Advanced search

Message Board

Respected readers, authors and reviewers, you can add comments to this page on any questions about the contribution, review, editing and publication of this journal. We will give you an answer as soon as possible. Thank you for your support!

Name
Email
Phone
Title
Content
Verification Code

NewsMore+

Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
Display Method:
N-variate distribution and its annotation on forest spatial structural parameters: a case study of Quercus aliena var. acuteserrata natural mixed forest in Xiaolong Mountains, Gansu Province of northwestern China
Zhang Ganggang, Liu Ruihong, Hui Gangying, Zhang Gongqiao, Zhao Zhonghua, Hu Yanbo
Accepted Manuscript  doi: 10.13332/j.1000-1522.20180228
[Abstract](112) [FullText HTML](86) [PDF 1166KB](18)
Abstract:
ObjectiveTo accurately describe and intuitively express forest structure information, and provide basic information for forest structure regulation and reconstruction, N-variate distributions were used to comprehensively and systematically characterize the spatial structure of the Quercus aliena var. acuteserrata natural mixed forest in Xiaolong Mountains, Gansu Province of northwestern China.MethodEach tree in the 70 m × 70 m permanent sample plot was located and surveyed. The mingling (M), uniform angle index (W), dominance (U) and crowding (C) of each tree were calculated by the Winkelmass software. The relative frequency of N-variate distributions was counted by the Excel Pivot Tables, and their corresponding multivariate diagrams were graphed by the R 3.4.3 and Origin 2015.ResultIn the Quercus aliena var. acuteserrata natural mixed forest, the whole forest and most trees were randomly distributed, well mixed, relatively dense. The whole forest was moderately differentiated and each dominance degree occupied near 20% trees. Among the bivariate distribution, trivariate distribution and quadrivariate distribution, the most prominent characteristics of the spatial structure was as follows: no matter how the structural parameters were combined, most trees were randomly distributed or well mixed under different structural combinations.ConclusionThe N-variate distribution comprehensively and systematically describes the spatial structure characteristics from different levels and angles. Different distributions make their respective advantages complementary to each other and realize the stepwise interpretation process from point to hyperploid. 3D figures with double X horizontal coordinates or double Y vertical coordinates intuitively graphe the structure information of the multivariate distribution. The N-variate distributions provide prior information for forest structure regulation and reconstruction.
Cloning and expression analysis of PwPEBP gene and promoter sequence in Picea wilsonii
Li Xingfen, Miao Yahui, Sun Yongjiang, Zhang Mengjuan, Zhang Lingyun
Accepted Manuscript  doi: 10.13332/j.1000-1522.20180344
[Abstract](28) [FullText HTML](33) [PDF 2253KB](10)
Abstract:
ObjectiveThrough the research of PwPEBP gene and its promoter expression characteristic and biological function in Picea wilsonii, this paper aims to explore PEBP genes in plant growth and development in the process of response to adversity stress function and mechanism of action.MethodIn this study, we had obtained the cDNA sequence of PwPEBP by Picea wilsonii transcriptome data. Based on the bioinformatics analysis of PwPEBP protein by TMHMM, GOR4 and other online software, the open reading frame (ORF) sequence of PwPEBP was cloned by PCR technology. The expression level of the gene in different tissues, different adversity and hormone treatment was analyzed by RT-qPCR. The promoter sequence of PwPEBP was cloned by chromosome step method, and the prediction of the basic promoter region, transcription starting point and the action element of the PwPEBP promoter sequence was carried out by the on-line software BDGP and Plantcare. Finally, the function of PwPEBP promoter was transferred into tobacco leaves by agrobacterium-mediated method.ResultPwPEBP cDNA was 1 408 bp with an open reading frame flanked (ORF) of 585 bp encoding 194 amino acids.The protein molecular formula of PwPEBP was C966H1 484N250O299S6. The protein had no peptide and transmembrane domain. Hydrophobicity analysis showed that the hydrophobic sites of PwPEBP were uniformly distributed, suggesting that the protein was hydrophilic.25 phosphorylation sites were found with NetPhos. The phylogenetic tree analysis showed that the PwPEBP and PEBP of the Picea sitchensis were clustered into a new PEBP protein. The tissue-specific expression analysis showed that PwPEBP were all expressed in stem, root, mature needle, young needle, pollen and seed. However, the expression level of PwPEBP in mature needle was the highest and the lowest in young needle. The expression of PwPEBP under stress and hormone treatments showed that the expression of PwPEBP was induced, respectively, but not by the salt stress.The sequence length of PwPEBP Promoter was 903 bp. The online analysis showed that it contained cis-acting elements such as GA, ABA, MeJA and SA.The GUS color reaction and Luc quantification experiment further showed that PwPEBP promoter sequences with cis elements could respond to GA, ABA, MeJA and SA hormones.ConclusionPwPEBP gene in Picea wilsonii widely responds to abiotic stress such as drought, low temperature and high temperature, especially in drought. Meanwhile PwPEBP is also involved in the signaling pathways of ABA, GA, MeJA and SA hormones.
Research on image recognition of five bark texture images based on deep learning
Liu Jiazheng, Wang Xuefeng, Wang Tian
Accepted Manuscript  doi: 10.13332/j.1000-1522.20180242
[Abstract](40) [FullText HTML](28) [PDF 1251KB](10)
Abstract:
ObjectiveAiming at the problem that the existing algorithm and recognition process are too complicated in bark image recognition, a method based on deep learning was proposed to identify the bark images of different tree species.MethodTaking the bark texture image of five common tree species as an example, the deep learning method based on convolutional neural network was used to input the original image directly as input, and the low-level and high-level features of the image were performed by convolution and pooling layer. Automatic extraction solved the difficulty and problem of manually extracting texture features. On this basis, the CNN model structure was improved, and the ELU excitation function with Maxout was used instead of the ReLU function to solve the model offset and zero gradient problem. The loss function was improved, the specification parameters were added to optimize the structural parameters, and the learning rate was dynamically adjusted using the piecewise constant attenuation method. Finally, the softmax classifier was used to output the image categories.ResultA total of 10 000 images of 5 types of bark texture images were tested, and 200 images of each type were selected as test sets. The final training recognition accuracy rate reached 93.80%, and the test set recognition accuracy rate was 97.7%. In addition, in order to verify the feasibility of the proposed method, and the traditional artificial feature extraction method, the HOG feature, the Gabor feature and the gray level co-occurrence matrix statistical method were extracted, and the SVM classifier was trained. Through experimental comparison, the method identification accuracy was the highest.ConclusionThe tree-skin image recognition method based on deep learning proposed in this paper is feasible, which improves the recognition efficiency and precision, and provides a new reference for the intelligent identification of tree species.
