Content of Scientific notes 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 Analysis of the Effect of Enzyme Pretreatment on the Decolorization of Paulownia Shulei Li,Hong Zhang,Yibo Li,Jieying Yuan,Feifan Xie,Hanxing Wang,Jie Chu,Ruijin Yu Scientia Silvae Sinicae    2023, 59 (5): 157-164.   DOI: 10.11707/j.1001-7488.LYKX20210565 Abstract （97）   HTML （5）    PDF （1667KB）（122）       Knowledge map    Save Objective: This study explored the bleaching effect and influence of the second-generation biological complex enzyme on tung wood, and provided theoretical basis and scientific basis for the decolorization and biological improvement of tung wood and the development of tung wood pulping. Method: Paulownia elongata was used as the experimental material, and the cellulose second-generation enzyme (CTEC2) was used for pretreatment. The changes of color difference index and chemical components of samples before and after pretreatment were analyzed by controlling pretreatment time(60, 75, 90, 105 min), temperature(30, 50, 70 ℃) and pH value(3, 5, 7), The thermal degradation properties of the samples were analyzed by TGA(thermo gravimetric analysis), the changes of microstructure were investigated by SEM(scanning electron microscope), and the changes of crystallinity after pretreatment bleaching were measured by XRD(X-ray diffraction). Result: 1) Color determination: when the pretreatment conditions were pretreatment temperature 50 °C, pH value 7 and pretreatment time 105 min, the bleaching effect of paulownia wood was the best, and the brightness and whiteness were improved, and the bleaching effect will also be improved with the extension of pretreatment time. 2) Component determination showed that CTEC2 had the best pretreatment effect on Paulownia wood at 50 °C and pH 7. The relative content of cellulose increased by 10.76%, hemicellulose content decreased by 11.13%, acid-soluble lignin content decreased by 3.05%, acid-insoluble lignin content decreased by 4.22%, and extract content decreased by 1.15%. 3) From the TGA curve, the temperature corresponding to the maximum mass loss rate of pretreated paulownia wood increased, and the thermal stability increased. It can be seen from the SEM images that the pretreatment can effectively destroy the lignocellulose structure. XRD showed that the crystallinity of pretreated paulownia wood cellulose increased. Conclusion: CTEC2 can change the main chemical components of paulownia wood, reduce the content of lignin, hemicellulose and extract, so as to achieve bleaching and decolorization effect. The optimum conditions for bleaching pretreatment of paulownia wood were temperature 50 °C, pH 7 and pretreatment time 105 min. Table and Figures | Reference | Related Articles | Metrics Select Distribution Law of Tree Height-to-Diameter Ratio in Each Stratum of Typical Natural Broad-Leaved Forest in Mid-Subtropical Zone Minghai Yan,Jinchi Wang,Qinglin Huang,Chongyang Zhuang,Qunrui Zheng,Mingxiu Zhuo,Xiaohui Guan Scientia Silvae Sinicae    2023, 59 (4): 149-156.   DOI: 10.11707/j.1001-7488.LYKX20210632 Abstract （146）   HTML （15）    PDF （821KB）（259）       Knowledge map    Save Objective: To reveal the distribution law of tree height-to-diameter ratio in each stratum of typical natural broad-leaved forest in mid-subtropical zone, to provide a typical reference in the aspect of height-to-diameter ratio of broad-leaved trees for the sustainable management of artificial broad-leaved forest, semi-natural broad-leaved forest and natural broad-leaved forest in mid-subtropical zone. Method: In Jian’ou Wanmulin provincial nature reserve, 50 m×50 m plots were set up in 5 typical natural broad-leaved forest in mid-subtropical zonerespectively. Themean tree height-to-diameter ratio and standard deviation of each stratum in the typical stand was calculated to analyze its changes with the stratum, and the Mann-Whitney U test was used to analyze the significance test of the difference between the average height-to-diameter ratio in each stratum. Skewness and kurtosis are used to describe the degree of deviation and dispersion of the height-to-diameter ratio distribution. The normal distribution and Weibull distribution function were selected to fit the distribution of the height-to-diameter ratio of each stratum in each plots, and the fitting effect was tested by χ2 test. Result: The mean tree height-to-diameter ratio in 5 sample plots was integrated, the mean tree height-to-diameter ratio of the whole stand was 103.1, and the mean tree height-to-diameter ratio of each stratum decreased with the increase of the stratum height. The order and value were as follows: the stratum Ⅲ (112.7) > the stratum Ⅱ (89.0) > stratum Ⅰ (66.9)and NLRS(112.7) > LRS(78.3).The mean tree height-to-diameter ratio between the stratum Ⅱ and stratum Ⅲ in plot 4 was significantly different, and the average height to diameter ratio of trees between stratum in other plots was extremely significant.The results of skewness showed that the tree height-to-diameter ratio of each stratum was skewed to the right. The variation of skewness of the tree height-to-diameter ratio in each stratum was irregular.The normal distribution function was used to fit the distribution of tree height-to-diameter ratio of each stratum, and all the results passed the Chi-square test. However, most of the results of Weibull distribution function did not pass the Chi-square test. Conclusion: In the typical natural broad-leaved forest of the mid-subtropical zone,the tree mean height-to-diameter ratio of each stratum has an extremely significant difference, and the tree mean height-to-diameter ratio decreases with the increase of the stratum height.The distribution of tree height-to-diameter ratio in each stratum was right skewed. The tree height-to-diameter ratio of the whole stand and the stratum Ⅰ was relatively dispersed, while the stratum Ⅱ and stratum Ⅲ were relatively concentrated. The fitting effect of normal distribution function on tree height-to-diameter ratio of each stratum was good, but the fitting effect of Weibull distribution function was not ideal.In the typical natural broad-leaved forest of the mid-subtropical zone, the height-to-diameter ratio distribution was significantly different from that of diameter distribution. The height-to-diameter ratio distribution of the whole forest and the stratum Ⅲ was normal, but the diameter distribution of the whole forest and the stratum Ⅲ was inverted J. The average height/diameter ratio in each stratum and the distribution of height/diameter ratio in each stratum reflected in this study belong to the height/diameter ratio characteristics under ideal circumstances. Table and Figures | Reference | Related Articles | Metrics Select Preliminary Survey on the Diversity of Mammalian and Avian in the Non-Protected Area of Burhan Buda Mountain, Qinghai Province, with Infrared Camera-Trapping Technology Ye Li,Yonghong Shi,Xianjin Xu,Faju Jing,Zhenliang Shi,Guohu Liu,Diqiang Li Scientia Silvae Sinicae    2022, 58 (12): 155-163.   DOI: 10.11707/j.1001-7488.20221214 Abstract （123）   HTML （1）    PDF （14038KB）（68）       Knowledge map    Save Objective: This study aims to understand the species diversity status of the mammalian and avian species in the Burhan Buda Mountain area in the central part of Qinghai Province,which belongs to the category of non-protected areas,and to provide reference for further research on species distribution on the plateau and for formulating wildlife protection and resource management plans. Method: A total of 23 infrared camera locations were deployed in the altitude range of 3 000-4 500 m in the Burhan Buda Mountain,from May to October 2017 and March to May 2019. Result: In this study,an intensive survey was conducted,with an effort of 4 703 camera days,and a total of 2 868 effective independent photographs were taken,in which 22 species of mammals belonging to 5 orders and 10 families,25 species of birds belonging to 5 orders and 12 families,and 4 domestic animal species were identified. Based on the RAI (relative abundance index),the four most abundant mammal species successively were Pseudois nayaur (6.44),Marmota himalayana (5.12),Lepus oiostolus (2.59),and Vulpes ferrilata (2.17),and the four most abundant bird species successively were Tetraogallus tibetanus (4.72),Phoenicurus ochruros (3.36),Alectoris magna (3.15) and Phoenicurus erythrogastrus(2.59). Among the detected species,there were 5 species listed as Class Istate key protected wild animals and 15 species as ClassⅡ state key protected wild animals in China. There were 6 species classified as endangered species,2 species classified as vulnerable species,and 12 species classified as near threatened species in the Red List of China's Vertebrates. There were 5 species endemic to China,including 3 species of mammals,Gervus albirostris,Cervus elaphus and Procapra picticaudata,and two avian species of Pseudopodoces humilis and Alectoris magna. Conclusion: The preliminary results reflect the current status of the mountain mammalian and avian species resources in the central of Qinghai Province,and provide a data basis for further study on long-term monitoring of biodiversity,management of grazing land and human-animal conflicts in the traditional plateau grazing areas of non-protected areas. Table and Figures | Reference | Related Articles | Metrics Select Driving Factors of the Temporal Stability of Biomass of Mixed Broadleaf-Conifer Forest Shuijin Yu,Juan Wang,Haiyan He,Chunyu Zhang,Xiuhai Zhao Scientia Silvae Sinicae    2022, 58 (11): 181-190.   DOI: 10.11707/j.1001-7488.20221117 Abstract （117）   HTML （1）    PDF （2666KB）（215）       Knowledge map    Save Objective: The objective was to investigate the effects of biodiversity, DBH structure and topography on the temporal stability of biomass and clarify the main driving factors for the temporal stability of biomass at different spatial scales. Method: Based on two large fixed sample plots in Jiaohe, Jilin, the influences of different spatial scales was quantitatively analyzed by randomly sampling 20 m×20 m, 40 m×40 m, and 60 m×60 m plots. Three types of nested models were constructed using generalized additive models: stability~biodiversity + DBH structure (model 1), stability-biodiversity + topographic factors (model 2), stability-biodiversity + DBH structure + topographic factors (model 3), and compared with stability~biodiversity (model 0). The relative contributions of different explanatory factors are evaluated by the variation of Akaike information criterion (△AIC), the variation of Bayesian information criterion (△BIC), the variation of adjusted determination coefficient (△Radj2) and the variation of deviance explained (△DE). Result: The analysis of the generalized additive model shows that at the three scales of 20 m×20 m, 40 m×40 m, and 60 m×60 m, the relative contribution rates of biodiversity are 15.18%, 12.66%, and 47.64%, respectively; the relative contribution rates of DBH structure are 11.30%, 72.38%, and 23.48%, respectively; the relative contribution rates of topography are 73.52%, 14.96%, and 28.88%, respectively. Biodiversity and DBH structure are only significantly correlated with the temporal stability of biomass on the 60 m×60 m scale (P < 0.05). Among them, species richness and Faith phylogenetic diversity index are significantly negatively correlated with the temporal stability of biomass. The maximum diameter at breast height and basal area per hectare are significantly positively correlated with the temporal stability of biomass, and the coefficient of variation of diameter at breast height is significantly negatively correlated with the temporal stability of biomass. Among the topographic factors, the aspect is significantly related to the temporal stability of biomass at the 20 m×20 m scale, and the elevation and slope are significantly related to the temporal stability of biomass at the 60 m×60 m scale. The explanation rate of the deviation of the above explanatory variables on the temporal stability of biomass increases with the spatial scale. The driving factor for the temporal stability of volume is basically the same as the temporal stability of biomass. Conclusion: The relative influences of topographic factors, DBH structure and biodiversity have significant scale effects on the temporal stability of biomass and shift along different spatial scales. Topographical factors play a major role in the temporal stability of biomass at the scale of 20 m×20 m. DBH structure plays a major role in the temporal stability of biomass at the scale of 40 m×40 m and biodiversity plays a major role in the temporal stability of biomass at the scale of 60 m×60 m. The results provide a theoretical basis for improving the stability of the northeast coniferous and broad-leaved mixed forest ecosystem. Table and Figures | Reference | Related Articles | Metrics Select Biological Activity of Crude Extracts from Leaves of Seven Non-Host Plants against Corythucha ciliata Adults (Hemiptera: Tingidae) Xin Zhan,Min Zhuang,Guohua Li,Shuyan Yin Scientia Silvae Sinicae    2022, 58 (7): 156-162.   