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2021, 34(4): -1-0.
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miRNAs Analysis of Poplar Root Tips Treated with Nitrate- or Ammonium-Nitrogen
KAN Dong-xu, LU Yan, WU Jiang-ting, CHEN Xin, SHI Wen-guang, ZHOU Jing
2021, 34(4): 1-12. doi: 10.13275/j.cnki.lykxyj.2021.04.001
Objective To screen the differentially expressed miRNAs from root tips of poplar through small RNAs high-throughput sequencing technology, to study the regulation mechanism of miRNAs and their target genes related to nitrate or ammonium responses and try to identify and explain the morphological characteristics of poplar root tips growth and development. Method Using root tips of poplar as the research object, the high-throughput sequencing technology for small RNA library construction was applied to reveal the genetic differences of nitrogen forms in miRNA level, and to identify the differentially expressed miRNAs. Meanwhile, degradation sequencing technology was used to identify the miRNA target genes, and the functional annotation, clustering and metabolic pathway enrichment of the differentially expressed target genes were analyzed. Through conjoint analysis, the regulation network of miRNA-target pairs in the root tips of poplar was clarified under different nitrogen forms treatments. Result 523 known and 42 novel miRNAs were identified from miRNA libraries. A total of 96 miRNAs with significantly different expression were identified. Under ammonium treatment, 44 miRNAs were upregulated and 52 downregulated. Among them, the upregulation of vvi-MIR399d-p3_1ss13GA and the downregulation of novel miRNA PC-5p-35885_222 were the most significant. The KEGG pathway analysis of differentially expressed target genes of miRNAs in the libraries showed that some significantly different expression target genes were involved in nitrogen response pathway. Real time fluorescence quantitative PCR confirmed 7 randomly selected miRNA-target pairs, and the results were consistent with the sequencing data. Conclusion miRNAs and their target genes may play important roles in nitrogen response of poplar root tips after treatments with different forms of nitrogen, thus the root length under nitrate-nitrogen treatment is almost twice that under ammonium-nitrogen treatment.
Genetic Differentiation and Genetic Diversity of Hippophae rhamnoides subsp. sinensis and H. rhamnoides subsp. yunnanensis
WANG Tian-yi, XU Yue, WANG Luo-yun, ZHANG Jian-guo, ZENG Yan-fei
2021, 34(4): 13-21. doi: 10.13275/j.cnki.lykxyj.2021.04.002
Objective To evaluate the genetic differentiation between Hippophae rhamnoides subsp. sinensis and H. rhamnoides subsp. yunnanensis, to clarify their geographic boundary in ambiguous areas, and estimate the genetic diversity within each taxon. Method 18 Simple Sequence Repeat (SSR) makers were used to analyze the genetic variation of 32 H. rhamnoides subsp. sinensis and H. rhamnoides subsp. yunnanensis populations. Phylogenetic analysis and cluster analysis were conducted to identify the grouping of these populations according to their morphology and geographic distribution. The genetic differentiation coefficients were calculated among populations within each taxon, and the Analysis of Molecular Variance (AMOVA) was conducted to estimate the variance components at different levels. The genetic diversity parameters, such as allele number (NA), effective allele number (NE), observed heterozygosity (HO), expected heterozygosity (HE) and inbreeding coefficient (FIS), were calculated for each taxon and each population. Result The genetic diversity of H. rhamnoides subsp. sinensis was higher than that of H. rhamnoides subsp. yunnanensis. Compared with H. rhamnoides subsp. yunnanensis, H. rhamnoides subsp. sinensis had lower genetic differentiation coefficients between populations; and AMOVA analysis found that the percentage of variance among populations within taxa was lower in H. rhamnoides subsp. sinensis (25.5%) than in H. rhamnoides subsp. yunnanensis (36.7%), suggesting that the differentiation among geographical populations of H. rhamnoides subsp. sinensis was lower than that of H. rhamnoides subsp. yunnanensis, and the genetic variation of H. rhamnoides subsp. sinensis was mainly between individuals. Phylogenetic analysis suggested that all individuals of H. rhamnoides subsp. sinensis mainly clustered into one clade, while several highly differed clades were found in H. rhamnoides subsp. yunnanensis, and the subsp. sinensis was closer with Sichan subsp. yunnanensis clade than with others. By population genetic cluster analysis, all H. rhamnoides subsp. sinensis and H. rhamnoides subsp. yunnanensis individuals were divided into two major branches, and hybridization between them were found in several populations, especially in populations Hongyuan and Songpan that located in northern Sichuan province. Conclusion H. rhamnoides subsp. sinensis has higher genetic diversity and lower genetic differentiation than that of H. rhamnoides subsp. yunnanensis. Hongyuan and Songpan counties in northern Sichuan province are most likely to be the distribution boundary between H. rhamnoides subsp. sinensis and H. rhamnoides subsp. yunnanensis.