Evaluation of salt tolerant performance of BpCHS3 transgenic plants in Betula platyphylla
Li Xiaoyuan, Wang Chu, Wang Fang, Jiang Jing
Accepted Manuscript  doi: 10.13332/j.1000-1522.20180224
[Abstract](20) [FullText HTML](21) [PDF 882KB](3)
Abstract:
ObjectiveChalcone synthase (CHS) is a key enzyme in the biosynthesis pathway of flavonoids. Overexpression of CHS promotes an accumulation of flavonoids and enhances the ability of plants to resist abiotic stresses such as salinity and drought. The objective of the study is to elucidate the function of BpCHS3 to salt tolerance.MethodOur previously obtained transgenic birch plants of BpCHS3 were used in this study. The content of anthocyanins in leaves, salt stress index, chlorophyll fluorescence and photosynthetic parameters under NaCl stress were determined. QRT-PCR and Northern Blot were used to determine the relative expression levels of five key enzyme genes of downstream of CHS and BpCHS family members in the flavonoid metabolic pathway.ResultThe wild type (WT) had a salt damage index of 83% in the 25th day under 0.3% NaCl stress, whereas transgenic birch was only 39%. The chlorophyll fluorescence and photosynthetic parameters of transgenic Betula platyphylla seedlings under 0.4% NaCl stress showed that the Fv/Fm for most transgenic lines was still normal in the 9th day, while Fv/Fm was reduced to 0.66 and the ΦPSII and qP showed a decreasing trend for WT. The WT strain had a higher decline than the transgenic lines. The mean value of Pn for five transgenic lines was still higher than 43.47% of WT under salt stress in 6 days. It is believed that the overexpression of BpCHS3 gene in Betula platyphylla under salt stress can maintain its higher photoelectron transport activity, increase the primary light energy conversion efficiency of PSII reaction center, and maintain a higher net photosynthetic efficiency. qRT-PCR and Northern Blot showed that the introduced target gene BpCHS3 was expressed in BpCHS3 transgenic lines. All of them showed up-regulated expression in different levels. Only BpCHS3 expression was significantly up-regulated in BpCHS family members. Both BpCHS1 and BpCHS2 were down-regulated or not significantly different from WT lines. Anthocyanin content of BpCHS3 overexpression lines was significantly lower than that of WT lines. It is speculated that overexpression of BpCHS3 results in co-suppression of two other CHS family members affects the synthesis of anthocyanins.ConclusionThe salt tolerance of BpCHS3 transgenic birch was increased, which was not related to the content of anthocyanin. The overexpression of BpCHS3 may promote the accumulation of other flavonoids, thus enhancing the salt tolerance of Betula platyphylla.
Comparative study on physical mechanic properties of Phyllostachys edulis in different latitudes
Zhang Wenbo, Fei Benhua, Tian Genlin, Hu Tao, Yue Xianghua, Chang Yanting, Jiang Zehui
Accepted Manuscript  doi: 10.13332/j.1000-1522.20180245
[Abstract](14) [FullText HTML](18) [PDF 733KB](1)
Abstract:
ObjectiveThe purpose of this study was to investigate the variation of physical mechanic properties of Phyllostachys edulis distributed in different subtropical provenance regions.MethodThree natural populations of Moso bamboo were obtained distributing in Anhui, Guangxi, and Zhejiang provinces, 8 physical mechanic properties were analyzed using one-way ANOVA and principal component analysis based on R.ResultThe physical mechanic properties of Moso bamboo were significantly different from 3 populations, the peaks of shrink, moisture content, micro fibril angle and bending strength were all from Guangxi Zhuang Autnomus Region. The variable coefficient of these traits did not show obvious trend and regulation. PCA analysis showed that bending strength, modulus of elasticity, oven-dried volume shrinking ratio, air-dried volume shrinking ratio, and moisture content were the most dominant properties in the 8 physical mechanics properties.ConclusionOverall consideration, the Moso bamboo from Guangxi Zhuang Autnomus Region was characterized by high strength and high density during these 3 provinces, it is more suitable for processing and utilization as engineering materials. The research results will provide the theoretical basis for excavating excellent species of Moso bamboo in different geographical environments and rationally utilizing the bamboo resources in China’s entire distribution latitude.
Optimization of preparation process of birch veneer/glass fiber composite
Lin Bin, Zhai Xueyong, Li Rui, Sun Lipeng, Zhang Yuanting, Yin Yuxue, Liu Zhenbo
Accepted Manuscript  doi: 10.13332/j.1000-1522.20190049
[Abstract](21) [FullText HTML](18) [PDF 996KB](3)
Abstract:
ObjectiveIn order to investigate the influence of process factors on the acoustic vibration performance of composites, the process parameters of composite preparation were optimized to improve the acoustic vibration performance of composites.MethodThe test was designed according to the structure principle of laminated veneer lumber to prepare birch veneer/glass fiber composites. FFT was used to detect the acoustic vibration properties of composite materials. The comprehensive score after normalization of the specific dynamic elastic modulus (E/ρ), the ratio of elastic modulus and shear modulus (E/G), acoustic radiation damping (R), loss tangent (tanσ), and sound velocity (v) was used as the response indicators to analyze the influence of hot-press time, hot-press pressure and resin sizing amount on the acoustic vibration performance of composite materials. Based on the single factor experiment, the response surface methodlogy was used to establish the quadratic regression model of process factor and response value to optimize the preparation conditions of composite materials.ResultWithin the scope of the single factor experiment, when the hot-press time was 10−25 min, the pressure was 0.6−1.3 MPa, and the resin sizing amount was 140−180 g/m2, the acoustic vibration performance of the composite materials was significantly improved. Those experiments used Design-Expert to perform quadratic polynomial regression fitting on the acoustic vibration performance test results of composite materials, eliminating the factors that have no significant influence on the model, and the response surface model of composite scores was established. The optimal process conditions optimized by the response surface model were hot-press time 24.5 min, hot-press pressure 1.3 MPa, resin sizing amount 180 g/cm2. Under the conditions, the E/ρ of the composite reached 25.27 GPa, E/G was 15.99, R was 6.48 m3/(Pa·s3), tanσ was 0.001 25, v was 5 026.55 m/s, and the comprehensive score reached 98.19.ConclusionThe P of the comprehensive score model was less than 0.000 1, the deviation between the measured value and the predicted value was less than 5%, indicating that the response value has a highly significant relationship with the regression model. It also shows that the regression model is accurate and reliable.
