Content of Review in our journal

Published in last 1 year |  In last 2 years |  In last 3 years |  All Please wait a minute... For Selected: Download Citations EndNote Reference Manager ProCite BibTeX RefWorks Toggle Thumbnails Select Research Progress for Carbon Footprint Assessment of Wood and Bamboo Products Wanli Lao,Xiaoling Li,Xinfang Duan Scientia Silvae Sinicae    2024, 60 (1): 142-150.   DOI: 10.11707/j.1001-7488.LYKX20230098 Abstract （124）   HTML （9）    PDF （926KB）（249）       Knowledge map    Save Climate change is an important aspect of global governance, assessing greenhouse gas emissions from human activities is key to address climate change, which has gained more and more attention by governments, scientific research institutions and enterprises all over the world. China has proposed a goal of carbon peak and carbon neutrality (“double carbon” goal). In this context, as a measure of greenhouse gas emissions, carbon footprint is becoming increasingly important. Evaluating the carbon footprint of wood and bamboo products is very important for China's wood and bamboo processing enterprises to implement the national“double carbon”goal, which plays an important role in promoting low-carbon and high-quality development. Research status of carbon footprint evaluation for sawn lumber, modified wood, wood-based panels and their products, glued laminated timber, cross laminated timber, and other wood and bamboo products were summarized. And the recent progress of evaluation methods was also analyzed. At present, life cycle assessment method is widely used to assess carbon footprint of wood and bamboo products globally. The standards for carbon footprint assessment are mainly ISO/TS 14067, GHG Protocol and PAS 2050. There is no international consensus on the assessment methods of biological carbon storage and its delayed carbon emission in wood and bamboo products, as well as the content of carbon footprint evaluation results. Due to the differences in wood and bamboo processing technology of different countries, the carbon footprint assessment results of the same product are significantly different. In addition, researchers often use different standards and hypotheses in carbon footprint evaluation, resulting in low comparability of the results for same product. Finally, we put forward four research topics which should be solved in the future: 1) In-depth study on the accounting methodologies of biological carbon storage and its delayed carbon emission to scientifically quantify the positive contribution of wood and bamboo products to climate change mitigation. 2) The formulation of international unified product category rules which is suitable for carbon footprint evaluation of wood and bamboo products, to further enhance the comparability of carbon footprint accounting results and promote the international mutual recognition of the results. 3) The establishment of a tracking system for the whole life cycle of wood and bamboo products is urgently needed to provide reference for the full life cycle carbon footprint assessment of wood and bamboo products. 4) Building a nationwide unified carbon emission factor database for China wood and bamboo industry, in order to provide fundamental data support for accurately measuring the carbon footprint of wood and bamboo products. Table and Figures | Reference | Related Articles | Metrics Select The Current Status and Market Development Potential of Processing Technology and Products Using Bamboo as a Substitute for Plastic Hanzhou Ye,Jinhe Fu,Haitao Cheng,Fuming Chen,Shuyan Yang,Ge Wang Scientia Silvae Sinicae    2024, 60 (1): 129-141.   DOI: 10.11707/j.1001-7488.LYKX20230140 Abstract （104）   HTML （5）    PDF （1232KB）（254）       Knowledge map    Save China has a wealth of bamboo resources, cutting-edge bamboo processing technologies, strong research and development capabilities, and strong international competitiveness. The bamboo industry is a green and promising sector of the Chinese economy that contributes significantly to the advancement of both economic growth and environmental protection. The conventional plastics sector is currently confronted with issues such a heavy reliance on non-renewable resources, excessive energy consumption, and significant environmental damage. Governments and groups around the world have introduced a number of “plastic ban” policies and initiatives to promote sustainable plastic alternatives in response to the expansion of the global economy and people’s rising concern for environmental protection. Bamboo presents a range of opportunities and options for the development of bamboo-based plastic substitutes because it is an eco-friendly, low-carbon, renewable, and degradable bio-based material with a variety of processing units, excellent material properties, and great processing selectivity and product designability. Bamboo-based plastic substitutes have steadily garnered regulatory, commercial, and consumer favor as an eco-friendly replacement. The Bamboo as a Substitute for Plastic Initiative was introduced in November 2022 by the Chinese government and the International Bamboo and Rattan Organization in an effort to reduce plastic pollution, combat climate change, and quicken the implementation of the UN 2030 Sustainable Development Agenda. In November 2023, 《The Global Action Plan for Bamboo as a Substitute for Plastic (2023—2030)》 was officially released. With the Bamboo as a Substitute for Plastic Initiative, China has made it clear that it is committed to protecting the environment, and various decision-making levels have been used to strongly encourage the development of the bamboo industry. This article analyzes the urgent need for and viability of alternative bamboo to plastic solutions based on the benefits of China’s bamboo resources and bamboo industry as well as the traditional plastic industry’s need for a green transformation. This paper focuses on the current state of typical key industry products like automotive parts, electric appliance shells, cooling tower tower packings, pipes and tubes, building decoration materials, and disposable tableware and their potential for bamboo as a substitute for plastic. Furthermore, the study proposes actionable recommendations, development trends, and future prospects for the adoption of bamboo as a substitute for plastic. This research seeks to provide some reference for the promotion and deployment of bamboo-based plastic alternative technologies and goods in China. Table and Figures | Reference | Related Articles | Metrics Select Progress on Physiological and Ecological Responses of Trees to Drought Stress and Rewatering Ren You,Xiangwen Deng,Yanting Hu,Shuai Ouyang,Liang Chen,Wenhua Xiang Scientia Silvae Sinicae    2023, 59 (11): 124-136.   DOI: 10.11707/j.1001-7488.LYKX20220250 Abstract （403）   HTML （19）    PDF （1415KB）（284）       Knowledge map    Save Tree mortality under drought stress is an important physiological and ecological process that alters the structure and function of forests and influences forest management decisions. Under drought stress conditions, the water and carbon metabolisms in trees have malfunctioned, which leads to tree mortality. However, the exact physiological mechanisms of tree mortality in drought-stressed environments and the physiological-ecological response of various organs in trees during the drought-rewatering process have not yet been elucidated, and this scientific question is currently at the forefront of research worldwide. There are at least three hypotheses for the mechanism of drought mortality in trees: hydraulic failure, carbon starvation and the biological attack hypothesis. The hydraulic failure hypothesis suggests that under drought stress, the xylem of a tree reaches a threshold of embolism and is unable to restore water conduction, thus causing the tree to die of dehydration and desiccation; the carbon starvation hypothesis suggests that under drought stress, stomata are tightened or even closed and the tree cannot photosynthesize to produce organic matter, but the tree is depleted of available carbon in order to maintain its normal growth and metabolism; the biological attack hypothesis suggests that drought stress affects the distribution of biological factors and growth rate, making the tree vulnerable to attack by insects and pathogens, thus causing the tree to die. All hypotheses have been shown to explain a proportion of tree mortality, but are insufficient to explain all tree mortality in drought-stressed environments, and in particular the role of non-structural carbohydrate depletion in the mortality process remains unclear. This paper introduces water relations under drought stress and provides an overall account of the specific physiological processes involved in xylem embolism in the hydraulic failure hypothesis. It then discusses the effects of long-term drought stress on tree growth and development, transpiration, and the resulting changes in non-structural carbohydrate dynamics, explores the physiological mechanisms of individual tree organs during drought mortality, and summarizes the progress of research on physiological and ecological changes in trees during the drought-rehydration process. The current study shows that the hydraulic failure hypothesis remains the dominant hypothesis for tree mortality under drought stress, while the contribution of changes in non-structural organic carbon in trees to tree mortality remains undetermined. Post-drought rehydration can restore plant physiological functions and can compensate to a certain extent for the damage caused by drought, which affects both the morphological and physiological characteristics of trees. This paper also suggests directions for future research on tree mortality, with the aim of providing recommendations for the rational planting and management of trees in the future. Table and Figures | Reference | Related Articles | Metrics Select Enlightenment from the Operation of the VCS Market to China's National Greenhouse Gas Voluntary Emission Reduction Trading Market Chunguang Sheng,Qiqi Zhu,Yaxuan Qi,Qi Yan,Guangyu Wang Scientia Silvae Sinicae    2022, 58 (12): 141-154.   