DOI: 10.11707/j.1001-7488.20220716 Abstract （167）   HTML （6）    PDF （1540KB）（77）       Knowledge map    Save Objective: The main purpose of this paper is to study the reasons that seven plants, including Metasequoia glyptostroboides, Liquidambar formosana, Broussonetia papyrifera, Populus tomentosa, Chaenomeles sinensis, Liriodendron chinense and Fraxinus chinensis do not become the hosts of Corythucha ciliata although the volatiles from the leaves of these seven plants have a significant attracting effect on C. ciliata adults, soas to provide a basis information for the use of non-host plants by tree species arrangement or their extracts to prevent and control C. ciliate. Method: The crude extracts from the leaves of the seven non host plants were obtained by grinding and filtration. The crude extracts were fed to the adults of C. ciliata to determine the impact on their survival. The crude extracts and dilutions of different volume fraction were applied to the leaves of Platanus acerifolia to determine the repellent activity against the adults of C. ciliata. Result: The survival status of C. ciliata adults fed with crude leaf extracts of 7 non-host plants was significantly lower than the control (water), and the median lethal time, 99% lethal time and average survival time were extremely significant shorter than those of C.ciliata adults treated with water, especially C. sinensis. The crude extracts from the leaves of the seven non-host plants all have repellent effects on C. ciliata adults. The highest repellent rate was B. papyrifera (74.84%), followed by F. chinensis (70.74%), L. formosana (53.90%), C. sinensis (53.33%), M. glyptostroboides (51.66%), P. tomentosa (49.47%) and L. chinense (43.19%). When the crude extracts were diluted, the repellent effects decreased, but the effects did not decrease unidirectionally with the decrease in volume fraction. Conclusion: That the crude extracts of these seven non-plant which have an attractive olfactory effect, contain substances that are toxic or and repellent to the adults of C. ciliata, may be one of the reasons why these plants are not used by C. ciliata. Among the seven plants, the extracts of B. papyrifera had the strongest repelling effect and the extracts of C. sinensis have the greatest toxicity to C. ciliata. The possible applications of the two plants in the control of C. ciliata can be studied further. Table and Figures | Reference | Related Articles | Metrics Select Neighborhood Competition Effect in Mixed Broadleaved-Conifer Forest in Jiaohe, Jilin Province Jialin Su,Juan Wang,Chunyu Fan,Chunyu Zhang,Xiuhai Zhao Scientia Silvae Sinicae    2022, 58 (5): 187-194.   DOI: 10.11707/j.1001-7488.20220519 Abstract （188）   HTML （10）    PDF （2501KB）（114）       Knowledge map    Save Objective: The CSR (complete spatial randomness) null model of the point pattern analysis requires that the habitat background is homogeneous, but the most factors in natural forest habitat are heterogeneous, which will inevitably influence the point pattern analysis. This paper attempts to divide the heterogeneous plots into several relatively homogeneous subareas by the method of habitat division, and discusses the interaction rules among individual trees in different habitat subareas through the analysis of mark point pattern, in order to provide theoretical support for the management and operation of forest management. Method: Based on the data of 21.12 hm2 natural mixed broadleaved-conifer forest, the forest plot was divided into two relatively homogeneous habitats (A and B) according to the topographic variables. The interaction effects between adjacent individuals were tested by using mark correlation function combined with the complete spatial randomness simulation process. Result: The mark correlation analysis of individual tree species showed that the vast majority of tree species in areas A and B showed negative spatial correlation between individual DBHs. Moreover, at the scale of r < 6 m, the number of tree species with negative correlation in area A was significantly higher than that in area B. At the scale of r < 9 m, no positive correlation between the individual DBHs was detected. Without considering the heterogeneity of habitat conditions, mark correlation analysis was carried out in the whole sample plot. At the scale of 0-8 m, the individual DBHs of canopy layer showed a significant negative correlation, and there was no significant spatial correlation between those of subcanopy layer and understorey layer. When the spatial autocorrelation of the attributes of individual DBHs in each forest layer was tested in a relatively uniform habitat, there was no significant spatial correlation between the individual DBHs of the sub-canopy layer and the understory layer, while those of the canopy layer had significant negative correlation at small scale. The interaction scale of the canopy individuals in area A was 0-6.9 m, and that of area B was 0-5.6 m. Conclusion: Under different habitat conditions (i.e., subzone A and B), the spatial negative correlation scales of DBH of adjacent individuals in the forest canopy are different. Therefore, in the process of forest management, the influence of habitat differences should be fully considered when determining the final stocking density of retained trees. Table and Figures | Reference | Related Articles | Metrics Select Karyotype Analysis of 18 Excellent Individuals in F1 Generation of Interspecific Hybridization of Oil-Tea (Camellia oleifera) Yanmin Li,Deyi Yuan,Tianwen Ye,Ya Chen,Chunxia Han,Shixin Xiao Scientia Silvae Sinicae    2022, 58 (4): 165-174.   DOI: 10.11707/j.1001-7488.20220417 Abstract （243）   HTML （5）    PDF （2856KB）（98）       Knowledge map    Save Objective: Interspecific hybridization of Camellia oleifera is an important way of germplasm innovation. This study aims to clarify the law of genetic variation of parental and offspring chromosome, which could help guide the selection of descendant materials and the configuration of backcross combination, and provide reference for the subsequent cross breeding research. Method: The root tips of cuttings of parents and 18 excellent F1 plants were selected as materials, the chromosome karyotype characteristics of parents and hybrids were studied by means of an improved chromosome preparation technique and karyotype analysis software, and the chromosomal inheritance and variation of parents and hybrids were analyzed by karyotype near coefficient clustering. Results: 1) The karyotype of male parent 'Huashuo' and female parent 'Youza 2' was 2B type, with m-type chromosome in the majority and sm-type chromosome in the minority. The karyotype formula of female parent 'Youza 2' was 2n = 91 = 53m (4SAT) + 38sm (2SAT). The variation range of chromosome relative length was 1.26% ~ 2.97%, the proportion of chromosomes with arm ratio greater than 2 was 17.8%, the chromosome length ratio was 2.36, and the karyotype asymmetry coefficient was 62.36%. The karyotype formula of male parent 'Huashuo' was 2n = 90 = 62m (2SAT) + 28sm (4SAT), the relative length of chromosomes ranged from 1.50% to 3.00%, the proportion of chromosomes with arm ratio greater than 2 was 4.4%, the ratio of chromosome length was 2.00, and the asymmetry coefficient of karyotype was 59.38%. 2) Most of the karyotype parameters of hybrid progenies were between male and female parents, most of chromosomes were m-type and sm-type, a few of chromosomes were st-type. The number of sm-type chromosomes was greater than that of m-type ones in some hybrid progenies (YH-14 and YH-18). The variation range of chromosome length was large, with generally in 1.05%~3.32%, most of which were M1 and M2 chromosomes. The variation range of the karyotype asymmetry coefficient was 61.01%~63.38%, and the karyotype was 2A or 2B type. 3) The results of karyotype cluster analysis showed that when the similarity coefficient of karyotype was 0.9660 and the distance coefficient was 0.0340, the hybrid progenies could be divided into two groups: most of them were clustered with the female parent 'Youza 2', only YH-11 and YH -15 were clustered with male parent 'Huashuo' into the other group. Conclusion: The karyotype parameters of most of the hybrid progenies are between the male and female parents, and the karyotype parameters of a few hybrid progenies vary greatly. In addition, the karyotypes of most individual plants in the hybrid progeny population are more similar to that of the female parent 'Youza 2', and only a few are more similar to that of the male parent 'Huashuo'. The results can provide a theoretical basis for the cross breeding of Camellia oleifera and the creation of new Camellia oleifera germplasm. Table and Figures | Reference | Related Articles | Metrics Select Variation in Physiological and Ecological Responses of Mulberry Trees with Different Breeding Methods to Waterlogging Stress Yong Li,Jin Huang,Cui Yu,Rongli Mo,Zhixian Zhu,Zhaoxia Dong,Xingming Hu,Cuxiong Zhuang,Wen Deng Scientia Silvae Sinicae    2022, 58 (3): 175-186.   