Betula Costata Research Articles

Differences and similarities in radial growth of Betula species to climate change

Betula platyphylla and Betula costata are important species in mixed broadleaved-Korean pine (Pinus koraiensis) forests. However, the specific ways in which their growth is affected by warm temperatures and drought remain unclear. To address this issue, 60 and 62 tree-ring cores of B. platyphylla and B. costata were collected in Yichun, China. Using dendrochronological methods, the response and adaptation of these species to climate change were examined. A “hysteresis effect” was found in the rings of both species, linked to May–September moisture conditions of the previous year. Radial growth of B. costata was positively correlated with the standardized precipitation-evapotranspiration index (SPEI), the precipitation from September to October of the previous year, and the relative humidity in October of the previous year. Growth of B. costata is primarily restricted by moisture conditions from September to October. In contrast, B. platyphylla growth is mainly limited by minimum temperatures in May–June of both the previous and current years. After droughts, B. platyphylla had a faster recovery rate compared to B. costata. In the context of rising temperatures since 1980, the correlation between B. platyphylla growth and monthly SPEI became positive and strengthened over time, while the growth of B. costata showed no conspicuous change. Our findings suggest that the growth of B. platyphylla is already affected by warming temperatures, whereas B. costata may become limited if warming continues or intensifies. Climate change could disrupt the succession of these species, possibly accelerating the succession of pioneer species. The results of this research are of great significance for understanding how the growth changes of birch species under warming and drying conditions, and contribute to understanding the structural adaptation of mixed broadleaved-Korean pine (Pinus koraiensis) forests under climate change.

Evolution of vegetation of the Lake Khanka Depression in the southernmost of the Russian Far East in the Holocene

This paper presents recently obtained palynological results regarding to the evolution of vegetation of the Khanka Depression in the Holocene. Radiocarbon-dated pollen records evidence that the evolution of vegetation in this area was more complicated than one has previously thought. As a result of a rapid increase in heat supply in the Early Holocene, the plants of the Manchurian flora, primarily Ulmus davidiana, Ulmus laciniata, Quercus mongolica, and Pinus koraiensis, began to expand to the Khanka Depression. However, Sphagnum mires with Betula grandulosa, Betula pubescens, and sparse forests of Larix, still remained in plains and valleys. Picea jezoensis, Pinus pumila, Betula grandulosa, Betula alnobetula, Betula pubescens, Pinus pumila and Larix were widespread in the mountains. During the Middle Holocene these cold-tolerant plants of the north-boreal flora, completely disappeared. Broad-leaved and fir-pine forests have become widespread. The vegetation of the Khanka Depression compared with modern one was characterized by great diversity of broad-leaved plants. At the beginning of the Late Holocene cooling has caused the expansion of Betula grandulosa, Betula alnobetula, Abies nephrolepis, Picea jezoensis, Betula pubescens, Betula costata, and Alnus hirsuta. The areas of forb meadows expanded on the plains. Larch sparse forests, thickets with domination of Betula grandulosa and Sphagnum mires reappeared. However, some thermophilic plants, such as Pinus koraiensis, Abies nephrolepis, Quercus mongolica, Juglans mandshurica, Ulmus davidiana, and Ulmus laciniata have survived. Since 1 300 cal BP, vegetation of the Khanka Depression began to degrade due to fires, plowing of the land, and deforestation.

Nitrogen supply influences photosynthetic acclimation of yellow birch (Betula costata Trautv.) to the combination of elevated CO2 and warmer temperature

Nitrogen supply influences photosynthetic acclimation of yellow birch (Betula costata Trautv.) to the combination of elevated CO2 and warmer temperature

Intelligent Automation Manufacturing for Betula Solid Timber Based on Machine Vision Detection and Optimization Grading System Applied to Building Materials