The Interspecific Water Relations of Juglans Regia-Woad/Sickle Senna Agroforestry System in a Hilly Area of Southern Taihangshan Region
HE Chun-xia, CHEN Ping, ZHANG Jin-song, MENG Ping, SUN Shou-jia, GAO Jun
2021, 34(4): 22-31. doi: 10.13275/j.cnki.lykxyj.2021.04.003
Objective The objective of this study is to find out the water relations (competition or facilitation) of various fruit-crop agroforestry systems and to provide theoretical basis for agroforestry configuration in southern Taihangshan region. Method In order to quantify the interspecific water relation, the stable carbon isotope technique and the thermal dissipation probe (TDP) method were used to study the water use efficiency (WUE), water consumption and soil water content of component species in a walnut (Juglans regia)-woad (Isatis tinctoria)/sickle senna (Senna tora) agroforestry system. Result The results showed that the soil water content of agroforestry system was greater than that of sole walnut, sole woad and sole sickle senna systems, and the sole walnut system had higher soil water content than sole crop systems. The WUE of woad system decreased with their growth, while that of sickle senna system increased with their growth in 2012, but decreased in 2013. The sole walnut and sole woad/sickle senna systems presented a larger water consumption than that in agroforestry system. The water consumption of sole walnut were respectively 1.11 and 1.07 times that of intercropped walnut in 2012 and 2013. The water consumption of sole woad and sole sickle senna systems were 1.83 and 2.26 times that of intercropped woad and intercropped sickle senna in 2012, and 1.96 and 2.60 times in 2013, respectively. Walnut consumed more water than the crops in agroforestry system in 2013, and the water use was equivalent between trees and crops in 2012. Woad and sickle senna in the tree row consumed more water than that at other places (but the water consumption of both the crops was slightly lower than in other places on flowering stage in 2013). The total income of the agroforestry system was respectively 1.49 and 1.24 times that of sole walnut and sole crop systems in 2012, and 1.24 and 1.47 times in 2013. Conclusion In these agroforestry systems, walnut improved water condition, and reduced total water consumption comparing to sole woad/sickle senna system. The land equivalent ratio of the agroforestry system achieved to 1.9. Although the production of walnut fruit decreased a little, the total income increased by 1.2 times comparing to sole systems when adding the income of the medicine harvest. It is concluded that walnut-woad/sickle senna intercropping system is suitable at this area.
Cloning, Expression and Protein Interaction of ThSHR3 Genes in Taxodium hybrid ‘Zhongshanshan406’
XUAN Lei, WANG Zhi-quan, YIN Yun-long, HUA Jian-feng
2021, 34(4): 32-39. doi: 10.13275/j.cnki.lykxyj.2021.04.004
Objective To obtain the SHORT-ROOT 3 gene (ThSHR3) from Taxodiumhybrid 'Zhongshanshan 406' by cloning and to identify and analyze its characteristics and related functions based on proteome and transcriptome data of adventitious roots of Taxodium hybrid 'Zhongshanshan406'. Method The full length of ThSHR3 gene was cloned by RACE technology and the bioinformatics characteristics were analyzed by bioinformatics software. Semi-quantitative PCR and real-time quantitative PCR were used to detect the expression characteristics of ThSHR3. The subcellular localization of ThSHR3 protein was confirmed by transient expression of protoplasts, and the protein interaction of ThSHR3 was verified by bimolecular fluorescence complementation (BiFC) technique. Result The authors assembled a full-length of ThSHR3 gene, which consists of 2 019 bp nucleotide sequence, containing a 1 446 bp open reading frame (ORF) encoding 482 amino acid proteins. ThSHR3 protein has conserved GRAS domains in the C-terminal, such as LHRI, VHIID, LHRII, PFYRE and SAW. Phylogenetic analysis showed that ThSHR3 belongs to the SHR subfamily. ThSHR3 gene showed a gradually increased expression pattern in the development of adventitious root. Transient expression analysis of protoplasts showed that ThSHR3 protein was located in the nucleus. Further BiFC experiment revealed that ThSHR3 protein and ThSCR protein which also belongs to GRAS protein family can interact with each other in nucleus. Conclusion This study indicates that ThSHR3 plays an important role in regulating the development of adventitious roots of Taxodium hybrid 'Zhongshanshan 406'.
Outer Upper Crown Profile Simulation and Visualization for Cunninghamia lanceolata Based on UAV-borne LiDAR Data
XU Zhi-yang, LIU Hao-dong, CHEN Yong-fu, CHEN Qiao, LI Hua-yu, WANG Juan
2021, 34(4): 40-48. doi: 10.13275/j.cnki.lykxyj.2021.04.005
Objective To obtain the upper crown structure parameters (crown vertex, tree height, crown width and upper crown length) and to simulate and visualize the outer upper crown profile of Cunninghamia lanceolata based on Unmanned Aerial Vehicle (UAV) LiDAR data in order to provide reference for recognizing the individual tree crown characteristics and tree species. Method By means of local maximum method in LiDAR360 software, the Pit-Free CHM (canopy height model), which was generated from LiDAR point clouds by LASTools open source software, was used to detect the crown vertex. Then point clouds segmentation based on CHM seed points was carried out with the use of the previous crown vertex. After that, the individual tree point clouds was selected in ArcGIS software manually, and the samples of less segmentation were purified automatically by python programming (the entire following work was done automatically by programming), then the individual tree point clouds data was ready. Secondly, the upper crown structure parameters (crown vertex, tree height, crown width and upper crown length) were extracted from purified individual tree point clouds. Thirdly, according to certain interval, the purified individual tree point clouds were hierarchically sliced to get two outer upper crown profile parameters (relative depth into the crown of interest, branch length) as model variables by width percentile method. By the way of stratified relative depth into the crown of interest, the abnormal outer upper crown profile parameters of modeling and validation samples were removed according to the method of 3 times standard deviation respectively. Three candidate basic models, quadratic polynomial, power function and exponential function, were selected for model fitting and verification. Finally, the optimal fitting model was used to visualize the 3D scene at the sample plot scale. Result The results showed that the accuracy of tree detection was 79.63%. The correlation of the extracted values to the measured data was analysed. The R2 of tree height, crown radius was 0.890 5 and 0.845 6. The fitting R2 of the three models were 0.807 0, 0.817 0, and 0.806 0, respectively. The power function fitted the outer upper crown profile for C. lanceolata better. Conclusion For performing tree species crown shape correctly, it is of great importance to get and purify the individual tree point clouds effectively on the condition that the stand density is very high. The outer upper crown profile model for C. lanceolata based on UAV-LiDAR can perform the crown shape well. It can provide a useful basis for the recognization of C. lanceolata.
