bacteria and A. planipennis and the possible use of these interactions for the control of the pest.
      Citation: Forests
      PubDate: 2022-06-22
      DOI: 10.3390/f13070974
      Issue No: Vol. 13, No. 7 (2022)
       
  • Forests, Vol. 13, Pages 875: Evidence for Alternate Stable States in an
           Ecuadorian Andean Cloud Forest

    • Authors: Ana Mariscal, Daniel Churchill Thomas, Austin Haffenden, Rocío Manobanda, William Defas, Miguel Angel Chinchero, José Danilo Simba Larco, Edison Jaramillo, Bitty A. Roy, Mika Peck
      First page: 875
      Abstract: Tree diversity inventories were undertaken. The goal of this study was to understand changes in tree community dynamics that may result from common anthropogenic disturbances at the Reserva Los Cedros, a tropical montane cloud forest reserve in northern Andean Ecuador. The reserve shows extremely high alpha and beta tree diversity. We found that all primary forest sites, regardless of age of natural gaps, are quite ecologically resilient, appearing to return to a primary-forest-type community of trees following gap formation. In contrast, forests regenerating from anthropogenic disturbance appear to have multiple possible ecological states. Where anthropogenic disturbance was intense, novel tree communities appear to be assembling, with no indication of return to a primary forest state. Even in ancient primary forests, new forest types may be forming, as we found that seedling community composition did not resemble adult tree communities. We also suggest small watersheds as a useful basic spatial unit for understanding biodiversity patterns in the tropical Andes that confound more traditional Euclidean distance as a basic proxy of dissimilarity. Finally, we highlight the conservation value of Reserva Los Cedros, which has managed to reverse deforestation within its boundaries despite a general trend of extensive deforestation in the surrounding region, to protect a large, contiguous area of highly endangered Andean primary cloud forest.
      Citation: Forests
      PubDate: 2022-06-03
      DOI: 10.3390/f13060875
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 876: Acid Hydrolysable Components Released from
           Four Decomposing Litter in an Alpine Forest in Sichuan, China

    • Authors: Shu Liao, Kai Yue, Xiangyin Ni, Fuzhong Wu
      First page: 876
      Abstract: Acid hydrolysable components have been thought to release from plant litter at early periods of decomposition and to be sensitive to hydrological change. Variations in snow depth and timing may alter the release of acid hydrolysable components from decomposing litter in seasonally snow-covered ecosystems. Here, we measured the release of acid hydrolyzable components from four foliar litters (fir, cypress, larch and birch) in deep and shallow snow plots during winter (snow formation, snow coverage and snowmelt stages) and growing seasons in an alpine forest from 2012 to 2016. We found that the content of acid hydrolysable components was 16–21% in fresh litter across species, and only 4–5% of these components remained in the litter after four years of decomposition when 53–66% of litter mass was lost. The content of acid hydrolysable components greatly decreased within 41 days and during the growing seasons of the fourth year of decomposition, suggesting that acid hydrolysable components in plant litter are not only released at early periods but also at a very late period during litter decay. However, the content of acid hydrolysable components increased significantly at snowmelt stages. Reduced snow cover increased the content and remaining level of acid hydrolysable components during the four years of decomposition by altering leaching, microbial biomass and stoichiometry. We propose that more effective partitioning of chemical fractions should be incorporated to distinguish the carbon and nutrient release during litter decomposition within a complex context of the changing environment.
      Citation: Forests
      PubDate: 2022-06-03
      DOI: 10.3390/f13060876
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 877: The Mechanical Properties of Wood-Based Grid
           Sandwich Structures

    • Authors: Dongxia Yang, Changsheng Fan
      First page: 877
      Abstract: In order to reduce the weight of the panels used in buildings and minimize the use of wood, it is of great practical significance to study the mechanical properties of wood-based sandwich structures for adaptation to modern wood-structured buildings. In this paper, a wood-based pyramid structure specimen with large interconnection space was designed and prepared first. Based on the results of the flat compression, in order to strengthen the core layer of the sandwich structure, an interlocking grid structure can be used. The mechanical properties of two kinds of structure specimens, including bearing capacity, compressive strength, specific strength, load–mass ratio, safety factor distribution, and specific energy absorption, were studied by means of experimental test, theoretical analysis, and finite element analysis. It was concluded that the apparent density of the two structures was lower than that of the materials of which they were composed. However, the overall flat compressive strength of the two structures was higher than that of their constituent materials, which were high-strength materials in the field of natural materials. The mechanical properties of the interlocking grid structures were better than those of the pyramid structures. Based on the criterion of cell structure stability, it can be concluded that the wood-based pyramid structure was a flexural-dominant structure, and the interlocking grid structure was a tensile-dominant structure. The results show that the core layer design plays an important role in the mechanical properties and failure modes of wood-based sandwich structures.
      Citation: Forests
      PubDate: 2022-06-03
      DOI: 10.3390/f13060877
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 878: Structure and Stability of Agroforestry
           Ecosystems: Insights into the Improvement of Service Supply Capacity of
           Agroforestry Ecosystems under the Karst Rocky Desertification Control

    • Authors: Shilian Jiang, Kangning Xiong, Jie Xiao
      First page: 878
      Abstract: Agroforestry provides essential ecosystem services; its structure and stability directly determine ecosystem function and service provision. Sustaining agroforestry ecosystem functions and services in the long term is necessary to meet the needs of people. This study conducted a literature search and statistical analysis based on WOS and CNKI literature databases. We reviewed 136 literature reports on studies of agroforestry ecosystem structure and stability. The landmark results are summarized in five aspects of agroforestry ecosystems: structure characteristics, structure optimization, structure design, stability research, and influence factors. On this basis, the key scientific issues that need to be solved are summarized, and their insights for improving the supply capacity of agroforestry ecosystem services under the rocky desertification control are discussed.
      Citation: Forests
      PubDate: 2022-06-04
      DOI: 10.3390/f13060878
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 879: Dendroclimatological Analysis of Fir (A.
           borisii-regis) in Greece in the frame of Climate Change Investigation

    • Authors: Aristeidis Kastridis, Vasiliki Kamperidou, Dimitrios Stathis
      First page: 879
      Abstract: The potential correlation between fir tree-ring width (Abies borisii regis Mattf.) variability and the respective variability of the main climatic parameters in the region of University Forest of Pertouli (central Greece) are being analyzed in the current study, taking into consideration a 60-year period (1961–2020). Correlation and response function analyses were applied to examine the climate–tree-growth relationship. Precipitation was found to be the most crucial and driving factor that most intensively influences the tree growth of A. borisii-regis trees under Mediterranean climate conditions. It was evident that this species is characterized by drought sensitivity and even a short and mild drought event could significantly influence adversely its growth and productivity. June, May and July precipitation present the higher and statistically significant correlation of monthly precipitation with tree-ring width, affecting the ring-width variability by 31.2%. Temperature (mean, max or min) does not seem to highly influence the tree growth, despite the obvious and statistically significant trend increase that has been recorded in the last decades within the frame of climate change. June maximum temperature presents a strong negative correlation with tree-ring width, while April maximum temperature is positively correlated with tree-ring width. The combined impact of precipitation and max temperatures on tree-ring growth is 38.5%. Snow did not reveal any statistically significant correlation to tree-ring width, independent of the height of monthly snow accumulation. A. borisii-regis grown in high altitudes in the Mediterranean region demonstrate high adaptability to the recorded temperature increase and could potentially be able to adapt in future to even warmer climate conditions. The constructed tree-ring chronology could be utilized towards the implementation of further dendroclimatological analyses and climate reconstruction.
      Citation: Forests
      PubDate: 2022-06-04
      DOI: 10.3390/f13060879
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 880: Response of Soil Enzyme Activities to Natural
           Vegetation Restorations and Plantation Schemes in a Landslide-Prone Region
           

    • Authors: Donglei Guo, Yansheng Ou, Xiaohe Zhou, Xia Wang, Yunfei Zhao, Jia Li, Jinjin Xiao, Zhiguo Hao, Kaichang Wang
      First page: 880
      Abstract: Soil enzyme activities in different plantation types and land use patterns could indicate changes in soil quality. This research was aimed at exploring the dynamics of soil enzyme activities involved in carbon, nitrogen and phosphorus cycling, and their responses to changes in soil physicochemical properties resulting from natural vegetation restorations and plantation schemes. Knowing about the effects of soil physicochemical properties on soil enzyme patterns is crucial for understanding ecosystem functions and processes. The study selected four main land-use types (natural forestland, natural grassland, artificial forestland, and artificial grassland) and one control plot (bare land) in the West Qinling Mountains, China, which is a typical landslide region. We collected the soil samples from each land use type and tested their physicochemical properties and enzyme activities compared with control land. The results showed that both natural vegetation restoration and artificial plantation schemes have significant effects on enzyme activities. Soil physicochemical properties explained 92.2% of the variation in soil enzyme activities for natural vegetation restoration, while it only explained 77.8% of the variation in soil enzyme activities for plantation schemes. Furthermore, natural vegetation had a greater effect than the plantation schemes on soil enzyme activities.
      Citation: Forests
      PubDate: 2022-06-05
      DOI: 10.3390/f13060880
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 881: Nondormant Acorns Show Higher Seed Dispersal
           Effectiveness Than Dormant Ones

    • Authors: Yueqin Yang, Xianfeng Yi
      First page: 881
      Abstract: Seed dormancy has been thought to be an important survival strategy to tune the seed dispersal timing. Although a theoretical trade-off between seed dormancy and dispersal is often proposed, empirical field evidence of the trade-off between seed dormancy, spatial dispersal, and seedling recruitment is still lacking. Here, we tracked seed dispersal of several Fagaceae species exhibiting different levels of dormancy both in artificial enclosures and in the field. We presented evidence that oak species with nondormant acorns rather than those bearing dormant species exhibit reduced spatial dispersal. Despite the empirical evidence that seed germination is negatively correlated with spatial dispersal, nondormancy rather than dormancy showed higher seed dispersal effectiveness, demonstrating a negative correlation between seed dormancy and dispersal fitness. Our study, using the oak-rodent system, may provide solid evidence of a dispersal–germination trade-off between spatial and temporal correlation, highlighting the ecological role of seed germination schedule in seed dispersal and life-history evolution.
      Citation: Forests
      PubDate: 2022-06-05
      DOI: 10.3390/f13060881
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 882: Effect of Climate on Carbon Storage Growth
           Models for Three Major Coniferous Plantations in China Based on National
           Forest Inventory Data

    • Authors: Lianjin Zhang, Guanghui Lai, Weisheng Zeng, Wentao Zou, Shanjun Yi
      First page: 882
      Abstract: Forest inventory data (FID) are important resources for understanding the dynamics of forest carbon cycling at regional and global scales. Developing carbon storage growth models and analyzing the difference and climate effect on carbon sequestration capacity have a great importance in practice, which can provide a decision-making basis for promoting high-quality development of forestry and implementing the carbon emission peak and carbon neutralization strategy. Based on the carbon storage dataset of 2680 sample plots from the ninth national forest inventory (NFI) of China, the carbon storage growth models and climate-sensitive variable-parameter carbon storage growth models for three major coniferous plantations (Larix spp., Pinus massoniana, and Pinus tabuliformis) were developed by using weighted nonlinear regression method. The effects of two climate factors (mean annual temperature (MAT) and mean annual precipitation (MAP)) on carbon storage growth and carbon sequestration capacity were analyzed and compared. The mean prediction error (MPE) of carbon storage growth models for three major coniferous plantations was less than 5%, and total relative error (TRE) was approximately less than 2% for self- and cross- validation. The maximum current annual increment of carbon storage for P. massoniana, Larix, and P. tabuliformis was 2.29, 1.89, and 1.19 t/(ha·a), respectively, and their corresponding age of inflection point was 9a, 14a, and 30a, respectively. The maximum average increment of carbon storage for P. massoniana, Larix, and P. tabuliformis was 1.85, 1.50, and 0.94 t/(ha·a), respectively, and their corresponding age of quantitative maturity was 16a, 24a, and 53a, respectively. The maximum average increment of carbon storage for the P. massoniana and Larix plantations was approximately 1.97 and 1.60 times, respectively, that of P. tabuliformis plantation. The average increment of carbon storage for the P. massoniana and Larix plantations reduced approximately by 4.5% and 3.8%, respectively, when the MAT decreases by 1 °C. The average increment of carbon storage for the Larix and P.tabuliformis plantations decreased by approximately 6.5% and 3.6%, respectively, when the MAP decreases by 100 mm. Our findings suggest that: the carbon sequestration capacity is from highest to lowest in the P. massoniana, Larix, and P. tabuliformis forests. MAT and MAP have different effects on the carbon growth process and carbon sequestration capacity of these plantations. The greatest impact on carbon sequestration capacity was detected in the Larix plantation, followed by the P. massoniana and P. tabuliformis plantations. It is essential to coordinate regional development and employ scientific management strategies to fully develop the maximum carbon sequestration capacity in terms of plantations in China. In the present study, we estimate the carbon storage in major coniferous plantations in China and describe a useful methodology for estimating forest carbon storage at regional and global levels.
      Citation: Forests
      PubDate: 2022-06-06
      DOI: 10.3390/f13060882
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 883: Long-Term Effects of Fire Severity and
           Climatic Factors on Post-Forest-Fire Vegetation Recovery

    • Authors: Bin Hao, Xu Xu, Fei Wu, Lei Tan
      First page: 883
      Abstract: As a major disturbance to forest ecosystems, wildfires pose a serious threat to the ecological environment. Monitoring post-fire vegetation recovery is critical to quantifying the effects of wildfire on ecosystems and conducting forest resource management. Most previous studies have analyzed short-term (less than five years) post-fire recovery and limited the driving factors to temperature and precipitation. The lack of long-term and multi-faceted observational analyses has limited our understanding of the long-term effects of fire on vegetation recovery. This study utilized multi-source remote sensing data for a long time series analysis of post-fire vegetation recovery in China based on Google Earth Engine (GEE) cloud computing platform. Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Normalized Burn Ratio (NBR), and Normalized Difference Moisture Index (NDMI) were selected to quantify the low, moderate, and high severity of burned areas. Ridge Regression Model (RRM) was used to analyze the relationship between 15 driving factors and the vegetation regeneration process. The results show that it took at least 7–10 years for the vegetation index to recover to the pre-fire level after a forest fire. The recovery rate of high severity combustion areas was the fastest within the first two years. From the results of Ridge Regression, it came out that the overall fitting degree of the model with NDVI as the dependent variable was superior than that with EVI. The four variables of temperature, precipitation, soil temperature, and soil moisture were able to explain the change in more detail in vegetation indices. Our study enriches the research cases of global forest fires and vegetation recovery, provides a scientific basis for the sustainable development of forest ecosystems in China, and provides insight into environmental issues and resource management.
      Citation: Forests
      PubDate: 2022-06-06
      DOI: 10.3390/f13060883
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 884: Characteristics and Risk of Forest Soil Heavy
           Metal Pollution in Western Guangdong Province, China

    • Authors: Jian Kang, Xiaogang Ding, Hongyan Ma, Zhiming Dai, Xiaochuan Li, Jian-Guo Huang
      First page: 884
      Abstract: West Guangdong is an important ecological barrier in Guangdong province, so understanding the spatial patterns and sources of heavy metal pollution of forest soil in this region is of great significance for ecological protection. In this study, the concentrations of heavy metals (Cd, Pb, Cu, Zn, and Ni) in forest soil were determined. Geostatistics, single-factor pollution index (PI), potential ecological risk index (RI), principal component analysis (PCA), and Pearson’s correlation analysis were used to evaluate and analyze the characteristics of heavy metal pollution of forest soil. The results showed that the average concentration did not exceed the critical value. Cd, Pb, and Cu were enriched in southwest Xinxing County, while Zn and Ni were enriched in most areas of the Yunan and Yuncheng districts. Two groups of heavy metals from different sources were identified by PCA and a correlation analysis. Cd, Pb, and Cu in their respective enrichment areas were mainly from marble and cement production, whereas Zn and Ni were primarily from transportation and chemical fertilizer. Most of the study area was safe or slightly polluted while the heavy metal-enriched areas were moderately to severely polluted. The potential ecological risk was at a lower level in the study area but moderate in southwest Xinxing County. In summary, human factors impact the spatial patterns and ecological risks of heavy metals in forest soil. This study provides a scientific basis for forest soil pollution control and ecological protection.
      Citation: Forests
      PubDate: 2022-06-06
      DOI: 10.3390/f13060884
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 885: Changes in the Parasitism Rate and Parasitoid
           Community Structure of the Horse Chestnut Leafminer, Cameraria ohridella
           (Lepidoptera: Gracillariidae), in the Czech Republic

    • Authors: Lubomír Volter, Eva Prenerová, František Weyda, Rostislav Zemek
      First page: 885
      Abstract: The horse chestnut leafminer, Cameraria ohridella, Deschka and Dimić, is a moth that has invaded most of Europe since it was first recorded in Macedonia near Lake Ohrid in 1985. It attacks horse chestnut trees and causes aesthetic and vitality problems. The parasitism rate, other mortality rates, and parasitoid structure were studied during a five-year survey at six sites in the Czech Republic. The results showed that the total parasitism rates varied from 1.9% to 20.5%, with an average of 7.2%, similar to other those published studies. The parasitism rate was significantly related to year, the developmental stage of C. ohridella, latitude, and greenery maintenance but not to C. ohridella population density, altitude, or area size. In contrast, the total other mortality rates varied from 13.7% to 59.5%, with an average of 31%, but overall temporal changes in the values indicated a declining trend. The parasitoid complex was predominantly polyphagous parasitoids of the family Eulophidae, similar to that found previously in south-eastern Europe. The results further revealed that the most abundant parasitoid species, Minotetrastichus frontalis (Nees), was gradually replaced by Pediobius saulius (Walker). The increasing abundance of P. saulius is thus an interesting adaptation of an autochthonous parasitoid to a new host.
      Citation: Forests
      PubDate: 2022-06-07
      DOI: 10.3390/f13060885
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 886: Divergent Tree Growth and the Response to
           Climate Warming and Humidification in the Tianshan Mountains, China