Wood material is the foundation of wood structure architecture, and its production technology and equipment technology decide the development and upgrading of modern wood structure architecture. Aiming at the problems of low automation degree, low material utilization rate, low production efficiency and high labor costs in the process of traditional wood processing, we explore the integration and innovation of the traditional wood processing industry and modern industrial Internet information technology on the basis of studying the properties of Betula (Betula costata) solid wood materials, wood comprehensive utilization rate, wood structure component development and processing technology requirements, and form an intelligent, automatic and industrial production mode for building materials. Through technology and methods such as mechanical design, automation technology, machine vision, deep learning, optimization algorithm, electronic design automation, computer aided manufacturing, etc., the key technologies of intelligent automatic optimization of wood materials were studied, and intelligent automatic production lines of Betula species identification, log optimization sawing, solid timber longitudinal multiblade sawing, sawn timber quality detection and solid timber optimizing cross-cuts are built. Based on the machine vision method, features are extracted; a tree species, defect classification and recognition model database is established; an image processing algorithm with high recognition accuracy, as well as fast processing speed and high robustness are studied; non-destructive testing and classification methods of machine vision are optimized; key problems of online rapid classification, detection and optimization of sawing are solved and production quality and processing efficiency are improved. Finally, the timber defect detection accuracy and Betula timber yield are analyzed, and the comprehensive utilization value of optimized sawing timber is compared with the comprehensive utilization value of manually marking sawing timber. The processing cost and efficiency of Betula sawing timber with an intelligent automatic production line are calculated. The test results show that the average detection accuracy of timber defect type, size and location is 89.69%, 89.69%, 92.25% and 82.29%, respectively, and the detection stability is high. By adopting intelligent automatic detection, classification and optimization sawing production line of wood, the comprehensive utilization value of optimized sawing timber is 14.13% higher than that of manual marking sawing timber, and 16,089.29 m3 more building materials can be processed annually. In the process of intelligent automatic wood processing, the intelligent detection system is used to detect defects, improve production performance and production efficiency and reduce labor costs. Compared with the traditional wood processing process, the method studied in this paper is improved to optimize the production line processing performance and processing technology. The research and development of an intelligent automatic production system for solid wood can promote the application and development of an automatic industrial production mode for sawn timber for the wood structure construction industry, deepen the integration of artificial intelligence technology, Internet technology and the whole wood processing industry and lead the upgrading of building materials for wood structures to an intelligent manufacturing production mode.

Dynamic variation of non-structural carbohydrates in branches and leaves of temperate broad-leaved tree species over a complete life history

The composition of non-structural carbohydrates (NSC), one of the photosynthetic products of plants, reflects the survival strategy of a plant. Although several studies have investigated variation of NSC content in woody plants over a set time scale, few studies have considered the dynamic variation of NSC over a continuous life history. In this study, the leaves, new twigs, and old branches of seven temperate broad-leaved tree species (diffuse-porous species:Betula platyphylla,Betula costata,Tilia amurensis,Acer pictumsubsp.mono; ring-porous species:Ulmus davidianavar.japonica,Ulmus laciniata,Fraxinus mandshurica) were observed at three life history stages (seedling, sapling, and mature tree) to measure the dynamic changes of NSC and its influencing factors throughout the entire life cycles of these species. The results showed that life history, wood type, and environmental factors (soil nitrogen and phosphorus content, soil pH) significantly affected the NSC content in leaves and branches (including both new twigs and old branches). As plants grew, the NSC content in the leaves and branches generally showed an upward trend, meaning the total non-structural carbohydrate (TNC) content and soluble sugar (SS) content increased significantly, and the starch (ST) content was relatively stable. Lastly, there was no significant difference in NSC content between the canopy layers of mature trees. This indicates that the influence of life stage on NSC content in leaves and branches of plants may be dominated by genetics instead of being regulated by light factors.