Development of Volume-derived Biomass Models for Three Coniferous Forest Types in China
ZENG Wei-sheng
2021, 34(4): 49-57. doi: 10.13275/j.cnki.lykxyj.2021.04.006
Objective Stand-level biomass models/tables are important quantitative tools for implementing forest resources inventory and monitoring. Developing volume-derived biomass models for three coniferous forest types in China is not only an exploration of methodology, but also provides reference for practice. Method Based on field measurement data of 3000 sample plots from three coniferous forest types (Larix spp., Pinus tabulaeformis and Cunninghamia lanceolata) in China, the volume-derived biomass models were developed through ordinary regression (OR), weighted regression (WR), and segmented modeling (SM) approaches; and the relevant published models were compared. Result The coefficients of determination (R2) of the volume-derived biomass models for the three coniferous forest types based on WR approach were between 0.912~0.937, the mean prediction errors (MPEs) were between 0.93%~1.58%, the total relative errors (TREs) were within ± 2.0%, and the TREs for validation were within ± 2.6%. The R2 values of the models based on SM approach were between 0.915~0.953, the MPEs were between 0.81%~1.55%, the TREs were within ± 0.3%, and the TREs for validation were within ± 1.3%. Using the data of this study to test the applicability of the relevant published biomass models for the three coniferous forest types, the TREs were 11.62%, −25.19% and −6.26%, respectively, and the errors for different biomass classes were quite higher, even systematic deviations appeared, and seriously exceeded the allowable error. Conclusion The stand-level biomass per hectare is linearly related to volume stock. The WR approach should be used preferentially when developing volume-derived biomass models, and the sample plots should be much enough and evenly distributed. When one model is not enough to obtain accurate estimates for different biomass classes perfectly, the SM approach can be used. The volume-derived biomass models developed in this study have low MPEs, indicating that they can be applied in practice.
Dynamic Analysis on Economic Benefit, Growth and Production of Eucalypt Plantations with Different Initial Densities
ZHANG Cheng, OUYANG Lin-nan, CHEN Shao-xiong
2021, 34(4): 58-65. doi: 10.13275/j.cnki.lykxyj.2021.04.007
Objective To study the economic benefit of Eucalyptus plantations with different initial planting densities by monitoring their growth. Method Three initial planting density treatments were tested, i.e. 1250 tree·hm−2, 883 tree·hm−2 and 667 tree·hm−2. The data of 16 years' growth were collected and analyzed to calculate the timber yield, mean annual increment (MAI), internal rate of return (IRR) and net present value (NPV). Result It is showed that the DBH of the plantation with initial planting density of 1250 tree·hm−2 was significantly different from that with the initial planting densities of 883 and 667 tree·hm−2 in the growth process (p < 0.05). Meanwhile, there was no significant difference in stand volume among different initial planting densities (p > 0.05). The largest timber yield and MAI of middle diameter timber were at the plantation with initial planting density of 883 tree·hm−2 in the range of 7th to 12th years and the 16th year, followed by the plantations with initial density of 667 tree·hm−2 and 1250 tree·hm−2. At the 16th year, the timber yield of middle diameter timber of the plantation with initial planting density of 1250 tree·hm−2 exceeded that of the plantation with initial planting density of 667 tree·hm−2. Large diameter timber began to appear at the plantation with initial planting density of 883 tree·hm−2 at the 16th year. The harvesting rotations of the plantations with initial planting densities of 1250, 883 and 667 tree·hm−2 were 7, 9 and 9 years respectively. At the 9th year, The NPV of the plantations with initial planting densities of 1250 and 883 tree·hm−2 reached the peak, while that of 667 tree·hm−2 was at the 8th year, The peak NPVs of the plantations with initial planting densities of 1250, 883 and 667 tree·hm−2 were 30994, 40193 and 31288 CNY·hm−2 and the peak IRRs were 37%, 41%, 42% respectively. Conclusion Overall, the plantation with initial planting density of 883 tree·hm−2 has the highest NPV and IRR, as well as higher growth potential, followed by that with initial planting densities of 667 tree·hm−2 and 1250 tree·hm−2.
Effects of Afforestation on Soil Nutrient and Carbon Sequestration in Reclaimed Area of Opencast Coal Mine, Wuhai, Inner Mongolia
YAN Jie, YU Xiao-juan, TANG Ming, DUAN Wen-yan, LI Xin, HAO Yi-ming, SHENG Min
2021, 34(4): 66-73. doi: 10.13275/j.cnki.lykxyj.2021.04.008
Objective To better understand the variation rule of soil carbon pool composition and soil nutrient before and after afforestation and the influence of soil nutrient to soil carbon pool composition in reclaimed mine. Method This study was conducted in grassland and forest land of Populus alba var. pyramidalis in reclaimed mine to explore the variation and relation of soil inorganic carbon pool, active organic carbon pool, chronic organic carbon pool, inert organic carbon pool and soil nutrient, and contribution of soil nutrient to soil carbon. Result The results showed that the contents of soil nutrients and soil carbon increased after afforestation in reclaimed mine. The content of soil total nitrogen, available nitrogen, total phosphorous, available phosphorous, total potassium and available potassium in forest land increased by 29.27%, 17.21%, 23.08%, 27.04%, 51.18% and 53.19% than in grassland, while the content of soil nitric nitrogenin forest land decreased by 71.84% than in grassland. The content of soil organic carbon, particle organic carbon, non-particle organic carbon, dissolved inorganic carbon, dissolved organic carbon, microbial biomass carbon and reducing sugar carbon in forest land increased by 50.35%, 62.46%, 22.56%, 113.53%, 230.23%, 274.63% and 72.54% than in grassland. There was a significant positive correlation between soil inorganic carbon pool and active organic carbon pool, but no significant correlation with chronic organic carbon pool and inert organic carbon pool. The soil nutrient factors accounted for 40.7% of contribution rate to soil carbon sequestration. The correlation analysis also showed that there was a significant positive correlation between soil total potassium, available potassium and carbon pool composition. Conclusion The comprehensive analysis shows that afforestation can improve the soil nutrient status and carbon sequestration significantly in reclaimed area of Wuhai opencast coal mine. This conclusion can be used as a reference for further study on the improvement of soil quality and the restoration of ecological function in reclaimed mine of arid desert areas.