    • Authors: Zhongtong Peng, Yuandong Zhang, Liangjun Zhu, Qingao Lu, Qifeng Mo, Jiaqing Cai, Mingming Guo
      First page: 886
      Abstract: In recent decades, the global climate has changed significantly. The climate in Northwest China became warm-wet, especially in the Tianshan Mountains. In order to explore the response of tree growth to recent climate change, the two dominant trees species, Picea schrenkiana Fisch. et Mey. and Larix sibirica Ledeb., were studied with the dendrochronological method in the western Tianshan Mountains (WT) and the eastern Tianshan Mountains (ET). Our results showed that: (1) The tree growth of four sample sites in the WT significantly increased in recent decades, while the trees in the three sample sites in the ET significantly decreased. (2) In the WT, except for the Manas site, the tree-ring chronologies of the other three sites were significantly positively correlated with the mean annual minimum temperature. Tree-ring chronologies in the WT, except for Bangfanggou site, were significantly positively correlated with annual precipitation. In the ET, only the tree chronology of L. sibirica in the Balikun site was significantly negatively correlated with the annual temperatures, including the mean minimum, mean and mean maximum temperature. (3) The proportion of trees with a significant upward growth trend at each site decreased from west to east, and the proportion of trees with a significant downward growth trend at each site increased from west to east along the whole Tianshan Mountains. (4) The correlation of tree-ring chronologies with the annual temperature and annual precipitation was not stable during the study period. Warm-humidification promoted the growth of trees in the WT but inhibited tree growth in the ET, which may be exacerbated drought stress in the ET where the increase in precipitation was not enough to offset the increased evapotranspiration potential caused by warming.
      Citation: Forests
      PubDate: 2022-06-07
      DOI: 10.3390/f13060886
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 887: Mapping the Long-Term Evolution of the
           Post-Event Deformation of the Guang’an Village Landslide, Chongqing,
           China Using Multibaseline InSAR Techniques

    • Authors: Kui Zhang, Faming Gong, Li Li, Alex Hay-Man Ng, Pengfei Liu
      First page: 887
      Abstract: On 21 October 2017, days of heavy rainfall triggered a landslide in Guang’an Village, Wuxi County, Chongqing, China. According to the field investigation after the incident, there is still a massive accumulation body, which could possibly reactivate the landslide. In this study, to explore the long-term evolution of the deformation after the initial Guang’an Village Landslide, a time-series InSAR technique (TS-InSAR) was applied to the 128 ascending Sentinel-1A datasets spanning from October 2017 to March 2022. A new approach is proposed to enhance the conventional TS-InSAR method by integrating LiDAR data into the TS-InSAR process chain. The spatial–temporal evolution of post-event deformation over the Guang’an Village Landslide is analyzed based on the time-series results. It is found that the post-event deformation can be divided into three main stages: the post-failure stage, the post-failure and reactivation stage, and the reactivation stage. It is also suggested that, although the study area is currently under the reactivation stage, there are two active deformation zones that may become the origin of a secondary landslide triggered by heavy rainfall in the future. Moreover, the nearby Yaodunzi landslide might also play an important role in the generation and reactivation of a secondary Guang’an Village Landslide. Therefore, continuous monitoring for post-event deformation of the Guang’an Village Landslide is important for early warning of a secondary landslide in the near future.
      Citation: Forests
      PubDate: 2022-06-07
      DOI: 10.3390/f13060887
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 888: Spatial Structure Dynamics and Maintenance of
           a Natural Mixed Forest

    • Authors: Chaofan Zhou, Di Liu, Keyi Chen, Xuefan Hu, Xiangdong Lei, Linyan Feng, Yuchao Zhang, Huiru Zhang
      First page: 888
      Abstract: Spatial structure dynamics play a major role in understanding the mechanisms of forest structure and biodiversity formation. Recently, researches on the spatial structure dynamics utilizing multi-period data have been published. However, these studies only focused on comparative analyses of the spatial structure of multi-period living trees, without an in-depth analysis of the change processes. In this study, we propose a new comprehensive analysis method for dynamic change of the spatial structure at the individual level, which includes three processes (living trees’ flow, mortality process and recruitment process) that have not been considered in previous researches. Four spatial structural parameters (SSSPs, Uniform angle index, Mingling, Dominance and Crowding) and a natural spruce-fir-broadleaf mixed forest with two-phase data were taken as an example to find out the laws of the spatial structure dynamics. All types of dynamic change were named and their proportions were analyzed. The proportion of changes in the SSSPs of individuals was relatively high, even though the mean values of the stand did not change considerably. The five values (0, 0.25, 0.5, 0.75, 1) of the SSSPs are in mutual flow, and the flows are typically one-step, with three-steps and four-steps changes being uncommon. The processes of mortality and recruitment have a higher influence on the spatial structure than the flow of living trees. The dynamic change of spatial structure analysis method created in this study can capture more features not discovered in earlier approaches, as well as guiding forest management in some ways. Understanding the nuances of these changes is a critical part of reasonable spatial structure and biodiversity maintenance, and should be the focus of future research efforts.
      Citation: Forests
      PubDate: 2022-06-07
      DOI: 10.3390/f13060888
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 889: Microsite Drivers of Natural Seed
           Regeneration of Eucalyptus globulus Labill. in Burnt Plantations

    • Authors: Ana Águas, Hugo Matias, Abel Rodrigues, Tanya Bailey, Joaquim Silva, Francisco Rego
      First page: 889
      Abstract: Fire regimes are changing in several regions of the world. In those regions, some exotic species may be better adapted to new regimes than the native species. This study focused on identifying the microsite characteristics associated with the occurrence of post-fire Eucalyptus globulus regeneration from seeds, outside the species native-range. This information is important in helping to assess the naturalization status of the species, to understand its invasion risk, and to manage wildlings in plantations. To characterize the establishment niche, pairs of microsites (sapling presence/absence) were sampled in four salvage-logged plantations of E. globulus two years after fire (20 pairs/plantation). Microsites of wildlings from three size classes and control microsites were established in one of these plantations (20 quartets) in order to characterize the recruitment niche and to assess ontogenic niche shifts. Two post-fire wildling cohorts were identified. The first emerged just after fire and was abundant. The second emerged after logging and was scarce, probably due to seed limitation. First-cohort wildlings were observed in microsites characterized by a high incidence of fire-related variables (charcoal, ash, increased soil pH and K). The aggregated distribution of these wildlings and their association with other species may indicate the existence of facilitative relationships and/or the exploitation of resource-rich patches. All these factors were relevant for first-cohort persistence and likely also for its establishment and recruitment. Second-cohort wildlings occurred in microsites where salvage-logging disturbance was evident, showing the importance of this disturbance for its emergence. Wildling size diversity was explained by the two recruitment events and by the asymmetrical competition between wildlings and adults. No niche shifts were detected. The high densities of E. globulus wildlings found established in burnt plantations indicated naturalization was in progress. The timing of major recruitment events and the phenology of the species should be considered for monitoring this regeneration and scheduling control interventions, if required.
      Citation: Forests
      PubDate: 2022-06-07
      DOI: 10.3390/f13060889
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 890: Aridity and High Salinity, Rather Than Soil
           Nutrients, Regulate Nitrogen and Phosphorus Stoichiometry in Desert Plants
           from the Individual to the Community Level

    • Authors: Kaiye Yuan, Hailiang Xu, Guangpeng Zhang, Junjie Yan
      First page: 890
      Abstract: The stoichiometric characteristics of plant nitrogen (N) and phosphorus (P) and their correlations with soil properties are regarded as key for exploring plant physiological and ecological processes and predicting ecosystem functions. However, quantitative studies on the relative contributions of water–salt gradients and nutrient gradients to plant stoichiometry are limited. In addition, previous studies have been conducted at the plant species and individual levels, meaning that how community-scale stoichiometry responds to soil properties is still unclear. Therefore, we selected typical sample strips from 13 sampling sites in arid regions to assess the leaf N and P levels of 23 species of desert plants and measure the corresponding soil water content, total salt content, total nitrogen content, and total phosphorus content. The aim was to elucidate the main soil properties that influence the stoichiometric characteristics of desert plants and compare the individual and community responses to those soil properties. Our results indicated that the growth of desert plants is mainly limited by nitrogen, with individual plant leaf nitrogen and phosphorus concentrations ranging from 4.08 to 31.39 mg g−1 and 0.48 to 3.78 mg g−1, respectively. Community stoichiometry was significantly lower than that of individual plants. A significant correlation was observed between the mean N concentration, P concentration, and N:P ratio of plant leaves. At the individual plant scale, aridity significantly reduced leaf N and P concentrations, while high salt content significantly increased leaf N concentrations. At the community scale, aridity had no significant effects on leaf nitrogen or phosphorus stoichiometry, while high salinity significantly increased the leaf N:P ratio and there were no significant interactions between the aridity and salinity conditions. No significant effects of soil nutrient gradients were observed on plant N and P stoichiometric characteristics at the individual or community levels. These results suggest that individual desert plants have lower leaf N and P concentrations to adapt to extreme drought and only adapt to salt stress through higher leaf N concentrations. The N and P stoichiometric characteristics of desert plant communities are not sensitive to variations in aridity and salinity in this extreme habitat. The results of this study could enhance our perceptions of plant adaptation mechanisms to extreme habitats within terrestrial ecosystems.
      Citation: Forests
      PubDate: 2022-06-07
      DOI: 10.3390/f13060890
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 891: Assessing the Resource Potential of
           Mountainous Forests: A Comparison between Austria and Japan

    • Authors: Mathias Leiter, Mathias Neumann, Tomohiro Egusa, Koji Harashina, Hubert Hasenauer
      First page: 891
      Abstract: Domestic wood production in Japan is low, and more than 60% of the wood consumed is imported. This is surprising because two-thirds of Japan’s land area is covered by forests. The dominant explanations for this low wood self-sufficiency rate are the lack of forest road infrastructure and the small-scale forest ownership structure. Austria is a country that is similar in topography and ownership structure but has a high wood self-sufficiency rate. Therefore, previous research has compared Japan to Austria. However, these studies did not address basic forest properties in much detail. This study uses national forest inventory data from both countries to assess the forest structures and utilization percentages of the annual wood increment. In contrast to the hypothesis, the results show that the two countries have similar increment rates. In contrast to former studies, the findings indicate that Japanese plantation forests have a higher timber stocking volume than Austrian forests. In Japan, the proportion of the standing volume in the 40–60-year-old age class is much higher compared to the other age classes, indicating an unbalanced growing stock. The results show that the utilization percentage is much higher in Austria (88%) than in Japan (53%). Therefore, the Japanese forest sector has a high potential to increase the harvest of wood.
      Citation: Forests
      PubDate: 2022-06-07
      DOI: 10.3390/f13060891
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 892: Analysis of Forest Landscape Preferences and
           Emotional Features of Chinese Forest Recreationists Based on Deep Learning
           of Geotagged Photos

    • Authors: Xitong Zeng, Yongde Zhong, Lingfan Yang, Juan Wei, Xianglong Tang
      First page: 892
      Abstract: Forest landscape preference studies have an important role and significance for forest landscape conservation, quality improvement and utilization. However, there are few studies on objective forest landscape preferences from the perspective of plants and using photos. This study relies on Deep Learning technology to select six case sites in China and uses geotagged photos of forest landscapes posted by the forest recreationists on the “2BULU” app as research objects. The preferences of eight forest landscape scenes, including look down landscape, look forward landscape, look up landscape, single-tree-composed landscape, detailed landscape, overall landscape, forest trail landscape and intra-forest landscape, were explored. It also uses Deepsentibank to perform sentiment analysis on forest landscape photos to better understand Chinese forest recreationists’ forest landscape preferences. The research results show that: (1) From the aesthetic spatial angle, people prefer the flat view, while the attention of the elevated view is relatively low. (2) From the perspective of forest scale and level, forest trail landscape has a high preference, implying that trail landscape plays an important role in forest landscape recreation. The landscape within the forest has a certain preference, while the preference of individual, detailed and overall landscape is low. (3) Although forest landscape photographs are extremely high in positive emotions and emotional states, there are also negative emotions, thus, illustrating that people’s preferences can be both positive and negative.
      Citation: Forests
      PubDate: 2022-06-08
      DOI: 10.3390/f13060892
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 893: A Study on the Vulnerability of the Gross
           Primary Production of Rubber Plantations to Regional Short-Term Flash
           Drought over Hainan Island

    • Authors: Wei Cui, Qian Xiong, Yinqi Zheng, Junfu Zhao, Tangzhe Nie, Lan Wu, Zhongyi Sun
      First page: 893
      Abstract: Rapidly developing droughts, including flash droughts, have occurred frequently in recent years, causing significant damage to agroforestry ecosystems, and they are expected to increase in the future due to global warming. The artificial forest area in China is the largest in the world, and its carbon budget is crucial to the global carbon sink. As the most prominent plantation plant in the tropics, the rubber (Hevea brasiliensis (Willd. ex A. Juss.) Muell. Arg.) ecosystem not only has important economic significance, but also has the potential to be a major natural carbon sink in hot areas. Frequent drought events have a significant impact on rubber ecosystem productivity, yet there have been few reports on the vulnerability of rubber productivity to drought. The objective of this study is to evaluate the vulnerability of rubber ecosystem gross primary production (GPP) to short-term flash drought (STFD) in Hainan Island, utilizing the localized EC-LUE model (eddy covariance–light use efficiency) validated by flux tower observations as the research tool to conduct the scenario simulations which defined by standard relative humidity index (SRHI), in a total of 96 scenarios (timing × intensity). The results show that, in terms of time, the rubber ecosystem in Hainan Island has the highest vulnerability to STFD during the early rainy season and the lowest at the end of the rainy season. From the dry season to the rainy season, the impact of STFD gradually extends to the northeast. Spatially, the vulnerability of the northern island is higher than that of the southern island and that of the western part is higher than that of eastern Hainan Island. With the increase in STFD intensity, the spatial distribution center of the vulnerability of rubber ecosystem GPP in Hainan Island gradually moves southward. The spatiotemporal pattern of the vulnerability of the rubber ecosystem GPP to STFD over Hainan Island plotted by this study is expected to provide decision makers with more accurate information on the prevention and control of drought disaster risk in rubber ecosystems.
      Citation: Forests
      PubDate: 2022-06-08
      DOI: 10.3390/f13060893
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 894: Forest Management Units’ Performance in
           Forest Fire Management Implementation in Central Kalimantan and South
           Sumatra

    • Authors: Kushartati Budiningsih, Fitri Nurfatriani, Mimi Salminah, Nur Arifatul Ulya, Ari Nurlia, Irfan Malik Setiabudi, Daniel S. Mendham
      First page: 894
      Abstract: Wildfires in Indonesia are an annual phenomenon which peak in dry El Nino years, with up to 2.6 million ha of forest and land burnt in the drought year of 2015. This is an annual disaster for the country and surrounding region, with severe impacts on the environment, as well as human health, economic and social factors. Forest Management Units (FMUs, known locally as Kesatuan Pengelolaan Hutan, KPH) are the implementation agencies on the ground that play a strategic role in both the prevention and suppression of forest fires. FMUs are mandated to establish a local fire brigade, to provide adequate personnel and equipment, and to carry out fire prevention as well as suppression programs. This research aimed to analyze the performance of forest fire-related policy implementation. The study was based on five FMUs in fire-prone regions of Central Kalimantan and South Sumatra, Indonesia. The performance of the FMUs is measured by achievement of the policy objectives and effectiveness of policy implementation. Our analysis shows the policies, standards and objectives to manage fire are clear for FMUs, but there are challenges in their implementation, such that fire control activities have not been fully implemented. Most FMUs have limited capacity and resources, as well as complicated budget mechanisms and low community participation. Strengthening FMU capacity will significantly improve their performance in forest fire control, particularly in the initial stages. This can be done at three scales: personnel, organization and system.
      Citation: Forests
      PubDate: 2022-06-09
      DOI: 10.3390/f13060894
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 895: Molecular Genetic Identification Explains
           Differences in Bud Burst Timing among Progenies of Selected Trees of the
           Swedish Douglas Fir Breeding Programme

    • Authors: Charalambos Neophytou, Hubert Hasenauer, Johan Kroon
      First page: 895
      Abstract: Douglas fir is expected to play an increasingly important role in Swedish forestry under a changing climate. Thus far, seed orchards with clones of phenotypically selected trees (plus trees) have been established to supply the market with highly qualitative reproductive material. Given the high genetic variation of the species, its growth properties are significantly affected by the provenance. Here, we applied microsatellite markers to identify the origin of clones selected within the Swedish breeding programme. Moreover, we analysed the timing of bud burst in open-pollinated families of these clones. In particular, we aimed to explain the provenance effect on phenology by using molecular identification as a proxy. A Bayesian clustering analysis with microsatellite data enabled the assignment of the clones to one of the two varieties and also resolved within-variety origins. The phenological observations indicated an earlier bud burst of the interior variety. Within the coastal variety, the northern provenances exhibited a later bud burst. We found a significant effect of the identified origin on bud burst timing. The results of this study will be used to support further breeding efforts.
      Citation: Forests
      PubDate: 2022-06-08
      DOI: 10.3390/f13060895
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 896: Phylogenetic and Functional Structure of Wood
           Communities among Different Disturbance Regimes in a Temperate Mountain
           Forest

    • Authors: Peikun Li, Zihan Geng, Xueying Wang, Panpan Zhang, Jian Zhang, Shengyan Ding, Qiang Fu
      First page: 896
      Abstract: The mechanisms responsible for biodiversity formation and maintenance are central themes in biodiversity conservation. However, the relationships between community assembly, phylogeny, and functional traits remain poorly understood, especially following disturbance. In this study, we examined forest community assembly mechanisms in different disturbance regimes across spatial scales and including tree life history classes, using phylogenetic and functional trait metrics. Across disturbance regimes, phylogenetic structure tended to be over-dispersed, while functional structure tended to be clustered. The over-dispersion of phylogenetic structure also increased from small to large diameter species. Moreover, the explanation of spatial distance for the turnover of phylogenetic and functional structure was increased, while environmental distance explained less structure as disturbance intensity decreased. Our findings suggest that niche theory largely explains forest community assembly in different disturbance regimes. Furthermore, environmental filtering plays a major role in moderate to high disturbance regimes, while competitive exclusion is more important in undisturbed and slightly disturbed ecosystems.
      Citation: Forests
      PubDate: 2022-06-08
      DOI: 10.3390/f13060896
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 897: Alpine Litter Humification and Its Response
           to Reduced Snow Cover: Can More Carbon Be Sequestered in Soils'

