Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
Species components and hazards of alien invasive plants in Putuoshan Island, Zhejiang Province
ZHU Junyi, HU Junfei, OU Danyan, HUANG Yan, WEI Zilu, WU Haozhengji, JIN Shuihu
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.2020.20190538
[Abstract](1493) [HTML](94) [PDF](4)
Abstract:
  Objective  Alien invasive plants have huge negative impacts on the biodiversity and ecological security of native ecosystems. This research aims to understand the situation of invasive plants in Putuoshan Island, Zhejiang Province.  Method  Sample surveys were conducted in different areas of Putuoshan Island. According to the weighted statistics of distribution area, coverage and the Zhejiang invasion level, the harm degree and invasion grade of various invasive plants were assessed, and the key harm areas, and prevention and control areas of invasive plants in Putuoshan Island were determined.  Result  There were totally 47 alien invasive species of plants, belonging to 36 genera of 21 families, and all of them being herbaceous. Moreover, out of total observed invasive species, 80.85% (38 species) were found to be native of America. 23 species of plants were in moderate or serious harm, and 22 species could be seen in plants belonging to class Ⅰ and class Ⅱ degree.  Conclusion  Hilly mountains, desolated land and coastal wetlands are important ecological regions of Putuoshan Island where control of alien invasive species is much needed. Since the present situation of invasive plants in Putuoshan Island is serious, it is necessary to increase publicity about bad impacts of invasive species, carry out joint programs to control their spreading, and strengthen the quarantine inspection of alien plants into the island. Additionally, adequate risk assessment of non-native plants should be carried out before their intentional application to prevent and control any invasive hazards in future. [Ch, 1 tab. 31 ref.]
Growth, physiology and nutrient accumulation of Phoebe bournei seedlings under different amount of exponential nitrogen fertilization
WANG Xiao, WANG Yinglin, WEI Xiaoli, WU Gaoyin
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190259
[Abstract](1575) [HTML](82) [PDF](7)
Abstract:
  Objective  The purpose of this study is to determine the optimal exponential nitrogen (N) application amount for Phoebe bournei seedling cultivation, and to enrich fertilization measures for cultivation of high-quality P. bournei seedlings.  Method  Growth, physiology and nutrient status of P. bournei seedlings treated with 6 levels of exponential N rate ranging from 0 to 5 g per seedling were examined by pot experiment.  Result  Seedling height, ground diameter, leaf area, biomass, chlorophyll content and root activity increased first and then decreased with the increase of exponential N application, and reached maximum at 3 g per seedling. Accumulation of N, phosphorus (P) and potassium (K) was the highest in the treatment with the highest N application rate. The relationship between biomass, N concentration, N content and N supply demonstrated that the nutrient uptake of P. bournei was characterized by luxury consumption in the range of 3−5 g per seedling. Critical value method indicated that the critical range of the optimal mass fraction of N and K in leaves was 16.88−20.58 mg·g−1 and 9.78−11.38 mg·g−1 respectively, and the optimal N application amount was 3−4 g per seedling.  Conclusion  Based on the growth, physiology and nutrient accumulation of seedlings, it is recommended that the application exponential N rate of 4 g per seedling should be adopted.[Ch, 3 fig. 4 tab. 34 ref.]
Types and diversity of natural regeneration community after clear cutting of Phyllostachys edulis forests in Mount Tianmu, China
WANG Zhengyi, DAI Qilin, BAI Cheng, CHEN Han, KU Weipen, ZHAO Mingshui, YU Shuquan
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190472
[Abstract](56) [HTML](40) [PDF](4)
Abstract:
  Objective  Phyllostachys edulis(Moso bamboo) forest is one of the forest community types that have been expanding in the subtropical region of China in recent 30 years. The spread and invasion of Ph. edulis forests are becoming more and more serious, threatening the vegetation around the Moso bamboo forest. It has become an important problem of forestry ecological construction at present and in the future. The study aim is to know the type and species diversity of natural regeneration community, and their influencing factors after clear cutting of Moso bamboo forest.  Method  This paper is based on the monitoring data of secondary communities formed by natural regeneration after clear cutting of Moso bamboo forest in Mount Tianmu, TWINSPAN analysis was used to classify the natural regeneration communities, The differences of α diversity among different communities were compared, the influence of environmental factors was analyzed by redundancy analysis.  Result  (1)Species and types of natural regeneration community are varied after clear-cutting of Moso bamboo forest, can be divided into 11 different communities. There were significant differences in alpha diversity among different communities. (2) Through redundancy analysis, it was found that among the three topographic factors of elevation, slope direction and slope, elevation was the main factor that determined the alpha diversity of woody layer and herbaceous layer of natural regeneration community and was significant negatively correlated with it(P<0.05).  Conclusion  This paper reveals the distribution pattern of community and environmental factors in the early stage of succession and provides theoretical basis for vegetation restoration in the protected area. [Ch, 3 fig. 3 tab. 38 ref.]
On sustainable development of health and wellness tourism in Yushe National Forest Park based on SWOT-AHP model
ZHANG Caihong, XUE Wei, XIN Ying
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190463
[Abstract](44) [HTML](17) [PDF](0)
Abstract:
  Objective  Aimed at a strategy of sustainable development for the health and wellness tourism at Yushe National Forest Park, an analysis was made of the advantages, disadvantages, opportunities and threats with SWOT-AHP model employed.  Method  To be specific, a qualitative analysis is first conducted to establish an evaluation index system before Analytic Hierarchy Process (AHP) was used to quantitatively analyze these factors, and to determine the weights of the indicators and the weighted scores. Afterwards, by calculating the overall strength of the development of health and wellness tourism in Yushe National Forest Park, the quadrangle was drawn of the strategy for the development of health and wellness tourism in Forest Park with the strategic quadrangle coordinate P(x, y), strategic type azimuth θ, and strategic intensity coefficient ρ determined, and a suitable development strategy and strategic intensity selected for Yushe National Forest Park.  Result  It was found that in developing health and wellness tourism in Yushe National Forest Park the advantages outweigh the opportunities threats and disadvantages (A>O>T>D) with P(x, y) = P (0.553 6, 0.729 1) as the strategic quadrilateral barycenter coordinate and, the strategic type azimuth θ between π/4~π/2. It was concluded that the development of health and wellness tourism in Yushe National Forest Park belonged with the opportunity type, and growth strategies with a positive intensity (the strategic strength coefficient ρ = 0.966 5>0.5) should be adopted.  Conclusion  In conclusion, the development of health and wellness tourism in Yushe National Forest Park should adopt a positive growth strategy. Favorable ecological and environmental conditions (0.247 4) are the biggest advantage while the weak infrastructure (0.024 1) is the main disadvantage. The favorable development of tourism in Guizhou Province(0.150 7) offers a major opportunity for the development of health and wellness tourism in Yushe National Forest Park, however, it is also faced with the challenges of other tourist products from surrounding areas (0.068 8). [Ch, 2 fig. 2 tab. 20 ref.]