Display Method:
Land surface temperature retrieved from Landsat-8 and comparison with MODIS temperature product
Zhang Aiyin, Zhang Xiaoli
2019, 41(3): 1-13.   doi: 10.13332/j.1000-1522.20180234
[Abstract](30) [FullText HTML](33) [PDF 3761KB](8)
Abstract:
ObjectiveLand surface temperature (LST) is a key parameter for analyzing and simulating land surface processes from local to global scales, which plays an important role in the processes of energy exchange between land surface and atmosphere. As the latest achievement of the series of Landsat missions, Landsat-8 has two thermal infrared channels compared with previous Landsat version, and has higher spatial resolution compared with other sensors such as AVHRR or MODIS, it has greater advantages when it comes to the use of land surface temperature retrieval. This paper uses three different algorithms including the improved mono-window algorithms proposed by Wang (2015), the improved single channel algorithm proposed by Cristóbal (2018) and the split window algorithm proposed by Jiménez-Muñoz (2014), respectively to retrieve land surface temperature from Landsat-8 data in Beijing region, and chose MODIS LST product for cross validation in order to assess the accuracy and applicability of Landsat-8 used for LST retrieval, and provide a reference for the subsequent study of Landsat-8 LST retrieval.MethodThis paper determines and estimates 3 important parameters used for LST retrieval: atmospheric effective temperature, land surface emissivity, and water vapor contents. Sensitivity and differential analysis were conducted after getting the LST result by 3 algorithms. Comparative analysis methods between the retrieval result and MOD11A1 product with the closest satellite passing time to Landsat-8 include the comparison of average temperature between retrieval result and MODIS temperature product by different administrative regions and different ground features, as well as choosing the center region of Miyun Reservoir, which has lower scale effect and little temperature variation to compare the temperature difference between the above two.ResultThe general average temperature difference between the three algorithms was less than 1K, and the temperature difference between the improved single channel algorithm proposed by Cristóbal (2018) and the other two algorithms was the smallest, and the temperature difference between the improved mono-window algorithms proposed by Wang (2015) and the other two algorithms was the largest. The result of Landsat-8 LST retrieval was generally higher than MODIS temperature product, the mean temperature difference was 1.3 K. By selecting the center area of Miyun Reservoir to compare the results between Landsat-8 LST retrieval and the temperature products, the total average difference between the three algorithm results and the MODIS temperature products was 1.373 K.ConclusionThe retrieval results have an overall satisfying accuracy, among which, the split window algorithm proposed by Jiménez-Muñoz (2014) has the best sensitivity analysis result, and has the closest result to MODIS temperature product. The results of Landsat-8 retrieval are consistent with the distribution of MODIS temperature products in the overall LST distribution, but Landsat-8 can better distinguish the temperature differences between different types of small feature and have a greater advantage when it comes to the use of accurate retrieval of land surface temperature because of the higher resolution.
Biogeographic patterns and environmental interpretation of plant regional species richness in Alxa Plateau of northern China
Wang Jianming, Cui Panjie, Zhong Yueming, Li Jingwen, Chu Jianmin
2019, 41(3): 14-23.   doi: 10.13332/j.1000-1522.20180403
[Abstract](20) [FullText HTML](15) [PDF 794KB](1)
Abstract:
ObjectiveDesert ecosystem is characterized by extremely restricted water and nutrient availability, high precipitation and temperature variability. Alxa Plateau of northern China covers large-area typical temperate desert ecosystems, with a total area of more than 200,000 km2. These ecosystems are highly vulnerable to global environmental and land-use changes, whereas the relative influence of water, energy and habitat heterogeneity on plant regional species richness, and the associated difference among different functional groups, are still unclear.MethodWith the distributions of 811 native plants, plant regional species richness of three groups, climatic and habitat variables, we tried to explore the biogeographic patterns and the underlying dominant factors of overall, woody and herb plant regional species richness of Alxa Plateau.Result(1) Both the overall, woody and herb plant regional species richness in Alxa Plateau showed obvious longitudinal and latitudinal gradients, which increased from northwest to southeast. (2) We found that both plant regional species richness of three groups were positively correlated with water variables, but were negatively correlated with energy variables. Water and energy factors together explained 60.7%, 62.5% and 42.6% of the variation in overall, herb and woody species richness, respectively; and both water and energy factors could individually explained 15.2%−19.6% and 2.8%−5.3% of the variation in plant regional species richness of three groups. Habitat heterogeneity significantly explained 12.3%−29.3% of the variation in overall, herb and woody species richness, and also could individually explain 3.1%, 1.0% and 11.8% of variation in species diversity of three groups. The relative role of climate and habitat factors differed between herb and woody species richness. Herb plant regional species richness was predominantly determined by water and energy factors, whereas the woody plant regional species biodiversity was controlled by water, energy and habitat heterogeneity, together. (3) Water, energy and habitat heterogeneity together explained 54.4%−63.8% of the variance overall, herb and woody plant regional species richness, while with 36.2%−45.6% of the variance explained by other unknown factors.ConclusionOur results propose that the plant regional species richness patterns are predominantly shaped by water and energy factors together; and water availability is the most key limited factors in shaping these plant regional species richness patterns. Habitat heterogeneity also play a non-negligible role in regulating these regional species richness in Alxa Plateau. We highlight that the dominant factors of species diversity may differ markedly depending on the plant functional group, and other unknown factors such as soil, neutral factors and human disturbances may also greatly influence plant species richness in Alxa Plateau.
Formation mechanism of taxonomic structures for forest communities in different successional stages in Changbai Mountains of northeastern China
Fan Xiuhua, Xu Chengyang
2019, 41(3): 24-32.   doi: 10.13332/j.1000-1522.20180301
[Abstract](58) [FullText HTML](38) [PDF 1055KB](13)
Abstract:
ObjectiveTaxonomic structures are the intuitive reflection of the species compositions of communities and they can reflect the regulation of local processes, such as environmental filtering and interspecific competition.MethodBased on the species composition data collected in three large forest observational field studies, the taxonomic structures of the communities were analyzed at different sampling scales. Random null model was used and the " standardized effect size” (SES) of taxonomic ratios was calculated.ResultAs expected, the taxonomic ratios declined with increasing grain size in all plots. The quantitative relationship between genera/families and species, described by a linearized power function, showed a good fit. In the mixed conifer and broadleaved forest and Tilia sp.-Korean pine forest, the taxonomic ratios of the observed communities had significantly lower values than those of the simulated random community under the test of null model at almost all scales. But that was not the case for the secondary poplar-birch forest, SES was larger than 0.ConclusionThe results suggest that the effect of abiotic filtering is greater than the effect of interspecific competition in shaping the local community for the mixed conifer and broadleaved forest and Tilia sp.-Korean pine forest. In the secondary poplar-birch forest, competition dominated the taxonomic structure of the community. Local processes do influence the taxonomic structure, but their combined effects may vary with scale and successional stages.