DOI: 10.11707/j.1001-7488.20221213 Abstract （238）   HTML （2）    PDF （1478KB）（91）       Knowledge map    Save Objective: A systematical analysis was conducted on the advanced model of VCS market operation for 16 years, and summarize practical experiences in VCS market. Moreover, a series of problems exposed in the development process of the VCS market are deeply considered to form inspirations for the trading market of China's national voluntary emission reduction of greenhouse gas, in the hope of providing a theoretical basis for formulating relevant policies by the national competent authorities. Method: Based on the inductive analysis method, historical research method and comprehensive analysis method, the operation mechanism of the Verified Carbon Standard (VCS) market as an important component of the global voluntary carbon market was explored in terms of organizational framework, institutional system, project development process, registration and trading rules. Result: It was found that the VCS market has accumulated rich practical experiences in implementing gradual institutional changes, following the principle of openness and transparency, improving the environmental integrity of carbon credit, focusing on the synergy of projects, and building standardized digital technology applications for trading platforms. At the same time, the inconsistency of project prediction methods and the used tools appeared in the development process of the market has led to the problem of baseless carbon credit. The defective supervision mechanism of Verra has resulted in exaggeration of carbon credit and the lack of information disclosure on carbon credit of Verra has led to the asymmetry of market information, these problems are more worthy of consideration and prevention. Conclusion: 1) The inspirations of the VCS market to the construction of CCER market can be summarized into five aspects: First, paying attention to the updating of project rules and improve the quality of carbon credit; Second, strengthening the management of validation and certification bodies to improve the quality of carbon verification; Third, establishing an open and transparent project information disclosure system; Fourth, encouraging the development of CCER projects with synergistic benefits; Fifth, establishing a standardized CCER market and developing a carbon pricing mechanism. 2) 5 suggestions were made for CCER market construction: First, we should give play to the top-level design role of the national competent authorities and accelerate the introduction of relevant policies, systems and regulations; Second, unifying the CCER trading rules of the pilot carbon market, establishing a standardized market trading platform, encouraging and attracting financial institutions and the public for wide participation, and enhancing the vitality of the CCER market; Third, enhancing the function and role of forestry carbon sequestration project in realizing carbon neutrality and ecological civilization construction, emphasizing the additionality and credibility of the project; Fourth, strengthening the staff team building in CCER market; Fifth, strengthening international cooperation and integrating into the global voluntary carbon market system in line with international rules. Sixth, establishing an internationally recognized CCER standard system. The above inspirations and suggestions will be the direction and driving forces for CCER market construction in the future. Table and Figures | Reference | Related Articles | Metrics Select Damage of Coleoptera Longhorned Beetles in Wooden Components of Ancient Buildings in China Xingxia Ma,Jiaxin Li,Lin Wang,Yanhua Wang Scientia Silvae Sinicae    2022, 58 (12): 130-140.   DOI: 10.11707/j.1001-7488.20221212 Abstract （242）   HTML （8）    PDF （7692KB）（93）       Knowledge map    Save The larvae of the Coleoptera beetle live inside the wood, digging through the wood to obtain food, which can damage the wooden components of wooden structures or ancient buildings and even cause the collapse of buildings in a short time. Therefore, damage of Coleoptera longhorned beetles highly concerned by the ancient building protection, survey, and maintenance department. Systematic research on the longhorned beetles that endanger the wooden components of antient buildings has important guiding significance for the special survey of biological diseases and the design of preventive protection schemes in the protection and investigation of wooden structures of ancient buildings. This article inquired about the reports of longhorn beetles in ancient buildings and residential houses all over the country, summarized the species, distribution, living habits, and host wood species of longhorn beetles that endangered the wooden components of ancient buildings in China, and sorted out the damage identification technology and damage classification of longhorn beetles, analyzed damage risk and preventive measures of longhorn beetles in wooden buildings or ancient buildings. The main conclusion are as follows: 1) the main species of longcorned beetles that damage the wood components of buildings in China are Trichoferus campestris, Eurypoda antinata, Stromatic longicorne and Chlorophorus didema. 2) All the wooden components of ancient buildings in China are at the damage risk from longcorned beetles. 3) The important measures to prevent the damage of longcorned beetles on buildings are wood protection before the processing of wood components, including log peeling, drying treatment, preventive treatment and other measures. 4)Ancient buildings should be regularly inspected and monitored for pests, so that pests can be found and eliminated timely. Table and Figures | Reference | Related Articles | Metrics Select Thirty Years of Agrobacterium-Mediated Genetic Transformation of Populus Yingnan Chen,Chuanjing Hu,Qiang Zhuge,Jianjun Hu,Tongming Yin Scientia Silvae Sinicae    2022, 58 (12): 114-129.   DOI: 10.11707/j.1001-7488.20221211 Abstract （169）   HTML （8）    PDF （1257KB）（113）       Knowledge map    Save Poplar (Populus spp.) is one of the most important tree species used for land greening and industrial timber production in China, and efficiently and precisely breeding new cultivars with rapid growth, high quality and strong stress tolerance will be an important direction for the future theoretical and technological development in poplar breeding. The Agrobacterium-mediated genetic transformation system has been the critical technology for shortening breeding cycle and increasing breeding efficiency. A large number of researches have been conducted on developing the Agrobacterium-mediated genetic stable transformation system for poplar since it was proved to be a native host of Agrobacterium in 1980s. We performed a comprehensive analysis of existing literatures, reviewed the historical process of constructing Agrobacterium-mediated genetic transformation system in different poplar species, summarized the main factors affecting transformation efficiency, and also discussed some future perspectives in this area. This review will provide useful information for further improving the poplar transformation efficiency and present reference protocols for establishing transformation systems in recalcitrant plant species and elite cultivars widely applied in production. Table and Figures | Reference | Related Articles | Metrics Select Application Progress of Plant Fiber/Thermoplastic Polymer Prepreg in Automotive Lightweight Field Cuicui Wang,Mingpeng Li,Ge Wang,Shaohua Gu,Haitao Cheng Scientia Silvae Sinicae    2021, 57 (9): 168-180.   DOI: 10.11707/j.1001-7488.20210917 Abstract （373）   HTML （15）    PDF （5987KB）（237）       Knowledge map    Save Plant fibers as a macro material have the advantages of being a low cost abundant natural resource with a low density, high specific strength and high specific modulus, which is considered as the biodegradable renewable resource with the most promising research prospects. Plant fiber reinforced composite has a high use value and environmental protection without pollution, which not only significantly reduces the use of fossil fuels, but also reduces the greenhouse gas emissions, leading to huge market value and development prospects. Therefore, how to efficiently utilize the plant fiber resource, develop high-added value practical products and broaden the application fields have become key focuses of research and industry. Under the trend of automobile lightweight, substituting plant fiber for glass fiber and other reinforced composite materials will not only reduce the production cost and processing energy consumption, but also facilitate the construction of green, circular and low-carbon life system for auto parts products, effectively promoting the sustainable development of automobile industry. Prepreg, as an intermediate of advanced composite products, plays an important role in the development of automotive lightweight. Thus this study provides a brief overview of necessity of the continuous fiber reinforced thermoplastic polymer research; the preparation technology of continuous plant fiber as well as the continuous fiber/thermoplastic polymer prepregs commonly used in regards to the advantages, disadvantages and key technical problems. This review will expound upon the emerging technology of continuous plant fiber/thermoplastic polymer prepreg such as melt impregnation, extrusion-rolling, film stacking technique and fused deposition modeling. This paper also summarizes the application of continuous plant fiber/thermoplastic polymer composite materials used in automotive lightweight field, and analyzes the quality and production cost of automobile traditional and thin-walled door trim, as well as traditional and thin-walled bumper, in order to provide theoretical support for continuous plant fiber/thermoplastic prepreg for using in lightweight vehicles components. Finally, the research trend of continuous plant fiber/thermoplastic polymer prepreg is prospected. The future work will be focused on the preparation technology and evenly dispersed of continuous plant fiber, helping development of thinner prepreg, which thereby eliminates fiber buckling, improves the structure design, and further reduces the product cost. In order to achieve the stable production of continuous plant fiber/thermoplastic prepreg with lower porosity, improved quality and excellent performances, the existing preparation technology can be effectively combined so as to foster the strengths and circumvent the weaknesses, but also by combining the theory and practice further to develop the new manufacturing equipment and improve the production technology, so that the integrated development of material, equipment and process technology is expected to happen. At the same time, in order to promote the benign development of continuous plant fiber/thermoplastic prepreg, it is necessary to speed up the establishment of standardized evaluation system to regulate the market. Table and Figures | Reference | Related Articles | Metrics Select Current Status and Prospects of Wood Drying Stresses Research Zongying Fu,Yingchun Cai,Yongdong Zhou Scientia Silvae Sinicae    2021, 57 (9): 160-167.   