长白山暗针叶林群落物种多样性维持机制

PDF HTML阅读 XML下载 导出引用 引用提醒 长白山暗针叶林群落物种多样性维持机制 DOI: 10.5846/stxb202202210407 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（32001312） Species diversity maintenance mechanism of dark coniferous forests community in Changbai Mountain Author: Affiliation: Fund Project: The National Natural Science Foundation of China (General Program, Key Program, Major Research Plan) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:植物群落物种多样性维持机制一直是生态学研究的热点话题，其中生态位理论和中性理论是被普遍接受的两种理论观点，但是目前关于生态位理论和中性理论在群落物种多样性维持中的相对重要性还没有统一定论。基于长白山暗针叶林群落数据，采用单物种-面积关系模型探究特定树种对邻域物种丰富度的影响，并借助同质性和异质性泊松零模型检验其显著性。（1）群落水平上，在3-15 m空间尺度上，促进种占据优势地位，在>15 m空间尺度上，中性种逐渐取代促进种起主导作用，抑制种比例较低，并且随着空间尺度变化幅度不大。（2）物种水平上，采用同质性泊松零模型检验树种对邻域物种丰富度的影响，臭冷杉、花楷槭、青楷槭在0-20 m空间尺度上对邻域物种丰富度增加起促进作用，黄花落叶松、鱼鳞云杉在0-20 m空间尺度上抑制了邻域物种丰富度增加。花楸树、黑桦和硕桦在全部研究尺度上表现为中性种，髭脉槭、大青杨、红松等在不同研究尺度上表现为不同的作用效果。剔除了生境过滤作用的异质性泊松零模型检验结果与同质性泊松零模型结果差异不显著，表明研究样地内生境过滤作用对多样性格局形成影响不大，各树种间的相互作用对群落物种组成影响较大，进一步证明了生态位理论能够解释长白山暗针叶林物种多样性维持。 Abstract:The maintenance mechanism of plant community species diversity has always been a hot topic in ecological research. Niche theory and neutral theory are two widely accepted theoretical viewpoints, but the relative importance of niche theory and neutral theory in the maintenance of community species diversity has not been unified. Based on the data of dark coniferous forest community in Changbai Mountain, this study used the individual species-area relationship model (ISAR) to explore the impacts of specific tree species on neighborhood species richness, and used homogeneity and heterogeneity Poisson zero model to test its significance. The results showed that:(1) at the community level, in the 3-15 m spatial scale, the promoting species occupied the dominant position. At scale >15 m, the neutral species gradually replaced the accumulators, the proportion of repellers species was low, and the change range with the spatial scale was small. (2) At the species level, the homogeneity Poisson zero model was used to test the influence of tree species on the neighborhood species richness. At the spatial scale of 0-20 m, Abies nephrolepis, Acer ukurunduense and Acer tegmentosum promoted the increase of species richness in the neighborhood, while Larix olgensis and Picea jezoensis inhibited the increase of neighborhood species richness. Sorbus pohuashanensis, Betula dahurica and Betula costata were neutral species at the scale of 0-20 m. Acer barbinerve, Populus cathayana, and Pinus koraiensis showed different effects on different scales. There was no significant difference between the results of heterogeneity Poisson null model excluding habitat filtering and homogeneous Poisson null model, indicating that habitat filtering had little effect on the formation of diversity pattern in the study plot. It was mainly due to the interaction between tree species contributed to the species composition structure of the community, which further proved that niche theory could explain the maintenance of species diversity in dark coniferous forest of Changbai Mountain. 参考文献 相似文献 引证文献

Molecular and morphological analyses clarify species delimitation in section Costatae and reveal Betula buggsii sp. nov. (sect. Costatae, Betulaceae) in China.

Delineating closely related and morphologically similar species is difficult. Here, we integrate morphology, genetics, ploidy and geography to resolve species and subspecies boundaries in four trees of section Costatae (genus Betula): Betula ashburneri, B. costata, B. ermanii and B. utilis, as well as multiple subspecies and polyploid races. We genotyped 371 individuals (20-133 per species) from 51 populations at 15 microsatellite markers, as well as a subset of individuals, using restriction-site associated DNA sequencing and nuclear internal transcribed spacers. We determined the ploidy level of eight individuals using flow cytometry and characterized leaf variation for a subset of 109 individuals by morphometric analysis. Integration of multiple lines of evidence suggested a series of revisions to the taxonomy of section Costatae. Betula costata and B. ermanii were found to be valid. Molecular and leaf morphology analyses revealed little differentiation between diploid B. albosinensis and some samples of B. utilis ssp. utilis. By contrast, other B. utilis ssp. utilis samples and ssp. albosinensis formed a morphological continuum but differed based on genetics. Specifically, B. utilis ssp. albosinensis was divided into two groups with group I genetically similar to B. utilis ssp. utilis and group II, a distinct cluster, proposed as the new diploid species Betula buggsii sp. nov. Phylogenomic analysis based on 2285 620 single nucleotide polymorphisms identified a well-supported monophyletic clade of B. buggsii. Morphologically, B. buggsii is characterized by elongated lenticels and a distinct pattern of bark peeling and may be geographically restricted to the Qinling-Daba Mountains. Our integrated approach identifies six taxa within section Costatae: B. ashburneri, B. buggsii, B. costata, B. utilis ssp. utilis, B. utilis ssp. albosinensis and B. ermanii. Our research demonstrates the value of an integrative approach using morphological, geographical, genetic and ploidy-level data for species delineation.