Spatial distribution patterns of Quercus mongolica and Tilia mandshurica natural mixed forests
Li Yanli, Yang Hua, Deng Huafeng
2019, 41(3): 33-41.   doi: 10.13332/j.1000-1552.20180236
[Abstract](11) [FullText HTML](8) [PDF 1131KB](4)
Abstract:
ObjectiveSustainable management of natural forest is one of the most important forestry research topics in China and even in the world. The research target in this paper is the Quercus mongolica and Tilia mandshurica natural mixed forests in Sancha Village in Beijing. In order to obtain the spatial distributions and relationship between Quercus mongolica and Tilia mandshurica in the natural mixed forests, the scientific basis and theoretical references were provided for natural forest protection, management and intermediate cutting.MethodAn observational field plot was established with an area of 100 m × 100 m of Quercus mongolica and Tilia mandshurica natural mixed forests. By point pattern analysis, spatial distributions and relationship between Quercus mongolica and Tilia mandshurica was analyzed. The DBH class distributions of Quercus mongolica and Tilia mandshurica were obtained.ResultThe results showed that: (1) both the DBH class distributions of Quercus mongolica and Tilia mandshurica followed the shape of an inverse J. (2) The whole stand, Quercus mongolica and Tilia mandshurica showed an aggregated spatial distribution at small scale, with the scale increased, the aggregation intensity declined, then showed random distribution gradually. (3) Quercus mongolica and Tilia mandshurica showed aggregated distribution at small trees and middle trees stages, and showed random distribution at large tree stage, with tree growing, the aggregation intensity was declining. (4) Quercus mongolica and Tilia mandshurica showed a negative spatial correlation at small scale at first, then showed uncorrelated relationship. (5) The relationships of different growth stages of Quercus mongolica showed a negative spatial correlation at small scale, and uncorrelated relationship at other scales. (6) The relationships of different growth stages of Tilia mandshurica showed a positive spatial correlation at small scale, and uncorrelated relationship at large scale.ConclusionIn conclusion, Quercus mongolica and Tilia mandshurica natural mixed forests is stable in this region, and it is a growing population. Appropriate human interference could be applied in the forest for sustainable management of natural forest. The forest structure could become more suitable and stable after intermediate cutting.
Geographical variations of functional traits of typical tree species in northeastern China
Lian Zhenghua, Zhang Chunyu, Cheng Yanxia, Xin Benhua
2019, 41(3): 42-48.   doi: 10.13332/j.1000-1522.20180352
[Abstract](11) [FullText HTML](11) [PDF 916KB](2)
Abstract:
ObjectiveBy taking typical shade-intolerant and shade-tolerant tree species in northeastern China as objects, this study discusses the changing pattern of functional traits along geographic gradient and the underlying causes, which could provide scientific support for predicting the response and adaptation strategies of typical tree species to future environmental changes.MethodMethod of standardized major axis regression was applied to examine the intraspecific correlation among tree height, specific leaf area and wood density; and method of partial correlation analysis was applied to analyze the relationship between functional traits and climatic factors.ResultThere was no significant intraspecific correlation among tree height, specific leaf area and wood density. The geographical distribution pattern of plant traits changed with tree species, the height of Betula platyphylla, Fraxinus mandshurica and Acer pictum decreased with the increase of longitude; the height of Populus davidiana, Fraxinus mandshurica and Acer pictum decreased with the increase of latitude; the height of Betula platyphylla and Fraxinus mandshurica increased with elevation. The specific leaf area of Betula platyphylla and Populus davidiana decreased with increasing longitude, while that of Fraxinus mandshurica and Acer pictum increased with increasing longitude; the specific leaf area of Betula platyphylla, Populus davidiana and Fraxinus mandshurica increased with latitude. The wood density of Acer pictum increased with longitude, while that of Quercus mongolica decreased with latitude. The relationship between plant traits and climatic factors showed that the tree height of Betula platyphylla was negatively correlated with annual mean temperature, and the tree height of Betula platyphylla, Populus davidiana, Quercus mongolica, Fraxinus mandshurica and Pinus koraiensis was positively correlated with annual precipitation; the specific leaf area of Betula platyphylla was negatively correlated with annual precipitation, while that of Quercus mongolica, Populus davidiana and Fraxinus mandshurica was negatively correlated with annual mean temperature; The wood density of Quercus mongolica had significant positive correlation with annual mean temperature, while the wood density of Acer pictum was negatively correlated with the annual mean temperature.ConclusionGeographical patterns of functional traits and their underlying environmental driving mechanisms vary with tree species. In summary, tree height and specific leaf area are separately affected by precipitation and temperature; wood density is relatively stable, which is not significantly affected by climatic factors.
Dynamic change and prediction model of moisture content of surface fuel in Maoer Mountain of northeastern China
Man Ziyuan, Hu Haiqing, Zhang Yunlin, Liu Fangce, Li Yuan
2019, 41(3): 49-57.   doi: 10.13332/j.1000-1522.20180326
[Abstract](25) [FullText HTML](25) [PDF 855KB](9)
Abstract:
ObjectiveThe prediction of the fuel moisture content is the major part of forest fire research and the moisture content of surface fine fuel, semi-humus and humus determines the persistence of vertical fire and the probability of underground fire. The change of moisture content is mainly affected by weather conditions and topographical features, while there are few studies on the dynamic changes of moisture content of semi-humus and humus in China. Therefore, analyzing the dynamic changes of moisture content of these three layers of fuel has a guiding role in establishing China ’s forest fire forecasting system.MethodThe research conducted daily monitoring of surface fine fuel, semi-humus and humus moisture content under the typical coniferous and broadleaved mixed forest in Maoer Mountain of northeastern China, the meteorological data of forest were also monitored synchronously. This study also statistically analyzed the correlations between meteorological elements and the moisture content of three layers of fuel, and the meteorological element regression method was used to establish a moisture content prediction model for three layers of fuel.ResultDuring the whole monitor period, the moisture content of surface fine fuel fluctuated the most, with the minimum value of 10.99% and the maximum value was 253.30%. The semi-humus was the second, and the minimum value was 19.21% and the maximum value was 238.07%. The moisture content of humus was the most stable, and the minimum value was 48.45% and the maximum value was 193.83%. The change of moisture content of surface fuel was the most sensitive to the response of meteorological factors, mostly related to the meteorological factors on the current day or the previous day, followed by semi-humus, and the moisture content of humus was only related to air temperature. Three fuel types of regression prediction model for meteorological elements of moisture content were established. The average absolute error and the average relative error of the moisture content prediction model of surface fine fuel, semi-humus and humus were 22.2%, 23.5%, 17.1% and 7.1%, 14.8%, 23.4%, respectively. The prediction model of moisture content of fine fuel and semi-humus both can basically achieve the accuracy of forest fire prediction, while the accuracy of prediction model of moisture content of humus was bad.ConclusionThe three layers of fuel may have a forest fire during the fire prevention period. Attention should be paid to the prediction of underground fuels, including the moisture content of semi-humus and humus, in future forest fire prevention work.