DOI: 10.11707/j.1001-7488.20210916 Abstract （292）   HTML （11）    PDF （969KB）（457）       Knowledge map    Save The research on drying stresses is an important part of wood science, which is capable of guiding wood processing as well as providing an important basis for establishing and optimizing drying schedule. This study systematically and comprehensively summarized the research status of wood drying stresses from experimental research and numerical analysis, and discussed the merits and demerits for each method. It aimed to provide some valuable information for the further research on wood drying stresses, and to promote the correlational studies to a higher and deeper level as well as lay a foundation for the high quality drying of wood. In experimental research, the prong and slice method in traditional are still the commonly used method for testing wood drying stresses. The modern technologies, such as digital image correlation technology and near infrared spectroscopy, provide new opportunities to the research of wood drying stresses. However, so far there is still no a test method to wood drying stresses with high precision and good popular conditions. In terms of numerical analysis, the models of drying stresses based on wood rheological theory have become more robust, and reached a plateau. With the development of computer technology and numerical analysis software, the finite element method has been used to simulate wood drying stresses, which had some advantages in dealing with the anisotropic materials, and it is in rapidly developing stage now. Based on the current research, the experimental research and numerical analysis play irreplaceable roles in the investigation of wood drying stresses. The combination of the two is the key to comprehensively evaluating drying stresses. The exploration of new devices or technologies, which can rapidly, accurately and continuously detect wood drying stresses, is still the focus in the future research. The finite element method is the most potential numerical analysis method for wood drying stresses. The model with wide applicability should consider the multi-scale and multi-layer characteristics of wood, and also obtain accurate model parameters by the use of advanced instrument and equipment. Furthermore, the proposed model should be put into the control system of drying equipment, and providing the guidance and service to actual production. Reference | Related Articles | Metrics Select Advances in Research on Prediction Model of Moisture Content of Surface Dead Fuel in Forests Long Sun,Qi Liu,Tongxin Hu Scientia Silvae Sinicae    2021, 57 (4): 142-152.   DOI: 10.11707/j.1001-7488.20210415 Abstract （560）   HTML （22）    PDF （1054KB）（282）       Knowledge map    Save Forest fire is one of the important factors that affect the forest ecosystem. The spread and development of forest fire are deeply affected by the moisture content of forest fuels, especially the occurrence of forest fire is directly affected by the moisture content of dead fuels on the surface. Therefore, accurate prediction of the forest surface dead fuels moisture content is the key to predict forest fire risk and fire behavior, and it is particularly important to strengthen the study of forest dead fuels moisture content prediction model. This article summarizes the research status of forest fuels moisture content in terms of the research methods, research models and model accuracy, and comparatively evaluates the existing models. In view of problems in the current research, five prospects for future research are proposed: 1) Strengthen research on the dynamic of fuel moisture content in key fire risk zone. The existing forest fire danger factor collection stations and forest fire danger monitoring stations are used to obtain the monitoring data of forest fuel moisture content and meteorological factors under different environmental condition. The prediction model of forest fuel moisture content based on meteorological parameters in key fire danger zone is constructed. 2) Strengthen basic data monitoring and collection of forest fuels. In order to build a comprehensive forest fire risk rating system, the basic data monitoring and collection of forest fuels should be strengthened, a solid data foundation should be laid, and an accurate forest fuel type classification system should be established. 3) Strengthen the study on the spatial heterogeneity of the fuel moisture content. In the future research, the dynamic changes of fuel moisture content under different impact factors should be considered, especially the spatial heterogeneity of fuel moisture content of small-scale forests, so that the prediction of forest fire danger can be made more accurately. 4) Improve the accuracy of the models combined with boosted regression tree(BRT). In the study of the influencing factors of the accuracy of the fuel moisture content model, the BRT method should be used to randomly extract a certain amount of data multiple times to analyze the degree of influence of different influencing factors on the accuracy of the model. 5) Conduct research on large-scale fire risk early alarm combined with GIS. Based on RS and GIS technology, the remote sensing inversion model of the fuel moisture content is established. On the basis of accurate simulation of the spatial distribution of forest fuel moisture content, the fuel moisture content prediction models of different fire risk classes is established. Reference | Related Articles | Metrics Select Research Progress on Mineral Nutrition of Walnut Zhengrong Gong,Yifeng Wang,Han Wang,Wei Li,Mingjian Geng,Wenming Zhang,Lu Liu Scientia Silvae Sinicae    2021, 57 (1): 178-190.   DOI: 10.11707/j.1001-7488.20210119 Abstract （1482）   HTML （77）    PDF （8831KB）（820）       Knowledge map    Save Walnut is the most widely cultivated nut tree species, as well as an important woody oil crop in the world. In recent years, the cultivation scale of walnut in China has expanded rapidly, but the yield per unit area is relatively low. Inadequate nutrient management measures are one of the major reasons. In this paper, we review the literature relevant to walnut production at home and abroad, summarize the research results of walnut mineral nutrition, and clarify the suitable soil environment and mineral nutrition characteristics of walnut growth, and the nutritional functions and abundance and deficiency effects of essential mineral elements in walnut, so as to provide reference for improving quality and efficiency of walnut industry through high-efficiency nutrient management and fertilization practice. Walnut has a strong adaptability to the soil environment, and even the ameliorated soil with strong acid, strong alkali and high salt can also produce high yield. Walnut production has a relatively high demand for mineral nutrients, and the contents of marcoelements in adult trees are in the order of Ca, N, K, Mg, P and S. The abundance and deficiency standards of major mineral elements in adult walnut trees were sorted out according to the content of the elements in midsummer leaves, and the physiological disease symptoms caused by nutrient stress and their occurrence period were described. N, P and K deficiency can significantly affect the growth of young trees. The increase of some non-physiological diseases may be related to the abnormal nutrition of P and Ca. Walnut is sensitive to B and Cl, and their excessive supply is easy to cause toxicity. It has been proved that N, K, Ca, B, Zn and Cu are closely related to the quality and yield of walnut, however the roles of P, Mg, Fe and Mn need to be further clarified. Based on the analysis of the research difficulties in walnut mineral nutrition and the summary of the working experience in developed countries, some research and practice suggestions on walnut mineral nutrition in China are put forward. Table and Figures | Reference | Related Articles | Metrics Select Recent Advances and Prospect of the Genomic Selection in Forest Genetics and Tree Breeding Sheng Zhu,Minren Huang Scientia Silvae Sinicae    2020, 56 (11): 176-186.   DOI: 10.11707/j.1001-7488.20201119 Abstract （629）   HTML （27）    PDF （2416KB）（356）       Knowledge map    Save Genomic selection was supposed to be the key technology and hotspot of those studies on animal and plant genetic breeding. Some progress has been made toward the genetic improvement of some animal and plant species. The breeding cycle of tree species is long due to their long generation interval. Early selection is an effective way to shorten the breeding cycle of trees and speed up the breeding process. The studies of early selection of trees can be roughly divided into three stages, including early selection based on the correlation between the early and late trait values, molecular marker-assisted selection and genomic selection. The growth and wood quality traits, the main target traits for tree genetic improvement, are often complex traits controlled by quantitative traits. During the constant process of tree growth and development, these traits are suffered from the on-going influence of the environment. Meanwhile, the heritability of these traits may be gradually changing in the process of tree growth and development. However, the application of genomic selection in tree genetic improvement was limited by the unique characteristic and weak research basis of perennial tree species, such as long generation interval, large body size, long juvenile phase, the lack of multi-omics data (genomic and phenotypic data), and the imperfection of technology platform to facilitate tree researches. To speed the application process of genomic selection in forest genetic improvement, this paper attempts to provide a short overview of the principles and method of whole genomic selection, to summarize recent progress of genome-wide selection in forestry tree genetics and breeding, and to discuss the constraint factors which impact the application of genomic selection in forestry tree genetic improvement. The paper provides a brief introduction of the linear model, statistical estimation methods (SNP-BLUP, GBLUP & Bayesian) and analytical tools (rrBLUP, synbreed, BGLR, GVCBLUP, GAPIT, sommer, BLUPGA and so on) used for genomic selection. It summarizes the advantage of genomic selection applied in forestry tree breeding and the studies of using genomic selection in both broadleaf Populus, Eucalyptus, Elaeis & Hevea) and coniferous (Pinus & Picea) tree species, and dissects these reports of genomic selection in Elaeis guineensis as typical cases. These studies of genomic selection in forestry tree species show that genomic selection contributes to improving the efficiency of forest selection and to accelerating tree breeding. It discusses in detail the possible influence of the tree reference genome, the genome-wide association study, the breeding population, the linkage disequilibrium and the perennial attribute on the genomic selection of trees. Genomic selection has potential application prospects in tree genetics and breeding research. Nevertheless, its feasibility still needs to be further evaluated using vast amounts of simulated and real data. The current research on tree genomic selection is facing multiple challenges: 1) a relatively low quality of genome assembly for tree species, 2) genomic selection for simultaneously screening multiple target traits, 3) the designing of the rational experimental scheme according to the characteristics of the perennial tree species, and the development of the statistical model and analytical tool capable of analyzing the longitudinal character data. Table and Figures | Reference | Related Articles | Metrics Select Progress on the Mechanisms and Influencing Factors of Tree Mortality Caused by Forest Fire: A Review Daxiao Han,Rui Wei,Xiaohong Wang,Rizheng Cong,Xueying Di,Guang Yang,Huiying Cai,Jili Zhang Scientia Silvae Sinicae    2020, 56 (7): 151-162.   