Spatial Variability of Soil Moisture under Typical Vegetation Types on Karst Dolomite Slope in Dry Season
WU Ze-yu, XUE Liang, ZHANG Xian-song, LI Jin-yao, LI Sheng, WANG Jia
2021, 34(4): 74-83. doi: 10.13275/j.cnki.lykxyj.2021.04.009
Objective To investigate the spatial variation and distribution of soil moisture with typical vegetation types in Karst dolomite area in order to provide data for rapid vegetation restoration and ecological reconstruction. Method Considering soil of karst dolomitic grassland, shrub, plantation and natural secondary forest in Puding County of Guizhou Province as research object, soil samples were collected in two layers (0-10 cm and 10-20 cm) by using grid method in November 2019 to determine the soil bulk density, porosity and water content. The soil moisture content and spatial variation characteristics were analyzed by using classical statistics and geostatistics. Result (1) Significant differences were found in soil moisture content among different vegetation types (p < 0.01), but there was no significant difference between grassland and plantation. The soil moisture content decreased in the order as followed: natural secondary forest > grassland > plantation > shrub. The maximum (40.22%) was 2.16 times of the minimum (18.59%) and the coefficient of variation ranged from 5.34% to 29.42%. (2) The optimal model of semi-variogram of soil moisture in shallow layer of grassland and shrub was Gaussian model, while the others were exponential models. The range of grassland was the smallest (4.24 m), while the range of plantation was the largest (16.48 m); the sill value of shrub was the largest (14.42), and the nugget value of natural secondary forest was the largest (1.27). (3) The highest soil moisture content occurred on the uphill slope in all plots, and the shallow soil moisture content was higher than the deep one. Furthermore, the same vegetation type had similar spatial distribution pattern in the vertical direction. (4) The soil moisture content was positively correlated with total soil porosity while negatively correlated with soil bulk density. Vegetation type also affected soil moisture content to a certain extent, but not with the positive succession of vegetation. Conclusion The spatial structure of soil moisture among different vegetation types is obvious, and there has a strong spatial autocorrelation. The soil moisture content of the natural secondary forest is the highest among the four types; the soil moisture continuity is the worst in grassland and the best in the plantation; the distribution of soil moisture in the same vegetation type is similar in the vertical direction. In the same weather conditions, the vegetation type, slope, soil bulk density and porosity might be the important factors affecting the distribution of soil moisture content.
The Relationships between the Dust-holding Capacity and the Leaf Surface Structure & Particle Size in Five Evergreen Tree Species Locates in Hangzhou
LI Hai-mei, DANG Ning, YU Liang-qian, ZHANG Han-dan, CHEN Guang-cai
2021, 34(4): 84-94. doi: 10.13275/j.cnki.lykxyj.2021.04.010
Objective To study the relationship between leaf dust retention capacity and leaf surface structure and particle characteristics of landscaping tree species so as provide data for screening excellent landscaping tree species and improving the dust retention effect of vegetation. Method Five common evergreen tree species (Loropetalum chinense var. rubrum, Osmanthus fragrans, Pittosporum tobira, Photinia × fraseri and Cinnamomum camphora) in Fuyang District of Hangzhou were studied. The samples were collected from industrial zone, traffic zone and clean zone. The dust-holding capacity of these plants was recorded by weight difference method, the leaf surface structure, particle morphological structure and elemental composition of dust were observed by SEM-EDS. The relationship between leaf surface structure, particle morphology, particle size and dust holding capacity was analyzed. Result The results showed that the leaf dust retention capacity of the five tree species in the industrial area followed the order of L. chinense var. rubrum (7.36 g·m−2) > O. fragrans (6.53 g·m−2) > Pittosporum tobira (6.44 g·m−2) > Photinia × fraseri (4.28 g·m−2) > C. camphora (2.59 g·m−2), and the same pattern was observed in traffic zone and clean zone. The total PM10 retention amount of these tree species reached to 11.34 g·m−2, the order of retention capacity of these tree species was L. chinense var. rubrum, Pittosporum tobira, Photinia × fraseri, O. fragrans and C. camphora. The air quality in these zones showed obvious effect on the leaf retention capacity, followed the order of industrial zone > traffic zone > clean zone. The particles trapped in plant leaves consisted of regular particles and irregular mineral particles, which mainly included spherical, oval, fluffy polymer, chain polymer, irregular block and irregular sheet. Conclusion L. chinense var. rubrum shows the strongest dust-retention ability, while C. camphora shows the weakest retention of particulate matter. The percentage of coarse particles trapped in the leaves are higher than that of the fine particles. The particles trapped in leaves are mostly soot aggregates and minerals particles
Genetic Relationship Analysis and Fingerprint Construction of Carya illinoensis Varieties
HE Xu-dong, ZHENG Ji-wei, TIAN Xue-yao, JIAO Zhong-yi, DOU Quan-qin
2021, 34(4): 95-102. doi: 10.13275/j.cnki.lykxyj.2021.04.011
Objective Since the morphological appearances among pecan (Carya illinoensis) varieties are extremely similar due to the narrow genetic basis of the crossing parents, making it difficult to precisely identify by phenotypic characters only, this study aims at elucidating the genetic relationships and constructing fingerprint among pecan varieties, and establishing a rapid, efficient, stable, and accurate genotyping system for pecan based on fluorescent SSR markers combining high throughput capillary electrophoresis technology. Method A total of 54 SSR primers were selected from pecan and related species for preliminary screening and ten of them were labeled by fluorophore for further analysis. 