Analysis on surface potential fire behavior and combustion of Miaofeng Mountain Forest Farm in Beijing
Li Lianqiang, Niu Shukui, Chen Feng, Tao Changsen, Chen Ling, Zhang Peng
2019, 41(3): 58-67.   doi: 10.13332/j.1000-1522.20180361
[Abstract](31) [FullText HTML](14) [PDF 923KB](1)
Abstract:
ObjectiveForest combustion is the difficulty degree of igniting a forest and the characteristics of fire behavior after a fire. Analysis of combustible fire behavior and combustion can provide a scientific basis for the forest fire prevention management and fire zoning under the forest of Miaofeng Mountain Forest Farm.MethodThrough the investigation of surface combustibles of 12 major forest types in farm, combined with the continuous forest resources, this paper selects four categories of indicators: surface fire behavior, fire environment, flammable physical properties and bed structure to calculate the combustibility of 104 small class surface fuels by principal component analysis and cluster analysis, and the surface combustibles combustion index (CI) and ranking were calculated.Result(1) In 104 small classes, the potential fire behavior of each dominant tree species in small classes was from large to small: coniferous forests was generally larger and the surface fire intensity reached 2 000 kW/m, the spread speed was above 3 m/min, and the flame height was over 1.5 m. The shrub was second, and its surface fire intensity was 700−2 000 kW/m, the spreading speed is 1.5−3 m/min, and the flame height is 1−1.5 m. The broadleaved was the lowest and it had a surface fire intensity of 700 kW/m or less, a propagation speed of 1.5 m/min or less, and a flame height of 1 m or less. (2) Principal component analysis showed that, the fire behavior index was directly proportional to the combustion, and the altitude factor was inversely proportional to the combustion. The water content was inversely proportional to the combustion. The effective load and the bed height were directly proportional to the combustion. (3) Cluster analysis showed that, the small class surface fuel combustion index (CI) was divided into five grades: high combustion (Ⅰ), higher combustion (Ⅱ), combustion (Ⅲ), lower combustion (Ⅳ), low combustion (Ⅴ). Small-shift dominant species of each flammability class, such as Pinus tabuliformis, Larix gmelinii and Platycladus orientalis, distributed in the southeastern and northwestern of the forest farm. Mixed forest of the Pinus tabuliformis, Platycladus orientalis and Quercus variabilis, Acer monoMaxim. mainly located in the northwestern corner of the forest farm. Broadleaved pure forest, such as cork oak, Quercus variabilis, Phellodendron amurense, Acer mono, which were concentrated in the southeastern and northwestern of the forest farm. Mountain peach and shrubs such as Vitex negundo and a few broadleaved mixed forests, such as Quercus variabilis, Juglans mandshurica, which were distributed in the northwestern forest farm. The shrubs such as Vitex negundo, Armeniaca sibiricat, Rhamnus davurica and Spiraea salicifolia, mainly located in the southwestern and central forest farm.ConclusionThe potential fire behavior of small-scale of Pinus tabuliformis and Larix gmelinii forests is generally large, and it is easy to form high-intensity surface fires, which are prone to canopy fires. Combustibility is affected by fire environment, fire behavior and combustibles, especially combustible payload, bed height, altitude and moisture content factors. Small classes of the higher-combustion and high-combustion are located in the north and northwest of the forest farm. It is necessary to pay attention to the small-class classification management and scientific patrol of different combustion levels.
Analysis on spatial distribution of forest disasters in China
Zhang Ying, Ding Yufei
2019, 41(3): 68-79.   doi: 10.13332/j.1000-1522.20180254
[Abstract](19) [FullText HTML](17) [PDF 688KB](4)
Abstract:
ObjectiveForest fires, diseases, pests and rodents are important influencing factors in forest ecosystem, and have important influence on the stability and balance of forest ecosystem. It is of great significance to study the risk of forest disasters to improve the management ability and countermeasures of forest resource risk.MethodRelevant data on the number of forest disasters in China from 2003 to 2016 were collected in this study, and the spatial distribution of China ’s forest disasters was analyzed using the principal component cluster analysis method.ResultFrom 2003 to 2016, Hunan and Guizhou provinces ranked first top two provinces in terms of the total number of forest fires. Concerning total fire area, Heilongjiang Province was much higher than other provinces, while Beijing and Tianjin municipalities had the least total. In terms of the total area of affecting forests, Heilongjiang Province and Inner Mongolia autonomous region were relatively serious, which was dozens or even hundreds of times of other provinces and cities. In terms of affecting stand volume loss, Heilongjiang Province was also the most serious one, with an average annual forest fire loss of 686 100 m3. According to the degree of fire disaster, the spatial distribution of forest fires can be divided into three types, which are mild, moderate and severe fire zones, especially Heilongjiang Province was the most prominent. On the spatial distribution of forest diseases, pests and rodents disasters were divided into four categories based on the extent of the damage. Xinjiang and Inner Mongolia Autonomous Region fell into the IV category, where a large area diseases, pests and rodents occurred with a high proportion of moderate and severe ones. Other provinces and cities were belonging to the I –III category, where smaller (Beijing, Shanghai, etc.), moderate (Hainan Province) and larger (Heilongjiang Province, etc.) area diseases, pests and rodents happened.ConclusionThe number of forest fires and the area of forest damage were generally decreasing in 2003 to 2016, but the area of forest diseases and insect pests occurrence overall rised in recent years in China, especially in the proportion of forest insect and rodent, moderate and severe disaster area increased, and this should be paid more attention to. The study also discusses relevant issues, and provides a reference for the risk management of forest disasters.