CLUSTER COMPOSITION OF POLLEN PARTICLES OF ANEMOPHILIC PLANTS ENTERING ATMOSPHERE

A study is made on pollen emission into atmosphere of 21 species of anemophilous plants ( Betula divaricata Ledeb., Betula costata Trautv., Betula davurica Pall., Betula fruticosa Pall., Ulmus japonica (Rehd.)Sarg., Salix acutifolia Willd., Salix cinerea L., Salix purpurea L., Salix rosmarinifolia L., Alnus glutinosa (L.) Gaertn., Poa alpina L., Arrhenatherum elatius (L.) J. Presl & C. Presl, Briza maxima L., Deschampsia cespitosa (L.) P. Beauv., Urtica urens L., Carex altaica (Gorodkov) V.I. Krecz., Carex pallescens L., Carex flacca Schreb., Carex vesicaria L., Carex diluta M. Bieb., Plantago lanceolata L.), exposed by the Central Siberian Botanical Garden, SB RAS. These plants are widely spread over the territory of the Russian Federation and produce great amounts of allergenic pollen. The proportion of clusters of two or more pollen grains from the total number of pollen particles entering the atmosphere during the flowering periods of these plant species is estimated. It was shown that such clusters in significant quantities were formed in all series of experiments. At the same time, the proportion of pollen grains in their composition could reach 95% of the total number of pollen grains entering the atmosphere.

Stem taper functions for white birch (Betula platyphylla) and costata birch (Betula costata) in the Xiaoxing’an Mountains, northeast China

AbstractWhite birch (Betula platyphylla Sukaczev) and costata birch (Betula costata Trautv.) are valuable hardwood tree species growing in northeast China. Several taper studies have analysed birch species in the countries harbouring the boreal forests. However, this study presents an initial attempt to develop stem taper models using the fixed- and mixed-effects modelling for white birch and costata birch in Xiaoxing’an Mountains, northeast China. Ten commonly used taper models were evaluated by using 228 destructively sampled trees of both tree species comprising of 4582 diameter and height measurements. The performance of these models was tested in predicting diameter at any height, total volume and merchantable volume (10 and 20 cm top diameters). We incorporated a second-order continuous-time error structure to adjust the inherent autocorrelation in the data. The segmented model of Clark best predicted the diameter and total or merchantable volume when the upper stem diameter at 5.3 m was available. When diameter measurements at 5.3 m were not available, the models of Kozak and Max and Burkhart were superior to other models for white birch and costata birch, respectively. After model comparison, the best model of Clark was refitted as the NLME model.

Phytosociological study of Betula costata forests in central Honshu, Japan

Phytosociological study of <i>Betula costata</i> forests in central Honshu, Japan

Mycorrhizal synthesis of &lt;i&gt;Tuber pseudohimalayense&lt;/i&gt; with seven broad-leaved trees and &lt;i&gt;Pinus armandii&lt;/i&gt;

Truffle cultivation is successfully applied throughout the world for several truffles of European origin. However, just two Chinese black truffles (Tuber indicum and T. himalayense) have been cultivated with a favorable outcome so far. Tuber pseudohimalayense is a black truffle of significant economic relevance in China, but little is known about its mycorrhizal ecology and it is not cultivated in orchards yet. Here, we selected seven broad-leaved tree species (Quercus fabrei, Q. aliena, Castanea mollissima, Carya illinoinensis, Q. glauca, Castanopsis orthacantha, Betula costata), and one coniferous tree (Pinus armandii), and inoculated them with T. pseudohimalayense spore suspension using axenically germinated seedlings under greenhouse conditions. The obtained mycorrhizae, well-developed, were analyzed from the morpho-anatomical and molecular points of view, and their main characteristics described. Synthesized T. pseudohimalayense mycorrhizae showed similar characters on all tree species, with a typical interlocking pseudoparenchymatous mantle and Hartig net, swollen appearance, yellow-brownish color, and long hyaline emanating hyphae with right-angle ramifications. These features are similar to those reported for mycorrhizae formed by related black truffle species. The successful mycorrhizal synthesis of T. pseudohimalayense on multiple trees species indicates that it has potential for cultivation in China.