DOI: 10.11707/j.1001-7488.20200716 Abstract （271）   HTML （19）    PDF （2078KB）（298）       Knowledge map    Save The mechanisms of tree mortality caused by forest fire are of great guiding significance to forestry practices such as prescribed burning, fire loss assessment and restoration of burned area. However, the action way of forest fire on trees and the factors affecting tree mortality are still unclear. In this review, the forest fire behavior is associated with the burn of tree crown, bole, and roots, and whole-tree mortality. The biological mechanisms underlying fire-caused tree mortality and influencing factors are analyzed. Finally, the review summarizs the method of assessing fire injury and prediction models of tree mortality. It can be seen from the literature review that the direct mortality of trees after fire depends on the burn of leaves and meristem(bud and cambium). The boundary conditions during tissue heating and metric of localized heat-transfer are vital variables in determining and predicting fire-caused tree mortality. Carbon starvation caused by the reduction of canopy photosynthesis and phloem transport and water stress induced by cavitation and deformation of xylem contribute to tree mortality following fire. Compared to carbon starvation, the impact of hydraulic failure on post-fire tree mortality is greater in short term. The response of leaves during fire depends on stomatal conductance and stomatal sensitivity to an increase of vapor pressure deficit, and photosynthesis rate per unit area will increase temporarily due to increasing mineral nutrient after burning. In addition, the variations of secondary metabolites such as phytohormone, phenol, terpene and alcohol, which are correlated with insect attacks, can reflect physiological responses in delayed mortality. Crown scorch variables following fire are reliable to evaluate tree survival and growth condition within short-term. Leaf flushing in the second year following fire can be used as a supplementary standard. For now, independent indicator variables, comprehensive rating indexes and statistical empirical models are the most simple and effective method to predict tree mortality, while biophysical model based on process is further research trend in the future. In addition, this paper also summarizes existing problems in the field, andproposes the corresponding opinions and suggestions in future study related to post-fire tree mortality. Reference | Related Articles | Metrics Select Mechanism of Endangerment of Ostrya rehderiana with Extremely Small Populations Xiaoyu Shi,Di Fu,Yujie Hu,Zhehao Chen,Lilin Wang Scientia Silvae Sinicae    2020, 56 (7): 142-150.   DOI: 10.11707/j.1001-7488.20200715 Abstract （387）   HTML （25）    PDF （1822KB）（153）       Knowledge map    Save Most PSESP (Plant Species with Extremely Small Populations) in China are endemic species, and contribute greatly to the maintenance of species diversity in China. As one of the endemic species in Zhejiang Province, Ostrya rehderiana has only 5 naturally-regenerated mature individuals that occur in the same region. The reveal of its mechanism of endangerment is an important basis for the protection and restoration of the population. We reviewed the studies on potential endangerment mechanism of O. rehderiana and classified them into two categories: the external factors like climate change, human disturbance and pest damage, as well as the internal factors such as photosynthetic capacity, growth rhythm, seed vigor and genetic diversity. 1) External factors: Climate change since Quaternary Glaciations led to a sharp decrease in the number of the effective population of O. rehderiana; man-made disturbance made O. rehderiana greater survival pressure and smaller population size; damage from diseases and insects also affected the survival rate of seedlings. 2) Internal factors: The narrow range of light adaptation and low photosynthetic rate of O. rehderiana made it inferior in the competition for light resources in the community, which impaired its environmental adaptability. The features of growth rhythm, such as short pollination time, low pollen germination rate and short life span, resulted in low seed yield and poor quality. The seed structure and the restrictions of endogenous nutrients and phytohormones led to the low seed germination rate and very few naturally-regenerated seedlings. The extremely small population size and the low level genetic diversity made the inbreeding of O. rehderiana very serious, which led to decreased heterozygosity, bringing about the weaker heritability, fertility, vitality and adaptability in offspring. In summary, human disturbance and climate change should be the direct reasons for the sharp decrease of the population size. The frequent inbreeding and lower genetic diversity might have led to potential defects in development and reproduction. In addition, due to the competition for resources with other populations in the community, it might be too difficult for O. rehderiana seedlings to naturally regenerate, which also makes the recovery of its population size improbably. However, the past protection of O. rehderiana, one of the PSESP with very low level genetic diversity, only focused on the removal or control of endangered factors, but not its unique genetic problems. Therefore, in order to protect O. rehderiana effectively, multiple method should be used, such as designing artificial hybridization strategy, together with vegetative propagation, increasing fertility of wild individuals, sustaining genetic diversity in the limited gene pool, combined with in-situ conservation, ex-situ conservation and reintroduction to the wild, the species of O. rehderiana might be finally protected and recovered. Table and Figures | Reference | Related Articles | Metrics Select Research Progress in Reproductive Behavior and Chemical Ecological Regulation of the European Woodwasp (Sirex noctilio), a Severe Invasive Pest Min Bao,Haili Qiao,Juan Shi,Youqing Luo,Pengfei Lu Scientia Silvae Sinicae    2020, 56 (6): 127-141.   DOI: 10.11707/j.1001-7488.20200613 Abstract （251）   HTML （5）    PDF （2443KB）（146）       Knowledge map    Save The European woodwasp (Sirex noctilio) (Hymenoptera:Siricidae), originated from Europe, Asia (Republic of Georgia, and Mongolia) and North Africa, is a major forestry invasive pest in the world. It has been introduced to many countries, causing great economic losses to their pine resources. In 2013, it was first found that the woodwasp invaded China and settled in northeast of China on Pinus sylvestris var. mongolica. Therefore the monitoring techniques are urgently needed to monitor the population transmission situation, in order to control the invasive pest. In this paper, we summarize the reproductive behavior and chemical ecology regulation in S. noctilio. As to reproductive behavior, males emerge a few days to weeks earlier than females and male's population is more abundant than female's. Its eclosion is affected by climate and the height of the eclosion hole on the trunk. Males aggregate in the upper tree branches for brighter light there. Courtship behavior is regulated by physical factors (light and sound) and chemical factors (host plant volatiles and pheromone). Sirex adults are sexually mature at emergence. Both parthenogenesis and hermaphroditism can be carried out in this insect. If females are parthenogenetic, unmated females oviposit only unfertilized eggs, which develop into males. Once mating happen, mated females can oviposit both fertilized and unfertilized eggs, fertilized eggs develop into females, while unfertilized eggs develop into males. The female can lay eggs after eclosion, and some of them can lay eggs after mating. The amount of laying eggs is affected by temperature and humidity, the shape of female and the symbiotic fungus in the trunk. As to chemical ecological regulation, pheromones from female's cuticle are attractive to males, while pheromones released by males are attractive to either males or virgin females. The release of pheromone is consistent with the mating rhythm. Health and damaged host plant volatile, physiologically stressed trees (pesticide injection and circumcision) in particular, are attractive to S. noctilio, including monoterpenes, sesquiterpenes, aromatic compounds, green leaf volatiles, carbohydrates and so on. There is a dynamic releasing rhythm in volatiles from physiologically stressed hosts. The wasp can carry symbiotic fungus. Volatiles of fungi are composed of monoterpenes, aldehydes, esters and ketones, which can trigger behavioral responses of both wasps and their parasitoids. It is indicated that parasitoids locate the larvae and eggs by symbiotic fungi volatiles. Finally, forest structure improvement, natural enemies and nematode control, satellite remote sensing monitoring, inspection and quarantine are commonly used for monitoring and controlling S. noctilio in forests. Table and Figures | Reference | Related Articles | Metrics Select Application of Phenotyping Techniques in Forest Tree Breeding and Precision Forestry Liming Bian,Huichun Zhang Scientia Silvae Sinicae    2020, 56 (6): 113-126.   DOI: 10.11707/j.1001-7488.20200612 Abstract （764）   HTML （52）    PDF （6359KB）（503）       Knowledge map    Save The lack of efficient phenotyping capability has become a bottleneck to the studies of forest tree breeding, and the key difficulty of phenotyping is to capture accurate phenotypic data so that the results acquired can be correctly explained. The central challenge of precision forestry is automatic, large-scale and real-time analysis of phenotypic traits. Conventionally, evaluation of tree phenotypic traits is manually-performed, subjective, inefficient, destructive and error-prone. The manual analysis is unable to meet the needs of exploring the internal relationships among "genotype-phenotype-environment" and unraveling the formation mechanism of specific biological traits in a comprehensive manner. Modern phenotyping technology uses a system equipped with various types of imaging sensors to automatically collect a large number of phenotypic data, such as forest morphology, structure, physiology and biochemistry, so as to monitor the growth of individual trees. In addition, the nondestructive measurements enable continuous monitoring of the same individual trees to obtain the phenotypic traits related to growth and development. For example, in stress studies, phenotyping technology can clarify the model of response and resistance of the trees to the stress. Effective implementation of remote sensing to phenotype trees that facilitates accurate, high-throughput, automatic and non-destructive screening of trees in genetic tests is critical for accelerating tree improvement and breeding strategies for higher yield and stress-resistance in precision forestry. We present a review of recent advances in forestry phenotyping and an introduction of individual-based and stand-based forestry phenotyping. Thus, various techniques for tree phenotyping were presented together with applications of these techniques. The measured parameters, spectral range, imaging principle, advantages and disadvantages of visible camera, fluorescence imaging sensor, near-infrared camera, hyperspectral imaging sensor, thermal infrared imaging sensor, and LiDAR scanner, as well as the development of tree phenotype information collection were analyzed. Furthermore, faster and higher-resolution tree data collection would lead to the improvement of precision-forestry practices. Future application of phenotyping platforms requires:1) establishing new platforms to obtain the key phenotypic traits of stands and individuals so as to improve the accuracy and throughput; 2) using environmental monitoring techniques to analyze the phenotypic responses of trees under abiotic stress so as to carry out breeding for high resistance varieties; 3) using the phenotypic changes under biological stress to promote the accurate monitoring, classification, identification and control of pests and diseases; 4) using high throughput phenotyping technology to combine with genome wide selection, quantitative trait loci and genome wide association study to identify the function of genes. In this paper, it was described that advances in phenotyping technologies lead to real-time, high-quality and high-throughput data on trees to accelerate tree improvement through breeding and to optimize precision forestry practices. Table and Figures | Reference | Related Articles | Metrics Select Current Status and Prospects of Impacts of Organic Mulching on Soil Conditions Xiaodan Sun,Yuqian Ye,Gang Wang,Qingwei Guan Scientia Silvae Sinicae    2020, 56 (6): 103-112.   