Characteristics of soil stoichiometric in natural restoration process of Maolan karst forest vegetation, southwestern China
Wu Peng, Cui Yingchun, Zhao Wenjun, Shu Deyuan, Hou Yiju, Ding Fangjun, Yang Wenbin
2019, 41(3): 80-92.   doi: 10.13332/j.1000-1522.20180136
[Abstract](27) [FullText HTML](21) [PDF 887KB](4)
Abstract:
ObjectiveThe dynamics of soil nutrition and stoichiometric characteristics of different successional stages during the process of natural restoration in Maolan karst forest vegetation of southwestern China were studied to explore the relationship between them, and quantitatively evaluate the degree of explanation of impact factors on soil stoichiometric characteristics, and clarify the intrinsic coupling relationship between the vegetation community succession and soil property evolution, in order to provide the theoretical basis for restoration and reconstruction of degraded karst forest.MethodTaking he herb stage, shrub stage, arbor stage and climax stage as the research objects, three fixed sample plots were set up in each succession stage, 12 soil profiles were randomly set up according to different niche conditions and laminated sampling. The contents of SOC, TN, TP and TK were measured and the stoichiometric ratio was calculated.ResultThe mean contents of SOC, TN, TP and TK of soil in the research region were 54.72, 4.67, 0.73 and 8.53 g/kg, respectively. There were significantly or very significantly positive correlations between the contents of SOC, TP and TN, showing relatively consistent law of change. The ratios of C:N, C:P, C:K, N:P, N:K and P:K were 11.95, 79.16, 6.50, 6.64, 0.550 1 and 0.085 2, respectively. In terms of coefficient of variation, except TK content and C:N belonged to weak variability, the soil nutrient content and stoichiometric ratio were all medium variability. With the forward succession of vegetation, the SOC, TN and TP contents in different succession stages basically increased, but the change trend of TK content was reverse V-shape, showed arbor stage > climax stage > shrub stage > herb stage. The contents of SOC, TN and TP of different soil depth at each succession stage showed that 0–10 cm was higher than 10–20 cm, but the content of TK had no obvious change. The variation trend of the soil stoichiometric characteristics with the succession was quite different. At the soil profile level, except for no significant difference between the depth of different soil layers in C:N, the others showed that 0–10 cm was higher than 10–20 cm. The results of redundancy analysis showed that soil depth and community succession were the main factors to regulate soil nutrition content and stoichiometric characteristics in the region, with the explanatory degree of 32.82% and 32.19%, respectively.ConclusionSoil organic carbon content in the study area was relatively high, N and P contents were rich , plant growth restricted by N (or P) element may be caused by the low effectiveness of soil nutrient content.Reducing human disturbance, and appropriate protection can promote the positive succession of community, improve the stability and anti-interference of the karst forest ecosystem, and conducive to the accumulation of soil nutrients.The results preliminarily reveal the degree to which many influencing factors can explain soil nutrition content and stoichiometric characteristics, which is of important guiding significance to the protection of karst forest.
Dynamics of soil respiration and its influencing factors at the early stage of ecological restoration of two kinds of climate in earthquake-affected area
Wu Jianzhao, Yan Siwei, Cui Yu, Luo Qinghu, Lin Yongming, Wang Daojie, Wu Chengzhen
2019, 41(3): 93-104.   doi: 10.13332/j.1000-1522.20180192
[Abstract](8) [FullText HTML](20) [PDF 1151KB](3)
Abstract:
ObjectiveSoil respiration rate is one of the important parameters affecting the sensitivity and response pattern of ecosystems to stress, and the ecological restoration process can cause changes in soil respiration rate. To accurately understand the regional carbon cycle characteristics of disaster-affected areas under ecological restoration, it is crucial to study the dynamic changes of soil respiration in disaster areas and their relationship with environmental factors under different ecological restoration modes in different climate regions.MethodIn order to study the dynamic changes of soil respiration and its relationship with hydrothermal factors during the treatment of damaged ecosystems in the earthquake-affected areas, the demonstration area of ecological restoration of the arid-valley climate region (Weizhou Town, Wenchuan County) and subtropical monsoon climate region (Hanwang Town, Mianzhu City) was selected as the study area, with destroyed and treated area (DTA), natural recovery area (NRA) and undestroyed area (UA) as sample plots. Diurnal and seasonal dynamics of soil respiration rate (Rs), 5 cm deep soil temperature (T5) and moisture (W5) and near-surface temperature (T0) and moisture (W0) were measured using the LI-8100 soil carbon flux measurement system, precision thermometer and round knife method from September 2015 to September 2016, and analyze the dynamic characteristics of soil respiration and its response to soil temperature and moisture.Result(1) The highest Rs value of the daily scale appeared at 11:00−15:00, and the lowest value appeared at 10:00 or 18:00. In two climatic regions, the diurnal dynamics of soil respiration showed the tendency of UA > DTA > NRA, and showed obvious single peak curves with certain volatility; seasonal scale Rs was the highest in summer and autumn, and lowest in winter, and Rs showed UA > DTA > NRA in all seasons. (2) When the soil moisture in the arid-valley climate region and the subtropical monsoon climate region were < 27% and > 16%, respectively, soil respiration was mainly regulated by soil temperature; compared with the single-factor models of Rs and T5 or Rs and W5, the regression relationship between Rs and T5 as well as W5 was better, and the explanatory amount (R2) of T5 and W5 to Rs was both increased and was greater than 0.762. (3) The temperature sensitivity coefficients Q10 of DTA, UA, and NRA in the arid-valley climate region were 2.34, 1.95, and 2.78, respectively, and the Q10 values in the subtropical monsoon climate region were 1.99, 1.25, and 2.90, respectively. The performance of NRA was most sensitive to soil temperature changes, followed by DTA, and UA was the least sensitive.ConclusionCompared with UA, the soil respiration rates of DTA and NRA decreased by 41% and 50%, respectively in the arid-valley climate region, while only decreased by 21% and 23%, respectively in the subtropical monsoon climate region.