25 pecan varieties were genotyped by capillary electrophoresis, and the number of allele (A) and polymorphic information content (PIC) of each locus was scored and calculated by software. The fingerprint of pecan varieties was constructed using different combination of SSR markers and the genetic relationships among varieties were also investigated through cluster analysis. Result A total of 68 alleles were detected by ten pairs of SSR markers with an average of 6.8 alleles. The most (12 alleles) were screened at the Cc19 locus and the least (3 alleles) were obtained at the BFU-Jr locus. The polymorphic information content varied with locus from 0.2910 to 0.8435 (mean 0.5883). With the four optimal pairs of core primers, all of the 25 pecan varieties could be completely distinguished by the primer combinations of Cc19, PM-GA31, PM-CIN4, and PM-GA41. The cluster analysis demonstrated that the similarity coefficient of the 25 pecan varieties varied from 0.62 to 0.99. Two main clades were formed, in which some related varieties could be clustered together and some of them could not be completely corresponding with genetic background. Conclusion Compared with traditional dominant markers and polyacrylamide gel electrophoresis, the genotyping technology consisting of fluorescence-labeled SSR primers and capillary electrophoresis is quite practical with high throughput, fast speed, and stable and reliable result. The different varieties can be efficiently identified by the combination of core markers. In order to deeply reveal the real architecture of genetic relationship among pecan varieties, it is suggested that more crossing parents should be added and a certain number of more efficient markers covered the whole genome need to be selected during the analysis of genetic relationship.
Site Classes Grouping Method Based on Quantile Regression of Chinese Fir Plantations
ZHANG Bo, CHEN Ke-yi, ZHOU Lai, Sajjad Saeed, ZHANG Ya-xin, SUN Yu-jun
2021, 34(4): 103-110. doi: 10.13275/j.cnki.lykxyj.2021.04.012
Objective To optimize the efficiency of the site classes grouping strategy and improve the accuracy of site classification, site classes grouping model and to propose a site quality evaluation method based on quantile regression model. Method The traditional methods (standard deviation adjustment method) and quantile regression method were used to classify and evaluate the site quality of 418 pure Chinese fir (Cunninghamia lanceolata) forests at Jiangle Forest Farm in Sanming City, Fujian Province, and the results were compared. The baseline age (A0) was determined based on the high growth of the stand tree and the maturity of the Chinese fir plantations. Using standard deviation adjustment method and according to the standard age tree height value and exponential interval, the site classes curve cluster was constructed and divided into 8 levels. The quantile regression method was based on the guiding curve. According to the data distribution characteristics, 8 quantile points (0.01, 0.05, 0.15, 0.30, 0.70, 0.85, 0.95, and 0.99) were specified to construct the quantile regression model, and the quantile curves were used to divide the site classes. Result The results showed that the quantile regression model could quickly and accurately determine the site type of the pure Chinese fir plantation, based on the principle that the sum of squares (or the absolute value of the difference) between the average stand height and the prediction stand height of each site class curves is the smallest. The evaluation results of the site quality were not significantly different from the traditional methods. Conclusion The quantile regression model describes, classifies, regresses, predicts and verifies the correlation between stand growth and site quality from the perspective of data. The quantile regression curve cluster, based on the guided growth model, intuitively reflect the stand high changing under the different site class, so as to comprehensively and accurately predict the productivity of Chinese fir plantations.
Study on Phenotypic Variations of Elite Trees in Natural Populations of Hippophae rhamnoides L. subsp. sinensis Rousi in Shanxi
GUO Xue-bin
2021, 34(4): 111-119. doi: 10.13275/j.cnki.lykxyj.2021.04.013
Objective To study the variation of phenotypic traits and the relationship with ecological factors in natural population of Hippophae rhamnoides L. subsp. sinensis Rousi in Shanxi Province, so as to provide technical support for germplasm resource collection, preservation and breeding of H. rhamnoides. Method 10 phenotypic traits were investigated for 110 superior individuals in 11 natural populations of H. rhamnoides subsp. sinensis from Shanxi, China. The phenotypic variation among populations was studied using analysis of variance, coefficient of variation. The principal component analysis and cluster analysis were used to classify the population. Result The correlation analysis revealed the correlation between ecological factors and phenotypic traits. The results showed that 10 phenotypic traits of H. rhamnoides subsp. sinensis were significant (p < 0.05) or extremely significant (p < 0.01) among elite trees of different populations. The average variation coefficient of elite trees in natural populations was 5.23%~37.42%. There were significant positive correlations (p < 0.01) between the transverse and longitudinal diameter of fruit, the weight of a hundred fruits, the thousand-grain weight of seed and the branch length of the current year, while negatively correlated with fruit shape index and fruiting density (p < 0.01). The thousand-grain weight was positively correlated with the transverse and longitudinal diameter of fruit, and the weight of a hundred fruits (p < 0.01). Fruit shape index, fruit stalk length, branch length of the current year and latitude factor were extremely significantly (p < 0.01) and negatively correlated; the transverse and longitudinal diameter of fruit, the weight of a hundred fruits, the thousand-grain weight of seed, the branch length of the current year and altitude factor showed a extremely significant (p < 0.01) and positive correlation. The results of principal component analysis showed that the comprehensive score of elite trees in Xixian population was the highest, while that of Wuzhai population was the lowest. The cluster analysis was carried out using Euclidean distance between populations, and the elite trees of 11 populations were divided into 4 groups. The results revealed the phenotypic traits of elite trees of H. rhamnoides subsp. sinensis in Shanxi did not form the rule of continuous variation, and had the characteristics of random variation. Conclusion There are abundant phenotypic variations among elite trees in natural populations of H. rhamnoides subsp. sinensis in Shanxi. The comprehensive traits of elite trees in Xixian populations are the best, which can be referred to as a key area for collection of elite germplasm resources of H. rhamnoides subsp. sinensis.