    • Authors: Dingyi Wang, Xiangyin Ni, Hongrong Guo, Wenyuan Dai
      First page: 897
      Abstract: While carbon loss from plant litter is well understood, the mechanisms by which this carbon is sequestered in the decomposing litter substrate remains unclear. Here we assessed humus accumulations in five foliar litters during four years of decomposition and their responses to reduced snow cover in an alpine forest. In contrast to the traditional understanding (i.e., the three-stage model), we found that fresh litter had a high humus content (8–13% across species), which consistently increased during litter decomposition and such an increase primarily depended on the accumulation of humic acid. Further, reduced snow cover decreased humus accumulation at early stages but increased it at late stages. These results suggested that humification simultaneously occurred with decomposition during early litter decay, but this process was more sensitive to the changing climate in seasonally snow-covered ecosystems, as previously expected.
      Citation: Forests
      PubDate: 2022-06-09
      DOI: 10.3390/f13060897
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 898: Study on the Shear Strength of Root-Soil
           Composite and Root Reinforcement Mechanism

    • Authors: Pengcheng Li, Xuepei Xiao, Lizhou Wu, Xu Li, Hong Zhang, Jianting Zhou
      First page: 898
      Abstract: This study investigates the effects of root distributions and stress paths on the shear strength of root-soil composites using a consolidated-undrained (CU) triaxial test. On the basis of the limit equilibrium, two root reinforcement coefficients (n and m) are proposed for characterizing the effects of shear strength parameters on the principal stress considering different root distribution angles and root diameters. Then, n and m are introduced into the conventional limit equilibrium equation to develop a new limit equilibrium equation for root-soil composites. The results demonstrate that the root distribution angles (α) and root diameters (d) affect the shear strength of the root-soil composites. Under a consolidated-undrained condition, the effective cohesion (crs′) of the rooted soil is high and decreases in the order of 90°, 0°, 30° and 60°. For the same root distribution angle, crs′ increases with the increasing root diameter. Meanwhile, the effective internal friction angle (φrs′) changes slightly. The failure principal stress of the root-soil composites is positively correlated with n and m. Furthermore, the deformation of the samples indicates that the run-through rate of α = 90° and α = 0° are both 0. Meanwhile, the lateral deformation rate declines from 17.0% for α = 60° to 10.9% for α = 90°.
      Citation: Forests
      PubDate: 2022-06-09
      DOI: 10.3390/f13060898
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 899: Functional Traits of Quercus aliena var.
           acuteserrata in Qinling Huangguan Forest Dynamics Plot: The Relative
           Importance of Plant Size and Habitat

    • Authors: Jing Qiu, Anxia Han, Chunmei He, Xiaoxia Dai, Shihong Jia, Ying Luo, Zhanqing Hao, Qiulong Yin
      First page: 899
      Abstract: Variation in intraspecific functional traits is one of the important components of community variation, and has drawn the attention of researchers. Studying the variation of traits under different plant sizes and habitats helps to reveal the adaptation mechanism of plants. We explored intraspecific trait variations by focusing on the widespread species Quercus aliena var. acuteserrata in a 25 ha warm, temperate, deciduous broadleaved forest plot in the Qinling Mountains. We measured nine morphological and chemical traits for 90 individuals from different plant sizes and habitats. In addition, we evaluated the relative impact of plant size and environment on Q. aliena var. acuteserrata with multiple regression models. We found that plant size explained the most variance of traits. As plant size increased, the trees tended to have lower leaf nitrogen concentrations, lower leaf phosphorus concentrations, higher leaf carbon concentrations, higher leaf dry matter content (LDMC), and thinner leaves, indicating the transformation from rapid resource acquisition strategy to conservative resource-use strategy. Habitats could only explain the changes in chemical traits. Leaf carbon concentration was principally affected by topographical factors and was significant different among habitats. Leaf nitrogen concentration and LPC were significantly limited by soil N and P. In conclusion, shifts in size-dependent traits met the growth requirements of Q. aliena var. acutiserrata; the high tolerance traits associated with this tree species might elucidate important mechanisms for coping with changing environments.
      Citation: Forests
      PubDate: 2022-06-09
      DOI: 10.3390/f13060899
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 900: Changes in Soil Properties and Scots Pine
           Tree Growth Induced by Different Soil Ploughing Prior to Afforestation: A
           Case Study

    • Authors: Gediminas Survila, Iveta Varnagirytė-Kabašinskienė, Kęstutis Armolaitis
      First page: 900
      Abstract: Numerous studies have confirmed that forests have the potential for a significant contribution to carbon sequestration, but afforestation of former agricultural land can be attempted to adopt technologies that further encourage carbon sequestration. The aim of this study was to evaluate the impact of different soil cultivation methods, including deep ploughing and soil cultivation by making microsites and furrows prior to afforestation of former agricultural land, on chemical soil properties and tree growth in 20 years old Scots pine plantations. A naturally regenerated Scots pine stand, representing the non-ploughed soil, was included as a control site. Deep ploughing, among other soil cultivation methods, significantly altered the chemical soil properties. Furthermore, significant effects were indicated in the sites afforested after cultivation by making furrows. A recent study found that, due to deep soil cultivation, higher stocks of soil organic carbon (SOC) and total nitrogen (N) were incorporated into deeper soil layers and were protected from direct environmental impact. Twenty years post afforestation in deeply ploughed sites, we still found a decreased C:N ratio and disbalanced relationship between the concentrations of SOC and total N. The SOC and total N stocks were higher in the subsoil than in the topsoil in the sites afforested after deep ploughing. Moreover, deep ploughing and soil cultivation by furrows prior to afforestation resulted in higher total SOC and total N stocks in the forest floor and mineral 0–80 cm soil layer. A higher total phosphorus (P) concentration in the subsoil and total potassium (K) in the upper mineral soil layer were obtained in the deep ploughing sites and the sites, cultivated by furrows, compared to the non-ploughed sites. Significantly higher total P stock per entire profile was found for the deep ploughing sites and the sites cultivated by furrows than in the naturally regenerated stand. Different soil cultivation methods caused no differences in tree diameter at breast height (DBH) in 20 years old Scots pine stands both in the afforested sites and in the naturally regenerated forest. However, significantly larger tree height in all afforested sites than in the naturally regenerated Scots pine stands was obtained. A lower differentiation in tree DBH was obtained in the deep ploughing sites.
      Citation: Forests
      PubDate: 2022-06-09
      DOI: 10.3390/f13060900
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 901: Use of Hydrological Models to Predict Risk
           for Rutting in Logging Operations

    • Authors: Sima Mohtashami, Tomas Thierfelder, Lars Eliasson, Göran Lindström, Johan Sonesson
      First page: 901
      Abstract: Using hydrological models with a high temporal resolution to predict risk for rutting may be a possible method to improve planning of forwarder trails or to schedule logging operations in sites with low bearing capacity to periods when soil moisture content is at a minimum. We have studied whether descriptions of rut variations, collected in 27 logging sites, can be improved by using hydrological data, modeled by Swedish HYdrological Prediction for Environment (S-HYPE). Other explanatory variables, such as field-surveyed data and spatial data, were also used to describe rut variations within and across logging sites. The results indicated that inclusion of S-HYPE data led to only marginal improvement in explaining the observed variations of the ruts in terms of both “rut depths” within the logging sites and “proportion of forwarder trails with ruts” across the logging sites. However, application of S-HYPE data for adapting depth-to-water (DTW) maps to temporal changes of soil moisture content may be a way to develop more dynamic soil moisture maps for forestry applications.
      Citation: Forests
      PubDate: 2022-06-09
      DOI: 10.3390/f13060901
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 902: Using the Auction Price Method to Estimate
           Payment for Forest Ecosystem Services in Xin’an River Basin in
           China: A BDM Approach

    • Authors: Tan Li, BaoHang Hui, Le Zhu, Tianye Zhang, Tianyu Chen, Chong Su
      First page: 902
      Abstract: Accurately estimating the forest farmers’ protection costs for forest ecosystem services has become a hot issue in ecological economics. In this research, we propose a novel method of using an auction price model to evaluate the forest ecosystem services. We establish a functional relationship between forest farmers and the forestland that belongs to them based on experimental data from Xin’an River Basin in China. The results indicate that the average willingness of farmers to accept payment for forest ecosystem service protection in the low, middle, and high levels of forest quality is 17,123.10, 23,493.75, and 31,064.40 yuan/ha/year, respectively. Moreover, farmers with different individual characteristics, household characteristics, planting characteristics, policy cognition, and ecological awareness are also willing to be paid differently. This research can provide a reference for forest ecosystem protection policies and assist the sustainable forestry development.
      Citation: Forests
      PubDate: 2022-06-09
      DOI: 10.3390/f13060902
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 903: Effect of Thermo-Hydro-Mechanical Treatment
           on Mechanical Properties of Wood Cellulose: A Molecular Dynamics
           Simulation

    • Authors: Feiyu Ouyang, Wei Wang
      First page: 903
      Abstract: Based on molecular dynamics, a water and cellulose model was constructed to provide more theoretical support for the behavior characteristics of cellulose properties in thermo-hydro-mechanical treatment. In this paper, dynamic simulations were carried out under the NPT ensemble at 4, 5.5, 8, and 12 MPa, respectively. Moreover, we analyze the effects on the mechanical properties of wood cellulose in terms of the hydrogen bond numbers, small molecule diffusion coefficients, end-to-end distances, and mechanical parameters of the water–cellulose model. The results indicate that the densification of the water–cellulose model gradually increases with increasing pressure. The effect of pressures on mechanical properties is mainly due to the formation of massive hydrogen bonds within the cellulose chain and between water and cellulose. This is reflected in the fact that water molecules are more difficult to diffuse in the cellulose, which therefore weakens the negative effect of large amounts of water on the cellulose. The increase in end-to-end distance represents the stiffness of the cellulose chains being strengthened. The mechanical parameters indicate an increase in wood stiffness to resist deformation better, while reducing tensile properties at the same time. The dynamic simulation results in this paper can well correspond to macroscopic experiments.
      Citation: Forests
      PubDate: 2022-06-09
      DOI: 10.3390/f13060903
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 904: Impacts of Hurricane Michael on Watershed
           Hydrology: A Case Study in the Southeastern United States

    • Authors: Elijah Worley, Ning Liu, Ge Sun, Steven P. Norman, William M. Christie, Michael Gavazzi, Johnny Boggs, Steven G. McNulty
      First page: 904
      Abstract: Hurricanes are one of the most significant threats to coastal plain forest ecosystems and urban communities of the southeastern U.S., but their implications for watershed hydrology are unclear. Hurricanes have the potential to alter water balances, causing extensive flooding, biogeochemical cycle disruption, and water quality degradation, saltwater intrusion, and increased nutrient sedimentation export in coastal watersheds. This case study focused on Hurricane Michael, a recent catastrophic event that impacted the Gulf coast, the Florida panhandle, southwestern Georgia, and southeastern Alabama. Through empirical (Double Mass Curve) and process-based ecohydrological modeling (WaSSI model) on long-term streamflow data, we explored whether vegetation damage caused by this hurricane resulted in an increase in streamflow two years after the extreme event. We found that monthly streamflow from the Chipola River watershed with an area of 2023 km2 did not change (<6%) appreciably during the first two years following the storm, arguably because only a fraction of the gauged watershed lost substantial tree cover. However, spatially explicit hydrological modeling suggested that several sub-watersheds with the highest decreases in the Normalized Difference Vegetation Index (NDVI) significantly increased their monthly streamflow in 2019 by up to 22%. These modeled streamflow anomalies subsided by the second growing season when vegetation recovered. Overall, this study suggests that changes in vegetation cover after Hurricane Michael did not have lasting impacts on the hydrology of this watershed, and the hydrology of coastal watersheds may be more resilient to hurricane disturbances than previously thought.
      Citation: Forests
      PubDate: 2022-06-09
      DOI: 10.3390/f13060904
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 905: Responses of Nutrient Resorption to Human
           Disturbances in Phoebe bournei Forests

    • Authors: Dehuang Zhu, Suhong Peng, Jinyan Wang, Dafeng Hui
      First page: 905
      Abstract: Nutrient resorption plays an important role in the nutrient conservation of plants and ecosystem nutrient cycling. Although community succession and nutrient addition could regulate plant nutrient resorption, how resorptions of foliar nutrients vary with human disturbances remains unclear. With the economic development, Phoebe bournei forests (PF) have suffered varying degrees of human disturbances in China. In this study, the leaf nutrient resorption efficiency (RE) of the PF under two disturbances (i.e., severe and mild disturbances) were investigated. Results showed that the phosphorus (P) contents of green leaf, senesced leaf, and soil were low under both disturbances, reflecting that the PF had a potential P limitation. Phosphorus and potassium (K) REs were higher under the severe disturbance than those under the mild disturbance. The potassium resorption efficiency was the highest among the three REs under both disturbances. In addition, nutrient resorption efficiencies increased with green leaf nutrient contents under both disturbances. However, there were negative significant relationships of specific leaf area and leaf dry matter content with nutrient resorption under both disturbances. These findings provide a new perspective of nutrient resorption and revealed the potential impact of human disturbances on the nutrient cycle in forest ecosystems.
      Citation: Forests
      PubDate: 2022-06-10
      DOI: 10.3390/f13060905
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 906: Vegetation Type Classification Based on 3D
           Convolutional Neural Network Model: A Case Study of Baishuijiang National
           Nature Reserve

    • Authors: Xinyao Zhou, Wenzuo Zhou, Feng Li, Zhouling Shao, Xiaoli Fu
      First page: 906
      Abstract: Efficient and accurate vegetation type extraction from remote sensing images can provide decision makers with basic forest cover and land use information, and provides a reliable basis for long-term monitoring. With the development of deep learning, the convolutional neural network (CNN) has been used successfully to classify tree species in many studies, but CNN models have rarely been applied in the classification of vegetation types on larger scales. To evaluate the performance of CNN models in the classification of vegetation types, this paper compared the classification accuracy of nine dominant land cover types in Baishuijiang National Nature Reserve with four models: 3D-CNN, 2D-CNN, JSSAN (joint spatial–spectral attention network) and Resnet18, using sentinel-2A data. Comparing the difference in classification accuracy between the direct use of raw sentinel images and fused feature indices sentinel images, the results showed that adding feature indices can improve the overall accuracy of the model. After fusing the characteristic bands, the accuracy of the four models was improved significantly, by 5.46–19.33%. The best performing 3D-CNN model achieved the highest classification accuracy with an overall accuracy of 95.82% and a kappa coefficient of 95.07%. In comparison, 2D-CNN achieved an overall accuracy of 79.07% and a kappa coefficient of 75.44%, JSSAN achieved an overall accuracy of 81.67% and a kappa coefficient of 78.56%, and Resnet18 achieved an overall accuracy of 93.61% and a kappa coefficient of 92.45%. The results showed that the 3D-CNN model can effectively capture vegetation type cover changes from broad-leaved forests at lower elevation, to shrublands and grasslands at higher elevation, across a range spanning 542–4007 m. In experiments using a small amount of sample data, 3D-CNN can better incorporate spatial–spectral information and is more effective in distinguishing the performance of spectrally similar vegetation types, providing an efficient and novel approach to classifying vegetation types in nature reserves with complex conditions.
      Citation: Forests
      PubDate: 2022-06-10
      DOI: 10.3390/f13060906
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 907: Water Uptake and Hormone Modulation Responses
           to Nitrogen Supply in Populus simonii under PEG-Induced Drought Stress

    • Authors: Zhen Li, Xiaoling Wang, Yunshan Liu, Yangyan Zhou, Zhiliang Qian, Zequn Yu, Na Wu, Zhan Bian
      First page: 907
      Abstract: In the present study, the effects of nitrogen (N) supply on water uptake, drought resistance, and hormone regulation were investigated in Populus simonii seedlings grown in hydroponic solution with 5% polyethylene glycol (PEG)-induced drought stress. While acclimating to drought, the P. simonii seedlings exhibited a reduction in growth; differential expression levels of aquaporins (AQPs); activation of auxin (IAA) and abscisic acid (ABA) signaling pathways; a decrease in the net photosynthetic rate and transpiration rate; and an increase in stable nitrogen isotope composition (δ15N), total soluble substances, and intrinsic water use efficiency (WUEi), with a shift in the homeostasis of reactive oxygen species (ROS) production and scavenging. A low N supply (0.01 mM NH4NO3) or sufficient N supply (1 mM NH4NO3) exhibited distinct morphological, physiological, and transcriptional responses during acclimation to drought, primarily due to strong responses in the transcriptional regulation of genes encoding AQPs; higher soluble phenolics, total N concentrations, and ROS scavenging; and lower transpiration rates, IAA content, ABA content, and ROS accumulation with a sufficient N supply. P. simonii can differentially manage water uptake and hormone modulation in response to drought stress under deficient and sufficient N conditions. These results suggested that increased N may contribute to drought tolerance by decreasing the transpiration rate and O2− production while increasing water uptake and antioxidant enzyme activity.
      Citation: Forests
      PubDate: 2022-06-10
      DOI: 10.3390/f13060907
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 908: Drivers of Flammability of Eucalyptus
           globulus Labill Leaves: Terpenes, Essential Oils, and Moisture Content

    • Authors: Fabián Guerrero, Camilo Carmona, Carla Hernández, Mario Toledo, Andrés Arriagada, Lorena Espinoza, Jan Bergmann, Lautaro Taborga, Karen Yáñez, Yulian Carrasco, Ariel A. Muñoz
      First page: 908
      Abstract: Mediterranean climate regions have become more vulnerable to fire due to the extreme weather conditions and numerous Eucalyptus globulus plantation areas. The aim of this study is to analyze the fire hazard related to E. globulus in a forest fire scenario, based on the contrast of thermochemical parameters and their relationship with chemical properties, considering the predominant exotic forest species (E. globulus, Pinus radiata, Acacia dealbata, and Acacia melanoxylon) present in the Valparaiso region, Chile. The results revealed that although all of the studied species were highly flammable, E. globulus was extremely flammable, as its leaves contain high concentrations of essential oils, monoterpenes, and sesquiterpenes, which can generate a flammable atmosphere due to their low flashpoint and the strong negative influence shown between the essential oils, volatile terpenes, and limonene concentration. Moreover, the heat of combustion of E. globulus was positively correlated with its high essential oil contents. Finally, all of the studied species had low flashpoints and high heating values; therefore, they are predisposed to ignite in the presence of a heat source, releasing high amounts of energy during combustion, which contributes to the risk of the formation and spread of canopy fires among these tree formations.
      Citation: Forests
      PubDate: 2022-06-10
      DOI: 10.3390/f13060908
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 909: Influence of Juvenile Growth on Xylem Safety
           and Efficiency in Three Temperate Tree Species