Effects of rainfall process on runoff in small watersheds in the Loess Plateau of western Shanxi Province, northern China
Yang Yunbin, Zhang Jianjun, Li Liang, Sun Ruoxiu, Zhang Haibo, Zhang Jianan
2019, 41(3): 105-114.   doi: 10.13332/j.1000-1522.20180104
[Abstract](9) [FullText HTML](4) [PDF 885KB](3)
Abstract:
ObjectiveThis study aims to discuss the effects of precipitation process (rainfall patterns) on runoff in small watersheds, and provide the basis for the analysis of runoff and confluence on a small watershed scale.MethodCaijiachuan Small Watershed of the National Field Research Station of Forest Ecosystem in Jixian County, Shanxi Province of northern China was taken as the research object. Rainfall and runoff data were collected from 2007 to 2017 in the Caijiachuan Watershed and rainfall patterns were divided according to the location of rainfall in the precipitation process. LSD multiple comparison method was used to study rainfall characteristics of different rainfall patterns on the basis of rainfall process. The response relationship between rainfall pattern characteristics and runoff was explored in small watershed scales of different land use types.Result(1)The storms were divided into four rainfall patterns: rainfall concentrated early in the rainfall (Type Ⅰ); rainfall concentrated in the middle of the rainfall (Type Ⅱ); rainfall concentrated at the end of the rainfall (Type Ⅲ); and rainfall distributed uniformly over time (Type Ⅳ). Type I was characterized by shorter durations and higher intensities, which was the main type of rainfall, accounting for 44.6% of the total rainfall frequency. The average rainfall was 24.6 mm and rainfall erosivity was the strongest, which concentrated in June to August. Type Ⅳ had longer durations and lower intensities, with an average duration of 716 minutes and an average rainfall of 17.84 mm, rainfall erosivity was the weakest, mostly occurring in the early (May) and late (September) phases of the rainy season. The characteristics of Type Ⅱ and Type Ⅲ were between TypeⅠ and Type Ⅳ, which mostly occurred from June to August. The distribution of rainfall and frequency was relatively balanced. (2) The order of runoff depth and peak discharge in small watersheds under different rainfall patterns was Type Ⅰ > Type Ⅲ > Type Ⅱ > Type Ⅳ, lag time of flood peak was Type IV > Type II > Type III > Type I. (3) Runoff depth and peak discharge in the agricultural small watershed under Type I and Type III were higher than that in the closed small watershed, which was the opposite under Type II and Type IV. The peak flow appeared earlier in the agricultural small watershed. (4) Rainfall and duration had a greater impact on the runoff in the agricultural small watershed, intensity distribution had greater impact on the runoff in the closed small watershed.ConclusionThe rainfall characteristics of different rain patterns are significantly different. Type Ⅰ was the main rainfall pattern causing the runoff of small watersheds. The closed small watershed had a more significant role in reducing peak discharge and prolonging the appearance time of peak flow than the agricultural small watershed, especially for heavy rainfall and strong rainfall, the regulation effect was more obvious. The rainfall, rainfall duration and rainfall intensity distribution in the Loess Plateau of Western Shanxi Province are the important factors influencing the runoff production in small watershed.
Preliminary analysis on the summer habitat selection of Mongolia subspecies of goitred gazelle in Wulate, Inner Mongolia of northern China
Zhao Yu, Jin Kun
2019, 41(3): 115-123.   doi: 10.13332/j.1000-1522.20180049
[Abstract](50) [FullText HTML](34) [PDF 646KB](9)
Abstract:
ObjectiveDue to the lack of research on goitred gazelle (Gazella subgutturosa hillieriana) at home and abroad, it has some adverse effects on its protection. Therefore, this paper studies the habitat selection of Mongolia subspecies of goitred gazelle in summer, and will provide a basis for exploring habitat selection and habitat restoration of the species.MethodWe investigated the habitat selection of Mongolia subspecies of goitred gazelle in the Ass-Saxoul National Nature Reserve of Wulate, Inner Mongolia of northern China from July to August 2016, using methods of transects and random samples. Totally 71 quadrats with gazelle and its tracks were obtained and 15 habitat selection factors were measured. The Vanderploeg and Scavia selection index and principal component analysis were used to determine the main habitat factors.ResultThe results showed that goitred gazelle chose high plain and torso mountain, semi-shady slope, shrub with nitraria sibirica (Nitraria tangutorum); shrub numbers of no more than 10 or 20–30; the vegetation coverage of less than 20% or 60%–80%; and with the distance from the road and resident sites 10–15 km. Principal component analysis (PCA) indicated that the total cumulative contribution rate for 5 components was 76.504%, the contribution rate of the first principal component was 22.058%, in which the highest was terrain factors (slope orientation, slope position and slope degree); high contribution rate factors in other principal components were disturbance, water distance and vegetation factors.ConclusionTherefore, we suppose that gazelles ’ preference and avoidance for habitat selection is due to the unique seasonal characteristics of climate, topograghy, food and disturbance in summer and reflects its preference and trade-off for the actual habitat and resource distribution in the protected area.
Identification and evaluation of F1 hybrids between Rosa ‘Sanka’×R. multiflora var. cathayensis
Wu Yuying, Zhou Xuan, Xu Tingliang, Chang Zheng, Yi Xingwan, Gao Huabei, Zhao Hongxia, Wang Jia, Cheng Tangren, Zhang Qixiang, Pan Huitang
2019, 41(3): 124-133.   doi: 10.13332/j.1000-1522.20180255
[Abstract](11) [FullText HTML](8) [PDF 1012KB](3)
Abstract:
ObjectiveIn this study, we used modern rose cultivars ‘Sanka’ (2n = 4x = 28) and R. multiflora var. cathayensis (2n = 2x = 14) as parents to obtain F1 population through hybridization, and the hybrids were identified and evaluated. This will provide an important basis for improving the modern rose by R. multiflora var. cathayensis.MethodWe obtained 91 F1 hybrids derived from the combination of R. ‘Sanka’ × R. multiflora var. cathayensis. The hybrids were identified by morphological observation, flow cytometry, karyotype analysis and SSR markers.ResultThe results showed that, F1 hybrids integrated the morphological characteristics of both ‘Sanka’ and R. multiflora var. cathayensis, and the coefficient of variation ranged from 19.71% to 67.13%. Flow cytometry analysis showed that the 70 of the 91 hybrids were triploids (2n = 3x = 21), 18 were tetraploid, 1 was hexaploid (2n = 6x = 42), and 2 unable to be determined. Karyotype analysis of 21 non-triploid identified by flow cytometry analysis and 3 triploid hybrids of continuous flowering revealed that the chromosome number of 18 hybrids were consistent with the results of flow cytometry analysis. The accuracy of flow cytometry for measuring ploidy was 93.41%. From 26 pairs of SSR primers, 7 pairs of polymorphic primers were selected to amplify 2 tetraploids and 1 hexaploid, and found that the two tetraploid hybrids were false hybrids, and the hexaploid were true hybrids.ConclusionKaryotype analysis and SSR analysis were more accurate than morphological observation and flow cytometry to identify hybrids. The results provide important basis for rose polyploidy breeding, and provide new germplasm materials for the improvement of modern rose using R. multiflora var. cathayensis.