Naturalness evaluation of rivers based on the fuzzy comprehensive evaluation and the grey correlation analysis
YAN Lin, MA Lan, PAN Chengzhong, ZHANG Dong, SUN Zhanwei, ZHANG Jinge, LIU Jingjing, LI Junyou
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.2020.20190485
[Abstract](371) [HTML](209) [PDF](17)
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  Objective  To restore and better protect the naturalness of Yongding River, one of the five major rivers in Haihe River Basin, the current study is aimed at the naturalness evaluation of it based on the close-to-nature concept, which is of grate significance of the drinking water safety of residents in Beijing and the water environment of Haihe River Basin.   Method  Taking the Beijing gorge section of Yongding River as the study subject, the evaluation index system of river naturalness was constructed with 25 qualitative and quantitative indexes selected from five aspects, namely, hydrological elements, cross-sectional configuration, physical and chemical properties of water body, riparian zone conditions and social ecological value of river. Then, the weight of each index in the evaluation system was calculated with the weighting method of analytic hierarchy process intergrated with the entropy weight method before the naturalness of the river is evaluated and the natural grade is determined employing the fuzzy comprehensive evaluation method and the grey correlation analysis respectively.  Result  The naturalness of the river evaluated employing fuzzy comprehensive evaluation method is generally consistent with that using the grey correlation analysis, and among the 21 river segments, the natural, near-natural, degraded and artificial river segments accounted for 14.29%, 28.57%, 46.62% and 9.52% of the total river length, respectively, and the length is about 7.5, 15.0, 25.0 and 5.0 km.  Conclusion  In general, most of the investigated river segments are being degraded, but they all still display potential in restoring the naturalness and the fuzzy comprehensive evaluation method and grey correlation analysis are both feasible methods for river naturalness evaluation. [Ch, 3 tab. 27 ref.]
Study on rapid propagation system of superior clones in Cryptomeria fortunei
WANG Chen, ZHANG Junhong, ZHANG Miao, XU Wenting, LOU Xiongzhen, TONG Zaikang
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190484
[Abstract](532) [HTML](283) [PDF](24)
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  Objective  The induced clustered buds of Cryptomeria fortunei have strong differentiative capacity but insufficient elongation ability. In order to obtain the optimum medium of adventitious bud induction, proliferation, elongation culture and rooting induction, the rapid propagation system of C. fortunei was established.  Method  The annual shoot from 20-year-old C. fortunei were used as explants; the orthogonal test design was used to select the optimum medium. The propagation system of C. fortunei includes induction, proliferation, elongation, rooting and transplant.  Result  ① Adventitious buds from three clones could be induced on MS, DCR and WPM basic medium supplemented with different combinations of 6-BA, IBA and CH. But the proliferation ability of buds varied significantly among different mediums. When clones were cultured in WPM medium with 1.0 mg·L−1 6-BA and 0.1 mg·L−1 IBA, the induction rate and proliferation coefficient was the highest, which was 100% and 9.13, respectively. ②When three clones of C. fortunei were subcultured alternately with high concentration hormone and low concentration hormone, the effective shoot growth rate reached 456.87%. ③ The most suitable medium for the C. fortunei rooting was DCR medium with 0.1 mg·L−1 IBA, under which the rooting rate ratio was 100%. ④The rooted seedlings were transplanted to a mixed matrix with equal vermiculite and peat, after 15−20 days of seedling hardening, and the survival rate was 96.70%. Therefore, the potential propagation ability is 3 865 seedlings per maternal plant per year.  Conclusion  Thus, an efficient propagation technology for C. fortunei was established, which laid a technical foundation for industrialization of improved varieties. [Ch, 1 fig. 5 tab. 23 ref.]
Drying characteristics and drying schedule developed of Acacia melanoxylon wood
ZHOU Fan, ZHOU Yongdong, GAO Xin, FU Zongying, HOU Junfeng, WENG Xiang, LIN Shaohui
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190394
[Abstract](353) [HTML](191) [PDF](9)
Abstract:
  Objective  In order to provide the technical support for promoting the practical development and utilization of blackwood (Acacia melanoxylon) planted in China, its drying characteristics were investigated, and further its suitable drying schedule was drawn up.  Method  The drying characteristics of blackwood were determined using the 100 ℃ test method. The kiln drying experiments were conducted on the lumber of 25 mm in thickness to develop a suitable drying tecchnique.  Result  The main drying defects were initial cracking and twist deformation. The cross-sectional deformation degree was light, and there were no internal cracks. The blackwood was moderately easy to dry with the drying speed. The blackwood was a medium density hardwood with the air-dry density at 15% moisture content of 0.619 g·cm−3. Applying the proposed drying technique, the drying period of lumber was 268.0 h (11.2 d) as the moisture content of wood decreased from 110.40% to 8.42%. The drying rate remained relatively constant with an average value of 0.38%·h−1 during the whole process.  Conclusion  The findings provide the scientific basis for the actual production of kiln drying to ensure drying quality of the blackwood. [Ch, 2 fig. 6 tab. 25 ref.]
Differences and influencing factors of soil moisture in Karst microhabitats in southeast Yunnan
KUANG Yuanyuan, FAN Tao
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190383
[Abstract](394) [HTML](170) [PDF](17)
Abstract:
  Objective  This study aims to analyze differences in soil moisture and influencing factors of karst microhabitats of the eastern Yunnan Plateau, so as to provide scientific basis for the restoration of karst ecosystems.  Method  We studied karst niches (stone ditch, stone pit, soil surface) with different vegetation types, including limestone shrub, Pistacia weinmannifolia secondary forest and Pinus yunnanensis artificial mature forest under the forest-lake basin of Puzhehei karst.  Result  (1) In each niche soil moisture was significantly higher in the rainy season than in the dry season(P<0.05), and the order of average soil moisture was stone ditch (42.24%)>stone pit (41.63%)>soil surface (32.98%). (2) With natural and artificial restoration of limestone shrub, soil moisture increased from natural secondary forest over Pinus yunnanensis plantation to limestone shrub. Pistacia weinmannifolia secondary forest (35.80%)>Pinus yunnanensis artificial mature forest (31.67%)>limestone shrub (29.36%). (3) The difference in soil moisture in karst niches was influenced by the type of habitats, soil properties and vegetation type. Vegetation often preferred the karst niches of stone pit and stone ditch with superior habitat conditions.  Conclusion  Vegetation restoration in karst rocky desertification areas should be combined with vegetation communities and niche types, and stone ditch and stone pit niches should be given priority to vegetation restoration. The combination of natural restoration and artificial restoration can effectively improve karst ecosystems. [Ch, 4 fig. 2 tab. 28 ref.]