    • Authors: Manish Kumar, Pierre-André Waite, Sharath Shyamappa Paligi, Bernhard Schuldt
      First page: 909
      Abstract: The evolution of the internal water transport system was a prerequisite for high plant productivity. In times of climate change, understanding the dependency of juvenile growth on xylem hydraulic physiology is therefore of high importance. Here, we explored various wood anatomical, hydraulic, and leaf morphological traits related to hydraulic safety and efficiency in three temperate broadleaved tree species (Acer pseudoplatanus, Betula pendula, and Sorbus aucuparia). We took advantage of a severe natural heat wave that resulted in different climatic growing conditions for even-aged plants from the same seed source growing inside a greenhouse and outside. Inside the greenhouse, the daily maximum vapour pressure deficit was on average 36% higher than outside during the growing seasons. Because of the higher atmospheric moisture stress, the biomass production differed up to 5.6-fold between both groups. Except for one species, a high productivity was associated with a high hydraulic efficiency caused by large xylem vessels and a large, supported leaf area. Although no safety-efficiency trade-off was observed, productivity was significantly related to P50 in two of the tree species but without revealing any clear pattern. A considerable plasticity in given traits was observed between both groups, with safety-related traits being more static while efficiency-related traits revealed a higher intra-specific plasticity. This was associated with other wood anatomical and leaf morphological adjustments. We confirm that a high hydraulic efficiency seems to be a prerequisite for a high biomass production, while our controversial results on the growth–xylem safety relationship confirm that safety-efficiency traits are decoupled and that their relationship with juvenile growth and water regime is species-specific.
      Citation: Forests
      PubDate: 2022-06-10
      DOI: 10.3390/f13060909
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 910: Larval Instars and Adult Flight Period of
           Monochamus saltuarius (Coleoptera: Cerambycidae)

    • Authors: Lichun Fan, Jue Wang, Weitao Wang, Yanan Zheng
      First page: 910
      Abstract: Monochamus saltuarius is a vector of Bursaphelenchus xylophilus in Japan, South Korea, and the middle temperate zone of China. However, there are only a few reports on this species in China, and its biological characteristics are still unclear. In this study, we aimed to elucidate the larval development and adult flight period of M. saltuarius to provide a theoretical basis for the effective control of pine wilt disease in the middle temperate zone of China. Seven morphological variables of larvae were measured to determine the number of larval instars, and the adult specimens of M. saltuarius were collected from traps in forests to study the flight period of adults in Fushun, Liaoning, the epidemic center of pine wilt disease in the middle temperate zone of China. The results revealed that the full larval period of M. saltuarius was 279.6 d, and the larvae had five instar stages, with an average duration of 7.4, 14.3, 49.8, 83.6, and 124.5 d, respectively. Additionally, 78.4% of the overwintering larvae were fourth instar, and 21.6% were fifth instar larvae. We also found that the adults began to emerge from early May to late June, and the period was from early May to mid-August in the forest. During the investigations period from 2018 to 2020, the total number of adults captured was minimal at 744, and precipitation was highest at 291.54 mm in 2019. We characterized the larval instars and adult flight period of M. saltuarius, which is a prerequisite for developing appropriate management strategies. The results of this study will provide an important reference for the formulation of strategies to control M. saltuarius and pine wilt disease.
      Citation: Forests
      PubDate: 2022-06-10
      DOI: 10.3390/f13060910
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 911: Recent Advances in Forest Insect Pests and
           Diseases Monitoring Using UAV-Based Data: A Systematic Review

    • Authors: André Duarte, Nuno Borralho, Pedro Cabral, Mário Caetano
      First page: 911
      Abstract: Unmanned aerial vehicles (UAVs) are platforms that have been increasingly used over the last decade to collect data for forest insect pest and disease (FIPD) monitoring. These machines provide flexibility, cost efficiency, and a high temporal and spatial resolution of remotely sensed data. The purpose of this review is to summarize recent contributions and to identify knowledge gaps in UAV remote sensing for FIPD monitoring. A systematic review was performed using the preferred reporting items for systematic reviews and meta-analysis (PRISMA) protocol. We reviewed the full text of 49 studies published between 2015 and 2021. The parameters examined were the taxonomic characteristics, the type of UAV and sensor, data collection and pre-processing, processing and analytical methods, and software used. We found that the number of papers on this topic has increased in recent years, with most being studies located in China and Europe. The main FIPDs studied were pine wilt disease (PWD) and bark beetles (BB) using UAV multirotor architectures. Among the sensor types, multispectral and red–green–blue (RGB) bands were preferred for the monitoring tasks. Regarding the analytical methods, random forest (RF) and deep learning (DL) classifiers were the most frequently applied in UAV imagery processing. This paper discusses the advantages and limitations associated with the use of UAVs and the processing methods for FIPDs, and research gaps and challenges are presented.
      Citation: Forests
      PubDate: 2022-06-10
      DOI: 10.3390/f13060911
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 912: Modeling Primary Branch Diameter and Length
           for Planted Pinus koraiensis by Incorporating Neighbor Competition in
           Northeast China

    • Authors: Huilin Gao, Qifeng Liu, Ying Song, Mengzhu Jiang, You Yin
      First page: 912
      Abstract: Korean pine (Pinus koraiensis Sieb. et Zucc.) is the most important forest vegetation in northeast China. The timber quality of this tree species is largely driven by branch growth and distribution within the crown. Thus, developing branch diameter and length models, especially those that include competition indices, is essential. A total of 48 Korean pine trees were selected to conduct destructive measurements of branch characteristics. This was carried out on all live branches, and a branch diameter and length model was developed. Various indices, including the absolute depth into the branch base (DINC) from tree tip, were used. The equation with the largest Radj2 and smallest root mean square error (RMSE) values was selected as the best model. Each parameter from the best model was reparameterized to the tree variables and competition indices. Finally, the branch diameter model that included diameter at the breast height (DBH), tree height (HT), and the crown length index (CLI), and the branch length model that included DBH and HT exhibited the best performance. The Radj2 and RMSE values were 0.42 and 4 mm, respectively, for the branch diameter model, and 0.77 and 63 cm, respectively, for the branch length model. Branch diameter and length increased as DBH increased and decreased as HT increased. Furthermore, branch diameter decreased as the CLI increased.
      Citation: Forests
      PubDate: 2022-06-11
      DOI: 10.3390/f13060912
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 913: Soil C:N:P Stoichiometric Characteristics and
           Soil Quality Evaluation under Different Restoration Modes in the Loess
           Region of Northern Shaanxi Province

    • Authors: Rui Gao, Ning Ai, Guangquan Liu, Changhai Liu, Zhiyong Zhang
      First page: 913
      Abstract: Vegetation restoration is essential for the stability of the ecological system structure and function in the loess region of North Shaanxi Province. Natural and artificial restoration are the primary modes for vegetation recovery and soil quality improvement in this region. In this study, two adjacent watersheds with similar ecological environment conditions but different restoration modes were selected for research; one watershed is restored naturally (He Gou watershed), and the other is restored artificially (Chai Gou watershed). According to the study of soil stoichiometric characteristics and soil quality after the vegetation restoration in these two watersheds, the results showed: (1) Compared with the natural restoration, artificial restoration was more effective in increasing the content of soil organic carbon and total nitrogen, however, the total phosphorus content of the soil in the natural restoration mode was higher than that in the artificial restoration mode. (2) The ratios of soil C:N, C:P, and N:P showed a decreasing trend with the increase of soil depth at these two restoration modes. (3) In the 0–60 cm soil layer, the soil quality under the artificial restoration mode was better than that of the natural restoration, especially for the soil layer beneath 20 cm. (4) The minimal data set on the soil quality evaluation in the study area included soil organic carbon, capillary water holding quantity, available potassium, soil water content and available phosphorus. It showed a linear relation with the total index data set (y = 0.829x + 0.058, R2 = 0.76) and can reflect the soil quality more sensitively than the total indicator data set.
      Citation: Forests
      PubDate: 2022-06-12
      DOI: 10.3390/f13060913
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 914: Thermal Characteristics and Simulation of
           Enzymatic Lignin Isolated from Chinese Fir and Birch

    • Authors: Jinyue Wang, Suyun Hou, Ziling Shen, Jialong Wen, Chusheng Qi
      First page: 914
      Abstract: Lignin is one of the main components of the plant cell wall, and the thermal properties of in situ biomass lignin are crucial for the multi-scale modeling of biomass properties and the thermodynamic modeling of lignin. In this study, high yields of double enzymatic lignin (DEL) were successfully isolated from softwood Chinese fir (Cunninghamia lanceolate (Lamb.) Hook.) and hardwood white birch (Betula platyphylla Suk.) to represent the in situ wood lignin. Their thermal properties, including specific heat capacity, thermal conductivity, thermal stability, and thermal degradation kinetic parameters, were tested and simulated. The results showed that Chinese fir DEL has different chemical structural units and thermal properties than birch DEL. The specific heat capacities of Chinese fir DEL and birch DEL at 20 °C were 1301 and 1468 J/(kg·K), respectively, and their thermal conductivities were 0.30 and 0.32 W/(m·K). Their specific heat capacity and thermal conductivity showed a positive linear relationship over a temperature range of 20–120 °C. Chinese fir DEL had a better thermal stability and a higher carbon residue than birch DEL. The average activation energy and pre-exponential factor changed with the conversion rate, and their relationships were simulated using linear or quadratic equations in the conversion rate range of 0.02–0.60. A second-order reaction function was found to be the best mechanism function for DEL thermal degradation.
      Citation: Forests
      PubDate: 2022-06-11
      DOI: 10.3390/f13060914
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 915: Effects of Groundwater Mineralization and
           Groundwater Depth on Eco-Physiological Characteristics of Robinia
           pseudoacacia L. in the Yellow River Delta, China

    • Authors: Peili Mao, Longmei Guo, Banghua Cao, Yuanxiang Pang, Wei Liu, Chunxia Tan, Bo Jia, Zhenyu Cao
      First page: 915
      Abstract: Groundwater plays a significant role in influencing the growth and distribution of Robinia pseudoacacia L. plantations, with the largest planting area in the Yellow River Delta, by affecting the soil water–salt environment. This study aimed to clarify the mechanism of groundwater’s influence on the growth of R. pseudoacacia under different levels of groundwater mineralization (GWM) and groundwater depth (GWD). We simulated GWM of 0, 2 and 4 g L−1, and GWD of 0.8, 1.3 and 1.8 m. As GWM increased, soil relative water content (SRWC) and soil salt (dissolved salt) content (SSC) increased; sapling biomass (SB), stem mass (SM), leaf mass (LM), photosynthesis characteristics (maximum net photosynthetic rate (Pn), stomatal conductance (gs), intercellular CO2 concentration (Ci), transpiration rate (E) and water use efficiency (WUE)) decreased; root mass (RM), root mass ratio (RMR) and root–shoot ratio (RSR) first increased then decreased; stem mass ratio (SMR) first decreased then increased; and leaf mass ratio (LMR) increased. As GWD increased, SRWC decreased, but SSC first increased then decreased; SB, RM, RMR, RSR, and photosynthesis characteristics increased; SM and LM first increased then decreased; and SMR and LMR decreased. SRWC and SSC were negatively correlated with SB and photosynthesis characteristics. SRWC was negatively correlated with RMR and RSR, whereas it was positively correlated with LMR. SSC was negatively correlated with SMR, whereas it was positively correlated with LMR. The first principal component, including SB, RM, and photosynthesis characteristics, was related to sapling growth. The second principal component, including RMR, SMR, and RSR, was mainly related to biomass allocation. In conclusion, GWM and GWD affected the soil water and salt content, which were key factors influencing the photosynthesis and growth of R. pseudoacacia. Adjustments in biomass allocation and photosynthesis were the main adaptive strategies of R. pseudoacacia to salt, drought, and flooding stress.
      Citation: Forests
      PubDate: 2022-06-11
      DOI: 10.3390/f13060915
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 916: Management or Climate and Which One Has the
           Greatest Impact on Forest Soil’s Protective Value' A Case Study
           in Romanian Mountains

    • Authors: Cosmin Coșofreț, Gabriel Duduman, Ionuț Barnoaiea, Olivier Bouriaud
      First page: 916
      Abstract: The protective value of forests is expected to be affected by climate change. Applied forest management could absorb or enhance such an impact. In this context, we developed a new protective value index (PVI) that includes biometric and topographical indicators of forest stands. Using PVI and the LandClim model, we simulated 100 years with low- and high-intensity cuttings within three climate scenarios to analyze their influence on the protective value of forests included in the soil protection category. The management types had a low impact on PVI during the simulation period. However, the effects of moderate climate intensified in the second half of the simulation period. In contrast, the extreme climate had the highest impact on PVI and its variables throughout the whole period. The forest stands from lower elevation reached a higher protective value than intermediate and high elevation. Although the low-elevation forest stands are the most vulnerable to climate changes, the ongoing adaptation conducts to stands with higher protective value than stable forests from the higher elevation. The PVI is easily adaptable for different forest landscape models and can be widely applied to provide an integrated assessment of the forest protective value and the management measures to maintain or enhance it.
      Citation: Forests
      PubDate: 2022-06-12
      DOI: 10.3390/f13060916
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 917: Forest Vulnerability to Climate Change: A
           Review for Future Research Framework

    • Authors: Roshani, Haroon Sajjad, Pankaj Kumar, Md Masroor, Md Hibjur Rahaman, Sufia Rehman, Raihan Ahmed, Mehebub Sahana
      First page: 917
      Abstract: Climate change has caused vulnerability not only to the forest ecosystem but also to forest-dependent communities. Therefore, its management is essential to increase forest ecosystem services and reduce vulnerability to climate change using an integrated approach. Although many scientific studies examined climate change impact on forest ecosystems, forest vulnerability assessment, including forest sensitivity, adaptability, sustainability and effective management was found to be scant in the existing literature. Through a systematic review from 1990 to 2019, this paper examined forest vulnerability to climate change and its management practices. In this paper, descriptive, mechanism and thematic analyses were carried out to analyze the state of existing research, in order to understand the concept of vulnerability arising from climate change and forest management issues. The present study proposed a framework for integrated forest assessment and management for addressing such issues in future research. The conversion of forest land into other land uses, forest fragmentation, forest disturbance and the effects of climate change on the forest ecosystem are the existing problems. Forest vulnerability, effective adaptation to forest ecosystems and long-term sustainability are priority areas for future research. This study also calls for undertaking researchers at a local scale to involve communities for the effective management of forest ecosystems.
      Citation: Forests
      PubDate: 2022-06-12
      DOI: 10.3390/f13060917
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 918: Light Regimes Regulate Leaf and Twigs Traits
           of Camellia oleifera (Abel) in Pinus massoniana Plantation Understory

    • Authors: Yaqin Zhang, Qiqiang Guo, Siqiong Luo, Jinwen Pan, Shan Yao, Chao Gao, Youyan Guo, Gang Wang
      First page: 918
      Abstract: Camellia oleifera (Abel) is an economic tree species and one of the four largest oil plants in the world. The leaf and twig responses and plasticity indices of C. oleifera were investigated under four light regimes in Pinus massoniana understory plantations, namely, 100% light intensity (CK), 75% of CK (HL), 50% of CK (ML), and 30% of CK (LL). The morphological characteristics, biomass allocation, and physiological characteristics of C. oleifera leaves and twigs under different light regimes, as well as their plasticity indexes, were comprehensively evaluated. The results showed that leaf area, and specific leaf area, leaf total carbon, total nitrogen, total phosphorus and chlorophyll contents, and photosynthesis increased, which indicates that plants have the strongest adaptability under HL. No fruit appeared in twigs under LL and ML. The plastic morphological traits were greater than the biomass allocation and physiological traits. The plasticity of palisade/sponge tissue thickness and lower epidermis thickness were the lowest. In conclusion, C. oleifera have differences in sensitivity and regulation mechanism according to their differences in leaf morphological characteristics, biomass allocation physiological indicators, and response to light regimes. C. oleifera plants showed obvious phenotypic inhibition under CK, while they can adjust their strategies for using light energy to maintain their own growth and development under HL. The wide range of light adaptation and strong plasticity of C. oleifera may be two important reasons for its existence in heterogeneous habitats, but it needs at least 75% light regimes to complete its normal growth development and fruit setting. The study provides insights into the optimum light regimes for the improvement of the quality and efficiency of C. oleifera in P. massoniana understory plantations.
      Citation: Forests
      PubDate: 2022-06-12
      DOI: 10.3390/f13060918
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 919: Effects of Habitat Differences on Microbial
           Communities during Litter Decomposing in a Subtropical Forest

    • Authors: Hongrong Guo, Fuzhong Wu, Xiaoyue Zhang, Wentao Wei, Ling Zhu, Ruobing Wu, Dingyi Wang
      First page: 919
      Abstract: The differences between aquatic and terrestrial habitats could change microbial community composition and regulate litter decomposition in a subtropical forest, but the linkage remains uncertain. Using microbial phospholipid fatty acids (PLFAs), the litter decomposition associated with microbial organisms was monitored to characterize the differences of microbial communities in the forest floor, headwater stream, and intermittent stream. Habitat type did not significantly affect the concentrations of total PLFA. However, microbial community composition (fungi, G+ bacteria, and eukaryote) was significantly affected by the microenvironment among habitats. Compared with which in headwater stream, more individual PLFAs were identified in the natural forest floor and the intermittent stream during the whole decomposition period. The differences in individual PLFA concentrations were reflected in the forest floor and aquatic system in the early stage of litter decomposition, but they mainly reflected in the headwater stream and the intermittent stream in the later stage of litter decomposition. We linked the relationships between microbial community and litter decomposition and found that communities of decomposers drive differences in litter decomposition rate among habitats. Intriguingly, the microbial community showed the greatest correlation with the decomposition rate of litter in streams. These findings could contribute to the understanding of habitats difference on the microbial community during litter decomposition.
      Citation: Forests
      PubDate: 2022-06-13
      DOI: 10.3390/f13060919
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 920: The Reintroduction Analysis of European Bison
           (Bison bonasus L., 1758) in the North of Romania and the Identification of
           the Most Favourable Locations