DOI: 10.11707/j.1001-7488.20200611 Abstract （257）   HTML （16）    PDF （1389KB）（287）       Knowledge map    Save As a disturbance to soil ecosystem, organic mulching has a significant impact on soil structure and function, which plays an important role in urban soil conservation and urban soil restoration. The effects of organic mulching on soil environment were discussed, and its mechanisms were further clarified based on a literature review from Web of Science, CNKI, and other databases. It is important to further exploring the substance cycling process of soil ecosystem and improving the technical system of application of organic mulch, as well as strengthening the effects of urban soil conservation and restoration. Most studies illustrated that organic mulching could alleviate evaporation of surface water and direct infiltration of rainwater, promote soil aggregate structure, improve soil water retention, help to stabilize soil moisture and slow down soil erosion. Organic mulching cools the soil at high temperatures but keeps it warm at lower temperatures, which improves the conditions of plant growth. The greenhouse gas emission is uncertain because of the influences of soil conditions, mulching amount, mulching materials, and other factors. Due to the changes of soil water, air and heat, the activity, species and diversity of soil microorganisms after organic mulching are affected, and the activities of soil animals are also stimulated, which improves the soil structure and quality. The improvement of soil physical and chemical properties, the increase of nutrients and the changes of microbial community structure and function further enhance soil enzyme activity and accelerate the transformation rate of carbon and nitrogen in soil. Affected by the soil environment, the structure of plant root system was changed, fine root turnover was strengthened and rhizodeposition was increased. Additionally, the organic mulch itself provides the soil with carbon source, the substance cycle of soil ecosystem is accelerated, which causes the increasing sequestration of soil organic carbon, while the changes of soil carbon fractions remain contested. The decomposition of organic mulch increase soil organic matter and nutrient content, improve soil nutrition and increase soil fertility to varying degrees. At present, there are more and more studies on organic mulching on soil environment, however, the results have not been uniform, there is a lack of long-term in situ monitoring data, its mechanism has not been clearly understood, and the technical system in production practice still needs to be improved. Therefore, suggestions are put forward for future studies:1) Long-term dynamic monitoring and experimental studies should be carried out to clarify the changes of soil environment after organic mulching. 2) Comprehensively explore the effects of organic mulching on the transportation process of substance and energy in soil ecosystem, and deepen the understanding of the mechanism of the impacts. 3) Establish a sound technical system for organic mulch application to improve soil conservation and soil remediation effects. Reference | Related Articles | Metrics Select Research Progress on Total Synthesis of Precursor Components of Sex Pheromones from Six of Pine Caterpillar Species in China Fu Liu,Zhongwei Yuan,Xiangbo Kong,Sufang Zhang,Zhen Zhang,Zhifeng Guo,Zhenlin Li,Yanhui Song,Yibin Zhou Scientia Silvae Sinicae    2020, 56 (4): 170-180.   DOI: 10.11707/j.1001-7488.20200419 Abstract （247）   HTML （3）    PDF （1501KB）（112）       Knowledge map    Save There are six species of pine caterpillars in China,including pine caterpillars include Dendrolimus punctatus,D. superans,D. tabulaeformis,D. houi,D. spectabilis and D. kikuchii,and all the insects are serious pests of pine forests in China. Pine caterpillars have a strong reproductive capacity. When the pests break out,the all leaves of pines are eaten up quickly,which seriously hinders the growth of trees and even causes the trees to die. Furthermore,the pine caterpillars'infestation cause pines to decline,which can lead to the invasion of stem borers. Therefore,the control of pine caterpillars has always been an important research direction of forest entomologists in China. It is an important part of the comprehensive management of pine caterpillars to find an effective population monitoring method. Sex pheromone is an important means for the comprehensive management of pine caterpillars for its strong specificity and convenient application. Sex pheromone attractants can be used not only to monitor the occurrence period and population dynamics of pine caterpillars,but also to control the population number and prevalence by interfering with their mating. The active ingredients of sex pheromones in the 6 species of pine caterpillars could be divided into two main categories. The derivative of (Z,E)-5,7-dodecadien-1-ol and the derivative of (E,Z)-5,7-dodecadien-1-ol. Their precursors are the corresponding alcohols. In this paper,the synthesis methods of these two precursor compounds were summarized. The total synthesis of (Z,E)-5,7-dodecadien-1-ol could be roughly classified into three different synthetic ways. Route one,the Wittig reaction between aldehydes and phosphoranes; Route two,coupling reaction of E type iodinated alkene with unsaturated hydrocarbons; Other paths of reactions,including anti-Markovnikov addition of substituted olefins; rearrangement of thexylalkenyllalkynylboranes,and coupling reactions of organometallic reagents. In contrast,(E,Z)-5,7-dodecadien-1-ol could be synthesized by two ways. Route one,the Wittig reaction between α,β-unsaturated aldehydes and phosphoranes; Route two,coupling reaction of E type iodinated enol with alkynes. At present,the demand for sex pheromone of pine caterpillars is increasing day by day,and the design and optimization of its synthesis methods have become an important task. Consequently,this review will provide important reference for the researchers who carry out the similar research in China. Table and Figures | Reference | Related Articles | Metrics Select Research Progress on Effects of Forest Fire Disturbance on Carbon Pool of Forest Ecosystem Haiqing Hu,Bizhen Luo,Sisheng Luo,Shujing Wei,Zhenshi Wang,Xiaochuan Li,Fei Liu Scientia Silvae Sinicae    2020, 56 (4): 160-169.   DOI: 10.11707/j.1001-7488.20200418 Abstract （416）   HTML （22）    PDF （1456KB）（317）       Knowledge map    Save Forest ecosystem is an important carbon pool and plays an important role in mitigating climate warming. As a discontinuous ecological factor of forest,forest fire disturbance is the driving factor of biogeochemical cycle,which significantly changes the structure and function of the ecosystem,nutrient cycle and energy transfer,and causes the change of carbon pool and carbon distribution pattern in forest ecosystem,and in turn affects the process of forest succession and carbon sequestration capacity. This paper reviews the domestic and abroad research method on the impact of forest fire disturbance on forest carbon pool,and focuses on the direct and indirect effects of forest fire disturbance on forest carbon pool. The direct impact is mainly the direct carbon loss of forest ecosystem,while the indirect impact is mainly through forest ecosystem net primary productivity and soil respiration changes to affect the carbon cycle and carbon balance of forest ecosystems. The influence of forest fire disturbance on vegetation carbon pool,litter carbon pool and soil organic carbon pool are respectively clarified. The forest fire disturbance affects vegetation carbon pool and nutrient turnover by directly changing vegetation coverage,and ultimately affects vegetation fixation to carbon and the transfer of carbon from vegetation to soil leads to redistribution between different carbon pools. In terms of the effects of forest fire disturbance on the litter carbon pool of ecosystem,the main researches are mainly the change of litter production under different forest fire intensity and environmental gradient after forest fire disturbance. The influence of forest fire disturbance on soil organic carbon pool can be studied from small scale and large scale. Generally,in the small scale,the change of topographic conditions may be the main reason that affects the vertical distribution of soil organic carbon pool. At relatively large regional scales,the interactions of climate,soil texture,topography,vegetation,and human activities and management levels can affect the spatial migration and morphological transformation of soil organic carbon pools,which leads to the difference of soil organic carbon pools in different regions. On this basis,this paper points out the existing problems in the study. Finally,the quantitative research on the influence of forest fire disturbance on the carbon pool of forest ecosystem is put forward:1) Futher research on the effect mechanism of forest fire disturbance on the carbon pool circulation of forest ecosystem. 2) Strengthen the systematic study of "vegetation-soil-water-microbe-climate". 3) Improve the quantification of forest fires in the forest ecosystem by the forest fire disturbance at different time and space scales. 4) Futher discussion in-depth of the interaction between forest fire disturbance and carbon in forest ecosystems and its impact mechanism. Table and Figures | Reference | Related Articles | Metrics Select Advances in Pseudo-Lignin Deposition and Its Effects on Enzymatic Hydrolysis of Cellulose Ruyi Sha,Shasha Zhang,Zhan Yu,Fuquan Zhao,Chenggang Cai,Zhuqian Xiao,Jianwei Mao Scientia Silvae Sinicae    2020, 56 (3): 127-143.   