Growth, photosynthesis and ultrastructure of mesophyll cells for Cercidiphyllum japonicum seedlings with shading in summer
LI Donglin, JIN Yaqin, CUI Mengfan, HUANG Linxi, PEI Wenhui
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190370
[Abstract](722) [HTML](348) [PDF](42)
Abstract:
  Objective  To provide a scientific basis for seedling breeding and population protection, the effects of shading treatment on the growth and physiological functions of Cercidiphyllum japonicum seedlings were analyzed.  Method  With single factor random block design was adopted, using a LI-6400 portable photosynthetic system, a series of shading experiments were conducted on C. japonicum seedlings to study the effects of light on physiological characteristics, diurnal variation of net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and intercellular CO2 concentration (Ci) with seedlings being measured in summer under four light treatments: full light (L0), 55% transmittance (L1), 25% transmittance (L2), and 10% transmittance (L3). At the same time, changes in growth, in morphological indexes, and in the ultrastructure of leaf mesophyll cells were observed by sampling and transmission electron microscope technique.  Result  (1) Shading affected the leaf water content (LWC) and morphology compared to the control; with an increase in shading intensity, LWC increased (P<0.05), single leaf area (SLA) increased (P<0.05) too, both single leaf dry weight (SLWd) and lamina mass per unit area (LMA) decreased (P<0.05), and lamina area per unit mass (LAM) increased (P<0.05). (2) Shading had a strong effect on photosynthesis of seedlings. The “noon break” did not appear during the course of the day. The peak value appeared at 14:00, and other treatments were relatively mild with the peak value appearing at 12:00. The variation curve for Gs was similar to Pn, and Ci basically showed a concave change. The daily average for Pn, Gs, and Tr were L0>L1>L2>L3, but the order of Ci was reversed. (3) Chlorophyll and carotenoid content in leaves increased significantly with shading condition (P<0.05), and both chlorophyll and carotenoid content increased progressively with an increase of shading intensity (P<0.05). Long-term shading improved the light capture ability of leaves. (4) With full light: the outline of cells in the mesophyll tissue could be identified, the number of chloroplasts was small, the arrangement of chloroplasts was close to parallel to the cell wall, there was a large cavity in the center of the cells, the arrangement of thylakoid body was uniform, and the starch granules and osmium granules were few. With shading, the number of chloroplasts increased, the proportion of chloroplasts in the whole cell increased, the shape of chloroplasts gradually became spherical or oval, the number of starch grains increased, and the thickness of thylakoid lamellar was so. (5) For intensity shading L2 and L3, height (H) and basal diameter (D) decreased (P<0.05), the biomass model D2H decreased significantly (P<0.05), and normal growth and development of seedlings affected. However, there were no significant differences between growth indexes of seedlings for L1 (mild shade) compared to L0 (P>0.05). Thus, intensity shading has a great effect on the growth of seedlings.  Conclusion  The mild shading possibly beneficial for the growth environment of forests and having no obvious inhibitory effect on seedling growth, but the effective radiation intensity should be more than 55% of natural light intensity. [Ch, 3 fig. 4 tab. 29 ref.]
Diversity and flora of wetland plants of Changxing County, Zhejiang Province
LIU Zheng, LI Ying, ZHU Pei, CHU Xudong, HE Guoqing, SUN Yong
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190436
[Abstract](405) [HTML](206) [PDF](20)
Abstract:
  Objective  Wetland is a precious natural resource and an important ecosystem with irreplaceable functions. The wetlands in Changxing County play an important role in Zhejiang Province. A survey of the diversity of vascular plants in wetlands was carried out to provide scientific basis for the restoration and protection of wetland ecosystem in Changxing County.  Method  The diversity of vascular plants and the flora in wetlands were studied by route survey and quadrat survey.  Result  (1) There were 464 species of vascular plants, belonging to 277 genera 95 families. Among them, there were 7 species of ferns in 7 genera of 7 families, 4 species of gymnosperms in 3 genera of 2 families, and 453 species of angiosperms in 267 genera of 86 families which included 393 species of dicotyledons in 222 genera of 68 families and 60 species of monocotyledons in 45 genera of 18 families. (2) Families of 2−9 species and 1 species were dominant in the composition of plant families, accounting for 88.42%. Genera consisting of 2−5 species and 1 species were dominant, accounting for 97.11%. (3) Aquatic plants accounted for 82.54% of the total species of wetland plants, and herbaceous plants accounted for 85.86%. (4) There were 11 distribution types of family, dominated by pan-tropic family and north temperate distribution family, in addition to world-wide distribution. There were 12 distribution types of genus, dominated by north temperate distribution genus, and the number ratio of tropical genus to temperate genus was 0.77.  Conclusion  The vascular plants in Changxing County are abundant, and the flora shows typical temperate and transitional characteristics. [Ch, 7 tab. 25 ref.]
Purification effect of immobilized effective microorganism community of fly ash ceramsite on aquaculture wastewater
CHEN Shuang, WANG Liangkai, WEN Tao, MAO Xinyu, XU Ming, SHAO Xiaohou
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190443
[Abstract](392) [HTML](179) [PDF](11)
Abstract:
  Objective  With ash and pond sediment as main raw material, the purpose of this research is to prepare biological ceramics with efficient nitrogen and phosphorus removal for treatment of polluted aquaculture water by immobilizing effective microorganism (EM) community.  Method  The optimal proportion of fly ash ceramsite was determined by isothermal adsorption test. The fly ash ceramsite was fixed with EM and treated for 6 days in simulated aquaculture wastewater with ammonia nitrogen, total nitrogen and total phosphorus concentrations of 50, 55 and 20 mg·L−1.  Result  Under the preheating temperature of 300 ℃ and the firing temperature of 1 100 ℃, when the mass ratio of fly ash ceramsite was m (fly ash)∶m (active sediment)∶m (limestone powder)∶m (iron powder)=50∶40∶5∶5, the modified fly ash ceramsite immobilized EM had the best purification effect on nitrogen and phosphorus in the simulated aquaculture wastewater. After 6 days, the maximum removal rates of ammonia nitrogen, total nitrogen and total phosphorus were 99.14%, 92.18% and 44.35%, respectively.  Conclusion  Fly ash ceramsite itself has a certain adsorption and purification capacity of nitrogen and phosphorus. After the immobilization of ceramsite with EM, water purification effect can be enhanced.[Ch, 5 fig. 4 tab. 24 ref.]