Effects of Different Tree Species Plantations on Soil Bacterial Community Diversity in South Subtropical China
QIN Xin-hao, LIANG Yan, CHENG Chao-fan, QIN Lin
2021, 34(4): 120-127. doi: 10.13275/j.cnki.lykxyj.2021.04.014
Objective To examine the effects of plantations composed of different tree species on soil bacterial community diversity in south subtropical China, and to provide reference for the selection of tree species for the adaptive management strategy of plantation ecosystem in this region. Method The richness, Shannon index, Simpson index and evenness of soil (0-20 cm) bacterial communities under four indigenous tree species (Pinus massoniana Lamb., Castanopsis hystrix (Lamb.) Hook., Mytilaria laosensis Lec. and Michelia macclurei Dandy) plantations and the plantation of exotic tree species Eucalyptus urophylla × E.grandis were studied by using PCR-DGGE technology in the Experimental Center of Tropical Forestry of Chinese Academy of Forestry in Pingxiang, Guangxi. Moreover, the relationship between soil bacterial community diversity and soil physichemical properties was discussed. Result No significant difference in diversity of soil bacterial communities was observed among the five types of plantations (p > 0.05). The bacterial community diversity of the five plantations was significantly and positively correlated with total nitrogen and total phosphorus (p < 0.05). Conclusion There is no significant difference between the native tree species plantation and the exotic eucalyptus plantation in this area in view of soil bacterial community diversity.
Effects of Harvesting Intensity on Fine Root Biomass and Morphological Characteristics of Mixed Plantations of Cunninghamia lanceolata and Broadleaved Trees
WU Zhi-long, ZHOU Cheng-jun, ZHOU Xin-nian, LIU Fu-wan, CHEN Wen, LAN Jian-hua
2021, 34(4): 128-133. doi: 10.13275/j.cnki.lykxyj.2021.04.015
Objective To compare the differences in fine root biomass and morphological characteristics of mixed plantation of Cunninghamia lanceolata and broadleaved trees under different harvesting intensities, reveal the relationship between fine root growth and harvesting intensity, and provide basic data and theoretical references for the management of regional mixed plantation of Cunninghamia lanceolata and broadleaved trees. Method A mixed plantation of Cunninghamia lanceolata and broadleaved trees in northern Fujian Province in China was used as the research object. Selective harvesting at medium intensity (34.6% removal of growing stock volume), high intensity (48.6%), at extra-high intensity (67.6%), and clear-cut harvesting (100%) were conducted and non-cutting as the control in August 2011. After 5 years of natural recovery, the basic data of biomass and morphological characteristics of living fine root (≤ 2 mm) of tree species were collected from two soil depths (0-10 cm and 10-20 cm) via root drilling methods. The influence of harvesting intensity on the total biomass and morphological characteristics of fine root in the 0-20 cm soil layer was analyzed. Result For the total fine root biomass, non-cutting, selective harvesting at medium and high intensities were 219.35, 225.31 and 257.96 g·m−2, there was no significant difference among them (P > 0.05). But the total fine root biomass under selective harvesting at extra-high intensity and clear-cut harvesting were significantly reduced by 47.0% and 66.3% respectively compared with non-cutting (P < 0.05). For the specific root length and specific root surface area, there was no significant difference between selective harvesting at various intensities and non-cutting (P > 0.05). The specific root length and specific root surface area under clear-cut harvesting were significantly increased by 41.5% and 71.2% respectively compared with non-cutting (P < 0.05). The changes of root length density and root surface area density with harvesting intensity increasing were consistent with their change of total fine root biomass. The root length density and root surface area density under selective harvesting at extra-high intensity were significantly reduced by 51.9% and 46.9% respectively compared with non-cutting (P < 0.05). The root length density and root surface area density under clear-cut harvesting were significantly reduced by 54.9% and 49.2% respectively compared with non-cutting (P < 0.05). Conclusion 5 years after harvesting, the fine root biomass and the ability to absorb water and nutrients of the mixed plantation of Cunninghamia lanceolata and broadleaved trees can be maintained under selective harvesting at medium and high intensities, but will be significantly reduced under selective harvesting at extra-high intensity and clear-cut harvesting. From the perspective of effectively maintaining and promoting the growth of fine roots of forest trees, it is recommended that suitable harvesting intensity of similar forests should not exceed the selective harvesting at high intensity.