DOI: 10.11707/j.1001-7488.20200314 Abstract （299）   HTML （9）    PDF （2852KB）（199）       Knowledge map    Save Lignocellulosic biomass is one of the most abundant renewable resources on earth. In order to improve the conversion rate of lignocellulosic biomass, increase the enzymatic hydrolysis efficiency of cellulose and the yield of fermentable sugars and to reduce the usage of cellulase and the conversion cost of biomass, it is essential to obtain the pretreated lignocellulosic biomass. However, the natural barrier between lignin, cellulose and hemicellulose limits the availability of cellulase to the cellulose components encapsulated inside. The main pretreatment methods of lignocellulose covered physical method, chemical method, physical chemical method and biological method. At present, the more adopted pretreatment methods include the dilute acid(hydrochloric acid, sulfuric acid, nitric acid, etc.)with the mass fraction less than 4% at the temperature of 120-210℃, high temperature hot water method, steam explosion method and liquid hydrothermal method. The dissolution and removal of lignin or most of the hemicellulose by various pretreatment methods is beneficial to improve cellulase accessibility. At present, a large number of studies have shown that lignin can significantly inhibit the enzymatic hydrolysis of cellulose, pretreatment can reduce lignin content and improve the efficiency of cellulose hydrolysis. In recent years, studies have shown that the relative content of Klason lignin would increase after the pretreatment of lignocellulose under severe conditions by using dilute acid and high temperature water. During the pretreatment processes of lignocellulosic biomass, lignin droplets may be deposited on the surface of the cellulose in the form of pseudo-lignin, so that it can inhibit cellulase hydrolysis more than natural lignin. However, no relevant review paper was found in the published articles. In this paper, the formation processes of lignin droplets and pseudo-lignin during the pretreatment of biomass were described. The possible mechanisms of pseudo-lignin production were put forward, and its composition and properties were reviewed. On this basis, the effects of lignin droplets and pseudo-lignin on the enzymatic hydrolysis of lignocellulose were summarized. Finally, the effects of lignin droplet and pseudo-lignin on the enzymatic hydrolysis of cellulose were discussed, and then the regulation strategy of pseudo-lignin formation was summarized. The authors believe that it is of great significance to study the mechanisms, structure characteristics, regulation mechanisms of the production of pseudo-lignin in the process of biorefinery. The formation of pseudo-lignin is a heterogeneous reaction process. At the same time, the formation mechanisms of pseudo-lignin can be studied from the mesoscale behavior due to the influence of mass transfer(molecular level)and the flow(macroscopic statistical level), and at the same time, the related models and theories should be established to realize their scientific quantitative descriptions and regulation. Moreover, it is beneficial to the development of lignocellulosic biomass refining processes and also it is conducive to promote the formation and development of an interdisciplinary scale of science. Table and Figures | Reference | Related Articles | Metrics Select Advances in the Carbon Sequestration of Mature Forests Wanze Zhu Scientia Silvae Sinicae    2020, 56 (3): 117-126.   DOI: 10.11707/j.1001-7488.20200313 Abstract （586）   HTML （39）    PDF （1211KB）（487）       Knowledge map    Save Mature forest is often referred to as the old-growth forest or the late-successional forest, which plays an important role in maintaining biodiversity and long-term carbon balance. In recent ten years, the carbon sequestration in mature forests under different environmental regimes and global change scenarios has received increasing attention since the founding that the old-growth forests can accumulate carbon in soils. Understanding the carbon storage and carbon source/sink dynamics of mature forests can be helpful for evaluating and predicting the role of mature forests in regional carbon cycles. It is also essential to evaluate the full range of forest C mitigation and to develop the close-to-nature forest management practices. On the basis of introducing the thresholds of mature forest ages, this paper analyzes the dynamics of carbon storage and distribution in natural mature forest, and the mature forest productivity and their influencing factors. Three carbon source/sink hypotheses of mature forest are summarized:1) The carbon neutral hypothesis proposes that net ecosystem productivity in forests steadily increases to a maximum with the age of forests, followed by gradual decline. The total ecosystem photosynthetic assimilation is increasingly offset by higher autotrophic and heterotrophic respiration at the mature forest stage, eventually, old forests are believed to reach (that is, C neutrality). 2) The carbon sequestration hypothesis suggests that many old-growth forest ecosystems in tropical, subtropical, and northern and temperate regions can continue to accumulate carbon, and act as a net sink for atmospheric carbon dioxide for centuries. The carbon sequestration in the mature forests is mainly in the soil, which is probably related to the increasing productivity of mature forests caused by climate change, and the increasing conversion of vegetation carbon into soil carbon with the increase of forest maturity, as well as the decreasing heterotrophic respiration in mature forest soil due to the global warming and atmospheric nitrogen deposition. 3) But very few studies have shown that the old-growth forests serve as a het carbon source. Accelerated carbon cycling of litters, dead trees, and soil organic carbon pools, especially when coupled with limited growth potential, could potentially drive the mature forest ecosystems to become a net source of carbon under future regional climate change scenarios. A growing number of studies have confirmed that the mature forests can sequester carbon, supporting the mature forest sink hypothesis. The future research should be focused on:1) Ttrengthening the carbon fluxes observation of mature forests by using eddy covariance approach. 2) Exploring the process of carbon source/sink and its formation mechanism in mature forest based on ecosystems respiration and its composition. 3) Studying the effects of global change on carbon sequestration in mature forests. Reference | Related Articles | Metrics Select Carbon Aerogel Based on Biomass Cellulose Yuan Chen,Yanming Han,Dongbin Fan,Tingting Yan,Gaiyun Li,Siqun Wang Scientia Silvae Sinicae    2019, 55 (10): 88-98.   DOI: 10.11707/j.1001-7488.20191010 Abstract （723）   HTML （33）    PDF （5466KB）（537）       Knowledge map    Save As a new type of lightweight aerogel, the biomass cellulose carbon aerogel has unique isotropic 3D network and hierarchical porous structure. Based on the individual structure, the carbon aerogel owns the excellent properties of aerogel (high specific surface area, high porosity and low density), carbon materials (heat resistance and electrical conductivity) and biomass materials (biodegradable and biocompatible). In recent years, it has becomes one of the hotspot research fields in nano-functional materials. The raw material of biomass cellulose carbon aerogel is widely available, including plants (wood, bamboo, fruits and vegetables), marine life and bacteria. Based on the differences in raw material form, the preparation methods of biomass carbon aerogel are summarized as gel carbonization method and biomass direct carbonization method. In addition, this paper introduces the main properties and modified methods, such as light and more porous, hydrophobic, stability, electrical conductivity, and metal doping and heteroatom doping modification. These excellent material properties make it been widely used in the insulation, electrochemical, adsorption, and many other fields. Also, it is potential to be used more forward-looking emerging material fields, such as drug release, antimicrobial materials, tissue engineering and electromagnetic shielding. The functional preparation, characterization and application of biomass cellulose carbon aerogel are emerging. Based on the research, this paper discusses the prospective of biomass cellulose carbon aerogel. As a new type of green material, the biomass cellulose carbon aerogel provides an application prospect for high-value and functional application of biomass materials. Table and Figures | Reference | Related Articles | Metrics Select Current Situation and Regional Distribution of City-Trees in China Guangfa Qie,Liwen Cao,Hongming Liu,Xin Fan Scientia Silvae Sinicae    2019, 55 (10): 76-87.   DOI: 10.11707/j.1001-7488.20191009 Abstract （251）   HTML （6）    PDF （2007KB）（117）       Knowledge map    Save Objective: The scientific selection of city trees is still an important work in the future.Based on the statistical data of the Municipal Tree Survey of the State Forestry Administration in 2017 and related data, the selection of city-trees in 348 cities above prefecture level in China was summarized, and the characteristics of overall application, species selection and regional distribution, application problems of city-trees were analyzed.In order to provide a basis for tree species selection and greening work in cities in China.The analysis results are as follows, there are 245 selected city-trees in China, accounting for 70.4% of the total number of cities, and 27 cities choose two type of city-trees at the same time; all prefecture-level cities in Hebei, Jiangsu, Zhejiang, Jiangxi, and other provinces, as well as Beijing, Tianjin, and Chongqing, have selected city-trees; from the tree species composition, the city-trees cover 81 species of 29 families and 56 genera, mainly concentrated in Pinaceae. Leguminosae, Rosaceae, Oleaceae, Cypress, and Lauraceae plants, among which Sophora japonica, Cinnamomum camphora, and Ginkgo biloba were selected by 49, 49, and 19 cities, respectively. Ficus is the most commonly used urban tree species in southern cities. From the geographical location, the choice of urban trees in different regions has its own characteristics, while in northern cities, S. japonica, cedrus and ginkgo are selected as the most popular ones. Pinus tabulaeformis, elm and weeping willow are more used as city-trees, C. camphora, C.longepaniculatum, Koelreuteria paniculata and magnolia are more used in the Yangtze River valley, camphor, phoenix wood, almond and osmanthus are more used in the southeastern coastal areas, among which the frequency of using S. japonica as city-tree in North China and Northwest China was 53.3% and 50.0% respectively, and the frequency of using camphor tree in central and Eastern China were 46.2% and 20.3% respectively. In the process of choosing city trees, there are still some problems in many cities, such as the application of city trees is not extensive, the use is unreasonable, and the name is not standardized. It is urgent to improve the greening in cities. Table and Figures | Reference | Related Articles | Metrics Select Research Progress on Wood Structure and Properties of Branch-Trunk Junction Deng Liping, Zhou Xianwu, Lü Jianxiong, Jianxiong Wang, Yurong Ren, Haiqing Zhao Scientia Silvae Sinicae    2019, 55 (9): 149-156.   