Research progress on evolution trends and maintenance measures of soil fertility quality in Cunninghamia lanceolata plantations
GUO Jiahuan, SUN Jiejie, FENG Huili, CAO Penghe, YU Yuanchun
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190478
[Abstract](478) [HTML](182) [PDF](18)
Abstract:
In recent years, the growing contradiction between degradation of soil fertility quality and forestry production has seriously threatened the survival and development of human beings. Aiming at the hot issue of degradation and maintenance of soil fertility quality in plantations, this paper systematically elaborates the evolution trend of soil fertility quality in management of Cunninghamia lanceolata plantations from the perspectives of soil physical property, soil chemical property, soil microorganism, soil enzyme activity and allelopathy. Many studies have shown that degradation of soil fertility quality and continuous decrease of productivity are common problems in C. lanceolata plantations, and the main contributing factor is unsustainable forestry practice. The results of soil fertility maintenance in C. lanceolata plantations are reviewed from such aspects as rotation management, mixed compound afforestation, forest density adjustment, fertility compensation and sustainable forest management. The research on soil fertility quality maintenance in C. lanceolata plantations is prospected. [Ch, 1 tab. 48 ref.]
Quality evaluation of Shajiabang National Wetland Park from the perspective of coordinated development
ZHU Ying, WU Yingqian, LI Xin
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190448
[Abstract](483) [HTML](149) [PDF](13)
Abstract:
  Objective  The aim is to conduct a scientific assessment of the coordinated development between environmental construction and social service in wetland parks and the overall quality of wetland parks.  Method  Based on the clarification of the quality connotation of wetland parks, this paper, taking Shajiabang National Wetland Park as the research object and applies analytic hierarchy analysis. The quality evaluation indes system of wetland parks is established from the perspective of environmental factors and social services, and the construction of a quality evaluation model as well as a grade classification of wetland parks with the theory of coordinated development degree was introduced.  Result  There has been a significant promotion of the quality grade of Shajiabang National Wetland Park from 2009 to 2018 with arise from Level 1 to Level 4. The coordinated development between environmental construction and social services has been constantly facilitated with the coordinated development index rising from 0.143 to 0.665. Environmental factors such as water quality, invasion of alien species, plant species and bird species affect the quality of wetland parks to a great extent while service factors such as the number of popular science education courses and that of the ecological lecturers are positively correlated to the quality improvementof the wetland parks.  Conclusion  With a higher growth rate than the environmental quality index, the service quality index of wetland parks exerts larger impact on the quality of wetland parks. Therefore, it is advisable that efforts should be focused on the improvement of social service functions so as to effectively promote the overall quality of wetland parks. [Ch, 1 fig. 4 tab. 17 ref.]
Analysis of biomass allocation and allometric growth of Picea schrenkiana in Tianshan Mountains
LAN Jie, XIAO Zhongqi, LI Jimei, ZHANG Yutao
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190384
[Abstract](745) [HTML](313) [PDF](21)
Abstract:
  Objective  A proper understanding of the above-ground and underground biomass allocation and carbon storage of Picea schrenkiana, an important tree species in Xinjiang mountainous areas of great significance to the forest resources investigations in Xinjiang. To establish the allometric growth models of trunk, branch, leaf, root, the above-ground part and the whole plant with DBH(D), tree height (H) and DBH-H (D2H, D3/H and DbHc).   Method  Analysis of the of above-ground and underground biomass distribution pattern of 30 P. schrenkiana trees by whole plant harvesting method.  Result  There were significant differences in the biomass of trunk, branch, leaf and root of P. schrenkiana (P<0.01). The biomass of whole P. schrenkiana trees ranged from 12.04−2 014.34 kg·plant−1, and the biomass of the above-ground part and the underground part were 10.16−1 475.17 and 1.88−539.18 kg·plant−1 respectively. The biomass of trunk, branch, leaf and root accounted for 56.86%, 13.03%, 5.96% and 24.15% of the whole plant, and the range of root-shoot ratio was 0.08−0.55. At the plant level, the biomass model of each organ based on DBH(D) and tree height(H) variables was established. The optimal biomass model of root biomass was W=a(D2H)b, and other organs was W=aDbHc. Slope position, slope, altitude and soil thickness are the main environmental factors affecting the biomass of spruce.  Conclusion  The allometric growth model based on tree height (H)-DBH can better fit the biomass of each organ of P. schrenkiana, and can effectively estimate its biomass and carbon reserves. [Ch, 4 fig. 3 tab. 30 ref.]
Community structure characteristics for landscape-recreational forests in the urban parks of Foshan City
ZHAO Qing, HU Rouxuan, XU Dongxian, WEI Yuhan, TANG Honghui
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190396
[Abstract](354) [HTML](147) [PDF](9)
Abstract:
  Objective  With an attempt at the clarification of the dominant species and structural characteristics of landscape-recreational forests in different ecological niches, the current paper is aimed to conclude the rules and research the existing problems of the construction of landscape-recreational forests.  Method  With the method of community ecology employed and 20 sample plots in Qiandeng Lake Park, 40 sample plots in Wenhua Park, and 20 sample plots in the Pingzhou Park selected as researching areas, the research was conducted with every tree surveyed using high-resolution remote sensing images. After the diameter classes, height classes and crown areas were clarified, an analysis was made of the differences among different types of landscapes.  Result  (1) Compared with Wenhua Park and Pingzhou Park, Qiandeng Lake Park enjoys a higher level of singleness in tress species with Khaya senegalensis as the dominant tree of large diameter, height, and canopy class; (2) Landscape-recreational forests on closed forest land and besides the buildings are mainly composed of medium-diameter trees while those on in the open forest land and besides the water are mainly composed of small diameter trees with larger diameter trees taking up a small percentage; (3) Landscape-recreational forests in the closed forest land and besides the buildings are mainly composed of the medium-height trees while, those in the open forest land and besides the water are mainly composed of small height trees, with large height trees taking up a small percentage; (4) Landscape-recreational forests are mainly composed of the medium canopy class trees with, the large canopy trees taking up only a small percentage.  Conclusion  To sum up, floristic characteristics of tropical or subtropical monsoon are all shown in the landscape-recreational forests of the three parks. There are differences in the distribution of diameter classes among the trees in the closed forest land and open forest land (the center forest land) as well as those besides the water and buildings (fringe forest land). The differences in the distribution of height class are gradually decreased with the location of landscape-recreational forests shifted from the downtown to subsidiary center and finally to the suburbs. It is necessary to conduct long-term dynamic canopy monitoring to reflect the trend of canopy distribution. [Ch, 3 fig. 4 tab. 20 ref.]