Development of microsatellite markers in Betula costata (Betulaceae) by next-generation sequencing and cross-species transferability test.

This study was conducted to develop the first species-specific microsatellite markers in Betula costata. A total of 178 primers were designed from 95,755 contigs and screened in two B. costata populations sampled from Mt. Hwaaksan and Mt. Gyebangsan. A total of 16 polymorphic microsatellite loci were selected and used for population genetic characterization. The average values of observed heterozygosity (HO) and expected heterozygosity (HE) of the Mt. Hwaaksan population were 0.488 and 0.493, respectively. The average values of HO and HE in the Mt. Gyebangsan population were 0.492 and 0.481, respectively. The null allele frequency was less than 0.2 in all loci. No significant linkage disequilibrium was detected in all combinations of loci. In addition, 26 polymorphic markers were selected by cross-species transferability test to B. costata using the microsatellite markers developed in four other Betula species. The cross-species transferability of the microsatellite markers developed in B. costata was conducted in two other Betula species. The transferability was 75% in B. ermanii and 100% in B. davurica. Therefore, the microsatellite markers developed and characterized in this study were expected to be useful for further genetic studies in B. costata and related species in the genus Betula.

富山県におけるチョウセンミネバリ Betula costata の分布の現状

富山県におけるチョウセンミネバリ Betula costata の分布の現状

Fire resistance of bark of 11 tree species

China is one of the countries with serious forest fires. Besides the methods of strengthening management of fire source and increasing forest fire monitoring and rescue efforts, improving the ability of forest itself to resist fire is also the key to prevent forest fires. In this study, we examined the characteristics of the bark across 11 main tree species in Korean pine broad-leaved forest at Jiaohe Forestry Experimental Area in Jilin Province. Fire resistance of bark acorss the tree species was evaluated comprehensively with four indices of water content, ash content, calorific value and oxygen index, using the methods of entropy weight, variance analysis and cluster analysis. Results showed that water content of bark was the highest in Phellodendron amurense. Calorific value of bark was the lowest and ash content was the highest in Ulmus davidiana. Oxygen index of bark was the highest in Fraxinus mandshurica. Bark fire resistance of 11 tree species followed the order of U. davidiana > Acer mono > Acer triflorum > Acer mandshuricum > F. mandshurica > Quercus mongolica > P. amurense > Tilia amurensis > Juglans mandshurica > Pinus koraiensis > Betula costata. The tree species in Korean pine broad-leaved forest could be classified to five categories according to bark fire resistance: U. davidiana belonged to the category of strongest fire-resistance; A. mono and A. triflorum belonged to the category of strong fire-resistance; A. mandshuricum, F. mandshurica, Q. mongolica, P. amurense, T. amurensis belonged to the category of common fire-resistance; J. mandshurica and P. koraiensis belonged to the category of weak fire-resistance; and B. costata belonged to the category of poor fire-resistance.

Vertical variation and model construction of area and dry mass for a single leaf from six broadleaved trees in mixed broadleaved-Korean pine forests.

Rapidly and accurately predicting leaf area (LA) and leaf dry mass (LDM) are essential for exploring the response of plant traits to climate change. Empirical models suitable for predicting LA and LDM of a single leaf for various broadleaved tree species at the regional scale have not been proposed. We selected six broadleaved tree species in four mixed broadleaved-Korean pine (Pinus koraiensis) forests in northeastern China, including Betula platyphylla, Tilia amurensis, Populus davidiana, Betula costata, Fraxinus mandshurica and Ulmus laciniata, and measured leaf length, leaf width, leaf thickness, LA and LDM at different canopy layers (top, middle, and low). Using the median of leaf length and width ratio as the classification criterion, the six species were sorted into two groups. We tested whether different canopy layers for each group of broadleaved tree species had significant impacts on the empirical model for predicting LA and LDM. We constructed empirical models suitable for predicting LA and LDM of a single leaf at different canopy layers at the regional scale, and verified their forecast accuracy, and further evaluated their applicability for predicting LA and LDM of same broadleaved tree species in other regions. These results showed that the LA of a single leaf increased significantly with the decreases of canopy height for the six tree species, while the LDM of some broadleaved tree species showed a downward trend. The canopy height had significant impacts on constructing the empirical model for LA and LDM. The average forecast accuracy of empirical model was 95% and 83% for LA and LDM of a single leaf across canopy layers for two groups of broadleaved tree species, respectively. The average forecast accuracy was 94% and 80% for predicting LA and LDM of corresponding broadleaved tree species in other regions, respectively, indicating that the empirical models constructed in this study had a universal applicability in Northeast China.

