• 中国中文核心期刊
  • 中国科学引文数据库(CSCD)核心库来源期刊
  • 中国科技论文统计源期刊(CJCR)
  • 第二届国家期刊奖提名奖

2020 Vol. 33, No. 6

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2020, 33(6): -1--1.
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2020, 33(6): 0-0.
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2020, 33(6): 1-1.
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Cloning of β-pinene Synthase Gene in Pinus massoniana and Its Response to Pine Wood Nematode Infection
LIU Bin, LIU Qing-hua, ZHOU Zhi-chun, LUO Ning, XIE Yi-ni, CHEN Xian-zhi
2020, 33(6): 1-12. doi: 10.13275/j.cnki.lykxyj.2020.06.001
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Objective To clone β-pinene synthase gene in Pinus massoniana (PmPinS) and analyze its sequence characteristics and expression pattern after pine wood nematode (PWN) infection in order to provide theoretical basis to probe into the defense mechanism of P. massoniana to pine wood nematode infection. Method Based on PCR amplification technology, the full-length coding region sequence of PmPinS was cloned, the homologous amino acid sequence alignment, and the phylogenetic and genetic characteristics were analyzed with bioinformatics method. The expression pattern of PmPinS in resistant and susceptible P. massoniana after inoculation with PWN was analyzed with real-time quantitative PCR. Result The full-length coding region sequence of PmPinS was cloned, including a complete open reading frame of 1878 bp, encoding a 625 amino acid, with a molecular weight of 71.95 kD. The secondary structure was α-helix and β-fold, containing the typical terpenoid synthase domains including RR (X)8W, DDXXD and NSE / DTE. Phylogenetic analysis revealed that PmPinS and (-) β-pinene synthase in P. contortus were aggregated into one branch with a sequence similarity of 93.16%. The expression of PmPinS in resistant P. massoniana was higher than the susceptible ones after PWN inoculation, which showed an up-regulation trend within the following 30 days after inoculation. However, the expression of PmPinS in susceptible P. massoniana began to fell rapidly 1 day after inoculation. 2 years after inoculation, the expression level of PmPinS was highly expressed in the stem tissue of resistant P. massoniana. In addition, exogenous application of α-pinene, β-pinene and their mixed solutions to PWN showed that α-pinene and β-pinene could significantly inhibit the survival rate of PWN, especially for the mixed solution with more inhibition. Conclusion PmPinS, as a member of the monoterpene synthase family of P. massoniana, may be involved in the synthesis of β-pinene with GPP catalyzed intricately. The PmPinS is highly specific-tissue expressed in the stem of resistant P. massoniana, and its possible catalytic products, α-pinene and β-pinene, have significant inhibitory effects on PWN, which might reveal that PmPinS plays a positive regulatory role in the defensive process to PWN.
Comprehensive Selection with Multi-characters for Secondary Provenance/Family of Tectona grandis in Southwest Hainan
LIANG Kun-nan, HUANG Gui-hua, LIN Ming-ping, YANG Guang, WANG Xi-yang, ZHOU Zai-zhi
2020, 33(6): 13-22. doi: 10.13275/j.cnki.lykxyj.2020.06.002
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Objective Comprehensive evaluation on growth traits, quality traits and adaptability of domestic secondary provenance/family introduced previously was conducted to select superior provenance/family most suited to local growth. Method Designed by completely randomized blocks with 4 tree-plot and 8 replicates, 19 secondary provenances/families of domestic teak species were analyzed by variance and correlation in survival rate, growth traits and quality traits of 4.5-year-old and 30.5-year-old trees to select superior secondary provenances/families according to clustering method and coordinate composite evaluation with multi-characters. Result There were significant or highly significant differences among provenances/families in survival rate, growth traits and quality traits of 4.5-year-old and 30.5-year-old trees except survival rate of 4.5-year-old trees. No significant correlation was found between 4.5-year-old trees and 30.5-year-old trees in all traits, however, there were significant or highly significant positive correlation among growth traits, between growth traits and survival rate, and between growths and stem form of among same aged trees. The growth traits and stem form were highly significant positive correlated with latitude of seed source and significant or high significant negative correlated with annual average temperature. Two secondary provenances and two secondary families were selected by cluster analysis and coordinate composite evaluation method, of which the individual volume of dominant tree of 30.5-year-old trees was higher than that of local provenance and local superior family increased by 261.65%-291.29% and 20.18%-26.11% respectively. Superior provenances had very remarkable effect on selection. Conclusion One provenance from Guangdong, one provenance from Yunnan and two families from Yunnan are identified as the teak provenances/family most suitable to be planted in southwest Hainan Province, and a further selection to the family from Yunnan will achieve greater gains.