Relationship between height and diameter at breast height(DBH) in mixed coniferous and broadleaved forest based on quantile regression
ZHANG Dongyan, WANG Dongzhi, LI Xiao, GAO Yushan, LI Tianyu, CHEN Jing
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190461
[Abstract](473) [HTML](205) [PDF](12)
Abstract:
  Objective  With the employment of nonlinear quantile regression method using dummy variables, the current study is aimed to establish a prediction model for the relationship between height and diameter at breast height (DBH) in Larix principis-rupprechtii and Betula platyphylla mixed forest so as to better predict the tree structure and site productivity of mixed forests.   Method   Taking L. principis-rupprechtii and B. platyphylla mixed forest of Saihanba Mechanised Tree farm in Hebei Province as the research object, with 83 pieces of standard land survey data used and dummy variables created, this paper adopted the least square method and nonlinear quantile regression method respectively in the construction of the relationship model of tree height and DBH of different species.   Result   The accuracy of the nonlinear quantile regression prediction model based on dummy variables was higher than that of the one constructed using the least square method. Specifically, when the least square method was used to fit the tree height and DBH relationship model of different tree species, the determination coefficient, average difference and average absolute error of different tree species models were within the range of 0.787−0.814, 1.581−1.877 and 2.447−2.654 respectively. When the nonlinear quantile regression method was used, the coefficient, average deviation, and average absolute error were within the range of 0.839−0.921, 0.213−1.469, 0.561−2.322. In accordance with the residual analysis, when the quantiles of τ is 0.7, the relationship model of tree height and DBH of different species demonstrated a higher accuracy.   Conclusion   To sum up, compared with the one constructed employing the least square method, the prediction model of tree height and DBH relationship of different tree species adopting the nonlinear quantile regression method has higher prediction accuracy. [Ch, 3 fig. 3 tab. 33 ref.]
Resistance of Phoebe sheareri to anthracnose induced by salicylic acid
HOU Panpan, CHEN Anliang, FEI Libin, MA Liangjin
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190342
[Abstract](618) [HTML](323) [PDF](33)
Abstract:
  Objective  The objective is to investigate the resistance of Phoebe sheareri to anthracnose induced by salicylic acid (SA).  Method  The 2-year old P. sheareri was used as material, spayed with 100, 200, 500 mg·L−1 SA. After 5 days, the leaves were collected and in vitro puncture inoculation method was used to determine the inhibition of anthracnose lesions, changes in soluble protein, superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) in the leaves.  Result  Leaves treated with different concentrations of SA could inhibit the anthracnose lesions, and the lesion inhibition rate with 100 mg·L−1 SA treatment reached 64.28%. After SA spray and inoculation with anthracnose, soluble protein, SOD, CAT and POD in leaves increased in 1−7 days, and decreased after 7 days. At the peak, the soluble protein was 2.57 times of ck, SOD was 1.21 times of ck, CAT was 2.04 times of ck, and POD was 1.46 times of ck. All physiological indexes were higher than those of ck within 15 days.  Conclusion  SA can induce the increase of soluble protein, SOD, CAT and POD of Phoebe sheareri and produce disease resistance.[Ch, 10 fig. 23 ref.]
Analysis of blocking effects of urban roadside forests on PM2.5
LIU Haodong, CHEN Yajing, LI Qingdian, XIAO Mao, GUO Huiling, SHEN Weixing, TAN Yajun, LI Chuanrong
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190335
[Abstract](1583) [HTML](797) [PDF](70)
Abstract:
  Objective  The present study is to analyze the dynamic change patterns of fine particulate matter (PM2.5) and the blocking effects of urban road forests, and further explore which type of forest belt has the optimal dust and haze control effects.  Method  Three types of urban road forests with a total of 12 configurations were selected. Firstly, the daily dynamics, interannual dynamics and horizontal spatial variations of PM2.5 in and out of the forest belt were analyzed. Then, the dust reduction rate was used to evaluate the blocking effect of different forest belts on PM2.5. Finally, the Pearson correlation analysis was carried out between the dust reduction rate and microclimate factors to explore the possible factors affecting the dust reduction rate of vegetation.  Result  The results showed that concentrations of PM2.5 in roadside forests were highest around 8:00 and 18:00 and lowest at 10:00 and 14:00. The annual dynamic pattern indicated the most obvious change in winter (136.74−194.18 μg·m−3), followed by autumn (63.48−104.96 μg·m−3), spring (28.68−36.31 μg·m−3), and summer (13.30−19.13 μg·m−3). The variation of PM2.5 in the horizontal space of the forest belt varies with seasons. In the spring and summer, PM2.5 gradually decreased from the edge of the forest to the interior of the forest, while in the autumn and winter, the dust margin increased at 25 m in the forest, but decreased at 25−30 m and was lower than the outer edge of the forest. The blocking rate of PM2.5 was highest in arbor-shrub-grass structure, followed by mixed conifer and broadleaved forest structure, and lowest in uniform arbor type. In spring and summer, the blocking rate of 12 kinds of roadside forests on PM2.5 was positive, while in autumn and winter only A5 (mixed conifer and broadleaved forest), B1, B2, and B3 (uniform arbor type) and C2 and C3 (arbor-shrub-grass structure) were positive, and the rest were negative. There were seasonal differences between microclimate factors and PM2.5. PM2.5 concentration was negatively correlated with wind speed in spring, autumn and winter, but positively correlated with relative humidity in autumn and winter, as well as temperature in spring and summer. The block rate of PM2.5 in roadside forests showed a significant positive correlation with temperature in autumn and relative humidity in autumn and winter, but had no significant correlation with other microclimate factors.  Conclusion  The belt width, the proportion of evergreen coniferous trees and shrubs of urban roadside forests should be reasonably increased to reduce PM2.5 and improve air quality. [Ch, 5 fig. 6 tab. 33 ref.]
Effects of shading and fertilization on growth and nitrogen accumulation of Phoebe zhennan seedlings
DENG Bo, YAN Lipeng, LIU Guihua, XU Mengyuan
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190399
[Abstract](1335) [HTML](332) [PDF](23)
Abstract:
  Objective  This study aims to reveal the effects of shading and fertilization on growth and nitrogen accumulation of Phoebe zhennan seedlings to provide scientific basis for the growth control of this plant.  Method  The two-split-plot test design was used to analyze the effects of shading, fertilization, and interaction of shading and fertilization on the growth, biomass accumulation and nitrogen accumulation of the 1-year-old P. Zhennan seedlings. The main plot contained three different shading levels: natural light (A1, 0% of shading rate), one-layer shading (A2, 54.5% of shading rate), and two-layer shading (A3, 85.3% of shading rate). Each main plot contained three different sub-plots with three different fertilization levels: no fertilization (B1), mild fertilization (B2, 3.3 g compound fertilizer per plant), and moderate fertilization (B3, 6.7 g compound fertilizer per plant). A total of 9 treatments were included in this study.  Result  The growth and nitrogen accumulation were significantly influenced by shading, fertilization, and their interaction (P<0.05). The seedling height, basal diameter, and biomass accumulation under A2B2 treatment were 77.2%, 30.3% and 62.1% higher than those under other treatments, respectively. Furthermore, the nitrogen accumulation reached the maximum under A2B2 treatment, 68.3% higher than that of other treatments. However, the nitrogen content was highest under A3B3 treatment, and was significantly higher than that under other treatments (P<0.05).  Conclusion  Moderate shading and fertilization can increase the nitrogen accumulation, and promote the photosynthesis, growth and biomass accumulation of P. Zhennan, but excessive shading and fertilization can inhibit its growth to some extent. [Ch, 3 fig. 4 tab. 24 ref.]