DOI: 10.11707/j.1001-7488.20220319 Abstract （264）   HTML （8）    PDF （7646KB）（167）       Knowledge map    Save Objective: In this study, we measured the dynamic changes of photosynthetic physiological parameters, osmotic adjustment substances and protective enzyme system of mulberry leaves of different breeding methods under waterlogging stress. The main purpose of this study is to reveal the response strategies and differences of mulberry trees derived from different breeding methods to waterlogging stress, so as to provide a theoretical basis for the ecological restoration and sustainable development of mulberry under the adverse environment such as the water level fluctuation. Method: The seedlings of two mulberry varieties (SG and AY), which were reproduced by grafting (JJ) and cutting (QC), were selected as the test objects. and the waterlogging stress (YS) was simulated through covering a pot with another pot. The dynamic changes of photosynthetic parameters, chlorophyll content, osmotic adjustment substance content (soluble protein, soluble sugar, proline, malondialdehyde) and leaf protective enzyme activity (superoxide dismutase, peroxidase, catalase, ascorbate peroxidase) were measured on 0 d, 3 d, 7 d, 12 d, and 18 d of the waterlogging treatment to explore the effects of different breeding methods on the response of mulberry trees to flooding stress. Result: 1) The chlorophyll content decreased with the increase of waterlogging days, and the chlorophyll content of different varieties was only slightly different (P>0.05); 2)The diurnal variation of net photosynthetic rate (Pn) of CK-treated leaves showed a bimodal curve, while the mulberry seedlings with YS treatment showed a single peak curve of diurnal variation of Pn. QC breeding had slightly greater Pn value than JJ breeding did (P>0.05). The dynamic changes of photosynthetic parameters (Pn, Gs and Tr) of mulberry leaves in all treatments showed a trend of first decline and then increase, and the Pn value of QC breeding was slightly greater than that of JJ breeding (P>0.05). 3) With the extension of waterlogging time, the content of osmotic adjustment substances in the leaves of each treatment showed a downward trend. 4)Mulberry in all treatments could remove reactive oxygen species and maintain growth by increasing superoxide during the entire flooding period, but the changes of peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) showed a downward trend. Conclusion: The waterlogging stress reduces photosynthesis of mulberry trees, but there are differences in photosynthetic capacity between seedlings with different breeding methods. The photosynthesis ability of QC breeding mulberry is stronger than that of JJ breeding in the waterlogging stress. With the prolongation of waterlogging time, the two mulberry varieties in this experiment do not reduce the osmotic potential by accumulating osmotic condition substances. The SOD is the main defensive enzyme of mulberry in response to waterlogging stress. As for the response speed to waterlogging stress, there is interaction between breeding methods and different varieties. SG seedlings bred by QC respond faster than that bred by JJ, while AY seedlings bred by JJ respond faster than that bred by QC. This experiment shows that SG is suitable for QC breeding while AY is suitable JJ breeding. Whether different breeding methods have an impact on the physiological and ecological response of other mulberry varieties under waterlogging stress still needs further research and verification. Table and Figures | Reference | Related Articles | Metrics Select Identification and Bioinformatics Analysis of Mariner-Like Element Autonomous Transposons in Phyllostachys edulis Jiamin Xie,Mingbing Zhou Scientia Silvae Sinicae    2022, 58 (1): 175-184.   DOI: 10.11707/j.1001-7488.20220118 Abstract （161）   HTML （14）    PDF （5416KB）（69）       Knowledge map    Save Objective: A transposon is a repeat fragment of DNA that can jump in the genome of an organism. According to the mechanism of transposition, transposons are divided into retrotransposons with "copy-paste" mode and DNA transposons with "cut-paste" mode. According to the integrity of the structure, the transposon can be classified into autonomous transposon and non-autonomous transposon. The autonomous transposon has a complete transposase and can independently produce transposase. The transposase of the non-autonomous transposon is incomplete, but contain necessary transpositional elements. The non-autonomous transposon can transpose under the assistance of the transposase from the autonomic transposon. Mariner-like element(MLE) is a kind of DNA transposons that are widely distributed in eukaryotic genomes, with the transposition mode of "cut-and-paste". Previous studies have shown that MLE transposons have great application in the fields of transgene, gene function analysis, gene therapy and so on. In order to reveal the distribution pattern and evolution dynamics of MLE transposons in the evolution of Phyllostachys edulis, the genome-wide mining of the MLE transposons in P. edulis genome were conducted. The distribution and deletion characteristics of autonomous MLE and non-autonomous MLE in the P. edulis genome were studied. Method: Utilization of the MLE transposon sequences of rice, soybeans and P. edulis, with the IRF, Blast and Fasta software, according to the specificity of TIR (Terminal Inverted Repeats) of MLE transposon and its encoding enzyme, the full-length intact MLE transposons were identified in P. edulis genome. According to TIR of the full-length intact MLE transposons, the corresponding non-autonomic MLEs were characterized. The distribution characteristics of autonomous and non-autonomous MLEs and the deletion patterns of non-autonomic MLE structures were analyzed. Result: Two intact autonomous MLE, PhV2MLE1A and PhV2MLE2A, were identified in this study. PhV2MLE1A is 3 950 bp in length, encodes 414 amino acids, and has a 30 bp length TIR. PhV2MLE2A was 12 990 bp, encodes 373 amino acids, and has 49 bp length TIR. According to the similarity of the TIR structure, two non-autonomous transposons corresponding to two autonomous MLEs were identified. In this experiment, two autonomous MLEs with complete structures and their corresponding non-autonomous transposons were obtained. At the same time, it was found that the structural deletion of different non-autonomous transposons was irregular. The distribution of MLE in the P. edulis was random, and the insertion preference was between the conservative sequence TA. Conclusion: A large number of MLE transposons were distributed in the genome of P. edulis. Most of MLE transposons lost their transposable activity due to the lack of transposases in the evolutionary process. Table and Figures | Reference | Related Articles | Metrics Select Effects of Different Thinning Intensity on Growth, Grain Yield, and Quality of Tree Penoy'Fengdan' Mengjiao Zhang,Shuaiying Shi,Zheng Liu,Xueling Zhu,Kun Fan,Guoan Shi Scientia Silvae Sinicae    2022, 58 (1): 162-174.   DOI: 10.11707/j.1001-7488.20220117 Abstract （257）   HTML （14）    PDF （1440KB）（93）       Knowledge map    Save Objective: In this study, the effects of different thinning intensity on plant growth, photosynthetic performance of different canopies, grain yield and oil quality of high density oil tree peony 'Fengdan' were investigated, which aimed to provide theoretical basis and technical support for accurate promotion and sustainable utilization of oil tree peony plantation. Method: This experiment was conducted in Qinyang experimental base of Henan Province, where the 'Fengdan' peony plantation was planted in October 2013. The initial planting density was 57 000 trees·hm-2. In 2017, the 'Fengdan' peony entered the high-yield period, and when the fruits were ripe, it was founded that shading resulted in the death of the weak seedlings under high density condition. The actual density of the seedlings was 46 800 plants·hm-2. In March 2018, after bud sprouting, thinnings were conducted with different intensities of 0% (CK), 17% (A), 35% (B), 47% (C) and 62% (D), respectively. The growth status, canopy photosynthetic parameters and yield traits and other indexes of plants were measured in 2019. Result: 1) Thinning had significant effects on the growth status, photosynthetic characteristics, grain yield and quality of 'Fengdan' (P < 0.05). The leaf area of the plant increased by 7.0%, 11.9, % 21.2% and 25.1% compared with the CK for the thinning intensities of A to D. The crown width, number of flowers, flower diameter, number of new leaves, leaf angle and number of new branches of plants showed the same change trend, while the tendency of plant height was the opposite. 2) Contents of leaf chlorophyll and soluble protein, rate of net photosynthetic (Pn), activities of SOD and CAT in the canopy layers were as follows: upper > middle > lower. The change of MDA content of leaves displayed opposite trend. Thinning significantly improved canopy light energy distribution and leaf photosynthetic performance. 3) The number of fruits, the number of grains and the quality of fruit pods per plant gradually increased with the increase of thinning intensity. The 100 grain mass and grain yield first increased and then decreased. The effect of 47% thinning intensity was the best, which grain yield was 47.97% higher than that of CK, and also significantly higher than other treatments (P < 0.05). There were not any differences in the fatty acid composition and content of tree peony kernel, but the total VE content first increased and then decreased with the thinning intensity. The components and content of VE in tree peony kernel treated with 47% thinning intensity were higher than those of other treatments, and the crude fat, starch and protein contents of the kernel also changed significantly with different thinning intensity. Conclusion: Reduction of the population density of oil tree peony through thinning can adjust the distribution of canopy light energy under growth stages, improve individual nutritional status and reduce space competition pressure, and maintain high and stable production performance of oil tree peony. It is most beneficial to improve the population structure of 'Fengdan' plantation by thinning in the range of medium intensity. The results suggest that thinning is an effective measure to promote photosynthetic performance, grain yield and quality of tree peony 'Fengdan'. Table and Figures | Reference | Related Articles | Metrics Select Effects of Polymer Soil Consolidation Agent on Soil Consolidation Performance and Its Application in Seedling Transplantation Shaoli Wang,Xuping Yang,Chaoxing Luo,Zhengqi Xiong,Shaobo Wang,Shengju Song,Lili Liu,Shaofeng Li Scientia Silvae Sinicae    2022, 58 (1): 151-161.   DOI: 10.11707/j.1001-7488.20220116 Abstract （195）   HTML （7）    PDF （35195KB）（103）       Knowledge map    Save Objective: In this paper, we investigated the soil consolidation performance and anti-vibration of polymer soil consolidation agent, and explored the application technology of polymer soil consolidation agent in seedling transplanting, by which this study aimed to form a new technology of seedling transplanting to gradually expand the application of polymer to the ecological environment engineering of afforestation and greening. Method: In this paper, konjac glucomannan (KGM) and chitosan (CA) were used as the main raw materials and polyvinyl alcohol (PVA) was used as assistant to prepare environmental-friendly soil consolidation agent through polymer blending technology. The characteristic soil in North China—cinnamon soil was taken as the research object, the soil was prepared into soil column samples by moulds, and the prepared binary blend KGM/CA soil consolidation agent was evenly spread on the soil column, and after drying, a hard film formed on the surface of the soil column. In order to test whether the compression resistance and the anti-vibration performance of consolidated soil columns can meet the requirements of seedling transplantation in the actual transportation process, two different test methods were used to simulate the transportation anti-vibration of consolidated soil column. Finally, the seedlings of mulberry, Sabina chinensis and Euonymus japonicus were as transplanting objects to explore the application of blending soil consolidation agent in seedling transplanting. Result: The results showed that when the concentration of acetic acid solution was 20%, the pH of the glue was 4.5, the blending temperature was 40 ℃ and the content of KGM, CA and PVA were 4.5%, 4.5% and 6.0% in the prepared of KGM/CA/PVA ternary blend adhesive, the formulation of consolidating agent had the best consolidation effect on soil column and the consolidated soil column had the best anti-vibration performance in transportation. Conclusion: By testing the anti-vibration of consolidated soil columns with two different test methods, it has been found that the prepared KGM/CA and KGM/CA/PVA blend soil consolidation agent meet the requirements of consolidated soil balls. Through the preliminary application of the blend soil consolidation agent in the transplanting process of mulberry seedlings, Sabina chinensis seedlings and Euonymus japonicus seedlings, it is found that the blend soil consolidation agent has good consolidation effect on loam and sandy soil. In addition, the application of this kind of consolidation agent not only makes the transplanting process of seedlings faster, and ensures the survival rate of transplanted seedlings, but also has no adverse effect on the growth of seedlings. Table and Figures | Reference | Related Articles | Metrics Select Microbial Diversity in Rhizosphere Soil of Rhododendron moulmainense with Different Tree Potential in Wutong Mountain of Shenzhen Jinyu Gong,Jingen Peng,Lijuan Xie,Yinfeng Zhang,Chaochan Li,Yanmei Wang Scientia Silvae Sinicae    2021, 57 (11): 190-200.   