Observation of Emergence Rhythm and Reproductive Behavior of Cricula variabilis: A Insect Pest of Machilus chinensis
ZHANG Jin-kun, HU Ke-yan, ZHANG Guo-xiang, Fan Ling-hua, FENG Ying, WANG Cai, WEN Xiu-jun, MA Tao
2020, 33(6): 23-31. doi: 10.13275/j.cnki.lykxyj.2020.06.003
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Objective To elucidate the pattern of emergence, calling, mating, and oviposition of Cricula variabilis, and provide references basis for the study on sex pheromones and ecology-friendly monitoring and controlling of this insect. Method The late-instar larvae were collected and bred in laboratory. Observation of the emergence and reproductive behavior of the adults were conducted, and relevant data were analyzed. Result Significant differences were found in the sex ration of emerged adults and in the number of occurrence in dark and light period. Adult emergence occurred throughout the day, amongst all male adult 78.49% emerged in the dark period, whereas 91.01% of female emerged in the light period. The emergence date of male was earlier than that of the female. Female calling occurrence peaked at 5:30−11:30 and the mating occurrence peaked at 7:00−10:30. The calling behavior of females was begun at the 1-day-old, which was the most vigorous. Female reproductive vigor was negatively correlated with the age. The average lifespan of female was greater than that of male under the same reproductive conditions, but there was no significant difference in the lifespan between male and female adults. Both mated and virgin adults could lay eggs, but mated female possessed higher eggs number, oviposition rate and duration. Conclusion Emergence of female C. variabilis mainly occurs during the day, and emergence of male mainly occurs at night. The adult’s calling, mating and other behaviors mainly carry out in the dark period. The reproductive behavior of female in early emergence is more active.
Study on the Function of cyp-33D3 Gene of Bursaphelenchus xylophilus with RNA Interference Method
FENG Meng-ting, SHENG Dong-ping, YE Jian-ren, CHENG Feng-mao, ZHANG Xiao-yang, QIU Xiu-wen
2020, 33(6): 32-38. doi: 10.13275/j.cnki.lykxyj.2020.06.004
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Objective To study the function of cytochrome P450 33D3 (cyp-33D3) gene in Bursaphelenchus xylophilus in order to further reveal the molecular pathogenesis mechanism of B. xylophilus, and provide useful information for its biological control. Method Double strand RNA (dsRNA) interference was used to investigate the effect of silencing of cyp-33D3 on feeding speed, individual size, number of eggs, hatching rate and pathogenicity of B. xylophilus. Result It was found that the feeding speed of B. xylophilus under ddH2O and gfp dsRNA treatments were faster than that under cyp-33D3dsRNA interference treatment in the first 5 days. Almost all the hyphae of Botrytis cinerea were consumed by B. xylophilus soaked under ddH2O and gfp dsRNA treatments. In contrast, a large portion of the hyphae still existed under cyp-33D3 dsRNA treatment. No significant effect was found on the individual size of B. xylophilus when cyp-33D3 gene was interfered by dsRNA (P > 0.05). Compared to ddH2O and gfp dsRNA treatments, the average number of eggs per female decreased 12 and 11 under cyp-33D3 treatment, and the hatching rate of eggs decreased by 46% and 43%, respectively. 40 days after the soaked B. xylophilus were inoculated in Pinus thunbergii seedlings, the pathogenicity of B. xylophilus under ddH2O and cyp-33D3 treatments were 100% and 43.1%, respectively, while the P. thunbergii seedlings inoculated with B. xylophilus under gfp dsRNA treatment still grew well. Conclusion The RNA interference of cyp-33D3 gene decreases the feeding speed, the number of eggs, hatching rate and pathogenicity of B. xylophilus. However, RNA interference of cyp-33D3 gene exhibits no significant effect on individual size of B. xylophilus.
Visual and Olfactory Response of Papilio polytes During Foraging and Courtship
LI Ming-tao, LIU Jie, CHEN Shun-an, SHI Lei, YAO Jun, CHEN Xiao-ming
2020, 33(6): 39-48. doi: 10.13275/j.cnki.lykxyj.2020.06.005
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Objective To analyze the recognition and selection rules of Papilio polytes' visual and olfactory response during foraging and courtship, and to further discuss their ecological significance. Method Through color-visit, odor-visit, color plus odor-visit, courtship and artificial models-visit experiments in natural population butterflies to analyze the visual and olfactory weight factor of P. polytes in foraging and courtship. Result Under the condition of odorless 7-color artificial flowers, the P. polytes showed obvious color tendency to red, blue, and purple. After spraying honey on the artificial flowers, the frequency of female and male butterfly foraging increased by 3.16 times. In the colorless floral volatiles foraging experiment (β-caryophyllene, benzaldehyde), the frequency of butterfly foraging was less; after add odor to color, the frequency of female and male butterfly foraging increased by 60 to 120 times, indicating that the attractant effect of color exceeds odor. However, compared with the single color and floral volatiles, the increase ratio was only 1%~5%, indicating that the effect of scent on the collection of P. polytes was small. In the process of courtship, the visit to the plastic seal model was similar to that of the natural population in the type and proportion of courtship, indicating that the butterfly could use color and stripes to identify male and female. Conclusion P. polytes is mainly visual and supplemented by olfaction when foraging and courtship.