DOI: 10.11707/j.1001-7488.20190916 Abstract （240）   HTML （16）    PDF （2404KB）（113）       Knowledge map    Save Branch-trunk junctions is an important part of tree's structure and function, which contains branch, the base of the branch involved in the xylem of trunk in the growth of the trunk, and also the knot formed after the branch was removed from the trunk. However, because of the negative impacts on the performance of the product, the research and utilization of the branch-trunk junctions is limited. With the development of bionics, the branch-trunk junctions have been gradually attracted great attention from scholars at home and abroad and related colleagues because of its complex structure, orderly connection and high toughness, decay resistance and other biological characteristics, and also as a kind of excellent biological composite materials. Many studies show that the branch-trunk junctions contain many artificial materials incomparable functions of intelligent composite material and structure characteristics. The deep research on branch-trunk junctions structure and its performance is expected to break its past use of limited territory and develop new application areas, and may also provide a new type of bionic research and development of high performance material beneficial enlightenment and the scientific basis. This paper summarizes the current research status of the structure and properties of the branch-trunk junctions from four fields,those are, the structure, chemical extraction, physical and mechanical properties. First of all, the structural characteristics at the level of macro observation and the intelligent adaptive performances changing with the external environments were respectivdy expounded. Secondly, the protective efficacy of the chemical extraction of knot was mainly summarized from the effects of chemical extracts on forest antisepticision and forest natural pruning. Then, the comparative studies of the branch-trunk junctions and tree stem in dry density, shrinkage properties and the change rule of physics were summarized. The related research on the correlations between mechanical properties and matrix material, and between structure arrangement and functional properties, and stress distribution characteristics was finally summarized. At the same time, this paper also describes examples of bionic engineering materials and structures and related branch-trunk junctions, as well as the related research providing some inspiration for the bionic design. In view of the complexity and particularity of branch-trunk junctions, the present studies on wood structure and properties of branch-trunk junctions awareness is relatively weak, and the research reports about branch-trunk junctions cell level fine structure and main chemical composition and the physical and mechanical properties is relatively less and not thorough. Based on these, the author research on wood structure and properties of branch-trunk junctions in the former, the paper brings forward several suggestions about further research on the wood material side of bionics, including those:1) Strengthening the macro and micro level of each branch-trunk junctions wood structural features and adaptive mechanisms of regulation. 2) Exploring the minor cellulose, hemicellulose and lignin and extracts and other chemical components and micro distribution mechanism of synergistic effect on the function of trees. 3) Carrying out branches, knots and parts of the trunk density, moisture variation and internal relationship of connection. 4) Exploreing the fine structure parameters on the branch-trunk junctions of wood physical and mechanical properties of the self adaptive control mechanisms, building the mathematical model of branch-trunk junctions fine structure and chemical composition of the wood structure parameters between physical and mechanical properties. Reference | Related Articles | Metrics Select Research Progress in Sex Differentiation in Angiosperms Xu Zilong, Chen Yicun, Gao Ming, Wu Liwen, Zhao Yunxiao, Wang Yangdong Scientia Silvae Sinicae    2019, 55 (8): 157-169.   DOI: 10.11707/j.1001-7488.20190817 Abstract （452）   HTML （25）    PDF （983KB）（262）       Knowledge map    Save Sex differentiation in angiosperms has a tremendous contribution to genetic diversity, offspring and environmental adaptation. Unisexual flower species, which are widely available in nature, play significant roles in economic development and social life, and their formation is an important way to avoid self-fertilization, promote cross-breeding, maintain genetic diversity and avoid sexual functional interference. The distribution of unisexual flower species in different evolutionary branches indicates that sex differentiation may be important in the evolution of genetic diversity and have a complicated regulatory network. Therefore, the study of the mechanism of sexual differentiation has vital theoretical significance and practical application value. Sex expression research involves morphology, biochemistry, cytology and molecular genetics. After reviewing the literature published in recent years, this paper presents a systematic summary of studies on sex differentiation from four aspects. 1) The formation of unisexual flowers originated from the ancestors of the bisexual flower, mainly through the two systematic evolutionary pathways of sexual organ loss or degradation. From the perspective of floral position and structures, unisexual flowers that have a variety of external morphological structures are divided into dioecy and monoecy. In terms of the flower development, the phenotypic characteristics of unisexual flowers are formed during four developmental stages, i.e., stage 0 (before the appearance of the sexual organ primordium), stage 1 (early development of the sexual organ primordium), stage 2 (pre-meiosis) and stage 3 (post-meiosis). The sex regulatory mechanisms of the species, which are involved in stages 0, 1 and 3, were discovered and proven. 2) Six major phytohormones, such as gibberellin, auxin and ethylene, play important roles in the regulation of sex differentiation. Gibberellin mainly promotes the development of stamens, while auxins, cytokinins and ethylene mainly promote the growth of carpels. The regulation mechanisms of related hormones has been elucidated, such as the ethylene synthesis pathway to regulate sex differentiation. 3) The molecular basis of organ loss or abortion has been investigated in different types of unisexual flowers. We integrated the sex-related or sex-determining genes in the identified species, and we explain the mechanisms of epigenetic regulation of sex formation, such as DNA methylation and small RNA, as well as the XY system, the X:A system and the ZW chromosome system, that are all used to regulate the pattern of sex differentiation. 4) Effects of environmental factors such as temperature, light intensity and mineral nutrition on sex differentiation. This paper presents a review of existing studies on sex differentiation in order to summarize different regulatory mechanisms of unisexual flower development, it deepens our understanding of sex expression, phylogeny evolution and regulatory mechanisms of sex differentiation. Reference | Related Articles | Metrics Select Progress of Preparation and Application of Lignin Micro/Nano-Spheres Xiong Fuquan, Wang Hang, Han Yanming, Chu Fuxiang, Wu Yiqiang Scientia Silvae Sinicae    2019, 55 (8): 170-175.   DOI: 10.11707/j.1001-7488.20190818 Abstract （542）   HTML （38）    PDF （2345KB）（268）       Knowledge map    Save Lignin is the second most abundant plant biopolymer on earth after cellulose. However, lignin is not used extensively due to its complex structures. Lignin micro/nano-particles can provide many opportunities for value-added applications of lignin. Self-assembly method of lignin micro/nano-spheres, which possess regular structure, include solvent and anti-solvent method, aerosol flow reactor and interfacial miniemulsion polymerization.When lignin and its derivatives are dissolved in solvent, such as tetrahydrofuran, dioxane and ethanol, and then dropped disionized water, the micro/nano-spheres can be formed. However, the micro/nano-spheres obtained through solvent and anti-solvent method may agglomerate in the drying process. Lignin precursor solution is directly atomized aerosol through aerosol flow reactor. When the micro/nano-spheres are prepared through interfacial microemulsion polymerization, lignin molecules will be linked by covalent and non-covalent bonded. Currently the micro/nano-spheres are mainly used in the fields of ultraviolet protection, drug carriers and nano-filler. When hydrophobic drugs are loaded by the micro/nano-spheres, the solubility of drugs in aqueous solution will be improved. And the loaded drugs exhibit the controlled release, a longer action time and a lower toxic and side effects. When photosensitive pesticides are loaded by the micro/nano-spheres, they display the characteristics of the controlled release and anti-photodegradation. The micro/nano-spheres are used to encapsulate the enzyme, which exhibit good stability and catalytic activity. Hydrophilic or hydrophobic outside surface of the micro/nano-spheres can be controlled through the change of self-assembly. Therefore, strong intermolecular interaction can be formed between the micro/nano-spheres and corresponding hydrophilic or hydrophobic polymer at the time of blending. In addition, the applications of the micro/nano-spheres have also been reported in the fields of adsorption materials, aggregation-induced emission nanomaterials and li-ion battery electrode materials. At present, studies on the micro/nano-spheres have been still in its infancy, there are much more to do. Because the interfacial miniemulsion polymerization can achieve synergies between non-covalent bond and covalent bond in the self-assembly process of lignin molecules, hollow lignin microspheres can be obtained by this method, which provides a new direction for the preparation of hollow lignin micro/nano-spheres. Moreover, light-emitting nanomaterials based on lignin may be as an important development direction due to the fact that lignin molecules have the characteristic of autofluorescence and aggregation-induced emission through J-aggregates. Reference | Related Articles | Metrics Select Research Advances in Forest-Runoff Relationship Liu Xiaodong, Liu Peiling, Dai Yuhang, Mo Qifeng, Lin Haojuan, Li Jiyue, Zhang Qianmei, Chen Xiuzhi Scientia Silvae Sinicae    2019, 55 (7): 155-162.   