DOI: 10.11707/j.1001-7488.20211119 Abstract （321）   HTML （14）    PDF （22863KB）（183）       Knowledge map    Save Objective: This study aimed to explore the relationship between the degradation of tree potential of Rhododendron moulmainense and the physical and chemical properties as well as the microbial community structure in the rhizosphere soil in Wutong Mountain of Shenzhen by analyzing the physical and chemical properties and microbial community diversity of the rhizosphere soil. Method: The water content, pH value, organic carbon, total nitrogen, and mineral nitrogen of rhizosphere soil of R. moulmainense trees with different tree potential in Wutong Mountain were analyzed. Additionally, the DNA of rhizosphere soil was extracted, and was used to investigate microbial diversity and community structure using high-throughput sequencing technology. Result: The result showed that there was no significant difference in physicochemical properties of rhizosphere soil among the three tree potentials. A total of 681 807 effective bacterial sequences were detected in rhizosphere soil of three tree rhizosphere, with an average of 79 898 effective bacterial sequences per sample, of which 2 008 OTUs were obtained, belonging to 438 species and 27 phyla. The dominant bacteria were Acideobacteria (36.3%-47.2%), Proteobacteria (31.2%-32.0%), and Chloroflexi (3.0%-7.7%). A total of 710 302 effective fungal reads were detected, with an average of 79 862 effective reads per sample, which concluded 1 129 OUT clusters, belonging to 489 species and 10 phyla. The dominant fungi were Basidiomycota (49.3%-59.3%), Ascomycota (32.0%-40.8%), Mortierellomycota (1.7%-4.6%). The result of alpha diversity analysis showed that there was no significant pattern in the richness and diversity of rhizosphere soil fungal community among different tree potentials, but the richness and diversity of bacterial community gradually increase with the decline of tree potential, and the greater the difference of tree potential, the more significant the difference of community richness index (Ace, Chao1, PD_whole_tree) (P < 0.05). Beta diversity analysis showed that there was no correlation between bacteria and tree growth. However, fungi were correlated with tree growth. LEfSe analysis showed that there were significant differences in fungal taxa between dominant Rhododendron rhizosphere soil (AR) and inferior Rhododendron rhizosphere soil (DR). The differential microorganisms were mainly Archaeorhizormyces, Phaeosphaeriaceae, Helotiales, Arthrobotrys, Pseudaleuria, and Pyronemataceae. The Helotiales belongs to the root fungus of the azalea plant. Conclusion: There is no difference in soil physicochemical properties among R. moulmainense trees with different growth potentials, indicating that the variation of soil physicochemical properties may not be big enough to affect R. moulmainense, growth potential. The differences in the structure of soil microbial communities are correlated with R. moulmainense, growth potential. Table and Figures | Reference | Related Articles | Metrics Select Effects of Combined Application of N, P and K Fertilizer on Growth and Leaf Color of Cotinus coggygria Jiaojiao Wu,Qiuling Tian,Xing Tan,Jiaxing Yue,Wen Zhang,Lan Gao,Linke Li,Yinuo Wang,Yun Liu Scientia Silvae Sinicae    2021, 57 (11): 179-189.   DOI: 10.11707/j.1001-7488.20211118 Abstract （576）   HTML （3）    PDF （6939KB）（111）       Knowledge map    Save Objective: This paper aimed to explore the effect of combined application of nitrogen, phosphorus and potassium on the growth and leaf color of Cotinus coggygria, and to solve the problems of poor growth and dim leaves of C. coggygria in autumn and winter. Method: In this study, 4-year-old potted seedlings of C. coggygria were used as experimental materials. Three factor and three-level orthogonal design experiments were carried out with urea (N 0, 7.5, 15 g·plant-1), calsium superphosphate (P 0, 12.5, 25 g·plant-1) and potassium sulfate (K 5, 10, 15 g·plant-1). Plant height (H), ground diameter (D) and leaf area (LA), leaf color parameters, leaf pigments including chlorophyll (Chls), carotenoids (Car), and anthocyanins (Ant), soluble protein content (SP), soluble sugar content (SS), and phenylalanine ammonia-lyase(PAL)activity were measured under the different N, P and K combination conditions, and the relationships between N, P and K and plant growth or leaf color were determined. Result: 1) The reasonable combined application of N, P and K was able to promote the growth of C. coggygria. The increment of plant height in treatment T3(N1P3K3) and T9(N3P3K2) was significantly higher than that of the control (p < 0.05). Except for T5(N2P3K3) and T7(N3P1K3), the growth of ground diameter of other treatments was significantly higher than the control(p < 0.05). Except for T1(N1P1K1), T4(N2P1K2), and T8(N3P2K1), the increment of leaf area in other treatments was significantly higher than that of the control (p < 0.05). 2) Reasonable combined application could also increase the pigment content of C. coggygria leaves. T6(N2P3K1), T7, T8 and T9 treatments could significantly increase the total chlorophyll content in the vigorous growth stage and the mid-discoloration stage. T5, T7, T8 and T9 significantly increased carotenoids content in the vigorous growth stage. T3, T4, T5, and T6 significantly increased anthocyanins content at the terminal discoloration stage. 3) The results of the redundancy analysis showed that N and K were the main nutritional factors affecting height, leaf area, chlorophyll and carotenoids, while P was the main nutritional factor affecting ground diameter and anthocyanins. Anthocyanins was a key factor for red color of C. coggygria leaves, which was positively correlated with phenylalanine ammonia-lyase activity and negatively correlated with soluble protein and soluble sugar. Conclusion: The response of plant growth and leaf color to different ratio of N, P and K application is different. Within the scope of this experiment, T3 (N, P and K applying amounts of 0, 25, 15 g·plant-1, respectively) and T9(N, P and K applying amounts of 15, 25, 10 g·plant-1, respectively) promote both growth and leaf color. But in the long run, N deficiency would affect the growth of C. coggygria and affect the color quality of leaf, finally. Therefore, T9 treatment can maintain growth and color quality of leaf, and enhance the ornamental value. Table and Figures | Reference | Related Articles | Metrics Select Effects of Water Management during Lignification on Morphology, Physiology and Afforestation Performance of Populus tomentosa Seedlings Dong Qiao,Yong Liu,Shuyong Tian,Feng Zhang,Yajing Wang,Xiaoli Li,Xuejin Feng,Yanan Zhang Scientia Silvae Sinicae    2021, 57 (11): 169-178.   DOI: 10.11707/j.1001-7488.20211117 Abstract （223）   HTML （6）    PDF （1642KB）（158）       Knowledge map    Save Objective: This research aimed to study the effect of late season irrigation on seedling's morphology, physiology and afforestation performance of Populus tomentosa, in order to provide a scientific basis for precision irrigation in hardening period of seedlings. Method: Tissue culture seedlings of P. tomentosa were transplanted in nursery field. Four different soil water potentials (-20 kPa, -40 kPa, -60 kPa, and -80 kPa) were set as the initial irrigation threshold, and the conventional irrigation(the initial irrigation threshold was at less than -80 kPa) served as the control. The seedlings were subjected to the different irrigation treatments at lignification stage to investigate the changes of seedling water consumption, morphology, physiology and afforestation performance. Result: 1) Late season irrigation had a significant effect on the growth of seedling height and root collar diameter(RCD) at hardening phase (p < 0.05). When the initial irrigation threshold were -20 or -40 kPa, the seedling growth was the largest at the lignification stage, and the seedling height increment, RCD increment and biomass were 15.51%, 6.41% and 57.5% higher than those of control, respectively, but the two treatments had no significant difference. 2) The differences in nutrient status had no obvious pattern among different treatments. However, The nutrient mass per plant with -20 and -40 kPa treatments was the largest, followed by that with -60 and -80 kPa treatments, which were significantly increased by 59.4%, 48.6%, 36.1% and 25.3% respectively compared with the control. 3) Treatments of -20 kPa could delay the defoliation time of seedlings for about 5-7 d and increase the accumulation of photosynthetic products by about 12.5% compared with the control. Although late season irrigation could cause partial dry shoots in winter, it had little effect on the overall overwintering of seedlings. 4)After outplanting, seedlings treated with the initial irrigation threshold of -40 kPa had the highest survival rate of 93%, two years later, its tree height and diameter at the breast height (DBH) were significantly higher than the control by 83.2% and 115.1%, respectively. Conclusion: Proper late season irrigation in hardening phase can promote seedling growth, nutrient reserve and significantly improve the seedling growth after outplanting. Although it reduces the cold tolerance slightly, it has little effect on the overall overwintering. By intergrating the seedling growth in the lignification stage and outplanting effect, the initial irrigation threshold of -40 kPa has the best effects when seedling are cultivated in areas with similar conditions to the experimental site. Table and Figures | Reference | Related Articles | Metrics Select Factors Influencing Aboveground Biomass in the Secondary Forest of Quercus aliena var. acutiserrata in Taibai Mountain Rongrong Pang,Jieying Peng,Yan Yan Scientia Silvae Sinicae    2021, 57 (10): 157-165.   