Stoichiometric Characteristics of C, N and P in Leaves of Torreya grandis Varieties and Soils
YUAN Ya-nan, LI Zheng-cai, WANG Bin, ZHANG Yu-jie, HUANG Sheng-yi
2020, 33(6): 49-56. doi: 10.13275/j.cnki.lykxyj.2020.06.006
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Objective To examine the effects of cultivar and dioecy on stiochiometry of Torreya grandis and provide data for management of T. grandis stands. Method The female (T. grandis cv. ‘Dielsii’ and T. grandis cv. ‘Merrilli’) and male T. grandis with age of about 300 years were selected from T. grandis National Forest Park in Zhuji of Zhejiang Province. The leaf and soil samples (0-20, 20-40 and 40-60 cm) of different T. grandis species were collected in the field to analyze the C, N, P contents and their stoichiometric characteristics. Result (1) There was no significant difference in C, N, P contents and stoichiometric characteristics between T. grandis cv. ‘Dielsii’ and male T. grandis. Dioecy had no significant effects on the stoichiometry of T. grandis. (2) There was no significant difference in C and N contents among T. grandis. The C and N contents in 0-20 cm soil layer of T. grandis cv. ‘Merrilli’ stand and in 20-40 and 40-60 cm soil layer of T. grandis cv. ‘Dielsii’ stand were the highest. The content of P in soil of T. grandis cv. ‘Merrilli’ stand (2.9, 1.5 and 0.9 g·kg−1) was significantly higher than that in T. grandis cv. ‘Dielsii’ stand and male T. grandis stand. (3) C:N in soil of T. grandis stand were more stable than C:P and N:P. The C:P and N:P in soil of T. grandis cv. ‘Merrilli’ stand was significantly lower than that in T. grandis cv. ‘Dielsii’ and male T. grandis stands. (4) The C content in T. grandis cv. ‘Merrilli’ leaves (533.0 g·kg−1) was significantly higher than that in T. grandis cv. ‘Dielsii’ leaves (502.8 g·kg−1) and male T. grandis leaves (502.7 g·kg−1). The change trend of C:N and C content in leaves was the same. The N content in leaves of T. grandis cv. ‘Merrilli’ (18.5 g·kg−1) was significantly lower than that of T. grandis cv. ‘Dielsii’ s leaves (23.2 g·kg−1) and male T. grandis leaves (23.2 g·kg−1). The change trend of N:P and leaf N content was same. (5) On the whole, there was no significant correlation between C, N, P contents and stoichiometric characteristics in leaves of T. grandis and soils. Conclusion Dioecy of T. grandis shows no significant effect on the stoichiometric characteristics of tree. Fertilization and other management activities have a significant impact on soil P content in soil of T. grandis stand.
Methods of Total RNA Extraction from Different Juglans regia Tissues and Leaves
CHEN Hao, AN Rui-yun, CHANG Qing-shan, WANG Zi, MAO Xing-ye
2020, 33(6): 57-64. doi: 10.13275/j.cnki.lykxyj.2020.06.007
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Objective To find the efficient methods of extracting total RNA contents in Juglans regia tissues and young and mature leaves. Method The young and mature leaves were used as the materials, and the total RNA was extracted by improved borax-CTAB method, improved borax-CTAB-isopropanol method, improved SDS method, improved TrizonⅡ method, and Plant kit method. The concentration, purity, electrophoregram and RT-PCR of the RNA were analyzed, which extracted by the improved borax-CTAB method, improved borax-CTAB isopropyl alcohol method from the total RNA of J. regia embryo, petiole, phloem and male flower. Result The total RNA were extracted successfully by the 5 methods mentioned above. The high concentration and integrity of the total RNA was extracted by the improved borax-CTAB method. The brightness of 28S rRNA was 2 times that of 18S rRNA. The ratios of A260/A280 and A260/A230 were approximately 1.9-2.1 and higher than 2.0. The concentration was up to 1 019.0 ng·μL−1. In different tissues, 18S rRNA and translation initiation factor (JreIF1A) fragments were amplified by RT-PCR. Conclusion Compared with the other three methods, the improved borax-CTAB method and the improved borax-CTAB-isopropanol method have better applicability for RNA extraction from different tissues of J. regia. They can avoid interference from impurities. And the purity and concentration of RNA extraction are in line with the experimental requirements.
Annual Forest Disturbance Detection Using Time Series Landsat 8 OLI Data
HU Sheng-yuan, PANG Yong, MENG Shi-li, YUE Cai-rong
2020, 33(6): 65-72. doi: 10.13275/j.cnki.lykxyj.2020.06.008
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Objective Using Improved Vegetation Change Tracker (VCT) algorithm to detect the annual forest disturbance in subtropical area of south China. Method Annual cloud-free images of the study area in growing season were composited using multi-time series Landsat 8 OLI remote sensing data from 2013 to 2019, then the Integrated Forest Z-score (IFZ) was extracted automatically by identifying the potential forest pixels and combining with the Normalized Difference Vegetation Index (NDVI), the occurring time of forest disturbance was determined through observing the changes of IFZ in time series, and the specific contents of forest change were analyzed further. Result The results obtained at Gaofeng Forest Farm of Guangxi Zhuang Autonomous Region showed that the detection accuracy of the forest disturbance areas by combining IFZ with NDVI was improved to 79.2% from 67.2%. Conclusion The forest disturbance detection method of IFZ combining with NDVI can not only increase the error detection but also reduce the missed detection rate of the VCT method. It optimizes the problem of high missed detection rate in rapidly change areas and characterizes the spatial and temporal pattern of the forest areas in Gaofeng Forest Farm more accurately.