    • Authors: Gabriel Dănilă, Sebastian Cătănoiu, Valerian Simioniuc, Sanda Roșca
      First page: 920
      Abstract: We analysed the possibility of reintroducing the European bison (Bison bonasus L.) in the north of Romania—in Suceava, Neamț, and Maramureș counties—as well as increasing the wild European bison population in Neamț county to improve the genetic quality of the existing population. Currently, there is a population of over 50 individuals in the wild in Vânători Neamț Natural Park, Romania. At the same time, an attempt was made to identify the connecting corridors between the free European bison in Neamț county and other populations through new nuclei of European bison released in Suceava and Maramureș counties. In this regard, the hunting grounds with the highest ecological potential for the analysed species were identified using GIS spatial analysis techniques. The aim was also to trace possible ecological corridors linking different reintroduction locations, taking into account the ecological claims of the species. The analysis also followed the size of the European bison groups to be released, the sex ratio of each group, and the periodicity of their releasing. In order to reach viable populations, scenarios and simulations were carried out depending on the age, number, and sex of the relocated specimens. In this regard, the dynamics and the minimum viable population that could survive without risk of extinction were highlighted. The analysis showed that the analysed area has a high potential for the reintroduction of European bison in the wild. The release and creation of new European bison nuclei in the wild creates the premises for natural contacts with the existing free populations in the wild, genetic improvement, and increasing fauna diversity with ecological, social, and economic implications.
      Citation: Forests
      PubDate: 2022-06-13
      DOI: 10.3390/f13060920
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 921: Two Centuries of Drought History in the
           Center of Chihuahua, Mexico

    • Authors: Aldo Rafael Martínez-Sifuentes, José Villanueva-Díaz, Juan Estrada-Ávalos, Ramón Trucíos-Caciano, Teodoro Carlón-Allende, Luis Ubaldo Castruita-Esparza
      First page: 921
      Abstract: Droughts are a climatic phenomenon with local, regional, and large-scale repercussions. Historical knowledge of droughts generated by modeled data allows the development of more accurate climate reconstructions to propose better approaches for the management of hydric resources. The objective of this research was to evaluate the association of precipitation and temperature with data from the NLDAS-002 to develop a reconstruction of droughts in the center of Chihuahua, Mexico using the SPEI from tree rings. We also identified the influence of ocean–atmospheric phenomena on the reconstructed drought index. The best association among chronologies was obtained with the earlywood band and accumulated seasonal precipitation from November of the previous year to June of the current year (r = 0.82, p < 0.05) and for temperature from January to July (r = −0.81, p < 0.05). The reconstructed drought index extended from 1775 to 2017 (243 years), where seven extreme drought events were identified. We found significant correlations between the reconstructed Standardized Precipitation Evapotranspiration Index and the Pacific Decadal Oscillation (r = 0.46, p < 0.05), Atlantic Multidecadal Oscillation (r = −0.34, p < 0.05), Multivariate El Niño Southern Oscillation Index (r = 0.29, p < 0.05), and Southern Oscillation Index (r = −0.22, p < 0.05). The historical reconstruction of hydroclimatology in the center of Chihuahua is important for planning a long-term assessment and for the management of water resources shared by Mexico and the United States.
      Citation: Forests
      PubDate: 2022-06-13
      DOI: 10.3390/f13060921
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 922: Life on the Edge: A Powerful Tsunami
           Overwhelmed Indian Ocean Mangroves One Millennium Ago

    • Authors: Valeska Decker, Carole T. Gee, Pia J. Schucht, Susanne Lindauer, Gösta Hoffmann
      First page: 922
      Abstract: In this paper, we demonstrate how subfossil mangrove wood can be used to elucidate the timing of past tsunami events. Although tsunamis generated by submarine earthquakes along the Makran subduction zone in the Arabian Sea are not unusual, rigorous age documentation is generally lacking. The best known is the only instrument-recorded tsunami, which affected the coastlines of Iran, Pakistan, India, and Oman in November 1945. Eyewitness accounts of the effect along the Oman coastline assert that this tsunami was not destructive. However, a 25-cm-thick shell layer in the lagoon adjacent to the city of Sur was attributed to the 1945 tsunami, although dating of the shell deposit proved difficult, and the radiocarbon dates of mollusk shells were regarded as unreliable. Here, we reinterpret the age of this tsunamigenic layer based on the new discovery of parallel-oriented woody axes in the sedimentological context of the tsunami shell layer in the Sur lagoon. The woody axes were analyzed anatomically and identified as pertaining to the gray mangrove Avicennia. Radiocarbon dating of the wood (905–722 cal BP), along with sedimentological investigations, suggests that the deposition of the woody axes should be attributed to an older tsunami event that occurred ca. 1000 years ago, which has been documented at other locations along the Arabian Sea coastline. From this, we conclude that mangroves grew in this lagoon at that time. Very little is known about ancient mangrove distribution in this region and, so far, no records have been provided for this time window at this site. We also deduce that the tsunami event that occurred one millennium ago must have been substantially more severe than the one in 1945. More accurate dating of tsunamigenic events will aid in calculating the recurrence intervals and magnitude of tsunamis generated along the Makran subduction zone.
      Citation: Forests
      PubDate: 2022-06-13
      DOI: 10.3390/f13060922
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 923: Effects of Habitat Filtering on Tree Growth
           and Mortality across Life Stages in an Old-Growth Temperate Forest

    • Authors: Daxiao Han, Guangze Jin
      First page: 923
      Abstract: A demographic (growth and mortality) trade-off plays a central role in the assembly and dynamics of ecological communities and contributes to tree species’ coexistence. On the basis of field investigation data from the 2010 and 2015 censuses, we evaluated the degrees to which the relative growth rate (RGR) and mortality rate (MR) of saplings and large trees were related to habitat filtering for temperate tree species from a 9 ha forest dynamics plot. The results showed that the relationship between RGR and MR was stronger in saplings than that in large trees. In saplings, the total P (TP) and organic C (OC) of the soil had a significantly positive correlation with RGR. In large trees, volumetric water content had a significantly negative correlation with RGR. In saplings, the bulk density and available P had a significantly positive correlation with MR. In large trees, MR showed a significantly negative correlation with aspect and a significantly positive correlation with TP and OC. Principal component analysis showed that species–habitat association status significantly affected the demographic parameters. A linear regression analysis revealed that the process of habitat filtering contributed to the ontogenetic variation that controlled RGR and MR as the community transitioned from saplings to large trees. Moreover, water availability for large trees played a key role in this process in an old-growth temperate forest.
      Citation: Forests
      PubDate: 2022-06-13
      DOI: 10.3390/f13060923
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 924: Habitat Significantly Affect CWD
           Decomposition but No Home-Field Advantage of the Decomposition Found in a
           Subtropical Forest, China

    • Authors: Hankun Wang, Ling Zhang, Wenping Deng, Junping Liu, Chunsheng Wu, Yi Zhang, Yuanqiu Liu
      First page: 924
      Abstract: The home-field advantage (HFA) effect has been reported to occur in coarse woody debris (CWD) and litter. It is thought that the HFA effect may be due to the specialization of decomposers in their original habitats. However, the relative contribution of microorganisms, particularly fungi and bacteria, to deadwood decomposition is unclear because of differences in their functional at-tributes and carbon requirements, and the microorganisms that drive the HFA effect of deadwood are also unclear. Here, we analysed a dataset of microbial PLFA and substrate properties collected from the soil and CWD of two subtropical trees, Cryptomeria japonica and Platycarya strobilacea, from forests dominated by one or the other of the two species, with both species present in the forests. Our results showed that habitat and tree types all significantly affected CWD respiration rates, the CWD respiration rates were significantly higher in the deciduous broadleaf forests (DBF) than in the coniferous forest (CF) regardless of tree types, but no a large HFA of CWD decomposition found (HFA index was 4.75). Most biomarkers indicated bacteria and fungi were more abundant in the DBF than in the CF, and the concentration of microbial PLFAs was higher in Platycarya strobilacea than in Cryptomeria japonica. In addition, the relative abundance of fungi and soil B/F were remarkably positively correlated with CWD respiration, indicating that fungi may be the primary decomposers of CWD. In conclusion, our work highlights the importance of interactions between the three primary drivers (environment, substrate quality and microbes) on CWD decomposition.
      Citation: Forests
      PubDate: 2022-06-13
      DOI: 10.3390/f13060924
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 925: Histological, Morpho-Physiological, and
           Biochemical Changes during Adventitious Rooting Induced by Exogenous Auxin
           in Magnolia wufengensis Cuttings

    • Authors: Yi Wang, Muhammad Asif Khan, Zhonglong Zhu, Tiemei Hai, Ziyang Sang, Zhongkui Jia, Luyi Ma
      First page: 925
      Abstract: Magnolia wufengensis, a rare ornamental tree species, is now in a huge gap between market demand and actual supply of seedlings. As cutting propagation is one of the most important means to solve the shortage of seedling supply, this study developed an efficient cutting propagation procedure of M. wufengensis, revealed the morphological and histological changes of adventitious root formation, and explored the rhythm correlation between rooting process and physiological and biochemical changes. Cuttings pre-treated with NAA:IBA (2:1) exhibited the best rooting performance. Anatomical analysis demonstrated that adventitious root primordia of M. wufengensis were initiated from cambial and parenchyma cells of xylem, with no relationship to the callus formed on the epidermis. The rooting process of M. wufengenis can be divided into four periods: induction phase (0–8 dap) (dap means days after planting), initiation phase (8–13 dap), expression phase (13–18 dap), and extension phase (18–28 dap). NAA:IBA (2:1) induced the accumulations of 3-indoleacetic-acid and increased the contents of peroxidase and polyphenol-oxidase near the wounding at induction phase. The initiation phase, with the first histological modifications to the formation of meristemoids, correspond to the increase of peroxidase, polyphenol-oxidase, and soluble protein contents. The synergistic reaction of low 3-indoleacetic-acid and high levels of gibberellins and zeatin also stimulates the initiation phase. In the expression and extension phase, high activities of polyphenol-oxidase, IAA-oxidase, and increased contents of soluble protein co-stimulate the emergence and outgrowth of adventitious roots. The present study not only provides optimized protocol by application of auxin combination but also presents insights in the histological, morpho-physiological, and biochemical changes in stem cuttings of M. wufengensis.
      Citation: Forests
      PubDate: 2022-06-13
      DOI: 10.3390/f13060925
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 926: Effect of Herbicide Clopyralid and Imazamox
           on Dehydrogenase Enzyme in Soil of Regenerated Pedunculate Oak Forests

    • Authors: Verica Vasic, Timea Hajnal-Jafari, Simonida Djuric, Branislav Kovacevic, Srdjan Stojnic, Sreten Vasic, Vladislava Galovic, Sasa Orlovic
      First page: 926
      Abstract: Clopyralid and imazamox are successfully used for weed control during the first years of regeneration of pedunculate oak forests. Hence, the question that arises is how these herbicides affect microorganisms, especially the activity of dehydrogenase enzyme, when they reach the soil. Two study sites were selected in regenerated pedunculate oak forests, and the two herbicides were applied in two doses that are used for weed control (clopyralid, 100 g a.i. ha−1 and 120 g a.i. ha−1; imazamox, 40 g a.i. ha−1 and 48 g a.i. ha−1). The effect of the herbicides was evaluated 7, 14, 21, 30, and 60 days after application. A significant reduction in dehydrogenase activity was found on days 7 and 14 at both sites. However, after 14 days there was a recovery of dehydrogenase activity for all treatments such that the values obtained on day 21 did not differ from the control values. The effect of clopyralid and imazamox on dehydrogenase activity was not dose-dependent. Dehydrogenase activity also depended on soil properties, soil sampling time and climatic conditions during the investigation years. The results show that clopyralid and imazamox can reduce soil dehydrogenase activity, but this effect is transient. This can be attributed to the ability of microorganisms to overcome the stress caused by the herbicide by developing the capability to utilize herbicides as a nutrient source and proliferating in such an environment.
      Citation: Forests
      PubDate: 2022-06-13
      DOI: 10.3390/f13060926
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 927: Mechanical Properties of Low-Stiffness
           Out-of-Grade Hybrid Pine—Effects of Knots, Resin and Pith

    • Authors: Rebecca Cherry, Warna Karunasena, Allan Manalo
      First page: 927
      Abstract: Out-of-grade pine timber is an abundant material resource that is underutilised because its mechanical properties are not well understood. Increasing trends toward shorter rotation times and fast-grown plantation pines around the world such as Pinus elliottii × P. caribaea var. hondurensis hybrid (PEE × PCH) mean low-stiffness corewood is becoming a larger portion of this out-of-grade population. This study characterised the modulus and strength properties in bending, compression parallel to grain (CParG) and compression perpendicular to grain (CPerpG), shear and tension strength of low-stiffness out-of-grade PEE × PCH. The effect of resin, knots and pith on these properties were also investigated. The results show that in clear wood, the MOE in bending, CParG, CPerpG and shear modulus are 6.9 GPa, 5.78 GPa, 0.27 GPa and 0.59 GPa, respectively, while strengths are 45.8 MPa, 29.4 MPa, 6.7 MPa, 5.7 MPa, respectively. The tensile strength is 32.4 MPa. Resin significantly increased density 45% higher than clear, but performed similar with the exception of CPerpG MOE and strength which were significantly different. Resin area ratio (RAR) has a moderate correlation with density with an R2 of 0.659 but low to no correlation for mechanical properties. Knots were significantly different to clear for all test types and within a range of 48% to 196%. Knots were high in CPerpG MOE and strength but lower for all other properties and had the largest negative impact on tensile strength. Knot area ratio (KAR) had low to moderate correlation with tension strength and CPerpG MOE with R2 of 0.48 and 0.35, respectively. Pith was within the range of 76% to 121% of non-pith samples for structural performance, some of which were significantly different, and pith samples were higher in density than non-pith. This new information is crucial for the effective establishment of grading rules, design optimisation and utilisation of low-stiffness out-of-grade PEE × PCH as a new material resource in civil engineering applications.
      Citation: Forests
      PubDate: 2022-06-13
      DOI: 10.3390/f13060927
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 928: Provision of Ecosystem Services in Riparian
           Hemiboreal Forest Fixed-Width Buffers

    • Authors: Mārcis Saklaurs, Zane Lībiete, Jānis Donis, Māra Kitenberga, Didzis Elferts, Edgars Jūrmalis, Āris Jansons
      First page: 928
      Abstract: The importance of riparian forest protection is widely acknowledged. However, scientific discussions are still ongoing as to the most suitable and effective protection activities for these forests. The quality of the provision of different ecosystem services in protected riparian forest buffers could provide an insight into the impact of protection regulations. Cultural ecosystem services in riparian forests have an important social-ecological context, especially with the growing interest in recreation activities in forests. The aim of our study was to compare provision of different ecosystem services in riparian forest buffers located both adjacent to (0–50 m) and distant from (51–200 m) the stream. In our study, four small-to-medium-sized rivers in Latvia were used. In total, six different indicators of ecosystem services were estimated, based on data from the National Forest Inventory and the European Soil Data Centre. Bayesian ordinal regression was employed to assess the differences between the two buffer strips. Our results showed that the majority of assessed ecosystem service indicators (Recreation potential of the forest ecosystem, Visual quality of the forest landscape, Potential for the presence of medicinal plants and Potential for the presence of nectar plants) were of higher quality in the adjacent (0–50 m) buffer. Only one indicator (Flora with phytoremediation potential) had significantly higher values in the distant buffer strips (estimate 0.24, CI: [0.11, 0.38]). The observed distribution of quality classes showed that, only for the indicator Potential of medicinal plants, the highest quality class was the most common (>60%), for other indicators dominated average quality class estimations. The obtained results suggested that the current protection status that riparian forest buffers have facilitated maintain the provision of several cultural and regulation & maintenance ecosystem services.
      Citation: Forests
      PubDate: 2022-06-13
      DOI: 10.3390/f13060928
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 929: Effects of Planting, Vegetation Management,
           and Pre-Commercial Thinning on the Growth and Yield of Lodgepole Pine
           Regenerated after Harvesting in Alberta, Canada

    • Authors: W. Richard Dempster
      First page: 929
      Abstract: A large long-term field trial was established in the Upper and Lower Foothills sub-regions of the Canadian boreal forest to monitor the effects of planting, vegetation management, and pre-commercial thinning on the development of lodgepole pine stands following harvesting. Data collected at the end of the trial’s regeneration phase, 17 to 20 years after its establishment, were tested for treatment effects and projected to rotation age. Planting generally improved stocking and increased projected growth and yield of lodgepole pine. On modal sites, planted trees were often greatly outnumbered by natural regeneration; however, on others, typically with either poorer or richer soils, satisfactory restocking was not achieved without planting. Control of competing vegetation by herbicide application facilitated regeneration of pine where it was otherwise difficult or impossible on sites with excessive herbaceous or hardwood competition. Pre-commercial thinning accelerated the growth of individual trees and was projected to shorten rotations in dense stands. Responses to the treatments varied depending on environmental factors. Particular treatments may be effective to meet management objectives under some site conditions but unnecessary or counterproductive elsewhere.
      Citation: Forests
      PubDate: 2022-06-14
      DOI: 10.3390/f13060929
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 930: A Multistage Stochastic Program to Optimize
           Prescribed Burning Locations Using Random Fire Samples

    • Authors: Dung Nguyen, Yu Wei
      First page: 930
      Abstract: Selecting the optimal locations and timing for prescribed burning is challenging when considering uncertainties in weather, fire behavior, and future fire suppression. In this study, we present a sample average approximation (SAA) based multistage stochastic mixed integer program with recourse to optimize prescribed burning decisions. The recourse component of the SAA model considers post-fuel-treatment suppression decisions to manage fire spreads in multiple future planning periods. Our research aims at studying how an SAA model may benefit from using random fire samples to find good locations for prescribed burning during the first planning period. Two hypothetical test cases are designed to compare the impact of fire sample sizes on solution quality, and to illustrate how to identify high-quality period-one prescribed burning solutions. Results suggest that running SAA models using larger fire sample sizes can lead to better period-one solutions, but this benefit will diminish after the sample size reaches to certain thresholds. We found multiple period-one prescribed burning decisions that may result in similar effects in mitigating future wildfire risks.
      Citation: Forests
      PubDate: 2022-06-14
      DOI: 10.3390/f13060930
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 931: Soil Respiration in Planted and Naturally
           Regenerated Castanopis carelesii Forests during Three Years
           Post-Establishment

    • Authors: Zhihua Wei, Chengfang Lin, Chao Xu, Decheng Xiong, Xiaofei Liu, Shidong Chen, Tengchiu Lin, Zhijie Yang, Yusheng Yang
      First page: 931
      Abstract: Reforestation through assisted natural regeneration usually accumulates more biomass carbon than through tree planting, but its effects on soil respiration (Rs) and its components, autotrophic respiration (Ra) and heterotrophic respiration (Rh), are poorly understood despite the importance in forest carbon cycling. In this study, we clear-cut part of a 35-year-old secondary Castanopsis carelesii (C. carelesii) forest and reforested the logged land with C. carelesii via two approaches—active tree planting and assisted natural regeneration—and measured Rs, Ra, and Rh as well as soil temperature and moisture in these forests. In the first two years following reforestation, Rs, Ra and Rh rates were mostly reduced in the two young forests compared to the secondary forest, likely due to reduced photosynthate production and thus carbon substrate input associated with the clear-cut. However, the Rh:Rs ratio was significantly greater in the young plantation than in the other two forests in the first two years, suggesting a greater loss of soil organic carbon from the young plantation. In the third year, the mean Rs, Rh, and Ra rates of the young forest established via assisted natural regeneration were similar to those of the secondary forest, but significantly greater than those of the young plantation. The rates of Rs, Rh, and Ra mostly increased exponentially with increasing soil temperature in all forests, but mostly lack significant relationships with soil moisture. These findings indicate that, compared with reforestation via tree plantation, assisted natural regeneration not only reduced the loss of soil organic carbon via soil respiration, but also had a more rapid recovery of soil respiration to the level of the secondary forest. Our study highlights that, in addition to temperature, carbon substrate availability is also important in regulating soil respiration following reforestation.
      Citation: Forests
      PubDate: 2022-06-14
      DOI: 10.3390/f13060931
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 932: Characterization of the Complete Chloroplast
           Genome Sequence of the Socotra Dragon`s Blood Tree (Dracaena cinnabari
           Balf.)