DOI: 10.11707/j.1001-7488.20211015 Abstract （385）   HTML （18）    PDF （1053KB）（379）       Knowledge map    Save Objective: The impacts of species diversity (species richness, species Shannon-Wiener index and species evenness), structure diversity (DBH Shannon-Wiener index, DBH evenness, coefficient of DBH variation, and DBH gini index) and environmental factors on aboveground biomass of the forests of Quercus aliena var. acutiserrata in the north slope of Taibai Mountain of Qinling Mountains were investigated to provide a theoretical basis for biodiversity conservation and harmonization of forest ecosystem functions. Method: Q.aliena var. acutiserrata forests in the north slope of Taibai mountain of Qinling Mountains were studied. The effects of species diversity and structural diversity on the aboveground biomass were analyzed based on inventory data (diameter at breast height ≥ 1 cm) and environmental factors in the permanent observation plots (100 m×150 m). The correlation between species diversity and aboveground biomass was determined by multivariate regression. Coupling with environmental factors, the structural equation modeling was conducted to compare the effects of species diversity and structural diversity on aboveground biomass. Result: The linear regression and structural equation modeling showed no significant correlation between the 3 indices of species diversity with the aboveground biomass. Among the structure diversity indices, a significant negative correlation was obtained between DBH pielou and aboveground biomass. However, a low percentage of aboveground biomass variation can be explained by the diameter pielou. Environmental factors had direct and indirect effects on aboveground biomass, while direct effects were more prominent. Conclusion: Community structure was an important factor for the aboveground biomass of Q. aliena var. acutiserrata forests. However, structural diversity was an inhibiting factor rather than promoting factor on aboveground biomass, indicating that the increased complexity of community structure did not benefit the accumulation of aboveground biomass. Environmental factors directly affected aboveground biomass; however, no significant effect was found on the correlations of aboveground biomass with species diversity or structure diversity. Although the importance of community structure to the aboveground biomass was proved in this study, community structure may not be the dominant factor for aboveground biomass of Q. aliena var. acutiserrata forests. Table and Figures | Reference | Related Articles | Metrics Select Stress Wave Tomography Imaging Algorithm Based on Ray Segmentation for Nondestructive Testing of Wood Tao Liu,Guanghui Li Scientia Silvae Sinicae    2021, 57 (9): 181-192.   DOI: 10.11707/j.1001-7488.20210918 Abstract （281）   HTML （7）    PDF （32303KB）（97）       Knowledge map    Save Objective: Stress wave nondestructive testing technology has been widely applied in wood and tree defect detection. The traditional stress wave imaging algorithm has low accuracy due to the limited sensor number. To improve the accuracy of the stress wave imaging algorithm and accurately reflect the position, size and decay of the internal defects of wood, the signal distribution of the stress wave on the cross section was investigated. Method: Four log samples(Pinus spp., Sapium sebiferum) and four live trees(Cinnamomum camphora, Sabina chinensis, Salix spp.) in Jiangnan University campus were selected as the samples for experiments, and the stress wave velocities were collected using FAKOPP instrument. Firstly, the stress wave velocities were corrected, and the wave ray diagram was generated, then the cross section was divided into many grid cells. Secondly, each stress wave ray was segmented, and the velocity of multiple segments on the ray was estimated, therefore the stress wave signal amount was increased and an improved stress wave ray diagram was also obtained. The velocity values of the grid cells were estimated using the improved propagation rays and the image processing method, thus the tomographic image of wood was generated. The Resistograph micro-drilling tool was used to evaluate the internal conditions of the live trees. Result: Experimental results showed that the proposed algorithm could accurately reconstruct the tomographic images of the four log samples. The Resistograph micro-drilling tool was used to perform multi-path drilling on live trees to get the resistance curves. Compared with the resistance curves, it was demonstrated that the proposed algorithm could also generated the tomographic images with a high resolution of 4 live trees. Conclusion: Based on the ray segmentation, the proposed algorithm might improve the accuracy and correlation of the initial grid cell velocity value, which could achieve high-quality imaging of wood defects, and could be effectively applied to nondestructive testing of wood. Table and Figures | Reference | Related Articles | Metrics Select Agrobacterium-Mediated Genetic Transformation System of Catalpa bungei Yunxin Cen,Jia Liu,Faju Chen,Jingyuan Yang,Qiang Liu,Tao Wang,Hongwei Liang Scientia Silvae Sinicae    2021, 57 (8): 195-204.   DOI: 10.11707/j.1001-7488.20210820 Abstract （371）   HTML （20）    PDF （10348KB）（152）       Knowledge map    Save Objective: Embryogenic callus of Catalpa bungei was used to establish an effective genetic transformation system, in order to provide a basis for the genetic improvement of C. bungei in the future. Method: Agrobacterium-mediated genetic transformation was carried out with embryogenic callus as explants. The optimal genetic transformation conditions were obtained through orthogonal test, and then exogenous genes were transferred into C. bungei. Result: Selective pressure screening was performed in 1/2 MS medium with different gradient concentrations of kanamycin. The differentiation rate of embryogenic callus was 0.00%, and the survival rate was only 5.71% in 1/2 MS medium supplemented with 60 mg·L-1 Kana. Therefore, 60 mg·L-1 Kana was identified as the selective pressure for genetic transformation of C. bungei. The orthogonal design was carried out by L18(37) table in Agrobacterium-mediated genetic transformation experiments. The transient expression rate was obtained by GUS histochemical staining. The intuitive analysis of the orthogonal test and one-way ANOVA were performed to the data obtained from the experiment. The results showed that Agrobacterium-mediated transformation efficiency was the highest under the conditions of 2 days of pre-culture, EHA105 of Agrobacterium strain, OD600 0.7 of liquid concentration, 300 μmol·L-1 of acetyleugenone(AS), 10 min of infection, and 5 days of co-culture time. And the two factors that have the biggest influence on the transformation efficiency are AS concentration and pre-culture time. A total of 32 resistant tissue groups were obtained by screening and culture of the infected embryogenic callus for 8 months. PCR detection was conducted on 15 resistant callus with high proliferation. The results showed that 86.67% resistant tissue groups had exogenous genes integrated into the genome of C. bungei. Endogenous hormone levels affect somatic embryo differentiation, cytokinin(CTK) and abscisic acid(ABA) promote somatic embryogenesis, and auxin(IAA) and gibberellin(GA) inhibit somatic embryogenesis. According to the determination of endogenous hormones, the levels of CTK and ABA in transgenic resistant tissue were significantly lower than those in the embryogenic callus of wild-type, while the levels of IAA and GA were significantly higher than those in the wild-type callus. Therefore, the level of endogenous hormones may be the reason for the poor somatic embryo differentiation ability of transgenic resistant tissue of C. bungei. Conclusion: Through Agrobacterium-mediated transformation of the embryogenic callus of C. bungei, PCR detection was conducted on 15 screened resistant callus, among which 13 resistant callus had integration of exogenous genes. The somatic embryo differentiation ability of transgenic resistant tissues is poor, and the change of endogenous hormone level may be the reason that the resistant callus is difficult to differentiate. Table and Figures | Reference | Related Articles | Metrics Select Spatial Distribution Characteristics of Dinochloa orenuda and Bonia levigata in Ganshiling, Hainan Island Xuan Hu,Ruijing Xu,Ze'an Shang,Qi Shu,Lianghua Qi Scientia Silvae Sinicae    2021, 57 (8): 189-194.   DOI: 10.11707/j.1001-7488.20210819 Abstract （357）   HTML （6）    PDF （1123KB）（244）       Knowledge map    Save Objective: To deeply understand the characteristics of spatial pattern of climbing bamboo in Hainan Island and reveal the ecological process of its population dynamics, and to provide basic data and theoretical support for the protection and management of tropical rainforest and the maintenance and restoration of biodiversity, the paper presents a study of spatial distribution and correlation between Dinochloa orenuda and Bonia levigata in Ganshiling, Hainan Island. Method: Based on a 1 hm2 sample plot of National Long-Term Ecosystem Research and Monitoring Station for Bamboo and Rattan Forest in Sanya of Hainan Province, two native climbing bamboos, D. orenuda and B. levigata, were selected to analyze the intraspecific and interspecific spatial distribution and correlation of climbing bamboo populations in the tropical rainforest of Ganshiling by using the paired correlation function g(r) of point pattern analysis. Result: Spatial pattern and spatial scale of climbing bamboo populations are closely related. On small and medium scale, D. orenuda population was significantly aggregated on the scale of 0.5-34.5 m, B. levigata population was aggregated on the scale of 0.5-13.5 m. However, at a larger spatial scale, uniform distribution and random distribution appear alternately. The spatial correlation between D. orenuda and B. levigata populations varies greatly with different scales. On the whole, the spatial relation varies with the distance between them. On small and medium scale as 0-35.5 m, there is a significant negative correlation between them. With the slow increase of scale, the two types of climbing bamboo tend to be uncorrelated.When the distance scale between them is about to break through the upper limit of the edge of 100 m, there is a positive correlation between them. Conclusion: In the populations of D. orenuda and B. levigata, their spatial distribution were basically the same. The difference was that compared with B. levigata, D. orenuda's aggregation scale range is larger. As a plants from the same family, under the condition of resource constraints, on a small scale(0-35.5 m), they are mutually exclusive because of the competition. On a large scale, they can coexist better. Table and Figures | Reference | Related Articles | Metrics Select Cloning and Expression of alpha-pinene synthase and (-)-limonene synthase Genes in Pinus armandi Xiaotong Kang,Hui Chen Scientia Silvae Sinicae    2021, 57 (6): 180-188.   