Seasonal Dynamics of Litterfall and C, N, and P Stoichiometric Characteristics of Six Tree Species in An Evergreen Broad-Leaved Forest on Jinyun Mountains
WEI Yu-jie, ZHAO Liang
2020, 33(6): 73-80. doi: 10.13275/j.cnki.lykxyj.2020.06.009
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Objective Taking 6 tree species in an evergreen broad-leaved forest in Jinyun Mountain National Nature Reserve as object to study the stoichiometric characteristics and seasons of litter C, N and P and analyze the relationship between them and the amount of litter. Method The grid method was used to evenly arrange 172 litter leaf collection frames in the plot. At the end of each month, the leaf litter in the collection frame were regularly collected for classification and weighing in laboratory. After crushing, the contents of C, N, P element were measured. Result (1) The seasonal variation of leaf litter of the six tree species were different. The litter peaks of the evergreen broad-leaved tree species Castanopsis fargesii and Machilus nanmu, and evergreen coniferous species Cunninghamia lanceolata appeared in spring; the litter peak of deciduous tree species Alniphyllum fortune appeared in summer; the wither peak of deciduous tree species Liquidambar formosana appeared in winter; while the evergreen coniferous tree species Pinus massoniana had no obvious wither peaks throughout the year. (2) The C, N and P contents of the litter of the six tree species were 481.35~542.23, 5.64~11.85, and 0. 39~0.72 g·kg −1, the N: P range was 13.05~19.15. The deciduous broad-leaved tree species had higher N and P contents, and the evergreen coniferous species had lower N and P contents. (3) The seasonal dynamics of C, N and P contents of the six tree species were obvious. There was a significant positive correlation between the C content of Pinus massoniana and the yield of litter (P < 0.05), the N content of Alniphyllum fortune and the yield of litter was significantly positively correlated (P < 0.05), the P content of Castanopsis fargesii and Pinus massoniana litter leaves showed a significantly negative correlation with the yield of litter leaves (P < 0.05), and the N: P of litter leaves of Pinus massoniana showed a positive correlation with the yield of litter (P < 0. 05). Conclusion The seasonal dynamics of the litter of six tree species in the evergreen broad-leaved forest of Jinyun Mountain are different. These six species show a pattern of low N and low P. The overall performance is limited by N and P together, and the N limiting effect is stronger than the P limiting. Within a growing season, the C, N, and P stoichiometric characteristics of the six species vary greatly from month to month, and the relationship between the amount of litter and the C, N, and P contents of the litter is related to the species characteristics. The relationship between quantity of litter and its stoichiometry is not obvious.
Stoichiometry and Homesotasis of Nitrogen, Phosphorus and Potassium in Leaf of Dominant Tree Species in China’s Coniferous Forests
DENG Bo-wen, XU Yao-yao, CHEN Yi-fei, ZHANG Shuo, ZHENG De-xiang, LIAO Xiao-li, LIN Ren-zhong, JIN Shao-fei
2020, 33(6): 81-87. doi: 10.13275/j.cnki.lykxyj.2020.06.010
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Objective To study the ecological stoichiometry and homeostasis characteristics of leaf in China’s coniferous forest. Method The nitrogen (N), phosphorus (P) and potassium (K) contents of dominant tree species and soils in coniferous forests were analyzed in investigate the stoichiometric characteristics and the effects of various environmental factors on the variations of leaf and soil stoichiometry. The mechanisms of adapting the coniferous forests to environments were discussed. Result The contents of N, P, and K of dominant tree species in China’s coniferous forests followed the order of N > K > P. Significant differences in N, N/P and N/K were found among different soil depth layers. Latitude took the greatest contribution to leaf N and P concentration which were 19.18% and 25.08%, respectively. Hydrothermal index, as the most pronounced factor, contributed 12.75% for the leaf P concentration. The annual precipitation was the greatest contributing factor to the ratios of N/P and P/K. All the leaf stoichiometric characters of coniferous tree species were kept stable except N. Conclusion The leaf stoichiometric characteristics of dominant species in China’s coniferous forests are mainly determined by latitude, soil, precipitation and temperature. The homeostasis analysis indicates that the dominant coniferous species in China have adapted to current soil environment.