Development of intelligent programming system for numerical controlled mortise and tenon joint
Tang Lin, Guan Huiyuan, Wang Ning, Dai Pengfei
2019, 41(3): 134-142.   doi: 10.13332/j.1000-1522.20180414
[Abstract](4) [FullText HTML](2) [PDF 1124KB](0)
Abstract:
ObjectiveCode generation is the key to realize the numerical controlled (NC) machining of mortise and tenon joint, but the traditional NC programming is difficult, inefficient and over-dependent on CAM software. So it is necessary to develop an intelligent programming system for the numerical controlled mortise and tenon joint.MethodFirstly, the joints were classified by group technology, and a parameterized artifact database was established based on the extraction of joints ’ dimension parameters. Intelligent dimension matching was implemented by transforming plentiful process experience and existing research results into functions. Then, the standard NC code template of each joint was set up according to template technology, and these standard NC code templates constituted the module of toolpaths. We used expression algorithm to complete the instantiation of code templates. The change of machining parameters leaded to the change of values in NC code templates, so the NC codes can be programmed automatically, the parameterized and modularized NC programs can be achieved. Based on the principle of post-processing, the compensation of NC code was achieved through the add-in that can calculate the compensation value automatically. At last, on the basis of those researches, an intelligent programming system for numerical controlled mortise and tenon joint was developed by the visualization program VB.ResultCombined with the actual authoring of three-way mitered joint part, the feasibility of the system was verified. By checking the dimensions of the processed part, the accuracy of the machining codes generated by the system was also verified.ConclusionThis system is simple, stable and efficient. It can simplify the programming process and generate program NC codes automatically. The system is helpful to transform processing of mortise and tenon joint from experience type to knowledge-based type.
Role of CMLs in regulating the competition of plant pollen pollination
Gao Shumin, Yang Muhan, Zhu Yuanyuan, Zhou Yan
2019, 41(3): 143-150.   doi: 10.13332/j.1000-1522.20180375
[Abstract](5) [FullText HTML](5) [PDF 722KB](0)
Abstract:
ObjectivePollen germination and pollen tube growth play a critical role in reproductive process of flowering plants. Pollen germination and pollen tube growth is regulated directly or indirectly by many factors, such as calmodulin-like proteins (CMLs). However, very little research has focused on the function of CMLs till now. The aim of this paper is to reveal the role of CML proteins in the competitive advantage of pollen, and to provide a theoretical foundation for further exploring the molecular mechanism of CMLs in plant pollen competitive advantage.MethodThis paper comprehensively summarizes the structure, expression level, cell localization and mechanisms of CMLs proteins involved in the regulation of pollen germination and pollen tube growth, and analyzes the pollen competition phenomena in different plants.ResultThere were about four conserved EF-hand domains in CMLs. When CMLs bind to Ca2+, its conformation changes enhanced its binding ability to downstream receptor proteins, and initiated Ca2+ dependent cascade signal amplification effect, which resulted in changes in Ca2+ concentration in pollen tube and influenced the formation of Ca2+ concentration gradient from germination aperture to the top of pollen tube, thus regulating the normal growth of pollen tube. The expression of CML proteins can also affect the concentration of Mg2+, NO and the binding of Ca2+ to EF-hand domains and the orientation of pollen tube growth. Different CML proteins had different physiological functions. Among them, CML proteins involved in pollen germination and pollen tube growth were mainly expressed in plant floral organs. During fertilization of some flowering plants, different ploidy pollens may have different germination rates and growth rates due to differences in genome size or nutrient content.ConclusionCMLs proteins may affect the process of pollen germination in vivo by differentially expressing in different ploidy pollens, and make them show competitive advantage in a certain period of time.
Progress of wood based metal functional composites
Chai Yuan, Fu Feng, Liang Shanqing
2019, 41(3): 151-160.   doi: 10.13332/j.1000-1522.20180382
[Abstract](6) [FullText HTML](6) [PDF 1143KB](2)
Abstract:
In order to compensate for the inherent defects of wood and change the physical, mechanical, chemical and structural characteristics of wood, the research on the wood functional modification has never been interrupted. All the technologies, including the initial wood-plastic technology, impregnation technology, acetylation technology, heat treatment technology, compression and bending technology, bleaching and dyeing technology, as well as the application of microwave processing technology, have greatly promoted the development of wood science. With the deepening research on the basic physical and chemical properties of wood, new wood-based composite materials have also been applied, such as wood based metal functional composite, which endow the wood new applications, including electromagnetic shielding, heat conduction and electrical conductivity. According to the functional properties of wood based metal functional composites, which can be divided into three categories: electromagnetic shielding wood, metallized wood and impregnated magnetic wood. Electromagnetic shielding wood, mainly used for space with radiation, such as floor, slab and siding, is mainly prepared by electroless metal plating and gluing metal materials. Electroless metal plating is a chemical method for metallizing the surface of wood. Gluing metal is a method of combining metal material with wood by the help of adhesive. The electromagnetic shielding effectiveness of wood can be improved, but the damage of electromagnetic radiation to the human body reduced by all methods above. Metallized wood is a composite material formed by impregnating low-melting alloy into wood cell in a melting state, then cooling and solidifying. The melting metal uses a wood conduit as a transmission path to make the composite material compressive strength, hardness, thermal conductivity, electrical conductivity and resistance. The magnetic fluid was impregnated into the wood under a certain pressure to produce the impregnated magnetic wood, which can be used in magnetic recording, memory, electromagnetic conversion, shielding, protection, medical and biotechnology, separation and purification, and many other areas. At present, the research on wood based metal functional composites mainly focuses on the electroless plating of wood surface, but not penetrate into the interior of wood. The metal can be penetrated into the wood to form metallized wood, but the substrate used in the existing research has not been treated, the permeability of the metal is low. The focus of the next step is how to improve the substrate and then maximize the performance advantages of the metallized wood, as well as further promote the application range of wood based metal functional composite materials. In this paper, the research status of three different functional composite materials (electromagnetic shielding wood, metallized wood and impregnated magnetic wood) was summarized. Meanwhile, we also proposed the shortcomings of wood-based metal functional composites in the existing research, and looked forward to the application and development prospects of metallized wood in more fields.

Establishment Time:1979

CN 11-1932/S

ISSN 1000-1522

Supervisor:Sinopec Research Institute of Petroleum Engineering

Sponsors by:

LinksMore+