    • Authors: Konrad Celiński, Joanna Sokołowska, Hanna Fuchs, Petr Maděra, Justyna Wiland-Szymańska
      First page: 932
      Abstract: The Socotra dragon`s blood tree (Dracaena cinnabari Balf.) is endemic to the island of Socotra in Yemen. This iconic species plays an essential role in the survival of associated organisms, acting as an umbrella tree. Overexploitation, overgrazing by livestock, global climate change, and insufficient regeneration mean that the populations of this valuable species are declining in the wild. Although there are many studies on the morphology, anatomy, and physiology of D. cinnabari, no genomic analysis of this endangered species has been performed so far. Therefore, the main aim of this study was to characterize the complete chloroplast sequence genome of D. cinnabari for conservation purposes. The D. cinnabari chloroplast genome is 155,371 bp with a total GC content of 37.5%. It has a quadripartite plastid genome structure composed of one large single-copy region of 83,870 bp, one small single-copy region of 18,471 bp, and two inverted repeat regions of 26,515 bp each. One hundred and thirty-two genes were annotated, 86 of which are protein-coding genes, 38 are transfer RNAs, and eight are ribosomal RNAs. Forty simple sequence repeats have also been identified in this chloroplast genome. Comparative analysis of complete sequences of D. cinnabari chloroplast genomes with other species of the genus Dracaena showed a very high conservativeness of their structure and organization. Phylogenetic inference showed that D. cinnabari is much closer to D. draco, D. cochinchinensis, and D. cambodiana than to D. terniflora, D. angustifolia, D. hokouensis, and D. elliptica. The results obtained in this study provide new and valuable omics data for further phylogenetic studies of the genus Dracaena as well as enable the protection of genetic resources of highly endangered D. cinnabari.
      Citation: Forests
      PubDate: 2022-06-14
      DOI: 10.3390/f13060932
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 933: The Use of Multilayer Perceptron (MLP) to
           Reduce Delamination during Drilling into Melamine Faced Chipboard

    • Authors: Albina Jegorowa, Jarosław Kurek, Michał Kruk, Jarosław Górski
      First page: 933
      Abstract: Drilling into melamine-faced-wood-based panels is one of the most common processes in modern furniture manufacturing. Delamination is usually the main and the most troublesome quality defect in this case. A lot of scientific studies draw the conclusion that the progress of tool wearing during the cutting of wood-based materials is the key problem. Therefore, tool condition monitoring and the replacement of worn tools at the right time is the most useful and common (in the industrial practice) way to reduce delamination. However, the automation of this process is still a problem due to various issues. There is yet no commercial (even prototypical) offer for the furniture industry in this regard. For this reason, it is considered advisable to try to use the multilayer perceptron (MLP) algorithm to automatically identify a drill’s condition during drilling in a laminated chipboard. It has been established that, for practical purposes, it is important to distinguish between the three different classes of tool conditions, which can be conventionally described as “Green” (keep working), “Red” (implicitly stop and replace) and “Yellow” (warning signal—stop and replace if you want to avoid deterioration in cutting quality). To register the signals generated in the cutting zone and those constituting the basis for the identification of the tool condition in the “on-line” mode, the following elements were used: contact sensor of acoustic emission, accelerometer for vibration, two-component force gauge and a microphone. The classification effects (with an overall accuracy above 70%) were ultimately fairly decent but slightly worse than those of the classification algorithms tested earlier (i.e., “nearest neighbors” or “support vector machine” algorithms). The most troublesome, however, is the fact that serious errors (mistakes between “Green” and “Red” classes) were occasionally noted (for about 1% of the analyzed cases).
      Citation: Forests
      PubDate: 2022-06-15
      DOI: 10.3390/f13060933
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 934: Towards the Third Millennium Changes in
           Siberian Triple Tree-Ring Stable Isotopes

    • Authors: Olga V. Churakova (Sidorova), Marina V. Fonti, Valentin V. Barinov, Mikhail S. Zharkov, Anna V. Taynik, Tatyana V. Trushkina, Alexander V. Kirdyanov, Alberto Arzac, Matthias Saurer
      First page: 934
      Abstract: Significant air temperature and precipitation changes have occurred since the 2000s in vulnerable Siberian subarctic regions and urged updates of available chronologies towards the third millennium. It is important to better understand recent climatic changes compared to the past decades, centuries and even millennia. In this study, we present the first annually resolved triple tree-ring isotope dataset (δ13C, δ18O and δ2H) for the eastern part of the Taimyr Peninsula (TAY) and northeastern Yakutia (YAK) from 1900 to 2021. We found that the novel and largely unexplored δ2H of larch tree-ring cellulose was linked significantly with δ18O for the YAK site, which was affected by averaged April–June air temperatures and evaporation. Simulated by the Land Surface Processes and Exchanges (LPX-Bern 1.0) model, the water fraction per year for soil depths at 0–20 and 20–30 cm was significantly linked with the new eco-hydrological tree-ring δ2H data. Our results suggest increasing evapotranspiration and response of trees’ water relation to rising thaw water uptake from lower (20–30 cm) soil depth. A positive effect of July air temperature on tree-ring δ18O and a negative impact of July precipitation were found, indicating dry conditions. The δ13C in larch tree-ring cellulose for both sites showed negative correlations with July precipitation and relative humidity, confirming dry environmental conditions towards the third millennium.
      Citation: Forests
      PubDate: 2022-06-15
      DOI: 10.3390/f13060934
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 935: The Impact of Climate and Adaptative Forest
           Management on the Intra-Annual Growth of Pinus halepensis Based on
           Long-Term Dendrometer Recordings

    • Authors: Jorge Olivar, Andreas Rais, Hans Pretzsch, Felipe Bravo
      First page: 935
      Abstract: Future climate predictions for the Mediterranean area include prolonged droughts and an increase in the frequency of extreme events. Silvicultural modification of stand density can buffer the response of tree growth to changes in climate by enhancing soil water availability. We analyzed the stem growth dynamics of Pinus halepensis, including the days of the year when 25%, 50% and 75% of the intra-annual basal growth was achieved, considering two different social statuses (suppressed and dominant) under four different thinning intensities (15%, 30% and 45% removal of the basal area) for 8 years, based on biweekly band dendrometer recordings. The moment the trees reached 25% of the intra-annual basal growth was significantly influenced by the amount of precipitation accumulated during the previous winter. On the other hand, the moment the trees reached 75% of the intra-annual basal growth was significantly influenced by water availability in a shorter term, which also affected the length of the growing period. Modification of competition through thinning showed a significantly positive impact on growth, causing a delayed attainment of 50% of the intra-annual basal growth. These results imply valuable information about forest dynamics that will support forest managers’ decisions dealing with low water-availability in forests.
      Citation: Forests
      PubDate: 2022-06-15
      DOI: 10.3390/f13060935
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 936: Growth Response of Nine Tree Species to Water
           Supply in Planting Soils Representative for Urban Street Tree Sites

    • Authors: Alexander Schütt, Joscha Nico Becker, Christoph Reisdorff, Annette Eschenbach
      First page: 936
      Abstract: In urban environments, newly planted street trees suffer from poor site conditions and limited water availability. It is challenging to provide site conditions that allow the trees to thrive in the long term, particularly under climate change. Knowledge about the hydrological properties of artificial urban planting soils related to the response of tree species-specific growth is crucial, but still lacking. Therefore, we established a three-year experimental field setup to investigate the response of nine tree species (135 individuals) to two common urban planting soils and a loamy silt reference. We determined and measured soil hydrological parameters and monitored tree growth. Our results revealed low plant available water capacities (6% and 10% v/v) and hydraulic conductivity restrictions with the drying of the sandy-textured urban planting soils. Therefore, tree species that are investing in fine root growth to extract water from dry soils might be more successful than trees that are lowering their water potential. Tree growth was overall evidently lower in the urban planting soils compared with the reference and differed between and within the species. We showed that using unfavorable planting soils causes severe, species-specific growth deficits reflecting limited above-ground carbon uptake as a consequence of low water availability.
      Citation: Forests
      PubDate: 2022-06-15
      DOI: 10.3390/f13060936
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 937: Does the Age of Pinus sylvestris Mother Trees
           Influence Reproductive Capacity and Offspring Seedling Survival'

    • Authors: Marta Pardos, Javier Vázquez-Piqué, Luis Benito, Guillermo Madrigal, Reyes Alejano, Manuel Fernández, Rafael Calama
      First page: 937
      Abstract: We assess how the age of Pinus sylvestris mother trees influences seed size, seed viability, germination capacity and later offspring seedling survival under greenhouse conditions. Thirty trees ranging from 30 to 219 years old were selected in the north facing slopes in the Sierra de Guadarrama, where we could find the oldest Pinus sylvestris trees in central Spain. Forty cones per tree were harvested to study cone and seed characteristics (size and weight), seed viability and germination capacity related to the mother tree age. In addition, 25 germinated seeds per tree were grown in a greenhouse to assess offspring seedling survival during a death trial, where watering was stopped. Significant differences between trees in cone and seed morphological traits were observed. The age of the mother tree had a significant effect on cone size, seed size, and seed weight, but there was no effect on seed germination capacity and seed viability. Seedling survival was mainly affected by the decrease in water availability. However, a significant effect of the tree age was found once soil moisture had reached 0%. Our results show the ability of overmature Pinus sylvestris trees to maintain a relatively high reproductive capacity that assures its persistence.
      Citation: Forests
      PubDate: 2022-06-15
      DOI: 10.3390/f13060937
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 938: Germination and Growth Characteristics of
           Quercus myrsinifolia Blume Seedlings According to Seed Coat Removal,
           Type of Potting Soil and Irrigation Cycle

    • Authors: Eun-Ji Choi, Seong-Hyeon Yong, Dong-Jin Park, Kwan-Been Park, Do-Hyun Kim, Eon-Ju Jin, Myung-Suk Choi
      First page: 938
      Abstract: The importance of evergreen oak species is increasing due to changes in the ecosystem caused by climate change and environmental changes such as fine dust and carbon dioxide. The Quercus myrsinifolia Blume seeds showed a recalcitrant seed property, where the germination rate decreased when the moisture content was decreased. For seedling propagation of evergreen oak, the effect of oak seed coat (pericarp and testa) removal on germination and seedling growth as well as the effect of potting soil and irrigation cycle on seedling quality were investigated. The germination rate and germination characteristics of Q. myrsinifolia evergreen oak seeds showed significant differences depending on the storage period and the presence or absence of seed coat. Seed coat removal significantly increased germination rate compared to intact seeds, accelerated mean germination time, and increased germination rate and germination value. There was no significant difference in germination rate according to the storage period. The growth of Q. myrsinifolia seedlings was much better in the seeds with the seed coat removed than the intact seeds. The root collar diameter of seedlings germinated from intact seeds was 2.44 mm, and the root collar diameter of seedlings from which the seed coat was removed was 3.38 mm. As a result of the growth characteristics according to the potting soil, 1- and 3-year-old Q. myrsinifolia seedlings showed excellent root growth in commercial potting soil and sand mixed potting soil. Consequently, seedling quality index was 0.124–0.257 according to irrigation and 0.149–0.262 according to potting soil. From observing the root growth of the seedlings according to the irrigation treatment, in the case of 3-year-old seedlings, the total root length was 432 cm when irrigated every 3 days, and the growth was the best. The above results are expected to contribute significantly to the mass propagation of Q. myrsinifolia, which is important for warming and urban greening.
      Citation: Forests
      PubDate: 2022-06-15
      DOI: 10.3390/f13060938
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 939: Windstorm Impacts on Forest-Related
           Socio-Ecological Systems: An Analysis from a Socio-Economic and
           Institutional Perspective

    • Authors: Federica Romagnoli, Mauro Masiero, Laura Secco
      First page: 939
      Abstract: Windstorms are considered among the most impacting natural events for European forests and related Socio-Ecological Systems (SES). Given that their intensity and frequency are increasing, an in-depth understanding of their impacts is crucial to mitigate risks and potential negative effects. However, so far, scientific research on windstorm impacts has mainly focused on environmental dimensions, while socio-economic and institutional ones are rarely taken into consideration. Our analysis aims at enriching the current scientific knowledge on windstorm impacts on forest SES by providing an overview of the state-of-the-art academic investigations on windstorm impacts on socio-economic and institutional dimensions. Overall, 46 papers were reviewed to identify the most recurrent post-windstorm dynamics and drivers that influence resilience and adaptation of socio-economic, institutional and related governance dimensions of European forest SES. Results show that the current scientific knowledge on socio-economic impacts of windstorms mainly concentrates on forest-related stakeholders and sectors, paying little attention to the broader social, cultural and institutional drivers that contribute to forest SES resilience. Further, cascade effects linking environmental, social and institutional dimensions are poorly analyzed. This restricted focus could lead to an incomplete understanding of the dynamics shaping socio-economic adaptability to windstorms, affecting long-term and sustainable recovery from extreme natural events. To correctly frame effective, intersectoral and coordinated recovery strategies gaining a deeper understanding of human–environment interactions is needed, as well as acknowledging the positive influence of causal relationships in improving forest-related SES resilience.
      Citation: Forests
      PubDate: 2022-06-15
      DOI: 10.3390/f13060939
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 940: Protein Markers for the Identification of
           Cork Oak Plants Infected with Phytophthora cinnamomi by Applying an
           (α, β)‑k‑Feature Set Approach

    • Authors: Ana Cristina Coelho, Gabriela Schütz
      First page: 940
      Abstract: Cork oak decline in Mediterranean forests is a complex phenomenon, observed with remarkable frequency in the southern part of the Iberian Peninsula, causing the weakening and death of these woody plants. The defoliation of the canopy, the presence of dry peripheral branches, and exudations on the trunk are visible symptoms used for the prognosis of decline, complemented by the presence of Phytophthora cinnamomi identified in the rhizosphere of the trees and adjacent soils. Recently, a large proteomic dataset obtained from the leaves of cork oak plants inoculated and non-inoculated with P. cinnamomi has become available. We explored it to search for an optimal set of proteins, markers of the biological pattern of interaction with the oomycete. Thus, using published data from the cork oak leaf proteome, we mathematically modelled the problem as an α, β-k-Feature Set Problem to select molecular markers. A set of proteins (features) that represent dominant effects on the host metabolism resulting from pathogen action on roots was found. These results contribute to an early diagnosis of biochemical changes occurring in cork oak associated with P. cinnamomi infection. We hypothesize that these markers may be decisive in identifying trees that go into decline due to interactions with the pathogen, assisting the management of cork oak forest ecosystems.
      Citation: Forests
      PubDate: 2022-06-15
      DOI: 10.3390/f13060940
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 941: Forests for a Better Future: Sustainability,
           Innovation and Interdisciplinarity

    • Authors: Angela Lo Monaco, Cate Macinnis-Ng, Om P. Rajora
      First page: 941
      Abstract: Forests offer a solution to climate change through carbon storage and providing ecosystem services and sustainable products [...]
      Citation: Forests
      PubDate: 2022-06-16
      DOI: 10.3390/f13060941
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 942: Regularly Planted Rather Than Natural
           Understory of Norway Spruce (Picea abies H. Karst.) Contributes to the
           Individual Stability of Canopy Silver Birch (Betula pendula Roth.)