Characteristics of δD and δ18O in Precipitation and Water Vapor Sources in Zigui Section of the Three Gorges Reservoir
WANG Ting, GAO De-qiang, XU Qing, JIN Xiang, ZHANG Bei-bei, ZUO Hai-jun
2020, 33(6): 88-95. doi: 10.13275/j.cnki.lykxyj.2020.06.011
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Objective To reveal the responsive mechanism of the hydrological cycling in forest ecosystems to climate change, it is necessary to examine the characteristics of hydrogen and oxygen stable isotopes (δD and δ18O, respectively) in precipitation, as well as water vapor sources of precipitation in Zigui section of the Three Gorges Reservoir Area of China. Method Using a stable isotope technique, examined the composition of rainfall δD and δ18O in Zigui section of the Three Gorges Reservoir Area in three hydrological years from September 2016 to August 2019, and established the local meteoric water line. Investigated the main environmental factors affecting the hydrogen and oxygen isotopic characteristics of atmospheric precipitation on annual and seasonal scales. Furthermore, traced the sources of atmospheric water in this area by calculating the D-excess (d) in the precipitation, and verified the results of the sources through the HYSPLIT. Result The relationship between δD and δ18O in rainfall was δD = 8.52 δ18O + 20.11 (R2 = 0.96, n = 186, p < 0.01). Precipitation δD and δ18O values had obvious seasonal changes, low in the wet season and high in the dry season. On the annual scale, the rainfall δD and δ18O were significantly negatively associated with temperature and precipitation. On the seasonal scale, precipitation was the main factor affecting the variation of δD and δ18O values in the wet season. According to d-excess and the HYSPLIT model, the precipitation water vapor during the wet season was mainly influenced by the ocean moisture carried by the southeast and southwest monsoon. During the dry season, the atmospheric vapor mainly derived from the Eurasian Continent and local water evaporation. Conclusion The seasonal variation of δD and δ18O in precipitation is affected by local environmental factors (precipitation and temperature) and different sources of water vapor in the study area. On annual scale, there were “precipitation effect” and “anti-temperature effect”. The precipitation water vapor in the wet season was mainly influenced by the ocean moisture while that in the dry season derived from the continent and local water evaporation.
Herb Species Diversity in the Water-level-fluctuation Zone in Zigui Section of Three Gorges Reservoir Area
SUN Peng-fei, SHEN Ya-fei, WANG Li-jun, YANG Shao, GUO Yan, XIAO Wen-fa, CHENG Rui-mei
2020, 33(6): 96-104. doi: 10.13275/j.cnki.lykxyj.2020.06.012
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Objective To study the spatial pattern and gradient variation of herb species , and then to understand the ecological adapatability of plants,so as to provide data for further understanding and maintaining the biodiversity in water-level-fluctuation zone. Method Based on survey of water-level-fluctuation site of Zigui Section of the Three Gorges Reservoir Area, the composition and plant community diversity of herbaceous species and their spatial pattern and gradient variation were investigated continuously from 2014 to 2019 on the transect with elevation 145-175 m above sea-level . Result The results showed that there were 39 herb species in total in 2014, belonging to 27 genera of 15 families. Gramineae, Compositae, Polygonaceae and Euphorbiaceae were the dominant families. There were 47 herb species belonging to 39 genera of 18 families in the water-level-fluctuation zone in 2019. The top dominant family was Compositae, followed by Gramineae, Euphorbiaceae, and Polygonaceae. The dominant species such as Digitaria sanguinalis, Setaria viridis, Echinochloa crusgalli, Xanthium sibiricum, Bidens pilosa, Cynodon dactylon, Cyperus rotundus were of high importance value over the five years. In addition, there was an obvious variation in species richness, community diversity, evenness and dominance along the distance gradient. The richness of community species followed a up-down trend on the elevation from 145 to 175 m above sea-level. Conclusion The results of study suggests that the variation of herb species diversity in the study area is originated from the habitat difference induced by the difference in the flooding time caused by different elevation.
Modeling of Individual Tree Mortality and Analysis of Influence Factor in Mongolian Oak Stand Based on Generalized Linear Mixed Effect Model
LI Chun-ming
2020, 33(6): 105-113. doi: 10.13275/j.cnki.lykxyj.2020.06.013
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Objective To establish a mortality model so based on the generalized linear mixed effect model so as to improve the precision of simulation and prediction. Method On 295 permanent plots established in 1995 at Mongolian oak (Quercus mongolica) natural forest in Jilin province, the individual tree-level mortality model was established taking the effects of stand characteristics, climate, and site type variables into consideration based on logistic regression and generalized linear mixed effect model. The fit of model was compared with conventional generalized linear model method, and validation data was used to verify the accuracy of model. Result The results showed that the good-fitness of the model was greatly improved after considering plot’s random effect compared with the fixed effect model. When considering random effects of intercept and diameter variables, the fitness was the best. The stand basal area, stand age, and mean annual precipitation in summer (May to September) were negatively correlated with mortality. The basal area in larger trees, the stand density, the mean annual temperature, and the precipitation in the form of snow between August in previous year and July in current year were positively correlated with the mortality. The effect of the initial tree diameter on the mortality was complicated, so it is needed to analyze combined with other factors. Conclusion Identifying the sources of variation and influence factor in tree mortality will help further adopt suitable forest management measures.