Relationship between Odontotermes formosanus Shiraki Infestation and Host Bark Micro-morphology and Contents of Fokienia hodginsii Henry
SHI Yu-fei, LU Ci-ding, CHEN Zhen-hong, LIANG Yun, LIN Jian-hui, LI Yuan-shun, YE Xiu-su, WU Mu-hua, LIN Qing-lan, LIANG Guang-hong
2021, 34(4): 134-140. doi: 10.13275/j.cnki.lykxyj.2021.04.016
Objective To clarify the mechanism of Odontotermes formosanus Shiraki infestation to Fokienia hodginsii Henry et Thomas with different ages in order to develop effective control measures. Method Based on the damaged degree of F. hodginsii, the micro-morphological structure of infested bark tissue from 1-, 2- and 4-year-old F. hodginsii was observed by using scanning electron microscope. Then the difference of some nutrient contents and plant secondary substances were measured and analyzed to determine the relationship between infestation degree and variation of these substances. Result One-year-old F. hodginsii had the highest infestation degree by O. formosanus, while it had the thinnest bark thickness, the lowest smoothness of waxy layer, and the lowest density of bark cracks, indicating that older host (> 1-year-old) individuals had certain physical resistance to O. formosanus. The polysaccharides, soluble protein, flavonoids and total phenols within bark of all trees showed no significant difference (p > 0.05), but the contents of soluble sugar and tannin were significantly different among the trees with different age (p < 0.05). The soluble sugar content was the highest and tannin content was the lowest in the bark of the 1-year-old F. hodginsii, while the soluble sugar content was the lowest and tannin content was the highest in the bark of the 4-year-old host, indicating the content of tannin was probably one of the key chemical factors to influence the resistance of F. hodginsii. Conclusion The damaged degree by O. formosanus is closely related to the ages of F. hodginsii, while the bark microstructure, waxy layer distribution, content of soluble sugar and tannin from different samples are significantly different, which determine conjointly their resistance to F. hodginsii.
Influence of Plant Community Characteristics on Bird Habitat of Wader in Tianfu National Wetland Park, Jiangsu Province
SHAO Jun-xue, HU Xin-xin, LI Xin, ZHOU Ting-ting, FENG Yu-qing, LIU Ning, ZHOU Min-jun, XIE Dong
2021, 34(4): 141-148. doi: 10.13275/j.cnki.lykxyj.2021.04.017
Objective To study the seasonal variation of habitat plant community characteristics and its influence mechanism on wader community in order to provide support for bird habitat management. Method From July 2019 to July 2020, the data of plant community characteristic were collected by sample method and the data of wader community were collected by line transect method in the bird habitat of Tianfu National Wetland Park, and regression model was established to study the influence mechanism by transforming variables. Principal component analysis (PCA) and cluster analysis (CLA) were used to classify the wader. Result The results of statistical analysis of the data collected from the bird habitat in Tianfu National Wetland Park showed that: (1) A total of 77 species of 72 genera and 30 families of herbaceous plants were recorded, and 230 waders of 18 species were recorded. (2) The ratio of plant community height to vegetation coverage was significantly positively correlated with the ratio of the total number of birds to the total number of wader. (3) The response degree of different functional traits of wader to the seasonal variation of plant community characteristics was different. Based on PCA and CLA, the waders were divided into 4 bird groups, among which the wader species of group 4 (medium-wing-length, medium-rictus and medium-tarsometatarsus) were more sensitively affected by the seasonal variation of plant community characteristics than the other bird groups. (4) At present, the management measures of Tianfu National Wetland Park Conservation and Management Center for all plant communities belong to non-differentiated disturbance. Conclusion The results show that the plant community characteristics of bird habitat in Tianfu National Wetland Park has significant effects on the community characteristics of wader, and the influencing mechanisms are different among different wader groups. The non-differentiated habitat management measures in the study area should be improved according to the vegetation community succession rules and the habitat requirements of the wader with different traits. It is suggested that the habitat management should accurately manage the characteristics of different plant communities according to the different habitat needs of different wader groups. it is also suggested to increase different types of habitat management measures.
Study on Reproductive Behavior of Phauda flammans (Walker) (Lepidoptera: Phaudidae)
WU Hai-pan, LIU Jun-yan, WANG Xiao-yun, LU Wen, ZHENG Xia-lin
2021, 34(4): 149-155. doi: 10.13275/j.cnki.lykxyj.2021.04.018
Objective To study the reproductive behavior of Phauda flammans (Walker) (Lepidoptera: Phaudidae) in laboratory aiming at providing basic information for population management of this species. Method The reproductive behavior and rhythms, including emergence, courtship, mating and oviposition, were observed. Result Both the male and female adult emergence occurred from 06:00 to 16:00, with the peak at 11:00−13:00. Courtship took place from 09:00 to 18:00, peaking at 11:00 to 16:00, when the males initiated searching females via crawling, flying, detecting, vibrating the antennae, or flapping wings. After locating, the males approached the female, extended claspers and attempted dorsolateral copulation. Following the successful grasp, the males aligned into a tail-to-tail or V-shape position. Most copulations initiated at 14:00−16:00, lasting 16.16 ± 0.26 hours. Both males and females only mated once in their lifetime. Oviposition often occurred from 10:00 to 14:00, during which the females laid eggs on the petioles or leaf tips of host plants, with an average number of 107.3 ± 3.0. The average hatching rate was 88.40% ± 1.60%. Conclusion P. flammans is a diurnal and monogamous moth species.