小兴安岭天然针阔混交林主要树种空间格局及其关联性

PDF HTML阅读 XML下载 导出引用 引用提醒 小兴安岭天然针阔混交林主要树种空间格局及其关联性 DOI: 10.5846/stxb201808101708 作者: 作者单位: 东北林业大学林学院,东北林业大学,东北林业大学林学院,东北林业大学,东北林业大学,东北林业大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31670627，31270666） Spatial point patterns and associations of populations in the coniferous and deciduous broadleaved mixed forest in Xiaoxing'an Mountain Author: Affiliation: College of Forestry，Northeast Forestry University,Northeast Forestry University,,,, Fund Project: The National Natural Science Fundation of China(31670627,31270666) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:在小兴安岭天然针阔混交林1.1 hm2的固定样地内，本文调查和统计了其物种组成和林分径级结构。运用空间点格局分析方法中的O-ring函数，对种群的空间分布格局及其关联性进行分析。结果表明：样地内共有乔木树种15种，重要值排在前四位的依次为红皮云杉（Picea koraiensis）、枫桦（Betula costata）、春榆（Ulmus davidiana）和色木槭（Acer mono），红皮云杉和枫桦属于样地内的优势种，重要值分别为15.81%和11.10%。林下更新状态良好，枫桦的径级结构有呈正态分布的趋势，其余三种均呈现倒"J"形。O-ring函数结果证实，四个主要树种的种群空间分布格局相似，均在0-5 m小尺度上呈聚集分布，随着尺度的增大，逐渐变为随机分布；红皮云杉与其他三个主要种群之间在较大尺度上均呈现显著正相关或无相关，在小尺度上仅与枫桦呈极显著正相关；色木槭在较小尺度上与其他三个种群呈弱负相关性，随着尺度的增大，逐渐变为无相关性。 Abstract:Species composition and populations' diameter class structure were investigated in a 1.1 hm2 permanent plot in the coniferous and deciduous broadleaved mixed forest in Xiaoxing'an Mountain. Using O-ring functions in the spatial point pattern analysis. the populations' spatial distribution patterns and spatial association are analyzed. The results showed that there were 15 arbor species in the plot. Picea koraiensis, Betula costata, Ulmus davidiana, and Acer mono ranked as the top 4 important species in our plot. Picea koraiensis and B. costata were the major dominant species with importance values of 15.81% and 11.10%, respectively. This forest was also founf to be in good regeneration condition. The size class structure of B. costata tended to be normally distributed, while that of the other three populations showed an inverted "J" shape. The results from the O-ring function showed that the spatial distribution pattern of the four main populations was similar, with distributions was aggregated at the 0-5 m scale. At increasing scales, distributions shifted from aggregated to random. Picea koraiensis had a significant positive or no correlation with the other three main populations at coarse scales, but only had a significant positive correlation with B. costata at fine scales. Acer mono had a non-significant negative correlation with the other three populations at fine scales. As the scale increased, no correlation was found. 参考文献 相似文献 引证文献

Energy efficiency performance enhancement of industrial conventional wood drying kiln by adding forced ventilation and waste heat recovery system: A comparative study

Conventional kilns dominate the wood drying industry. However, energy consumption during the process of ventilation remains a significant challenge. In this study, we designed a device to recover waste heat from exhausted wet air during kiln drying. To determine energy conservation, the device was installed in a 50 m3 kiln used for drying sawn timber in two different Chinese cities, and a traditional kiln with identical size was chosen to enable comparison. Two kinds of hardwood (Betula costata Trautv and Quercus mongolica) swan timbers were dried using conventional technology to investigate the energy saving effect of rainy seasons as well as seasonally different temperature. The results revealed that drying time and energy consumption decreased with the use of this energy-conserving device. Electrical and energy consumption were reduced by 18.9% and 38.5%, respectively. Waste heat recovery efficiencies ranged from 20.32% to 28.15%. Energy-conservation efficiency can be predicted to range from 12.23% to 22.74% annually. Equipment costs can be recovered within 3.5 years.