DOI: 10.11707/j.1001-7488.20210620 Abstract （291）   HTML （11）    PDF （4945KB）（115）       Knowledge map    Save Objective: This paper aims to study the alpha-pinene synthase gene and (-)-limonene synthase gene of Pinus armandi and their expression characteristics, and so as to provide theoretical support for revealing the terpene synthase gene in P. armandi to defense against Dendroctonus armandi and its blue-stain fungus Leptographium qinlingensis. Method: The cDNA sequences of alpha-pinene synthase gene and (-)-limonene synthase gene of P. armandi were cloned by PCR and race techniques, and the nucleotide sequence and amino acid sequence of the encoded protein were analyzed by bioinformatics method, and the phylogenetic tree was constructed. The expression differences of alpha-pinene synthase gene and (-)-limonene synthase gene were analyzed by real-time fluorescent quantitative PCR after being treated with MeJA and L. qinlingensis. Result: The full length of the coding region of alpha-pinene synthase gene was 1 887 bp. The protein was composed of 628 amino acids with a molecular weight of 71.59 kDa and the theoretical isoelectric point of 5.86. The full-length coding region of (-)-limonene synthase gene was 1 905 bp. The encoded protein was composed of 634 amino acids with a molecular weight of 73.01 kDa and the theoretical isoelectric point of 5.97. Real-time fluorescence quantitative PCR analysis showed that the expression of alpha-pinene synthase gene and (-)-limonene synthase gene was up-regulated at different time after MeJA treatment. The expression level of alpha-pinene synthase gene reached the peak on the second day, and that of (-)-limonene synthase gene reached the peak on the fourth day. Alpha-pinene synthase and (-)-limonene synthase gene was induced to express by L.qinlingensis, but the expression levels were significantly different at different time points after treatment with L. qinlingensis. The result showed that alpha-pinene synthase gene and (-)-limonene synthase gene were crucial genes in response to L. qinlingensis and MeJA treatments. Conclusion: The alpha-pinene synthase gene and (-)-limonene synthase gene of P. armandi are able to respond to the treatment of L. qinlingensis and MeJA, and play an important regulatory role in the defense of D. armandi and blue-stain fungus. This study provides a theoretical basis for further control of D. armandi. Table and Figures | Reference | Related Articles | Metrics Select Effects of Biochar and Its Aging Biochar on Soils Nutrients and Microbial Community Composition in Cunninghamia lanceolata Plantations: a Laboratory Simulation Experiment Yanlin Zhang,Caifeng Huang,Mingzhuo Bao,Chuifan Zhou,Zongming He Scientia Silvae Sinicae    2021, 57 (6): 169-179.   DOI: 10.11707/j.1001-7488.20210619 Abstract （323）   HTML （14）    PDF （3431KB）（143）       Knowledge map    Save Objective: This study aims to investigate the effects of biochar and its aging biochar on the soil main nutrient content and microbial community composition in Chinese fir plantation,and to provide a reasonable selection basis for the use of biochar in Chinese fir plantation in southern China. Method: Chinese fir leaves were used as raw materials to make biochar and the biochar was washed and acidified to simulate the long-term aging in the natural environment of southern China. The red soil in the second generation Cunninghamia lanceolata forest was collected as the experimental soil. Four groups treatments were set up,including no biochar(CK),3% biochar (BC),3% washed aged biochar (WBC),and 3% acidified aged biochar (OBC) added in the soil. After 150 days of indoor cultivation,the main soil nutrients were determined. At the same time,the high-throughput sequencing technology was used to analyze the community composition of soil bacteria and fungi. The correlation between the content of soil main nutrients and the relative abundance of main microorganisms was further analyzed. Result: The addition of biochar can significantly increase the content of total carbon,total nitrogen,dissolved organic carbon,available potassium and nitrate in soil. Aged biochar reduced the content of dissolved organic carbon. OBC also had a significant inhibitory effect on the content of dissolved organic nitrogen(P < 0.05). Venn diagram analysis showed that OBC had the most obvious promotion effect on soil microbial richness. Biochar and aged biochar had a promoting effect on the relative abundance of Proteobacteria,Gemmatimonadetes,Bacteroidetes,Gemmatimonadaceae,Sphingomonadaceae and Rhodospirillaceae. OBC significantly increased the relative abundance of Verrucomicrobia and Planctomycetes. Chloroflexi,Actinobacteria and Firmicutes were significantly negatively correlated with total carbon and total nitrogen,while Proteobacteria and Bacteroidetes were significantly positively correlated with available potassium and nitrate nitrogen. As for fungi,Ascomycota and Basidiomycota were the dominant phyla. WBC increased the relative abundance of Basidiomycota,Mucoromycota and Ganodermataceae. OBC reduced the relative abundance of Chytridiomycota. Ascomycota were significantly positively correlated with ammonium nitrogen and dissolved organic carbon,and the relative abundance of the Mortierellomycota was significantly positively correlated with dissolved organic nitrogen. Conclusion: Biochar can effectively improve the soil main nutrients content of Cunninghamia lanceolata plantation. However,the effect of biochar on soil nutrient improvement is weakened after washing and acidification. Biochar and aged biochar can increase the abundance of microorganisms in general,but there are differences in the regulation of relative abundance of main microbial groups. Table and Figures | Reference | Related Articles | Metrics Select Prediction of Potential Distribution of Ziziphus jujuba var. spinosa in China under Context of Climate Change Guanghua Zhao,Xinyue Cui,Zhi Wang,Hongli Jing,Baoguo Fan Scientia Silvae Sinicae    2021, 57 (6): 158-168.   DOI: 10.11707/j.1001-7488.20210618 Abstract （383）   HTML （38）    PDF （9486KB）（152）       Knowledge map    Save Objective: In order to provide a scientific basis for the development and utilization of Ziziphus jujuba var. spinosa germplasm resources,the suitable range for growing Z. jujuba var. spinosa was predicted under the context of climate change. Method: Based on the GIS technology and R language,data of 121 geographical concurrence points and 34 environmental factors were selected for the study. The default parameters of MaxEnt model were adjusted by using ENMeval package in R language,and the geographical distribution of suitable areas for Z. jujuba var. spinosa was predicted by using the optimized MaxEnt model. Person correlation analysis and VIF variance expansion factor were used to select the required factors for modeling,and the jackknife method was used to select the dominant environmental factors of the suitable area. According to the fifth climate model released by IPCC,the changes of future geographical distribution of Z. jujuba var. spinosa under different climate scenarios were discussed. Result: The model optimization showed that the MaxEnt model has the lowest complexity and the best when the feature combination is linear,quadratic and fragmented,and the regulation frequency multiplier is 3.5. The AUC of the working characteristic curve analysis method of the subjects was 0.946,indicating that the prediction model has high reliability and excellent accuracy. The jackknife test showed that the main environmental factors affecting the distribution of Z. jujuba var. Spinose were the annual mean temperature,the mean temperature of wettest quarter,the precipitation of wettest month,the precipitation seasonality,the elevation,and the base saturation of topsoil (0-30 cm). At present,the suitable growing areas for Z. jujuba var. spinosa in China are mainly concentrated in Shaanxi,northern Henan,central and southern Shanxi,Hebei,northern Ningxia and southeastern Inner Mongolia,northeastern Sichuan,western Liaoning and Shandong. Under the different climate scenarios in the future,the suitable areas for Z. jujuba var. spinosa will change in varying degrees. By the 2050s and the 2070s, the suitable areas for Z. jujuba var. spinosa will increase to a certain extent. The suitable areas under RCP 4.5 and RCP 8.5 scenarios respond sensitively,showing an increasing trend,and the increasing trend is weaker under RCP 2.6 scenario than under the other two scenarios. Conclusion: Climate,soil and terrain factors all affect the potential geographical distribution of Z. jujuba var. spinosa,among which climate factors account for the largest weight,which is most likely to cause the migration of geographical distribution of Z. jujuba var. spinosa. The optimized model can accurately simulate and predict the potential geographical distribution area of Z. jujuba var. spinosa. In the future,the climate change of global warming will change the distribution pattern of Z. jujuba var. spinose,the total suitable growing areas will increase,the expansion will be mainly in the middle and high latitudes,and the reduction will be mainly in the low latitudes. Under the three climate change scenarios,the center of suitable areas for Z. jujuba var. spinosa in the 2050s and the 2070s will migrate to high latitudes. The suitable area for Z. jujuba var. spinosa will migrate to the North China Plain and the Northeast Plain as a whole,and the priority should be given to arrange new planting areas in this region,so as to reduce the loss caused by climate change. Table and Figures | Reference | Related Articles | Metrics Select Migration Dynamics of the Rustic Bunting Based on the Ringing Monitoring in the Gaofeng Forestry Area of Nenjiang, China Xianda Li,Yumin Guo,Xiaoying Xing,Fawen Qian,Kejian Fang,Hengbiao Yao Scientia Silvae Sinicae    2021, 57 (5): 202-210.   DOI: 10.11707/j.1001-7488.20210520 Abstract （267）   HTML （9）    PDF （1778KB）（109）       Knowledge map    Save Objective: Populations of passerine birds that migrate for long distances are decreasing continuously. In recent years, the declining trend of the population number of Rustic Bunting (Emberiza rustica) is more prominent. Through the long-term monitoring and migration dynamics analysis of the Rustic Bunting population, we intent to provide a scientific basis for the species conservation. Method: From 2001 to 2017, 70 pieces of sticky net with 3 m high and 20 m long were set up in different habitats from 15th March to 31th May and from 15th August to 20th November in Gaofeng forest region, Nenjiang, China. Patrol was implemented once every half an hour. The birds trapped in the net were recorded and then released after banding. Meteorological data were recorded daily from 2001 to 2017 by Nenjiang meteorological station which located 6 km away from Gaofeng forest region, and downloaded from the website of China meteorological data sharing service. Data were analyzed by SPSS 22.0 software. Result: From 2001 to 2017, a total of 18 155 Rustic Buntings were recorded and banded, including 6 756 Rustic Buntings in spring and 11 399 in autumn. The quantity of banding records fluctuated greatly annually, showing a rapid downward trend in general. The spring migration peak of Rustic Bunting was from 1st to 20th April, while the autumn migration peak was from late September to early October, and the ratio of adult to juvenile was 25.4:74.6 and 43.3:56.7 respectively in autumn and in the following spring. The overwintering loss rate of young birds was as high as 41.3% compared with that of adult birds. The correlation analysis between the quantity of bandings and meteorological factors showed that the maximum wind speed and wind direction were the main factors that dominated the migration direction and migration timing of Rustic Bunting. Recapture indicated that Northeast China is an important and relatively stable migration corridor for Rustic Bunting and other birds. Conclusion: In recent years, the population of Rustic Bunting has decreased sharply. The number of the birds banded decreased by more than 90% compared with the year with the largest number of banding, which is worthy of attention. Abuse of pesticides, surface water pollution, habitat fragmentation and illegal hunting are the main threats to the survival of Rustic Bunting. It is suggested that measures such as timely increasing law enforcement and propaganda, reasonably using high-efficiency, low toxicity and low residue pesticides, strengthening the protection of bird habitat, taking long-term bird banding monitoring, further exploring the rule of migration of Rustic Bunting, and promoting the recovering of bird populations. Table and Figures | Reference | Related Articles | Metrics Select Molecular Identification and Disease Investigation of Trema levigata Witches'-Broom Phytoplasma Qionglian Wan,Lianchun Wang,Quan Wang,Xingping Xu,Fan Su,Jing Zhao,Hong Cai Scientia Silvae Sinicae    2021, 57 (5): 195-201.   