Characteristics and influencing factors of plant diversity in riverside rural settlement in Guangzhou
WANG Ziyan, WANG Cheng, TANG Sainan, ZHANG Chang, HAN Dan
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190391
[Abstract](524) [HTML](209) [PDF](13)
Abstract:
  Objective  This study aims to analyze the horizontal and vertical distribution characteristics of plants diversity in typical riverside rural settlement zones along the Nansha river of Guangzhou, and explore the variation law of plant diversity with the change of the river sections and residential activities.  Method  The basic data were obtained by field survey, satellite image interpretation and mathematical statistics.  Result  A total of 77 species of 70 genera and 44 families were recorded, including 42 species of trees, 19 species of shrubs, 13 species of herbs and 3 species of vines, among which Rosaceae and Palmae had the most species, followed by Moraceae and Rutaceae. There were no significant differences in dominant plant species in different river sections. The dominant trees were Dimocarpus longan, Ficus microphylla and Clausena lansium, while the main shrubs were Osmanthus fragrans, Murraya exotica and Aglaia odorata, and the main herbs were Musa nana and Bambusa textilis. In different reaches from the west gate to the east gate in the study area, tree diversity showed a downward trend as a whole, while no obvious trend was found in shrubs, herbs and overall evenness. However, the diversity and evenness index of trees, shrubs and herbs in the residential section were significantly higher than those in other sections, while the indices in the agricultural section were lower than those in other sections. The river width was significantly correlated with herb diversity, and building coverage was significantly correlated with shrub evenness. Vegetation in the study area was vertically distributed and divided into upper, middle and lower layers with 4 m and 8 m as boundaries. The dominant tree species in different height layers were different. M. nana, B. textilis and D. longan were dominant in the lower layer. D. longan, C. lansium, Taxodium distichum and Gironniera subaequalis were dominant in the middle layer. D. longan, F. concinna and Clausena lansium were dominant in the upper layer.  Conclusion  Human activities have little impact on large trees, but significant impact on small flexible plants such as potted shrubs and herbs. [Ch, 4 fig. 2 tab. 29 ref.]
Characteristics and impact factors of space utilization of young and middle-aged natural Larix gmelinii forests
YU Bao
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190382
[Abstract](677) [HTML](340) [PDF](8)
Abstract:
  Objective  Taking the over-cutting forest in Daxingan mountains as the research object, this study aims to define space utilization of forest, propose the calculation method for space utilization ratio and analyze space utilization law of natural stands from three aspects: horizontal space, vertical space and comprehensive space utilization of stands.  Method  Using the data of 14 sample plots, correlation analysis and stepwise regression analysis were applied to reveal the main factors influencing space utilization ratio of forest stands to provide theoretical basis for the structure optimization of natural stand, its tending and management.  Result  1) The utilization ratios of horizontal space, vertical space and comprehensive space in 14 plots were 62.5%−85.9%, 31.2%−65.5% and 50.1%−68.7%, respectively. The average levels were 73.6%, 46.0% and 59.2%, respectively. 2) With the growth of forest stands, the tree number, individual size and distribution pattern were constantly adjusted, and utilization ratio of horizontal space also changed. The horizontal space utilization ratio of stands was significantly positively correlated with tree number, renewal density as well as tree clustering coefficient (P<0.01), negatively correlated with stand stock (P<0.05) and stand mean breast-height diameter (P<0.01). 3) The vertical space size of stands at different growth stages varied. When stand growth, stand height, tree number and height of each layer were adjusted gradually, the vertical space size and space utilization ratio of forest stands changed dynamically. The utilization ratio of vertical space of stands had extremely significant positive correlation with height of renewal layer (P<0.01), significant negative correlation with tree number, renewal density and forest accumulation coefficient (P<0.05), and extremely significant negative correlation with the number of vertical layer, height of main forest, height of succession, height difference between main forest and renewal layer, height difference between succession layer and renewal layer, and number of plants in renewal layer (P<0.01). 4) The comprehensive space utilization ratio of stands was affected by both horizontal and vertical structure factors, which had significant positive correlation with stand density and plant number of main forest layer (P<0.05), significant negative correlation with vertical layer number and succession height (P<0.05), and extremely significant negative correlation with height of main forest layer, height difference between main forest layer and renewal layer (P<0.01).  Conclusion  Space size and space utilization ratio change dynamically with the growth of forest stands. The main factors affecting utilization of horizontal space, vertical space, and comprehensive space of stands include renewal density, height difference between succession layer and renewal layer, main forest height, stand density and succession height. To improve the utilization ratio of stand space and optimize stand structure, it is necessary to take three-dimensional technical measures that take into account such factors as horizontal and vertical structures. It's also important to reasonably regulate and control the forest stand density in different growth stages, ensure natural renewal capability of forest stands, and reasonably set the tree number and height distribution at all levels of stands to form a stepped distribution state and make full use of stand space. [Ch, 6 tab. 22 ref.]
Correlation between the remote sensing index of the underlying surface and the surface temperature in the villages in Hangzhou
JIN Jiale, SUN Jian, YANG Libin, DONG Chengfeng, QI Feng
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190379
[Abstract](591) [HTML](237) [PDF](19)
Abstract:
  Objective  In order to figure out how the underlying surface influences the thermal environment of villages and towns, the current study is aimed at a further analysis of the correlation between the characteristics of the underlying surface and the surface temperature of various villages and towns.  Method  First, single-channel algorithm was used to invert the underlying surface temperature of villages and towns. Then, based on the the features of different wave bands of remote sensing data, the normalized difference vegetation index (NDVI), normalized difference build-up index(NDBI), normalized difference impervious surface index(NDISI), normalized difference moisture index(NDMI) and modified normalized difference water index(MNDWI) were calculated. Lastly, on the basis of the results of surface temperature and remote sensing index in summer and winter in Hangzhou, a statistic analysis was conducted of the linear correlation between the characteristics of the underlying surface and the surface temperature of different types of villages and towns.  Result  The land surface temperature had a significant negative correlation with NDVI and NDMI; but a significant positive correlation with NDBI. The influence of NDMI and NDBI on surface temperature was greater than that of NDVI index, while the influence of NDISI and MNDWI on surface temperature was relatively weaker. The correlation between land surface temperature and surface remote sensing index in winter was weaker than in summer.  Conclusion  Reducing the building density, improving the underlying surface humidity and increasing vegetation coverage were all conducive to the reduction of the surface temperature of villages and towns in summer and the optimization of the thermal environment of villages and towns. [Ch, 7 fig. 2 tab. 27 ref.]