Factors Affecting Reproductive Success in Dioecious Tree, Acer barbinerve
WANG Li-bin, HUANG Yun-hao, ZHANG Xin-na, WANG Juan
2020, 33(6): 114-120. doi: 10.13275/j.cnki.lykxyj.2020.06.014
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Objectives The influences of biotic and abiotic factors on the reproductive success were examined with individuals of different genders in Acer barbinerve. Methods The reproductive growth and vegetative growth of 183 trees of Acer barbinerve were observed in a 21 hm2 forest plot. The linear regression analysis was used to test the trade-offs between reproductive growth and vegetative growth. And path analysis model was used to quantify the influences of biotic and abiotic factors on the reproductive success. Results There is a positive linear relationship between the reproductive growth and vegetative growth for both female and male trees (female: R2 = 0.40; p < 0.05; male: R2 = 0.69; p < 0.001). Slope and effective pollen amount have a significant negative effect on the flowering amount of female trees (path coefficients are −0.78 and −0.41, respectively). Soil moisture and diameter at breast height of female trees have a significant positive effect on the flowering amount of female trees (path coefficients are 0.24 and 0.67, respectively). The leaf area index significantly directly affects the effective pollen amount (path coefficient is 0.58). Therefore, the light condition represented by the leaf area index indirectly affects the flowering amount of female trees. Fruit quantities, fruit setting rate and reproduction-nutrition ratio of females, and flower quantities and reproduction-nutrition ratio of males do not significantly relate with considering explanatory variables. Conclusions There is a significant trade-off between vegetative growth and reproductive growth. Environmental factors and pollen restriction have little effect on the reproductive success of Acer barbinerve.
Rural Forest Landscape and Plant Communities in Hilly Areas of South China
TIAN Tian, ZHANG Xu-dong, DING Li-xia, HE Yun-he, BAI Yan-feng, JIANG Chun-qian
2020, 33(6): 121-130. doi: 10.13275/j.cnki.lykxyj.2020.06.015
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Objective To explore the suitable way of forests rehabilitation in rural areas of low hilly areas in south China, improve the forest structure, maintain biodiversity and ensure the sustainable development of forest ecosystems and the sustainable use of forest resources. Method Taking Xikou Village of Hangzhou, Zhejiang Province, as the research object, based on high-resolution GF-2 data and field surveys, the forest landscape and plant community characteristics were investigated and studied. Result The area of forest in Xikou Village accounted for 80.80% of the total area of the village. The main types of forest are broadleaved forests, coniferous and broadleaved mixed forest, Pinus massoniana forests, Cunninghamia lanceolata forests, bamboo forests, and Torreya grandis forests. In the village, the area of natural forest and artificial mixed forest is small, while the area of artificial single-layer pure forest is large, and the undergrowth vegetation coverage is low, and the plant diversity was obviously lost. Conclusion The overall structure of the forest ecosystem in Xikou Village is simple and the diversity is low. If the traditional afforestation and management mode continues, it is bound to lead to forest degradation, soil degradation and other problems. It is suggested that the existing broadleaved forest and coniferous and broadleaved mixed forest should be closed and reformed to promote its transformation to high-quality evergreen broadleaved forest. The ecological public-welfare forests of Pinus massoniana should be transformed by introducing and replanting native species to create mixed forests. Industrial plantation and non-timber plantation should be planted in small scale and small areas, and the local native broadleaved tree species and suitable broadleaved tree species should be selected to create mixed forests as green isolation zones and inlaid with small area of industrial forests and non-timber forests with reasonable tending and management measures.
SPME-GC-MS Analysis of Volatile Components in Euonymus sanguineus var. paedidus Flowers at Various Development Stages
LIU Zhi-hong, XIE Qing
2020, 33(6): 131-138. doi: 10.13275/j.cnki.lykxyj.2020.06.016
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Objective To study the changes of volatile components in Euonymus sanguineus var. paedidus flowers at 5 development stages (V1 to V5) and the causes of its pungent odor. Method The volatile components at various development stages and in petal (Y1) and disk (Y2) of E. sanguineus var. paedidus were analyzed by headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (SPME-GC-MS) as well as principal component analysis (PCA) and hierarchical cluster analysis (HCA). Result A total of 58 components accounting for 96.51%-98.56% of total were separated and identified. The major constituents were linalool (0.15%-70.79%), leaf alcohol (0.41%-65.51%), phenylacetonitrile (0.04%-62.20%), 2-ethenyl-1, 1-dimethyl-3-methylene-cyclohexane (0.02%-32.99%), (E)-β-ocimene (0.25%-21.26%), α-pinene (0.02%-20.41%), D-limonene(1.01%-11.74%)and methyl salicylate(0.14%-6.14%). The volatile components in all samples were dominated by alcohols (11.93%-69.66%), followed by hydrocarbons (14.47%-57.94%). Analysis of the volatile components revealed the qualitative differences among the samples studied. According to principal component analysis (PCA) and hierarchical cluster analysis (HCA), the volatile constituents at various development stages and in parts of E. sanguineus var. paedidus flowers were grouped into four different chemotypes. V1 and V2 were leaf alcohol (type I), V3 and V4 were complex and not obvious (type II), V5 and Y1 were linalool, (type III) Y2 was phenylacetonitrile (IV). Conclusion The volatile constituents of E. sanguineus var. paedidus are different at different development stages and the pungent odor is mainly related to phenylacetonitrile released by flower disk at flowering.