DOI: 10.11707/j.1001-7488.20210519 Abstract （264）   HTML （6）    PDF （12788KB）（62）       Knowledge map    Save Objective: Based on the investigation of Trema levigata broom in Xinping county, Yuxi city, Yunnan province, this study aimed to understand the occurrence and damage degree of the disease, and further determine the pathogens and their classification status by molecular biological method. Method: The incidence of the disease was obtained by general survey method, and its damage degree was evaluated. The total DNA of the affected plants was extracted, and the 16S rDNA sequences were amplified by using nested-PCR from the total DNA with phytoplasma universal primer pair P1/P7 and R16F2n/R16R2, then the amplified fragments were cloned and sequenced. A sequence analysis was performed with iPhyClassifier, an online classification and identification tool of phytoplasma, and a phylogenetic tree based on the 16S rDNA sequence was constructed by using Megax software to determine the pathogens and their classification status. The homology of related sequences were compared by online analysis software MUSCLE. Result: The survey result indicated that T. levigata witches' broom approximately occurred in east longitude 101°35'-101°53' and north latitude 23°56'-24°20'. It was mainly in the dry-hot valley region at the low altitudes from 600 to 400 m with relatively high temperature, which also showed that high temperature was conducive to the occurrence of phytoplasma disease. In this region, the disease occurred for three consecutive years. The average incidence rate was 38.9% with moderate damage in July 2018. The 1 246 bp 16S rDNA sequence of T. levigata witches' broom phytoplasma was amplified by PCR amplification (strain: TLWBYN0, GenBank accession: MN513329). Analysis showed that TLWBYN01 shared 99.8% similarity with the reference strain of Candidatus Phytoplasma asteris (GenBank accession: M30790), thus the phytoplasma under study was a 'Candidatus Phytoplasma asteris' related strain and belonged to a member of 16S rI group. The virtual RFLP pattern derived from the F2nR2 fragment of TLWBYN01 was most similar to the reference pattern of the 16SrⅠ, subgroup X (GenBank accession: JF781308), with a pattern similarity coefficient of 0.98. The enzymatic profiling of 17 restriction enzymes showed that only MseI was different from the 16S rI-X reference strain. Thus, the phytoplasma was a variant of 16S rI-X. TLWBYN01 had 99.2% and 99.6% homology respectively with phytoplasma of papaya bunchy top (JF781308) and lagenaria siceraria yellow little leaf (LT594117、LT594118), two members of 16S rI-X subgroup. Conclusion: Trema levigata witches' broom from Xinping county of Yuxi city is a local common disease with moderate damage. But once being infected, the plant growth could be seriously affected. T. levigata witches' broom phytoplasma belongs to the member of 16S rI group and is a variant of 16S rI-X subgroup with being less reported so far, and T. levigata is a new host of phytoplasma. These findings are of great significance for further study of phytoplasma. At the same time the plant is the pioneer tree species for greening and widely distributed, thus the investigation and study on the disease could provide a basis for prevention and control of forest diseases in this region. Table and Figures | Reference | Related Articles | Metrics Select Potential for Afforestation in the Three-North Region Where Implements Shelter-Belt Forest Program Danni Zhang,Xiya Chen,Chuanfu Zang Scientia Silvae Sinicae    2021, 57 (5): 184-194.   DOI: 10.11707/j.1001-7488.20210518 Abstract （329）   HTML （8）    PDF （15424KB）（382）       Knowledge map    Save Objective: This study was designed to analyze afforestation potential of the areas where implements the Three-North Shelter-belt Forest Program (TNSP). Potential areas available for afforestation and their spatial distribution will be obtained, aiming to provide a theoretical basis for building green "Belt and Road", ecological protection in the Three-North Region and the construction of shelter-belt forests consistent with local conditions. Method: A suitability evaluation model was established with 5 indicators, including soil type, land use type, aridity, altitude and slope degree. Indicator's threshold was determined based on conditions required for tree growth and divided by limit condition method. Arc-Gis Analyst Tools were applied to evaluate the afforestation potential with every single indicators, and the spatial distribution of potential areas available for afforestation. Based on the single indicators assessments, an integrated assessment was carried out to obtain future afforestation potential. Meanwhile, the maximum entropy model was applied to predict areas suitable for afforestation in the region of implementing TNSP, which will be compared with the integrated assessment. Result: The single-factor assessments showed that the maximum limiting factor was the aridity. According to the integrated assessment, the area suitable for afforestation may reach 584 600 km2, accounting for 17.52% of the total land area. The afforestation area will be concentrated in the northwest, east and southeast of the TNSP region. The accuracy of the maximum entropy model is higher than 0.8, at a good level. It shows that the probability of being suitable afforestation area is mostly contributed by Land Use Type. By removing the existing forests from the model assessment, the area suitable for future arbor forests is 1 109 400 km2 while the area for shrub forests is 1 441 100 km2, covering 33.24% and 43.19% of the total area of TNSP, respectively. Conclusion: The suitable afforestation area is concentrated in the Tianshan, Altay Mountains and the Junggar Basin in the northwest, and the area to the east of the Inner Mongolia and Ordos Plateau. The distribution pattern of suitable afforestation area on the edge of basin is strip-shaped by topography and the melting snow and ice. Affected by the farmland and pasture, the suitable afforestation area is fragmented in the east and south. Overall, the distribution of suitable afforestation area is mainly affected by agriculture and pasture in the east, by the aridity in the central and by aridity and altitudes in the west. Table and Figures | Reference | Related Articles | Metrics Select Effects of Elevated CO2 Concentration on Soil Microbial Functional Diversity and Carbon Source Utilization Characteristics in the Root Zone of Lycium barbarum Yun Xie,Fangyun Guo,Lihua Chen,Bing Cao Scientia Silvae Sinicae    2021, 57 (4): 163-172.   DOI: 10.11707/j.1001-7488.20210417 Abstract （230）   HTML （10）    PDF （6260KB）（227）       Knowledge map    Save Objective: This paper studied the differences in the functional diversity and carbon source utilization characteristics of soil microorganisms in the root zone of Lycium barbarum, by which determined the effects of doubled CO2 concentration on the functional diversity of soil microorganisms in the root area of L. barbarum, so as to provide theoretical basis for sustainable management of L. barbarum. Method: In this study, the cuttings of L. barbarum(wolfberry) were used as materials. An open-top chamber (OTC) was used to set three CO2 concentration gradients of atmospheric CO2 concentration (CK, 400±20 μmol·mol-1), and 1.5-time atmospheric CO2 concentration (TR1, 600±20 μmol·mol-1), and 2-time atmospheric CO2 concentration(TR2, 800±20 μmol·mol-1). The wolfberry saplings were subjected to the different CO2 concentrations. Soil samples were collected from the root zone at 30, 60, 90, and 120 days after treatment and analyzed by BIO-ECO technology for the functional diversity of soil microbial communities and the characteristics of carbon source utilization. Result: 1) The microbial carbon source metabolic activity (AWCD) in the root zone of L. barbarum significantly increased with the increase of CO2 concentration. Compared with the control, the AWCD of 1.5-time and 2.0-time atmospheric CO2 concentration increased by 22.56% and 36.45%, respectively. 2) With the increase of CO2 concentration, the Shannon index and McIntosh index of soil microorganisms increased significantly. The Simpson index increased in the early stages of treatment, but there was no significant change in the middle and late stage of treatment. 3) The main carbon source of the soil microbial community in Ningxia wolfberry root zone was amino acids, esters and amines. Under the elevated CO2 concentration, the carbon sources with higher soil microbial utilization rate were mainly esters and amines, while the utilization rate of sugars and acids was lower. Under 2.0-time atmospheric CO2 concentration, the utilization and metabolism of L-arginine, L-asparaginic acid, Tween-40, phenethylamine, and 4-hydroxybenzoic acid were significantly higher than that of the control, but the utilization and metabolism of γ-hydroxybutyric acid were significantly lower than that of the control. 4) The increase of atmospheric CO2 concentration significantly affected the utilization of carbon sources in the soil microbial community in the root zone of wolfberry. Sugars and amines were the main carbon sources that differentiated the soil microbial community in different periods. Conclusion: Elevated CO2 concentration can significantly increase the activity of microbial communities and the utilization of carbon sources, and all increase the species richness, species dominance, and community uniformity of soil microbial communities in the root zone of wolfberry. The highest metabolic activity and diversity of soil microbial community treated with one time increase of atmospheric CO2 concentration were found. Among the six major types of carbon sources, amino acid, ester and amine carbon sources are the main carbon sources utilized and transformed by the soil microbial community in the root zone of wolfberry. The carbon source utilization rate of soil microbial community is the strongest at 60 days (July). Therefore, the increase of atmospheric CO2 concentration is the main reason for the differences in the metabolic diversity and carbon source utilization of soil microbial communities in the root zone of Lycium barbarum. Table and Figures | Reference | Related Articles | Metrics Select Extractive Chemical Components of Quercus variabilis and Quercus acutissima Yuan Chen,Tingting Yan,Sheng Yang,Zongying Fu,Gaiyun Li,Haiqing Ren Scientia Silvae Sinicae    2021, 57 (4): 191-198.   