DOI: 10.11707/j.1001-7488.20190717 Abstract （235）   HTML （20）    PDF （1262KB）（630）       Knowledge map    Save The effects of forest cover change on water yield, a hotspot as well as a difficult issue in the fields of forestry, ecology and hydrology, still exist great debate. Observations of numerous watershed experiments that have been conducted for a century throughout the world also vary greatly and remain controversial. Here, based on the observations of globally published paired-watershed experimental and the time-trend result, we comprehensively presented the divergent opinions on the effects of forest cover change on water yield and analyzed the potential underlying mechanism. After that, we further summarized four aspects which need to be emphasized in future studies:1) to develop carbon and water coupling research at multiple scales; 2) to develop multiple sites and cross-regional integration research; 3) to concentrate on hydrological and ecological processes, mechanism and modeling; 4) to strengthen the cross-penetration and integration of different disciplines and technical fields studies. Reference | Related Articles | Metrics Select Research Methodologies for Genotype by Environment Interactions in Forest Trees and Their Applications Lin Yuanzhen Scientia Silvae Sinicae    2019, 55 (5): 142-151.   DOI: 10.11707/j.1001-7488.20190516 Abstract （341）   HTML    PDF （1310KB）（609）       Knowledge map    Save China is the largest wood importer and the second largest wood consumer in the world, and its dependence on external supply has exceeded 50% for several years. However, the average annual growth of forest per hectare in China is about half of that in the developed countries in forestry, which indicates that there is still larger gap in tree breeding in China, compared with the developed countries in forestry. Therefore, strengthening the large-scale experiments and accurate genetic evaluation of forest trees has great significance in improving the productivity of China's plantation forests through the precise selection and breeding of tree varieties. Genotype by environment interaction is one of the important contents of large-scale experiments and accurate genetic evaluation of forest trees. Genotype by environment interaction (G×E) refers to a lack of consistency in the relative performance of genotypes among different environments, and represents differences in genotype rankings or differences in performance inconstant among environments. Existing studies have confirmed that G×E is very common and often large in forest trees, and it is usually difficult to find consistently superior genotypes with broad adaptation. Since G×E can reduce heritability and genetic gain, understanding the G×E effects and their environmental drivers is vital to mating design, species/variety selection and genotype deployment. The paper reviews the current main analytical method for identifying G×E(including factor analytic method and BLUP-GGE joint analysis) and estimating heritability, and compares the strength and weakness of these analytical method (including stability analysis, type-B genetic correlation, AMMI, GGE biplot, factor analytic method and BLUP-GGE joint analysis), and also reviews the progress of G×E studies on growth traits (such as diameter at breast height, height and volume), form traits (such as stem straightness, branch angle and branch size) and wood properties (such as wood density and modulus of elasticity) in forest species (such as Pinus elliottii, Pinus taeda, Picea abies, Eucalyptus grandis, Pinus radiata and Pseudotsuga menziesii) of global economic importance. Moreover, the paper discusses the environmental drivers that cause G×E and strategies for dealing with G×E in tree breeding. Finally, the future research of G×E is proposed, alongside development of new analytical method, focusing on multi-variate model of G×E and integration of genomic selection with G×E. New genetic analysis model for forest trees should be adopted into G×E studies. The patterns and magnitude of G×E should be focused on multi-variate model for multi-environment trials. Accurate estimation of environment-specific genomic breeding values of forest trees should be performed. Reference | Related Articles | Metrics Select Progress in Sex Pheromone Components in Geometrid Species (Lepidoptera: Geometridae) and Their Applications Ma Tao, Huang Zhijia, Zhu Ying, Lin Na, Xiao Qiang, He Yurong, Wen Xiujun Scientia Silvae Sinicae    2019, 55 (5): 152-162.   DOI: 10.11707/j.1001-7488.20190517 Abstract （277）   HTML    PDF （3466KB）（434）       Knowledge map    Save Pheromone of Lepidoptera has been studied in detail at home and abroad. This study elucidates the latest classification system of Lepidopteran sex pheromone components in which all the components are respectively categorized into TypeⅠ, TypeⅡ, TypeⅢ and Type 0. TypeⅠ, is distributed in many superfamilies of Lepidopteran, and includes alcohol, aldehydes and acetic ester compounds with carbon number ranging from 10 to 18. TypeⅡ is widely distributed in geometrid, and consists of unsaturated C17-C23 hydrocarbon and their corresponding epoxides. TypeⅢ simply consists of C17-C23 hydrocarbon with single or multiple methyl branches, and it was found only in few Lepidopteran species. Type 0 is short-chain second alcohol or ketone compounds that are analogous to plant volatile organic compounds (VOCs). At present, pheromone components of 158 geometrid species from 93 genera have been characterized. Except for Sterrhinae whose sex pheromone components are categorized mainly in Type I, the other sex pheromone components in subfamilies of geometrid are mainly categorized in TypeⅡ. Most of geometrid sex pheromone components have the long carbon chain scaffold and unsaturated hydrocarbons (TypeⅡ) in structures, which seriously affects characterization and field application. This paper clarities the double bond position, epoxy structures and chiral conformation of the geometrid sex pheromone components, as well as the distribution pattern of pheromone components among geometrid subfamilies, genera and species. The sex pheromone research situation of the important species in China was also discussed, which provides reference for subsequent researches on geometrid pheromone and effective green control of insect pests of Lepidoptera with sex pheromones. Reference | Related Articles | Metrics Select Advances in studies on Influential Factors for Cooling Effect of Urban Forest Liu Haixuan, Xu Lijuan, Wu Ju, Xu Chengyang Scientia Silvae Sinicae    2019, 55 (4): 144-151.   DOI: 10.11707/j.1001-7488.20190415 Abstract （240）   HTML    PDF （1205KB）（461）       Knowledge map    Save Urban forest is an important green infrastructure alleviating urban heat island. This study was aimed to explore the internal and external factors influcening the cooling impacts of urban forest and to understand the mechanisms of such influence. It provides an scientific basis for optimization of urban forest structure and alleviation of the effects of urban heat island.The internal factors that affect urban forest cooling effect at individual tree scale were tree species, canopy structure and crown shape, while at stand scale, the factors mainly contained forest type, forest structure, green biomass and shape and size of the stand, moreover, the cooling effect of urban forest was studied mainly by remote sensing method at urban scale, and the representative indices included NDVI, LAI and landscape ecological indicators. In addition, the external factors that affected the cooling effect of urban forest included non-biological factors such as climate and ground types, as well as forest management. The internal and external factors affected the cooling effect of urban forest jointly by affecting the flow and exchange of energy inside and outside the forest.To alleviate the effect of urban heat island, on the one hand, it is necessary to strengthen theoretical research, attach importance to the theory of temperature field, and study the relationship between stand structure and energy transmission in urban forest by combining ground observation and remote sensing. On the other hand, it is important to strengthen the management of urban forests, optimize the stand structure from the perspective of promoting heat exchange, and rationally match buildings, forests and water to maximize the cooling effect. Reference | Related Articles | Metrics Select Cholesteric Liquid Crystal from Cellulose Nanocrystal: Formation and Application Qing Yan, Wang Lijun, Wu Yiqiang, Luo Sha, Wu Qinglin, Yan Ning Scientia Silvae Sinicae    2019, 55 (4): 152-159.   DOI: 10.11707/j.1001-7488.20190416 Abstract （472）   HTML    PDF （3950KB）（890）       Knowledge map    Save Liquid crystal is a special phase state with partially ordered arrangement, and shows remarkable difference between completely ordered solid state and completely disordered liquid state. As the representative liquid crystal, cellulose nanocrystal (CNC) is currently prepared by the strong acid hydrolysis of natural cellulose, including wood, bamboo, cotton, tunicate, bacteria and so on. The individual CNC is randomly dispersed in the CNC suspension at low concentration solution. With the concentration increased, the randomly dispersed CNCs spontaneously arrange to form cholesteric liquid crystals. Due to the special optical properties such as bragg reflection, polarized light dichroism and rotary polarization, cholesteric liquid crystals from CNCs can be applied as anti-counterfeiting optical information storage, intelligent windows and liquid crystal display. In this paper, the preparation and regulation method of cholesteric liquid crystals from CNCs are introduced. The preparation and comparison of different CNCs from a large variety of resources are proposed. The regulation effects of physical factors (ultrasonic, temperature, vacuum drying and magnetic field and other regulatory factors) and chemical factors (electrolyte and additives and other regulatory factors) on the pitch of cholesteric liquid crystals from CNCs are be discussed in order to make a theoretical contribution to the regulation preparation of cholesteric liquid crystal. In addition, the formation mechanism, the structure and optical properties of cholesteric liquid crystals from CNCs are introduced, and the application status in thermo-sensitive functional materials, optoelectronic functional materials and chiral mesoporous materials are summarized. The future development trends of cholesteric liquid crystals from CNCs are also discussed as the following:1) Adjusting the preparation method to obtain CNC with negative charges, rod-shape and small size distribution which are all necessary for CNC to form ideal cholesteric structure; 2) Developing less time consuming and greener preparation method of cholesteric liquid instead of slow evaporation self-assembly method; 3) Establishing the relevant regulatory model to achieve controllable preparation of cholesteric liquid crystals from CNC; 4) Copying stable chiral nematic structure from CNCs and developing high performance multi-functional materials in the future. Reference | Related Articles | Metrics page Page 1 of 2 Total 34 records First page Prev page Next page Last page