Screening of Two Endophytic Bacteria from Phyllostachys edulis Root Against Ceratosphaeria phyllostachydis and Their Function of Growth-Promoting
YANG Dou, WANG Qing-hai, WAN Song-ze, LI Li, ZHANG Yang
2020, 33(6): 139-147. doi: 10.13275/j.cnki.lykxyj.2020.06.017
Abstract:
Objective To obtain high efficient strains against Ceratosphaeria phyllostachydis from Phyllostachys edulis and evaluate their function of growth-promoting. Method The endophytic bacteria were isolated from the root of Ph. edulis by tissue separation and dilution plate method respectively. The antagonistic bacteria were screened by plate confrontation test. In addition, The growth curve, phosphate-dissolving ability and indoleacetic acid-producing ability of endophytic antagonistic bacteria were measured. Also, the effect of excellent strains on growth of Ph. edulis seeding were studied using soil pot experiment. Result A total of 118 endophytic bacteria were isolated from the root of Ph. edulis, 16 of which had antibacterial activity against C. phyllostachydis. Among them, the strains PN1 and PN6 had the most significant antibacterial activity, with bacteriostatic rates of 58.82% and 49.28%, respectively. In addition, the two strains had well ability to dissolve insoluble phosphate and produce IAA, and showed the greatest ability to solubilize Ca3(PO4)2 with 236.33 mg·L−1 and 278.21 mg·L−1, respectively, and the capacity of IAA-producing were 15.17 mg·L−1 and 12.36 mg·L−1, respectively. Strains PN1 and PN6 were identified as Burkholderia lata and Enterobacter ludwigii through the analysis of 16S rDNA gene sequences and evaluation on their morphological, physical and biochemical characteristics. Meanwhile, the result of pot experiment showed that PN1 and PN6 had significant growth-promoting effect on Ph. edulis seedling, the ground diameter increased by 39.51% and 42.59% respectively, and the seedling height increased by 54.42% and 62.51% respectively. Conclusion The strains PN1 and PN6 have well ability to prevent Ph. edulis shoot blight and to promote growth. They have great potential in the prevention of C. phyllostachydis and alleviating soil nutrient deficiency.
A Study on Flowering and Fruit Development of Sassafras tzumu
CHEN Hong-zhi, LIU Jun, JIANG Jing-min, SUN Yang, DONG Xin, FU Ai-ping
2020, 33(6): 148-154. doi: 10.13275/j.cnki.lykxyj.2020.06.018
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Objective To study the flowering and fruit development of Sassafras tzumu so as to further understand the biological characters of S. tzumu and provide references for its collection and utilization. Method Taking the S. tzumu trees with the age over 10-year-old in city forest park of Fuyang District, Hangzhou City as trial materials, the flowering habits and fruit growth process were observed from January to July 2018, and the flower and fruit structure of the trees were observed by paraffin section and stereomicroscope. Result (1) The mixed buds of S. tzumu were composed of raceme and new branch growth cones. The time form buds scales break to the end of flowering was about 60 days. (2) Two types of flower were observed, one type had 6 perianth segments, 12 pistils, 1 stamen and the other one had 8 perianth segments, 16 pistils, and 1 stamen. The former one had 3 staminodes and the latter one had 4 staminodes. (3) The growth of fruit followed a "slow -fast -slow" curve. The water content of the fruits decreased while the dry matter accumulation linearly increased with the growth of the fruits. The embryo began to grow in early May, and the fruit was fully mature when the skin was purple black in the end of June. Conclusion The flowering includes buds scales break, early florescence, blossom period, and final one. The flowering period is about 45 days at the population level, and can be pollinated and fruited normally. The growth of fruit can be divided into young fruit, expanding stage, peel discoloration and maturity, which lasts for 12 weeks. The fruits are berrylike drupe and dicotyledonous seeds without endosperm.
Vertical Distribution Characteristics of Soil Organic Carbon Content and Organic Carbon Density of Typical Forest Stands at Haituo Mountain, Beijing
NIE Hao-liang, BO Hui-juan, ZHANG Run-zhe, WANG Jiang, NIE Li-shui, WANG Dan
2020, 33(6): 155-162. doi: 10.13275/j.cnki.lykxyj.2020.06.019
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Objective To evaluate the forest soil carbon pools and provide references for the assessment of forest ecosystem services function in North China by exploring the vertical distribution of soil organic carbon (SOC) content and density in different typical forest stands in Haituo Mountain, Beijing. Method Three replicates of soil profiles from each plot were selected from five typical forest stands (Chinese pine, walnut tyurin, oak, coniferous-broadleave mixed stand, and aspen). One-Way ANOVA was employed to study the effects of stand types on SOC content and density in different horizons. Correlation analysis was conducted to analyze the relationship between the SOC content and different soil physical-chemical factors. Result The soil organic carbon content was between 9.35-50.25 g·kg−1 (mean=27.42). Stand types had significant effect on SOC content (p < 0.05). The mean SOC content of the stands studied followed the ascending order of aspen, coniferous-broadleave mixed stand, walnut tyurin, oak, Chinese pine. The SOC content in all these stands showed similar vertical distribution tendency, i.e. decreasing from top horizon to bottom, with a higher concentration on the top horizon (A+AB horizon accounted 57%). The SOC density ranged from 21.4 t·hm−2 to 76.6 t·hm−2 within 100 cm in these stands, with the mean of 45.7 t·hm−2. The mean SOC density of these stands followed the following descending order of aspen, walnut tyurin, coniferous-broadleave mixed stand, oak, Chinese pine. The vertical distribution pattern of SOC density in unit volume was similar with that of the SOC content: decreasing from top horizon to bottom, with a higher density on the top horizon(A+AB horizon accounted 35%-40%). The SOC content in these stands had significant positive correlation to total nitrogen content (r = 0.923−0.985), and significant negative correlation to bulk density (−r = 0.971−0.996). With the increase of soil depth, the relative carbon density per centimeter decreased successively. Conclusion Stand type is one of the main factors controlling the vertical distribution of SOC, and its effect tends to decrease with the depth of soil profile. The result of correlation analysis suggests that there is significant positive correlations between aspen and clay content, but there may be no significant correlations between other stands and clay content.