DOI: 10.11707/j.1001-7488.20210420 Abstract （370）   HTML （10）    PDF （8097KB）（242）       Knowledge map    Save Objective: This study focused on the extract content and chemical composition of different parts of oak, with the aim to provide scientific guidance for the processing and utilization of oak wood. Method: This study used the oak from Henan Province as the research object, using the Chinese wood chemical analysis standard, combined with Fourier transform infrared(FTIR) and gas chromatography mass spectrometry(GC-MS) method. The content and composition of the cold/hot water extract, 1% sodium hydroxide extract and phenyl alcohol extract from the bark, sapwood and heartwood with different heights in the trunk of Quercus variabilis and Quercus acutissima were analyzed in detail. Result: The results showed that the contents of cold/hot water and 1% NaOH extractives of Q. variabilis bark, sapwood and heartwood at different heights were significantly higher than those of Q. acutissima. Among them, the bark extractive had the highest content, the sapwood was the second, and the heartwood had the lowest content. The extract content had a tendency to be high at both ends and low in the middle with the height of the trunk. For the content of phenyl alcohol extract, the oak bark was much higher than the sapwood and heartwood, but the difference between two oaks was small and did not change with the height for the sap/hearwood. The FTIR spectra showed that the bark and sap/heartwood of Q. variabilis and Q. acutissima were obviously different. According to the absorption peak intensity, the bark might contain more alcohols, fatty acids, aromatics and alkane structural compounds, and there should be more acids, alcohols and unsaturated hydrocarbons in the sap/heartwood. The Result: s of GC-MS analysis showed that both the bark and sap/heartwood contained a small amount of alkane alcohols, esters and unsaturated alkenes. The bark contained abundant friedelin and its isomers. The sap/heartwood included γ-sitosterol et al. Conclusion: The main chemical components of the extracts of Q. variabilis and Q. acutissima in bark and sap/heartwood have a large difference, and there also have a certain difference in component contents. The height of the trunk also has a certain influence on the extract content of these two oaks. The middle trunk accumulated more cold/hot water and 1% NaOH extractives, but no significant compositional differences were found. In the actual processing and production of wood, the differences in the content and bark, sap/heartwood extractives of the two kinds of oak wood should be fully considered to provide a reasonable, comprehensive and high-value utilization processing plan. Table and Figures | Reference | Related Articles | Metrics Select Establishment and Evaluation of Tree Competition Index Based on Intersection and Crowding Xuefan Hu,Huiru Zhang,Guangshuang Duan,Jun Lu Scientia Silvae Sinicae    2021, 57 (4): 182-190.   DOI: 10.11707/j.1001-7488.20210419 Abstract （294）   HTML （12）    PDF （2199KB）（259）       Knowledge map    Save Objective: In order to provide a basis for better calculating the competition status of secondary forest of Mongolian oak and over-logged spruce and fir forest, a new competition index was constructed by adding the crowding to the competition index based on intersection angle. Method: Three representative plots of Mongolian oak secondary forest and three plots of over-logged spruce and fir forests with an area of 1 hm2 were selected in Tazigou and Jingouling forest farm of Wangqing Forestry Bureau, Jilin, China. The stands were investigated in 2013 and 2018, respectively. The competition index caCI based on intersection and crowding was constructed, dominant tree species were determined by dominance analysis, and the individual tree basal area growth model of dominant tree species was established to evaluate the competition index caCI, Hegyi, aCI and uaCI. Result: The results showed that caCI had a significant positive correlation with Hegyi, aCI and uaCI. The regression model and linear mixed-effects model of basal area growth showed that the basal area growth was positively correlated with the initial basal area, and negatively correlated with the competition index, suggesting that the major factor affecting the increment was the initial size of trees and that the competition among trees also had an effect on tree growth. The fitting accuracy of the linear mixed effect model was better than that of the regression model, which indicated that the growth dynamic of different tree species was significantly different, but the influence of the sample plot was slight. The fitting effect of the model with competition index was better than that of the model without competition index. Compared with Hegyi, aCI and uaCI, caCI showed the best performance in over-logged spruce-fir forests, followed by secondary forest of Mongolian oak, which indicated that caCI was suitable for forest with more complex spatial structure. Conclusion: The competition index caCI could effectively reflect the competition of secondary forest of Mongolian oak and over-logged spruce-fir forest, especially in the natural mixed forest with more complex forest structure. Table and Figures | Reference | Related Articles | Metrics Select Effects of Different Nitrogen Forms and Supply on Photosynthetic Characteristics and Growth of Phoebe bournei Seedlings under Elevated CO2 Concentration Xiao Wang,Xiaoli Wei,Gaoyin Wu,Shengqun Chen Scientia Silvae Sinicae    2021, 57 (4): 173-181.   DOI: 10.11707/j.1001-7488.20210418 Abstract （230）   HTML （5）    PDF （2290KB）（160）       Knowledge map    Save Objective: In this paper, the photosynthetic characteristics and growth performance of Phoebe bournei seedlings under different CO2 concentrations, different nitrogen forms and supply were studied to explore whether nitrogen fertilization could be used to regulate the photosynthesis of P. bournei seedlings. Method: One-year-old P. bournei seedlings were used as experimental materials. The open-top gas chamber was used for CO2 concentration treatment [ambient concentration: (350±70) μmol·mol-1; elevated concentration: (700±10) μmol·mol-1], and different amounts (medium dosage 0.8 g·plant-1, increased dosage 1.2 g·plant-1) of nitrate and ammonium were used to cultivate P. bournei seedlings. Result: Compared with ambient CO2 concentration treatment, after a long period of elevated concentration CO2 treatment (88 days), the net photosynthetic rate of P. bournei seedlings reduced by 26.93% (P < 0.05), and its Rubisco and RCA activity, soluble sugar, and starch, soluble protein content, seedling height and ground diameter were all significantly lower (P < 0.05) than those treated with ambient CO2. The photosynthetic down-regulation phenomenon of P. bournei seedlings eventually affected growth. Under long-term elevated CO2 concentration, the net photosynthetic rate of P. bournei seedlings subjected to increased nitrate or ammonium had no significant changes (P>0.05), its Rubisco and RCA activity, soluble sugar, starch, soluble protein content, and seedlings height and ground diameter increased or there was no significant change, indicating that increasing nitrate or ammonium nitrogen application can alleviate the adverse effects of long-term elevated CO2 concentration conditions on photosynthesis and growth of P. bournei seedlings. Conclusion: Under the condition of long-term elevated CO2 concentration, the application of increased nitrate or ammonium nitrogen can increase the activities of photosynthetic key enzymes, increase the content of organic matter, and eventually promote the growth of P. bournei seedlings to alleviate the negative impact of elevated CO2 concentration on the growth of P. bournei seedlings. Table and Figures | Reference | Related Articles | Metrics Select Tolerability of Emerald Ash Borer to High Temperature and Humidity Yingqiao Dang,Yanlong Zhang,Xiaoyi Wang,Ke Wei,Zhongqi Yang Scientia Silvae Sinicae    2021, 57 (3): 189-194.   DOI: 10.11707/j.1001-7488.20210320 Abstract （291）   HTML （4）    PDF （1028KB）（96）       Knowledge map    Save Objective: This study aims to explore the tolerance of emerald ash borer to a hot and humid environment and the possibility of colonization under high temperature and humidity conditions in southern China. Method: In this study, the survival rate of adults, the number of mature eggs per adult female, and the hatchability of fresh eggs were measured under different conditions of high temperature and humidity. Result: 1) Adults of emerald ash borer were relatively tolerant to constant high temperature and humidity. At 80% RH, both male and female adults were able to survive for more than 3 days at 38℃ when the relative humidity was 80%. The survival rate of males started to decrease on the third day at 41℃, while the mortality of females occurred only at constant temperatures above 42℃. Female adults were more tolerant than male adults, and females could survive for 24 hours at 43℃, while all males died within 12 hours. 2) Eggs of emerald ash borer could develop to maturity at 28℃, 38-43℃, 80% RH. The number of mature eggs per female at 38℃ and 41℃ were significantly more than that at 28℃. The number of mature eggs declined gradually with the increase of temperature when constant temperature was over 41℃, and no mature egg was observed at 44℃. 3) At 80% RH, eggs were easy to be infested by pathogens. However, some eggs still hatched at 28℃ and 38℃, but not at over 41℃. The egg hatchability decreased significantly under high temperature and humidity compared to the hatchability at 28℃. Conclusion: The results demonstrate that emerald ash borer has strong tolerance to high temperature and humidity, so that it is possible to survive and establish populations after being spread to some regions in central or southern China. Table and Figures | Reference | Related Articles | Metrics Select The Method of Matching Single Tree Information Extracted by Point Cloud to the Reference Data from Field Work through Bidirectional Selection Langning Huo,Xiaoli Zhang Scientia Silvae Sinicae    2021, 57 (3): 181-188.   DOI: 10.11707/j.1001-7488.20210319 Abstract （333）   HTML （12）    PDF （9594KB）（119）       Knowledge map    Save Objective: Based on the principle of bidirectional selection and judgment, a method was proposed to reasonably match the individual tree information extracted from point cloud data(LiDAR) with the reference information measured by the field work. Method: Using airborne LiDAR point cloud data, individual tree information such as tree position, number, height, and crown diameter was extracted. Firstly, the candidate reference trees were selected according to the information of the LiDAR tree. Then whether such candidate trees were the most reasonable LiDAR trees from the reference tree or not were evaluated again. Result: The matching accuracy, the heights and crown diameters accuracy after matching were used as the accuracy indicators. Compared with the other three commonly used matching methods, the height accuracy of individual tree using the proposed matching method was increased from 75.21% to 91.01%, and the crown diameter accuracy was also increased from 60.50% to 68.64% under the conditions with the same matching accuracy. When the height and crown diameter accuracy were controlled with the same value, the proposed method improved the matching accuracy from 33.52% to 61.11% comparing to the traditional method. Conclusion: The proposed method in this paper could match the single tree information quickly and efficiently between the ones extracted by remote sensing and the reference information measured on the field work. Compared with the traditional method, it could show some superiority when used in high-density and multi-layer stands. Table and Figures | Reference | Related Articles | Metrics page Page 1 of 4 Total 117 records First page Prev page Next page Last page