밀성박씨 경주 손곡문중 목판의 수종식별

This study was conducted to identify wood species of two printing woodblocks either from the Park clan’s documentary or Ji-dang documentary of Songok clan of the Milseong Park, Songok, Gyeongju, Korea. Eighty-eight woodblocks out of the total 282 woodblocks were randomly selected to compare anatomical features for the identification of wood species, using a light microscope. As a result, seven wood species were identified, and all of them were diffuse-porous hardwood species. The most significant portion, i.e., 39.8% of wood species was Carpinus laxiflora Blume. Then, Pyrus pyrifolia Nakai, Acer mono Maxim, Prunus sargentii Rehder, Tilia amurensis Rupr, Diospyros kaki Thunb, and Betula costata Trautv was 25.0%, 15.9%, 10.2%, 3.4%, 3.4% and 2.3%, respectively, indicating that all diffuse-porous hardwood species had been used for the woodblocks. It was believed that diffuse-porous hardwoods had been used because they provided an easy of engraving complex Chinese letters, of acquiring these wood species in Gyeongju areas, and a high resistance to repeated printing.

Response of species and stand types to snow/wind damage in a temperate secondary forest, Northeast China

Snow/wind damage is one of the important natural disturbances in forest ecosystems, especially in a montane secondary forest. However, the effects of snow/wind damage remain unclear which affects the management of these forests. Therefore, we investigated the responses of species, individual tree traits and stand structure to snow/wind damage in a montane secondary forest. Results show that, amongst the canopy trees, Betula costata exhibited the most uprooting, bending and overall damage ratio (the number of damaged stems to the total number of stems in a plot); Quercus mongolica showed the highest breakage ratio and Fraxinus mandshurica and Juglans mandshurica the least overall damage ratios. Among the subcanopy trees, Carpinus cordata, Acer mono, Acer tegmentosum and Acer pseudo-sieboldianum showed the least uprooting and breakage, and the most bending damage. A. pseudo-sieboldianum demonstrated the lowest breakage and highest bending damage ratios. These findings indicate that different species have various sensitivities to snow/wind damage. Larger trees (taller, wider crowns) tend to break and become uprooted, while smaller trees are bent or remain undamaged, suggesting that tree characteristics significantly influence the types of damage from snow and wind. Stands of Q. mongolica and B. costata had the highest damage ratios, whereas A. pseudo-sieboldianum had the lowest snapping ratio. In summary, the severity and type of snow/wind damage are related to individual tree attributes and stand-level characteristics. Therefore, selection of suitable species (e.g., shorter, smaller with deep root systems, hard wood, bending resistance and compression resistance) and appropriate thinning are recommended for planting in the montane secondary forests.

Competition among dominant tree species in a natural spruce-fir forest in Changbai Mountain

Dominant tree species are the main species in different layers of mixed-species forests. Examining competitive relationships among dominant tree species is important for proper management of mixedwood forests. In this study, we established a 100 m×100 m plot of uniform condition on Jingouling Forest Farm, Wangqing County, Jilin Province. The dominant tree species of the young forest community were first determined through dominance index analysis approach and the competitive relationships among dominant tree species were then examined using tree competition index that described intra- and inter-specific competition from the above and sides of individual tree crown. The results indicated three dominant tree species in this mixed-species community were Abies nephrolepis, Picea koraiensis and Pinus koraiensis. A. nephrolepis, Picea koraiensis, Pinus koraiensis, Betula costata, Tilia amurensis, Acer tegmentosum and Betula platyphylla were the main competitors of the dominant tree species, while A. nephrolepis was the major competitor for all three dominant tree species (1412.48), followed by Picea koraiensis (439.17) and Pinus koraiensis (245.28), they all had side squeeze effect (64.9%, 65.2% and 66.0% of the total competition for the three dominant tree species, respectively). The level of side and above competition decreased with individual tree DBH (diameter at breast height); the percentage of side competition was nearly equal to that of above competition in small trees and increased with tree size, reaching nearly 100% in large canopy trees. For the three dominant tree species, the side and above competition of three dominant tree species mainly came from A. nephrolepis, Picea koraiensis, Pinus koraiensis, T. amurensis, B. costata, A. tegmentosum and B. platyphylla, and the inter-specific competition was more intense than intra-specific competition (58.4%, 87.1%, 83.7% of the total competition for the three dominant species), both of which decreased with the increase of individual tree DBH.