Automatic navigation of production platform in greenhouse based on wireless positioning
ZHAO Chenyan, YAO Lijian, YANG Zidong, YAN Song, CAI Cuncheng
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190364
[Abstract](427) [HTML](203) [PDF](18)
Abstract:
  Objective  The current paper is aimed to put forward a path tracking method based on ultra wideband (UWB) positioning and fuzzy control with self-adjustment function in order to improve the accuracy of automatic vehicle navigation in greenhouse.  Method  Firstly, the UWB module was used to construct the wireless positioning system, with which the positioning error of the experimental data was fitted employing bivariate cubic polynomial while measurement point errors were corrected by means of data fitting. Secondly, the weight of lateral deviation and heading deviation was dynamically adjusted with a self-adjusting analytic fuzzy controller so as to obtain the front wheel angle. Finally, real vehicle tests of linear and rectangular path tracking were carried out with the results compared with those obtained employing pure tracking method.  Result  When the line path tracking with different initial stages is conducted, there was an average deviation of 22.4 cm, a standard deviation of 5.8 cm and a mean steady-state deviation of 5.4 cm. And the accuracy of this model has been improved by 28.4%, 40.2% and 34.9% respectively compared with that of pure tracking model. As for rectangular path tracking, the average deviation of the current method is 14.4 cm and the maximum deviation is 46.9 cm, with the maximum deviation mainly occurring at the corner of the rectangle. Similarly, the accuracy of this model is improved by 46.5% and 53.5% respectively, compared with that of the pure tracking model.  Conclusion  The method presented in this paper demonstrates favorable stability and control precision, and it could meet the needs of the automatic navigation operation of the production platform in the greenhouse. [Ch, 8 fig. 3 tab. 24 ref.]
Impact assessment of fuel regulation measures in Platycladus orientalis forest in Western Hills of Beijing
LI Weike, ZHANG Chen, GU Xinghan, NIU Shukui, YIN Jiyan, LIU Xiaodong
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190343
[Abstract](417) [HTML](163) [PDF](10)
Abstract:
  Objective  Based on the fuel distribution characteristics of the Platycladus orientalis forest in Western Hills of Beijing, fuel regulation measures of different intensities were implemented, and effects of the fuel regulation measures were evaluated according to the biodiversity and photosynthetic characteristics of understory vegetation.  Method  P. orientalis, a typical coniferous tree species in North China was selected as the research object. By investigating and analyzing distribution characteristics of P. orientalis forest fuel, regulation measures focusing on pruning, cutting and irrigation were formulated, including: unregulated stands (ck), pruning height 2.5 m and cleaning the surface litter appropriately (P1), pruning height 3.0 m and cutting shrubs and cleaning the surface litter appropriately (P2), pruning height 3.5 m and cutting shrubs and cleaning the surface litter appropriately (P3). Three sample plots of 20 m×20 m were established for each treatment, and changes of plant diversity and photosynthesis attributes of dominant shrubs were compared between regulated and unregulated stands.  Result  The biodiversity of understory vegetation was altered after different fuel managements, among which the species dominance (D) and diversity (H) of shrub layer and grass layer and the species evenness (J) of shrub layer after P2 management were significantly higher than those of ck. Compared with ck, the maximum net photosynthetic rate, light saturation point, light compensation point, dark respiration rate of the understory vegetation (Grewia biloba var. parviflora and Broussonetia papyrifera) all increased, while the apparent quantum efficiency decresed after P2 management. We observed that the accumulation of understory vegetation photosynthetic products was more obvious with P2 management.  Conclusion  The implementation of regulation measures changed the forest structure and increased the light intensity. The effects of different regulation intensity on biodiversity and photosynthetic characteristics of understory vegetation were different. P2 management was most conducive to stand recovery in the study area. [Ch, 2 fig. 4 tab. 26 ref.]
Extraction of polysaccharides of Abelmoschus esculentus using ultrasonic-assisted [Bmim] Cl-K2HPO4 aqueous two phases optimized by response surface method
HE Ziqiang, ZHANG Huiling, YANG Zhengxiong
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190339
[Abstract](421) [HTML](174) [PDF](9)
Abstract:
  Objective  This study attempts to explore the optimum technology of ultrasonic-assisted [Bmim]Cl-K2HPO4 extraction of okra polysaccharides.  Method  Cloud point titration was used to compare the phase separation ability and extraction ability of four aqueous two-phase systems, [Bmim]Cl-(NH4)2SO4, [Bmim]Cl-Na2HPO4, [Bmim]Cl-Na2CO3 and [Bmim]Cl-K2HPO4. [Bmim]Cl-K2HPO4 was determined to be the best aqueous two-phase system. The polysaccharides were extracted from okra (Abelmoschus esculentus) by ultrasonic-assisted [Bmim]Cl-K2HPO4. The effects of five single factors on the extraction rate were discussed: mass fraction of K2HPO4, extraction time, extraction temperature, liquid-solid ratio and mass fraction of [Bmim]Cl. On the basis of the optimum conditions of each single factor experiment, the Box-Behnken design of response surface was applied to optimize the extraction process of okra polysaccharides.  Result  The results showed that the effects of various factors on the extraction rate ranging from large to small included liquid-solid ratio, mass fraction of [Bmim]Cl, extraction temperature, extraction time, and mass fraction of K2HPO4. The optimum extraction conditions were aqueous two-phase system consisting of 5 mL ionic liquid [Bmim]Cl with mass fraction of 71.94%, and 5mL K2HPO4 with mass fraction of 22.31%, extraction time of 29.36 min, extraction temperature of 55.69 ℃, and liquid-solid ratio of 25.00 mL·g−1. Under the above optimized extraction conditions, the predicted value of extraction rate was 29.12%. The validation average was 31.22%, and RSD was 3.70%.   Conclusion  Ultrasonic-assisted extraction of [Bmim] Cl-K2HPO4 has such advantages as high extraction rate, short time and recyclable ionic liquids, and can be used in industrial production. [Ch, 8 fig. 3 tab. 24 ref.]