Physiological and Biochemical Changes of Toona sinensis Seeds During Artificial Aging
FANG Jiao-yang, ZHU Yan, WANG Cai-yun, YE Ke-ke, GAO Wei-dong, ZHANG Zi-han, YAN Jing-jing, LI Qing-mei
2020, 33(6): 163-169. doi: 10.13275/j.cnki.lykxyj.2020.06.020
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Objective To investigate the seed vigor and physiological and biochemical changes of Toona sinensis seeds during artificial aging by measuring the germination indexes, seedling morphological indexes, physiological and biochemical indexes of T. sinensis seeds at different aging degrees. Method T. sinensis seeds were treated with artificial aging at high temperature (40℃) and high humidity (RH 95%) for 1 to 8 days respectively. The seed germination indexes, seedling morphological indexes, relative electrical conductivity, MDA content, and antioxidant enzyme activity were measured after treatment. Result After the aging treatment, the seed vigor of T. sinensis decreased significantly, the relative electrical conductivity and MDA content increased significantly. During the aging process of seeds, the germination rate, germination index, and vigor index gradually decreased, the relative electrical conductivity and MDA content showed an increasing tendency, the activity of SOD and POD went up at initial and then went down along the seeds aging, and SOD was more sensitive to the aging of T. sinensis seeds. The correlation analysis indicated the relative electrical conductivity and MDA content had extremely and significantly negative correlation with seed germination indexes, while the POD activity showed a extremely and significantly positive correlation with seed germination indexes, the SOD activity was significantly and negatively correlated with germination rate, and extremely and significantly positive correlated with germination index and vigor index. Conclusion The peroxidation of membrane lipids and the dysfunction of the antioxidant enzyme system are the main reasons causing the aging of T. sinensis seeds. The relative electrical conductivity, MDA content and POD activity can be used to measure the vigor level of T. sinensis seeds.
Variations of Soil Enzyme Activity in Typical Evergreen Broadleaved Forests Along Altitude Gradient in Southeast Yunnan
LI Cong, LV Jing-hua, LU Mei, REN Yu-lian, DU Fan, TAO Hai, YANG Luo-ping, WANG Dong-xu
2020, 33(6): 170-179. doi: 10.13275/j.cnki.lykxyj.2020.06.021
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Objective To study the change of soil enzyme activities along altitude gradient in the Wenshan National Nature Reserve of Southeast Yunnan, and provide data for understanding the influencing process and mechanism of inter-connections among hydrothermal conditions, vegetations and soil physicochemical properties on soil enzyme activities. Method Three typical vegetation types (i.e., subtropical monsoon evergreen broadleaved forest, sub-humid evergreen broadleaved forest, humid evergreen broadleaved forest) along altitude gradient were chosen to study the changes of soil enzyme activities of these forests along altitude gradient and soil layers. The methods of forward selection, Monte Carlo permutation test, and redundancy analysis were used to analyze the effects of hydrothermal, vegetations and soil properties on soil enzyme activities along altitude gradient. Result (1) The soil enzyme activities varied with altitude gradient (P < 0.05). The activities of soil catalase, urease, sucrase increased, while the activities of soil acid phosphatase increased at first and then decreased. The soil enzyme activities decreased along with soil profiles. (2) The hydrothermal conditions, plant diversity, and soil properties followed different change patterns along altitude gradient. With the increase of altitudes, the annual precipitation increased, but plant diversity, annual temperature, and soil temperature decreased; the values of soil moisture content, soil organic carbon, total nitrogen, total potassium, available nitrogen and potassium increased, the total phosphorus and available phosphorus decreased at first and then increased; the soil bulk density and pH decreased significantly. Along with the soil profiles, the soil moisture content, soil organic carbon, total nitrogen, total phosphorus and potassium, and available nitrogen, phosphorus, potassium decreased, while the soil bulk density and pH increased. (3) The changes of hydrothermal conditions, vegetations and soil properties along altitude gradient had different degree of correlations with soil enzyme activities. Their importance was ranked as soil organic carbon > total nitrogen > bulk density > available potassium > pH > moisture content > available nitrogen > total potassium > available phosphorus > total phosphorus > Pielou index> annual precipitation > annual temperature > soil temperature > Simpson index > Margalef index > Shannon-wiener index. Conclusion Altitude will significantly alter the distribution of hydrothermal conditions, plant diversity, and physicochemical properties in Wenshan National Nature Reserve. This thus regulates the alteration of soil enzyme activities along altitude gradient and the soil layers. Soil moisture content, pH, bulk density, organic carbon, nitrogen, phosphorus, and potassium can explain the changes of soil enzyme activities along the altitude gradient.
2020, 33(6): 180-180.
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