    • Authors: Oskars Krišāns, Roberts Matisons, Jānis Vuguls, Endijs Bāders, Steffen Rust, Didzis Elferts, Renāte Saleniece, Āris Jansons
      First page: 942
      Abstract: Forest plantations, particularly high-density planted stands, are considered to be more prone to wind damage compared to naturally regenerated stands. The wind resistance (mechanical stability) of plantations can, however, be improved by close-to-natural management, for example, combining pioneer and shade-tolerant species. Presumably, the stability of such stands would be enhanced by the reduced competition of canopy trees and stronger root contacts provided by understory trees, which depend on spatial distribution. In the hemiboreal forest zone, silver birch (Betula pendula Roth.) and Norway spruce (Picea abies (L.) H.Karst.) form such a combination naturally. In this study, the static tree-pulling tests were performed to estimate the mechanical stability of canopy silver birch growing with random Norway spruce understory in naturally regenerated (post-clear-cut) and regularly planted bi-species mixed stands. The regular mixing of the high-density bi-species stand significantly improved the loading resistance of canopy silver birch compared to the naturally regenerated stands of similar composition and age. Such an effect might be related to the stratification of the canopy space between pioneer birch and shade-tolerant spruce, which improved the individual stability of the canopy trees. Further, a regular rooting network of the planted stands likely contributed to the stability by reducing weak spots. Accordingly, the wind resistance of trees in regularly planted bi-species stands might be improved, avoiding additional management.
      Citation: Forests
      PubDate: 2022-06-16
      DOI: 10.3390/f13060942
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 943: Verification of a Deep Learning-Based Tree
           Species Identification Model Using Images of Broadleaf and Coniferous Tree
           Leaves

    • Authors: Yasushi Minowa, Yuhsuke Kubota, Shun Nakatsukasa
      First page: 943
      Abstract: The objective of this study was to verify the accuracy of tree species identification using deep learning with leaf images of broadleaf and coniferous trees in outdoor photographs. For each of 12 broadleaf and eight coniferous tree species, we acquired 300 photographs of leaves and used those to produce 72,000 256 × 256-pixel images. We used Caffe as the deep learning framework and AlexNet and GoogLeNet as the deep learning algorithms. We constructed four learning models that combined two learning patterns: one for individual classification of 20 species and the other for two-group classification (broadleaf vs. coniferous trees), with and without data augmentation, respectively. The performance of the proposed model was evaluated according to the MCC and F-score. Both classification models exhibited very high accuracy for all learning patterns; the highest MCC was 0.997 for GoogLeNet with data augmentation. The classification accuracy was higher for broadleaf trees when the model was trained using broadleaf only; for coniferous trees, the classification accuracy was higher when the model was trained using both tree types simultaneously than when it was trained using coniferous trees only.
      Citation: Forests
      PubDate: 2022-06-16
      DOI: 10.3390/f13060943
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 944: China’s Forest Eco-Bank Project: An
           Analysis Based on the Actor-Network Theory

    • Authors: Guangcheng Wei, Xiangzhi Kong, Yumeng Wang, Qiang Gao
      First page: 944
      Abstract: The high degree of fragmentation and unsustainable exploitation patterns of forest resources have become prominent obstacles to the realisation of the economic and social value of China’s forest resources. China’s forest eco-bank (FEB) project was set up to achieve centralised utilisation of diffuse forest resources in an underdeveloped area. Analysing FEB projects is of great significance to countries with abundant forest resources aiming to benefit from the economic and ecological functions of such resources and achieve sustainable economic and social development. This study uses the actor-network theory framework to analyse cooperation among various actors in the implementation process of the FEB project in China. Our results indicate the following. First, the government was the principal actor playing a vital role in motivating the other parties and driving the project forward. Second, the diffuse nature of China’s forest resources is a major obstacle to their utilisation. The centralised integration of forest resources is a prerequisite for their effective utilisation. Finally, it is necessary to improve the balance of interests of the various actors to promote a more stable actor network and attract more actors to participate in the FEB project.
      Citation: Forests
      PubDate: 2022-06-16
      DOI: 10.3390/f13060944
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 945: Use of Harvester Data to Estimate the Amount
           of Merchantable Non-Utilized Woody Material Remaining after Mechanized
           Cut-to-Length Forest Operations

    • Authors: Myriam Delmaire, Eric R. Labelle
      First page: 945
      Abstract: An agreement between the provincial government of Québec, Canada and the forest industry executing forest management activities on public lands has been established regarding non-utilized woody material (NUWM) left on the cutting area. Problems linked to this agreement are compounded by labor shortages, which have an impact on the precision of the mandatory inventories. The objectives of this study were to: (1) reconstruct and estimate the merchantable NUWM volume beyond the last processed log of balsam fir and white spruce with the use of harvester on-board computer (OBC) data, (2) design a software tool to estimate and spatialize merchantable NUWM, and (3) perform an explorative comparison between the OBC method and conventional field inventory. In total, five sites were harvested to develop the volume algorithms. Each site was harvested by a single-grip harvester operating a different OBC system (OPTI4G, Log Mate 500, and Log Mate 510). Results suggest that, with Varjo’s model and linear regression, estimation of NUWM volume using OBC data is possible. The spatialization tool positioned NUWM within the harvest area for StanForD and StanForD 2010. The explorative comparison highlighted a possible cost reduction of approx. 36.8 $/ha and an increase of precision for the OBC method.
      Citation: Forests
      PubDate: 2022-06-17
      DOI: 10.3390/f13060945
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 946: SNP Detection in Pinus pinaster Transcriptome
           and Association with Resistance to Pinewood Nematode

    • Authors: Inês Modesto, Vera Inácio, Polina Novikova, Isabel Carrasquinho, Yves Van de Peer, Célia M. Miguel
      First page: 946
      Abstract: Pinewood nematode (PWN, Bursaphelenchus xylophilus) is the causal agent of pine wilt disease (PWD), which severely affects Pinus pinaster stands in southwestern Europe. Despite the high susceptibility of P. pinaster, individuals of selected half-sib families have shown genetic variability in survival after PWN inoculation, indicating that breeding for resistance can be a valuable strategy to control PWD. In this work, RNA-seq data from susceptible and resistant plants inoculated with PWN were used for SNP discovery and analysis. A total of 186,506 SNPs were identified, of which 31 were highly differentiated between resistant and susceptible plants, including SNPs in genes involved in cell wall lignification, a process previously linked to PWN resistance. Fifteen of these SNPs were selected for validation through Sanger sequencing and 14 were validated. To evaluate SNP-phenotype associations, 40 half-sib plants were genotyped for six validated SNPs. Associations with phenotype after PWN inoculation were found for two SNPs in two different genes (MEE12 and PCMP-E91), as well as two haplotypes of HIPP41, although significance was not maintained following Bonferroni correction. SNPs here detected may be useful for the development of molecular markers for PWD resistance and should be further investigated in future association studies.
      Citation: Forests
      PubDate: 2022-06-17
      DOI: 10.3390/f13060946
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 947: Magnetic Treatment Improves the Seedling
           Growth, Nitrogen Metabolism, and Mineral Nutrient Contents in Populus
           × euramericana ‘Neva’ under Cadmium Stress

    • Authors: Xiumei Liu, Lu Wang, Fengyun Ma, Jianyao Guo, Hong Zhu, Shiyuan Meng, Sisheng Bi, Huatian Wang
      First page: 947
      Abstract: This pot experiment was carried out to investigate the mechanism underlying nutrient metabolism and seedling growth responses to magnetic treatment following exposure to cadmium (Cd) stress. A magnetic device of 300 Gs was applied during Cd(NO3)2 solution treatment at 0 and 100 mM·L−1. One-year-old seedlings of Populus × euramericana ‘Neva’ were treated with different Cd(NO3)2 solutions in the presence or absence of magnetic treatment for 30 days. Seedling growth and physiological–biochemical indexes were measured under Cd stress. The contents of ammonium (NH4+–N), nitrate (NO3––N), and total nitrogen (TN) in leaves, as well as NH4+–N and TN in roots, were increased by magnetic treatment combined with Cd stress, although the NO3––N content was decreased. The activities of nitrate reductase (NR), nitrite reductase (NiR), glutathione reductase (GR), and glutamate synthase (GOGAT) in leaves and the activities of NR, glutamine synthetase (GS), and GOGAT in roots were stimulated by magnetic treatment; conversely, the NiR activity in roots was inhibited by magnetic effects. Magnetic treatment improved the synthesis of cysteine (Cys) and glutamine (Gln) in leaves and reduced the contents of glutamic acid (Glu) and glycine (Gly), while the contents of Cys, Glu, Gln, and Gly were increased in roots. The contents of Ca, Mg, Fe, Mn, Zn, and Cu in leaves were increased by magnetic treatment under Cd stress, whereas the content of K was reduced. In roots, the contents of K, Ca, and Fe were increased by magnetic treatment under Cd stress, but the contents of Na, Mg, Mn, Zn, and Cu were decreased. Magnetization could regulate the uptake of mineral nutrients by roots and translocation from the roots to the aboveground parts by affecting root morphology. Magnetic treatment could also improve nitrogen assimilation and the synthesis of free amino acids by stimulating the activities of key enzymes.
      Citation: Forests
      PubDate: 2022-06-17
      DOI: 10.3390/f13060947
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 948: Audio-Visual Preferences for the
           Exercise-Oriented Population in Urban Forest Parks in China

    • Authors: Jian Xu, Muchun Li, Ziyang Gu, Yongle Xie, Ningrui Jia
      First page: 948
      Abstract: The purpose of this study is to explore the audio-visual preferences of exercisers in urban forest parks in China and to make practical suggestions for park landscape design. Taking Beigushan Forest Park in Lianyungang City, Jiangsu Province as a case, based on field research and questionnaire survey, this study analyzed the audio-visual preference characteristics of exercisers in the park, revealed the correlation between audio-visual preference and exercisers’ behaviors and individual characteristics, and explored the influence of audio-visual preferences on exercise feelings by establishing a structural equation model. It was found that (1) the forest and its avenue landscape and birdsong are most preferred by exercisers; (2) the audio-visual preferences of people with different exercise forms differ, for example, people who slowly walk, run, and briskly walk have stronger preferences for natural soundscape and visual landscape, while people who use fitness equipment have stronger inclusiveness for human activity sound and prefer public facility-based landscapes. In addition, some individual characteristics such as exercise intensity and exercise frequency significantly affect exercisers’ audio-visual preferences; (3) visual landscape preferences have a greater direct impact on exercise feelings, with natural waterscape having the greatest direct impact, but overall soundscape preferences do not have a high degree of direct impact on exercise feelings, with natural sound still having a strong positive impact. These findings provide a more quantitative basis for the landscape design of urban forest parks from the perspective of exercise behavior.
      Citation: Forests
      PubDate: 2022-06-17
      DOI: 10.3390/f13060948
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 949: Change Analysis of Urban Tree Canopy in
           Miami-Dade County

    • Authors: Hartwig H. Hochmair, Adam Benjamin, Daniel Gann, Levente Juhász, Paulo Olivas, Zhaohui J. Fu
      First page: 949
      Abstract: This study mapped and analyzed urban tree canopy change between 2014 and 2019 within the Urban Development Boundary of Miami-Dade County, Florida. The goal was to identify local areas of tree canopy gain or loss over this 5-year period. The comparison is based on land cover maps delineated from WorldView-2 satellite data applying a random forest classification algorithm, in combination with publicly available vector data of infrastructure (roads, railroads) and land use maps (water, cropland). Existing urban tree canopy (EUTC) was computed for census block groups and municipalities to compare tree canopy cover loss or gain to support strategic planning of equitable urban reforestation. For the entire study area, the percentage of EUTC did not change significantly between 2014 (19.9 ± 1.2%) and 2019 (20.1 ± 1.5%). However, some municipalities experienced changes in EUTC by over 10%. Comparison of Landsat-8 Thermal Infrared satellite imagery between both periods identified land cover change patterns that were associated with an increase or decrease in surface temperature. A significantly negative relationship between percentage of African American population and tree canopy in 2014 turned statistically insignificant in 2019, whereas the negative relationship with percentage of Hispanic population further strengthened in 2019 compared to 2014.
      Citation: Forests
      PubDate: 2022-06-17
      DOI: 10.3390/f13060949
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 950: Validation of the Habitat Quality Index of
           Tetraclinis articulata Forests and Its Application in Cost-Effectiveness
           Analysis of Restoration Projects

    • Authors: Juan Miguel Moya-Pérez, Miguel Ángel Esteve-Selma, Adrián Ruiz Rocamora, Antonio Félix Carrillo
      First page: 950
      Abstract: The latest reports from the European Commission warn of the need to improve the conservation status of its forest habitats. Native populations of priority habitat 9570 (Tetraclinis articulata forests) in continental Europe are located in the southeast of the Iberian Peninsula. The LIFE-TETRACLINIS-EUROPE project aimed to improve habitat conservation conditions. As part of the results of this project, a habitat quality index was proposed with the intention of evaluating both its conservation conditions and its evolution after the implemented action measures. The variables used in this index were selected with the aim of achieving high representativeness of the quality of the habitat while at the same time being easily integrated into monitoring programs. In this paper, we intend to verify the suitability of the variables chosen for this index, its sensitivity to discriminate different conservation levels, and its possible inclusion in forest management programs through a cost-effectiveness analysis.
      Citation: Forests
      PubDate: 2022-06-17
      DOI: 10.3390/f13060950
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 951: Foliar Water Uptake Capacity in Six Mangrove
           Species

    • Authors: Katrien H. D. Schaepdryver, Willem Goossens, Abdulla Naseef, Sreejith Kalpuzha Ashtamoorthy, Kathy Steppe
      First page: 951
      Abstract: Foliar water uptake (FWU) is a mechanism that enables plants to acquire water from the atmosphere through their leaves. As mangroves live in a saline sediment water environment, the mechanism of FWU might be of vital importance to acquire freshwater and grow. The goal of this study was to assess the FWU capacity of six different mangrove species belonging to four genera using a series of submersion experiments in which the leaf mass increase was measured and expressed per unit leaf area. The foliar water uptake capacity differed between species with the highest and lowest average water uptake in Avicennia marina (Forssk.) Vierh. (1.52 ± 0.48 mg H2O cm−2) and Bruguiera gymnorhiza (L.) Lam. (0.13 ± 0.06 mg H2O cm−2), respectively. Salt-excreting species showed a higher FWU capacity than non-excreting species. Moreover, A. marina, a salt-excreting species, showed a distinct leaf anatomical trait, i.e., trichomes, which were not observed in the other species and might be involved in the water absorption process. The storage of leaves in moist Ziplock bags prior to measurement caused leaf water uptake to already occur during transport to the field station, which proportionately increased the leaf water potential (A. marina: −0.31 ± 0.13 MPa and B. gymnorhiza: −2.70 ± 0.27 MPa). This increase should be considered when performing best practice leaf water potential measurements but did not affect the quantification of FWU capacity because of the water potential gradient between a leaf and the surrounding water during submersion. Our results highlight the differences that exist in FWU capacity between species residing in the same area and growing under the same environmental conditions. This comparative study therefore enhances our understanding of mangrove species’ functioning.
      Citation: Forests
      PubDate: 2022-06-17
      DOI: 10.3390/f13060951
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 952: Identification and Functional Evaluation of
           Three Polyubiquitin Promoters from Hevea brasiliensis

    • Authors: Shichao Xin, Jinu Udayabhanu, Xuemei Dai, Yuwei Hua, Yueting Fan, Huasun Huang, Tiandai Huang
      First page: 952
      Abstract: Hevea brasiliensis is an economically important tree species that provides the only commercial source of natural rubber. The replacement of the CaMV35S promoter by endogenous polyubiquitin promoters may be a viable way to improve the genetic transformation of this species. However, no endogenous polyubiquitin promoters in Hevea have been reported yet. Here, we identified three Hevea polyubiquitin genes HbUBI10.1, HbUBI10.2 and HbUBI10.3, which encode ubiquitin monomers having nearly identical amino acid sequences to that of AtUBQ10. The genomic fragments upstream of these HbUBI genes, including the signature leading introns, were amplified as putative HbUBI promoters. In silico analysis showed that a number of cis-acting elements which are conserved within strong constitutive polyubiquitin promoters were presented in these HbUBI promoters. Transcriptomic data revealed that HbUBI10.1 and HbUBI10.2 had a constitutive expression in Hevea plants. Semi-quantitative RT-PCR showed that these three HbUBI genes were expressed higher than the GUS gene driven by CaMV35S in transgenic Hevea leaves. All three HbUBI promoters exhibited the capability to direct GFP expression in both transient and stable transformation assays, although they produced lower protoplast transformation efficiencies than the CaMV35S promoter. These HbUBI promoters will expand the availability of promoters for driving the transgene expression in Hevea genetic engineering.
      Citation: Forests
      PubDate: 2022-06-17
      DOI: 10.3390/f13060952
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 953: Over-Expression of Larch DAL1 Accelerates
           Life-Cycle Progression in Arabidopsis

    • Authors: Zha-Long Ye, Qiao-Lu Zang, Dong-Xia Cheng, Xiang-Yi Li, Li-Wang Qi, Wan-Feng Li
      First page: 953
      Abstract: Homologs of Larix kaempferiDEFICIENS-AGAMOUS-LIKE 1 (LaDAL1) promote flowering in Arabidopsis. However, their functional role in the whole life-cycle is limited. Here, we analyzed the phenotypes and transcriptomes of Arabidopsis plants over-expressing LaDAL1. With respect to the defined life-cycle stage of Arabidopsis based on the meristem state, the results showed that LaDAL1 promoted seed germination, bolting, flower initiation, and global proliferative arrest, indicating that LaDAL1 accelerates the meristem reactivation, the transitions of vegetative meristem to inflorescence and flower meristem, and meristem arrest. As a marker gene of meristem, TERMINAL FLOWER 1 was down-regulated after LaDAL1 over-expression. These results reveal that LaDAL1 accelerates the life-cycle progression in Arabidopsis by promoting the transition of meristem fate, providing more and novel functional information about the conifer age-related gene DAL1.
      Citation: Forests
      PubDate: 2022-06-17
      DOI: 10.3390/f13060953
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 954: Forest Dependence of Rural Communities in the
           Republic of Moldova