Study on the Early Growth Characteristics of Kandelia candel Plantation in Yanpu Bay, Cangnan, Zhejiang Province
LAI Hong-yun, WANG Yong-xue, ZHANG YI-han, LIANG Hai, YU Song-li, ZHANG Kai, ZHANG Li-yuan, SHUI Bo-nian
2021, 34(4): 156-165. doi: 10.13275/j.cnki.lykxyj.2021.04.019
Objective To compare the growth differences of Kandelia candel from the three provenances of Jiulongjiang and Yunxiao of Fujian Province and Shenzhen of Guangdong Province, and improve the seedling procurement and selection techniques of suitable forest land. Method Based on data from 7 sample plots, analysis of variance, multiple comparison and regression analysis were used to study the relationship between the height of Kandelia candel and the ground diameter and number of leaves. Result There were some differences in the growth of Kandelia candel in 7 sample plots, the average plant height, ground diameter and number of leaves of plot A (the landward forest land) were larger than those in plot D (the seaward forest land); the growth of plot C (the non-tidal gully forest land) was better than that in plot B (the middle landward forest land adjacent to tidal gully); and the growth of Kandelia candel in plot E (in the Spartina alterniflora region) was worse than that in plot A. The binary linear regression model of plant height, ground diameter and leave number was proved to be Y = −2.941 + 26.785X1 + 0.047X2 (R2 = 0.872, P < 0.01), the binary nonlinear regression model was proved to be Y = −356.815 + 26.396X1 + 340.407X20.01 (MS = 0.875, P < 0.01), and the unary linear regression model of plant height and ground diameter was proved to be Y = −48.961 + 89.203X1 − 23.88X12 + 2.548X13 (R2 = 0.941, P < 0.01), the unitary nonlinear model was proved to be Y = 289.888X1/(X1 + 8.913)(MS = 3.626, P < 0.01). The Kandelia candel provenance from Yunxiao was more suitable for introduction in Yanpu Bay than the other two provenances. Conclusion It is suggested that Kandelia candel forest land should be selected in the tidal zone with weak hydrodynamic force, and the habitat should be properly modified before planting in tidal ditch edge to reduce the impact of tidal current. It will take a long time to plant Kandelia candel after the Spartina alterniflora areas are cleared. Measures should be taken to reduce the stress of defaced organisms such as tide and barnacle when afforestation is carried out at the margin of marine forest. It is advisable to purchase seedlings from provenances whose climate is similar to that of the proposed planting area.
A Review of Study on Olfaction and Vision of Agrilus planipennis Fairmaire
FAN Zhi-zhi, ZHANG Zhen, ZHANG Su-fang
2021, 34(4): 166-174. doi: 10.13275/j.cnki.lykxyj.2021.04.020
Agrilus planipennis Fairmaire is an international quarantine pest. Its natural distribution area is in Northeast Asian countries, and it was discovered and caused serious damages in the United States and Canada in the early 20th century. In the 1960s, it occurred most seriously in northeast and North China, and then worsened in Tianjin, Beijing, Liaoning, Jilin and other places. It mainly damages the Fraxinus species introduced from North America, such as F. pennsylvanica Marsh, F. velutina Torr, F. americana Linn., etc. At present, the prevention and control of A. planipennis is one of the key points of forest pest control research. The sensory systems are indispensable for insect life, especially the olfaction and vision, which play a key role in the mating, oviposition, and host location of A. planipennis. This paper reviews the current research on visual and olfactory sensory mechanism, summarizes the utilization research on the vision and olfactory of A. planipennis, and lists the identification of the pheromones, plant volatiles, olfactory receptors and visual receptors of A. planipennis. This can provides a prospect for further study on the integrated mechanism of vision and olfaction of A. planipennis, in order to provide a basis for better prevention of this pest based on olfactory and visual systems.
Disturbances and Succession Laws of Main Natural Secondary Forests in Northeast China
ZHOU Chao-fan, ZHANG Hui-ru, LU Jun, ZHANG Xiao-hong
2021, 34(4): 175-183. doi: 10.13275/j.cnki.lykxyj.2021.04.021
Due to the excessive logging in the early stages, the natural forests in Northeast China were damaged to varying degrees, thus various types of secondary forests were formed. With the implementation of Natural Forest Protection Project, high-intensity commercial logging has been banned, so that most of the natural secondary forests in Northeast China have been restored to a certain content, but the whole process is slow. Understanding the succession law of secondary forest, using the ecological function of disturbance, and speeding up the succession process of the secondary forest through forest management measures has become the consensus of degraded secondary forest restoration. In this review, we introduce the ecological succession process of the main secondary forests derived from the three zonal top communities of Larix gmelinii forest, broadleaved Pinus koraiensis forest and Mountain spruce-fir forest in Northeast China, as well as the influence of interference on the succession process of secondary forests. It shows that artificial interferences may have both advantages and disadvantages on the succession of secondary forests, but most natural interferences are not conducive to the succession of secondary forests. Making good use of artificlal interferences such as logging, replanting and fire can effectively promote the succession process of secondary forests. Full cycle management of secondary forest successionandthe mechanism of natural disturbance on the succession of secondary forests in Northeast China is the focus of further research in the future.
Advances in Research of Walnut Blight
HAN Chang-zhi, ZHU You-peng, WANG Yun-qing
2021, 34(4): 184-190. doi: 10.13275/j.cnki.lykxyj.2021.04.022
Objective To study symptoms, pathogens and control measures of walnut bacterial black spot, and make clear the hot spots, difficulties and key points in future's research about walnut bacterial black spot. Method Based on bibliometrics, the authors analyzed the literatures about walnut bacterial black spot in domestic and foreign literature databases. Result Previous studies mainly focused on the harmful symptoms, disease cycle and control methods of the disease, while lacked the research on the molecular biology of this pathogen, such as protein secretion, pathogenic mechanism and interaction mechanism, as well as routine research reports such as early rapid detection and green prevention and control. Conclusion The pathogen of walnut bacterial black spot is Xanthomonas arboricola pv. juglandis, and the damage degree of walnut bacterial black spot is greatly affected by environmental humidity. Therefore, the key period of prevention and control is the initial infection period of walnut, such as leaf spreading period and flowering period, and the mixed agents of copper preparation, antibiotics and pesticides should be the main selection for prevention and control. In addition, attention should be paid to the study of pathogenic factors and pathogenic mechanism of walnut bacterial black spot in the future