    • Authors: Nicolae Talpă, Aurel Lozan, Aureliu Florin Hălălișan, Bogdan Popa
      First page: 954
      Abstract: The high dependency on forest resources and the fact that forests play an important role in the lives of people in poorer rural areas are well known forest characteristics. This depicts a deep connection between people and nature. For the rural communities, forest ecosystems display another important role, namely in alleviating poverty through stable provisions of vital functions and livelihoods. The present study aims to identify what influences the current level of the local communities of the Republic of Moldova’s dependence on forests, who still face poverty-related challenges, and how ecosystem services provided by forests are perceived by the rural population. After six years since the last forest dependency research, this time the level of dependence is investigated using the same methodology, but through improved socio-economic conditions. Although the consumption of non-timber forest products decreased, the pressure on forest resources remained at the same level due to the high dependence of communities on firewood. The highest dependency was found in low-income households, manifested by their necessity to spend an average share of 18.8% from their total income on firewood due to their restricted access to forest resources. Since most Moldovans rely more heavily on subsistence-oriented forest products such as fuelwood, forest management sustainability efforts might not be achieved as long as the need for wood products exceeds the supply, and neither will the living conditions of the poor be improved. Solutions should be sought based on cross-sectoral and long-term approaches by involving all stakeholders, and not neglecting local communities.
      Citation: Forests
      PubDate: 2022-06-18
      DOI: 10.3390/f13060954
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 955: Discovery and Biology of Spathius verustus
           Chao (Hymenoptera: Braconidae), a Potential Biological Agent on Two
           Monochamus Vectors of the Pinewood Nematode

    • Authors: Moo-Sung Kim, Jong-Kook Jung, Ki-Jeong Hong, Chang-Jun Kim, Bong-Woo Lee, Il-Kwon Kim
      First page: 955
      Abstract: Pine wilt disease in Korea can be managed by reducing vector density through chemical application. To reduce the side effects from pesticides, effective natural enemies must be identified and used to reduce the vectors’ natural density. Sentinel logs were used to investigate a parasitoid wasp parasitic to Monochamus alternatus and Monochamus saltuarius, the vectors of Bursaphelenchus xylophilus, which causes this disease. During 2016–2017, the parasitoid wasps distributed in the Pinus densiflora and Pinus koraiensis forests were surveyed using sentinel logs at six different areas. An ectoparasitoid wasp Spathius verustus Chao of M. alternatus and M. saltuarius was identified. We showed for the first time that S. verustus was parasitic to M. alternatus in South Korea and to M. saltuarius worldwide. The parasitism rates were affected by region and session but not by the sentinel log height in the tree and the distances between the trap and forest edge locations. Studies also showed that S. verustus appeared to prefer M. alternatus to M. saltuarius as a host. This study unveiled the ecological details of S. verustus. Further research on various environmental factors such as regional differences, host density differences, and the degree of damage from the pine wilt disease is required to understand the effects of environmental or ecological factors on parasitism rates.
      Citation: Forests
      PubDate: 2022-06-18
      DOI: 10.3390/f13060955
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 956: Wood Anatomical Traits Respond to Climate but
           More Individualistically as Compared to Radial Growth: Analyze Trees, Not
           Means

    • Authors: Angelo Rita, Jesús Julio Camarero, Michele Colangelo, Ester González de Andrés, Marín Pompa-García
      First page: 956
      Abstract: Wood encodes environmental information that can be recovered through the study of tree-ring width and wood anatomical variables such as lumen area or cell-wall thickness. Anatomical variables often provide a stronger hydroclimate signal than tree-ring width, but they show a low tree-to-tree coherence. We investigate the sources of variation in tree-ring width, lumen area, and cell-wall thickness in three pine species inhabiting sites with contrasting climate conditions: Pinus lumholtzii in wet-summer northern Mexico, and Pinus halepensis and Pinus sylvestris in dry-summer north-eastern Spain. We quantified the amount of variance of these three variables explained by spring and summer water balance and how it varied among trees. Wood anatomical variables accounted for a larger inter-individual variability than tree-ring width data. Anatomical traits responded to hydroclimate more individualistically than tree-ring width. This individualistic response represents an important issue in long-term studies on wood anatomical characteristics. We emphasized the degree of variation among individuals of the same population, which has far-reaching implications for understanding tree species’ responses to climate change. Dendroclimatic and wood anatomical studies should focus on trees rather than on the mean population series.
      Citation: Forests
      PubDate: 2022-06-18
      DOI: 10.3390/f13060956
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 957: Distribution Pattern of Woody Plants in a
           Mountain Forest Ecosystem Influenced by Topography and Monsoons

    • Authors: Xiayan Zhou, Zhao Wang, Wenxin Liu, Qianjin Fu, Yizhen Shao, Fengqin Liu, Yongzhong Ye, Yun Chen, Zhiliang Yuan
      First page: 957
      Abstract: Many areas are affected by the monsoon because of different sea and land positions. At the same time, the blocking effect of a mountain range forms different habitats on both sides of the mountain range. However, the distribution mechanism of woody plants is unclear in mountain forest ecosystems influenced by topography and monsoons. In this study, 10 plots, each with an area of 1 hm2 (100 m × 100 m), were randomly established on the south and north aspects of a mountain forest. We examined community structure differences and distribution preferences of woody plants on both sides of the mountain. Our findings were as follows: (1) The characteristics of woody plant assemblages differed among various aspects. (2) Network analysis showed that specialization index was 0.186 and modularity index was 0.235, and the torus translation test showed that a total of 45 species were detected to be associated with at least one of the habitats (45/106, 42.45%). (3) The community stability of the south aspect was higher than that of the north aspect. Our findings suggest that the distribution of woody plants among different aspects was specialized and not random in alpine forest ecosystems. This study contributes to a clear understanding of the distribution mechanism of woody plants in mountain forest ecosystems influenced by topography and monsoons.
      Citation: Forests
      PubDate: 2022-06-19
      DOI: 10.3390/f13060957
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 958: Changes in Soil Microbial Community and
           Carbon Flux Regime across a Subtropical Montane Peatland-to-Forest
           Successional Series in Taiwan

    • Authors: Chun-Yao Chen, I-Ling Lai, Shih-Chieh Chang
      First page: 958
      Abstract: Subtropical montane peatland is among several rare ecosystems that continue to receive insufficient scientific exploration. We analyzed the vegetation types and soil bacterial composition, as well as surface carbon dioxide and methane fluxes along a successional peatland-to-upland-forest series in one such ecosystem in Taiwan. The Yuanyang Lake (YYL) study site is characterized by low temperature, high precipitation, prevailing fog, and acidic soil, which are typical conditions for the surrounding dominant Chamaecyparis obtusa var. formosana forest. Bacterial communities were dominated by Acidobacteriota and Proteobacteria. Along the bog-to-forest gradient, Proteobacteria decreased and Acidobacteriota increased while CO2 fluxes increased and CH4 fluxes decreased. Principal coordinate analysis allowed separating samples into four clusters, which correspond to samples from the bog, marsh, forest, and forest outside of the watershed. The majority of bacterial genera were found in all plots, suggesting that these communities can easily switch to other types. Variation among samples from the same vegetation type suggests influence of habitat heterogeneity on bacterial community composition. Variations of soil water content and season caused the variations of carbon fluxes. While CO2 flux decreased exponentially with increasing soil water content, the CH4 fluxes exhibited an exponential increase together with soil water content. Because YYL is in a process of gradual terrestrialization, especially under the warming climate, we expect changes in microbial composition and the greenhouse gas budget at the landscape scale within the next decades.
      Citation: Forests
      PubDate: 2022-06-19
      DOI: 10.3390/f13060958
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 959: Phenotypic Variation in Seed Morphochemical
           and Seedling Traits in Four Chinese Provenances of Xanthoceras sorbifolium
           

    • Authors: Yuxin Chen, Kexin Wang, Zishuo Zhang, Lijin Ou, Xiaofei Luo, Fei Zhu, Peter M. Hirst, Yan Ao
      First page: 959
      Abstract: Variability in seed and seedling traits of Xanthoceras sorbifolium Bunge was evaluated at the population level. Seed samples were collected from four provenances in China and examined for variations in morphometric traits, chemical components, and seedling growth in the nursery stage. There were significant differences in the seed length, width, dry weight, 1000-seed weight, oil concentration, Mg and Cu concentrations, root biomass, and root–stem biomass ratio. The largest seed in terms of size and weight was from Ongniud Banner, Inner Mongolia (OB), but these seeds also had the lowest seed oil concentration. At the end of the first growing season in the nursery, seedlings stopped growing one month earlier in height than in diameter. The provenance difference in height was significant at the first 2 months after sowing but disappeared later. Genotypic variance (Vg) was found to be higher than corresponding environmental (Ve) variance for seed length, seed width, seed dry weight, 1000-seed weight, diameter, and root biomass, indicating that these parameters were strongly inherited and there was ample scope for improvement. Moreover, correlations between seed and seedling traits and climatic and geographical factors were assessed. Some significant intercharacter correlations were found, such as between seed length, width and seed weight, between oil concentration and seed size, and between seedling height, diameter, and root biomass. Combining the seed- and seedling-related parameters, our results indicated that Mulei, Xinjiang (ML) may be used as an ideal material for a further improvement program.
      Citation: Forests
      PubDate: 2022-06-19
      DOI: 10.3390/f13060959
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 960: Psychophysiological Impacts of Traffic Sounds
           in Urban Green Spaces

    • Authors: Boya Yu, Jie Bai, Linjie Wen, Yuying Chai
      First page: 960
      Abstract: The goal of this study is to investigate the psychophysiological effects of traffic sounds in urban green spaces. In a laboratory experiment, psychological and physiological responses to four traffic sounds were measured, including road, conventional train, high-speed train, and tram. The findings demonstrated that traffic sounds had significant detrimental psychological and physiological effects. In terms of psychological responses, the peak sound level outperformed the equivalent sound level in determining the psychological impact of traffic sounds. The physiological effects of traffic sounds were shown to be significantly influenced by sound type and sound level. The physiological response to the high-speed train sound differed significantly from the other three traffic sounds. The physiological effects of road traffic sounds were found to be unrelated to the sound level. On the contrary, as for the railway sounds, the change in sound level was observed to have a significant impact on the participants’ physiological indicators.
      Citation: Forests
      PubDate: 2022-06-19
      DOI: 10.3390/f13060960
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 961: Auxiliary Seed Treatment Is Necessary to
           Increase Recruitment of a Critically Endangered Species, Abies
           beshanzuensis (Pinaceae)

    • Authors: Rui Hu, Yajing Liu, Jiaxin Zhang, Hua Xing, Sha Jiang, Yu Liu
      First page: 961
      Abstract: Disordered germination is widely observed in plant species with extremely small populations (PSESPs) in China. Abies beshanzuensis M. H. Wu, a PSESP (with only three extant adults in Zhejiang Province, China) that also has poor seed germination in the field, belongs to the Pinaceae family. Pinaceae generally tend toward symbiosis with ectomycorrhizal (ECM) fungi to alleviate climate change-induced stresses. Therefore, exploring how to improve seed germination of A. beshanzuensis and whether it is an ECM species will contribute to increasing recruitment for conducting further conservation research. In this study, four temperature regimes (10/15 °C, 15/20 °C, 20/25 °C, and 25/30 °C) were selected to explore the response of seed germination to rising temperature. Based on the microscopic features of fine roots, together with molecular techniques, the mycorrhizal type of this species was identified. The seed germination of A. beshanzuensis was increased from 1–2% to around 4.5% by 14-day cold stratification and under 20/25 °C fluctuating temperature conditions. Our findings indicated that A. beshanzuensis may be endangered as a result of insufficient seedling recruitment due to poor germination under the current climate. A. beshanzuensis was confirmed as an ECM fungi-associated tree species. This study highlights the necessity of incorporating auxiliary seed treatment into population recovery programs of A. beshanzuensis, thereby better conserving the species under ongoing environmental changes.
      Citation: Forests
      PubDate: 2022-06-19
      DOI: 10.3390/f13060961
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 962: Chemical Compositions of Walnut (Juglans
           Spp.) Oil: Combined Effects of Genetic and Climatic Factors

    • Authors: Hanbo Yang, Xu Xiao, Jingjing Li, Fang Wang, Jiaxuan Mi, Yujie Shi, Fang He, Lianghua Chen, Fan Zhang, Xueqin Wan
      First page: 962
      Abstract: Walnut oil is a high-value oil product. Investigation of the variation and the main climatic factors affecting the oil’s chemical composition is vital for breeding and oil quality improvement. Therefore, the fatty acid, micronutrients, and secondary metabolites compositions and contents in walnut oil were determined in three species: Juglans regia L. (common walnut), J. sigillata Dode (iron walnut), and their hybrids (Juglans sigillata Dode × J. regia L.), which were cultivated aat different sites. The major fatty acids were linoleic (51.39–63.12%), oleic (18.40–33.56%), and linolenic acid (6.52–11.69%). High variation in the contents of fatty acids, micronutrients, and secondary metabolites was found between both species and sites. Interestingly, myristic, margaric, and margaroleic acid were only detected in the hybrids’ walnut oil, yet α-tocopherol was only detected in common and iron walnut oil. Climatic factors significantly affected the composition and content of fatty acid, whereas δ-tocopherol was mostly dependent on the genetic factors. The average relative humidity explained the most variation in the fatty acids, micronutrients, and secondary metabolites, which showed a significant positive and negative effect on the monounsaturated fatty acids and polyunsaturated fatty acids, respectively. These findings contribute to the provision of better guidance in matching sites with walnut trees, and improvement of the nutritional value of walnut oil.
      Citation: Forests
      PubDate: 2022-06-20
      DOI: 10.3390/f13060962
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 963: Forest Fire Detection of FY-3D Using Genetic
           Algorithm and Brightness Temperature Change

    • Authors: Zhangyu Dong, Jinqiu Yu, Sen An, Jin Zhang, Jinhui Li, Daoli Xu
      First page: 963
      Abstract: As one of China’s new generation polar-orbiting meteorological satellites, FengYun-3D (FY-3D) provides critical data for forest fire detection. Most of the existing related methods identify fire points by comparing the spatial features and setting thresholds empirically. However, they ignore temporal features that are associated with forest fires. Besides, they are difficult to generalize to multiple areas with different environmental characteristics. A novel method based on FY-3D combining the genetic algorithm and brightness temperature change detection is proposed in this work to improve these problems. After analyzing the spatial features of the FY-3D data, it adaptively detects potential fire points based on these features using the genetic algorithm, then filters the points with contextual information. To address the false alarms resulting from the confusing spectral characteristics between fire pixels and conventional hotspots, temporal information is introduced and the “MIR change rate” based on the multitemporal brightness temperature change is further proposed. In order to evaluate the performance of the proposed algorithm, several fire events occurring in different areas are used for testing. The Moderate-Resolution Imaging Spectroradiometer (MODIS) Thermal Anomalies/Fire products (MYD14) is chosen as the validation data to assess the accuracy of the proposed algorithm. A comparison of results demonstrates that the algorithm can identify fire points effectively and obtain a higher accuracy than the previous FY-3D algorithm.
      Citation: Forests
      PubDate: 2022-06-20
      DOI: 10.3390/f13060963
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 964: Oak Decline Syndrome in Korean Forests:
           History, Biology, and Prospects for Korean Oak Wilt

    • Authors: Won Il Choi, Dong-Hyeon Lee, Jong Bin Jung, Young-Seuk Park
      First page: 964
      Abstract: Oak decline syndrome has been observed in South Korea and Japan and variously referred to as Korean oak wilt (KOW) and Japanese oak wilt (JOW). We reviewed aspects of the historical occurrence of KOW, disease cycle, and its potential causes. KOW has been seen principally in Mongolian oak (Quercus mongolica Fisch. ex Ledeb.). The first occurrence of KOW was in 2004 in Seongnam, South Korea. KOW is associated with the fungus Raffaelea quercus-mongolicae, which is vectored by the ambrosia beetle Platypus koryoensis. In addition, it has been suggested that yeasts have evolved a symbiotic relationship with the vector without antagonism for the pathogenic fungus. The number of trees in Korea killed by KOW increased to about 331,000 in 2011, but then decreased to about 157,000 in 2019. We hypothesized that trees infected by R. quercus-mongolicae accumulate phenolic compounds in the sapwood and the vector (P. koryoensis) beetles then avoid these trees. Therefore, the number of hosts available for the beetle after a KOW outbreak decrease due to accumulation of phenolic compounds in the wood, although most oak trees survive outbreaks. Therefore, P. koryoensis beetles move longer distances after outbreaks to find susceptible host trees. Novel occurrence of KOW in Korea may be due to either (1) an increase in tree age (size) in Korean oak stands, for which the beetle has a known preference or (2) climate change, which may be increasing the number of weakened or stressed trees, for which P. koryoensis also shows a preference.
      Citation: Forests
      PubDate: 2022-06-20
      DOI: 10.3390/f13060964
      Issue No: Vol. 13, No. 6 (2022)
       
  • Forests, Vol. 13, Pages 965: Changes in the Abundance of Monoterpenes from
           Breathable Air of a Mediterranean Conifer Forest: When Is the Best Time
           for a Human Healthy Leisure Activity'

    • Authors: Domingo Sancho-Knapik, Eustaquio Gil-Pelegrín, Juan Pedro Ferrio, David Alonso-Forn, Rubén Martín-Sánchez, José Víctor dos Santos Silva, Junichi Imanishi, José Javier Peguero-Pina, María Ángeles Sanz
      First page: 965
      Abstract: The exposure to monoterpenes emitted by plants to the air might provide human health benefits during forest-based leisure activities. However, forests, especially Mediterranean ones, lack studies to relate forest production and the emission of monoterpenes, considering potential human forest exposure. Thus, the aim of this study was to analyze the variation in the abundance of monoterpenes in the human breathable air under the canopy of a Mediterranean conifer forest, evaluating the influence of different factors. For this purpose, from March to November 2018, we monitored the abundance of monoterpenes in the air at nose height, leaf development, air temperature and soil water potential in a mountain Mediterranean forest of Pinus pinaster located in Sierra de Albarracín (Teruel, Spain). We detected six monoterpenes, with α-pinene, β-pinene and limonene being the three most abundant. Temperature was the main environmental factor driving the abundance of monoterpenes in air, with a maxima of abundance found during summer. Leaf development in spring decreased the abundance, while after a drought period, the abundance increased. Thus, people enjoying forest-based activities in Mediterranean conifer areas would be more exposed to air monoterpenes when the temperature increases during the period after leaf development, as long as the trees are not severely water-stressed. If that is the case, the abundance of monoterpenes in the air would increase after the drought period.
      Citation: Forests
      PubDate: 2022-06-20
      DOI: 10.3390/f13060965
      Issue No: Vol. 13, No. 6 (2022)
       
 
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