Effects of exogenous oxalic acid on antioxidant enzymes and lignification of Bambusa oldhami shoots
YU Tun, ZHENG Jian, YU Xuejun
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190337
[Abstract](581) [HTML](274) [PDF](18)
Abstract:
  Objective  The purpose is to explore the preservation effect and mechanism of exogenous oxalic acid treatment on bamboo(Bambusa oldhami) shoots at low temperature.  Method  The peeled bamboo shoots were soaked in 5 mmol·L−1 oxalic acid solution for 10 minutes and stored at 6±1 ℃. The effects of oxalic acid treatment on H2O2 content, SOD activity, CAT activity, hardness, lignin content, key enzymes of lignin metabolism (PAL, 4-CL, CAD, POD) activities as well as their gene expression levels were measured regularly.  Result  Soaking the bamboo shoots in 5 mmol·L−1 oxalic acid solution for 10 minutes increased the activities of SOD and CAT, delayed the accumulation of H2O2, inhibited the increase of key enzymes of lignin metabolism (PAL, 4-CL, CAD, POD) activities and their gene expression level, and significantly reduced the accumulation of lignin and hardness increase in bamboo shoots without sheaths.  Conclusion  Exogenous oxalic acid treatment can retard the lignification process in bamboo shoots without sheaths by inhibiting lignin metabolism and improving antioxidant enzyme system. Thus, the quality decline during the cold storage could be postponed. [Ch, 4 fig. 32 ref.]
Imaging ules in chlorophyll fluorescence of soybean pods in response to Fusarium verticillioides
LONG Xiyang, XIAO Xinli, ZHANG Qihui, YANG Wenyu, LIU Jiang, ZHANG Jing
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190325
[Abstract](431) [HTML](223) [PDF](19)
Abstract:
  Objective  The current study, in order to establish the index for the rapid identification of the resistance of soybean pods, is focused on three cultivars of cultivars, namely the high-resistant cultivar ‘QWT15-2’, the medium-resistant cultivar ‘E1’ and the sensitive cultivar ‘E314’.  Method  The pods were first inoculated with Fusarium verticillioides in vitro, and then the changes of chlorophyll fluorescence parameters in pods were monitored with the employment of chlorophyll fluorescence imaging technology.  Result  After 24 hours of inoculation, the epidermal lesions of the pods were clearly observed through the chlorophyll fluorescence imaging system, and there was a significant change in the fluorescence parameters. To be specific, 0−5 days after mold infection, there was a significant decrease in the initial fluorescence parameters Fo, Fm, Fv of soybean pods, an increase in the non-photochemical quenching coefficient qN and a decrease in QNP, which was accompanied with an inclination of decline in the maximum photochemical efficiency Fv/Fm, actual photochemical efficiency ΦPSⅡ and electron transport rate RET.  Conclusion  The high-resistant culivar ‘QWT15-2’ maintained a relatively healthy tissue with stable fluorescence parameters. The medium-resistant cultivar ‘E1’ and the sensitive cultivar ‘E314’ were affected by mold infection with severe epidermal tissue damage and significant change in the fluorescence parameters. Fluorescence parameters such as Fv/Fm, Fm, Fv, qN and QNP are sensitive to mold infection and can be used as an indicator to evaluate the resistance of soybean pods in the field. [Ch, 4 fig. 17 ref.]
Forests landscape pattern changes and driving forces in Mount Tianmu
YU Fei, LI Zhiyong
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190306
[Abstract](428) [HTML](220) [PDF](30)
Abstract:
  Objective  This research studied the characteristics and driving forces of landscape pattern change in southern collective forest area to provide scientific basis for sustainable forest management.  Method  Landscape pattern change characteristics of state-owned forest in Zhejiang Tianmu Mount nature reserve and collective forest in surrounding community of the reserve in 2000, 2010 and 2017 were compared and studied by using landscape type area transfer matrix and landscape pattern index analysis method.  Result  Ecological forest was the dominant landscape in the reserve and communities. The area of ecological forest increased in the reserve and decreased in the communities, while the area of economic forest changed in an opposite way. The bamboo forest and hickory forest transformed to ecological forest in the reserve, while ecological forest transformed to economic forest, buildings and roads, then mutual transformation between different kinds of economic forest or mutual transformation between economic forest and cultivated land in the communities. The landscape pattern in the reserve changed little, but landscape fragmentation, heterogeneity and uniformity in the communities increased year by year, and the ascendancy of ecological forest had been on the decline. Policy factors, market demand changes and roads were the main driving forces behind the changes of forest landscape patterns.  Conclusion  Changes of landscape patterns in community may affect ecological and cultural functions of forest. Measures, such as policy making, tourism development and road construction can be taken. [Ch, 1 fig. 8 tab. 17 ref.]
Effects of wetland reclamation on kinetic characteristics of soil alkaline phosphatase
XU Chuanhong, LU Mingxing, FAN Diwu, CHENG Hu, HAN Jiangang
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190388
[Abstract](480) [HTML](200) [PDF](8)
Abstract:
  Objective  Enzyme kinetics study is a crucial method to reveal nutrient transformation in soil. The purpose of this study is to investigate the effects of wetland reclamation on transformation and availability of soil phosphorus and provide theoretical basis for nutrient conversion efficiency and quality improvement of wetland.  Method  Eight kinds of soil with different natural covers or land use patterns were collected in Hung-tse Lake estuary (shoal, Phragmites communis, Populus and paddy field) and Chongming Dongtan wetlands (shoal, Spartina alterniflora, P. communis and wheat field), and the soil alkaline phosphatase (ALP) was taken as an example to study kinetic characteristics of enzymatic reaction. One-Way ANOVA was used to compare the difference of soil ALP dynamic parameters under different land uses, and the correlation between physical and chemical properties of soil and kinetic parameters was explored by using redundancy analysis.  Result  Vmax (maximum reaction rate) and Km (Michaelis constant) of ALP kinetic parameters increased by 13.0%−313.4% and 21.0%−50.8%, respectively in Hung-tse Lake wetland, no matter whether the shoal naturally evolved into P. communis, or the reclaimed P. communis wetland into Populus plantation or paddy field. However, the Vmax/Km (catalytic efficiency) decreased by 25.0% during natural succession and increased by 2.3 times after artificial reclamation. For Chongming Dongtan wetland, Vmax and Km increased by 7.0 times and 6.2 times, and Vmax/Km increased by 11.1% after the transformation of shoal into P. communis. Moreover, the Vmax, Km and Vmax/Km decreased by 54.8%, 47.0% and 13.3% respectively after the conversion of P. communis into wheat field. Redundancy analysis results indicated that the Vmax/Km was positively correlated with total nitrogen (Hung-tse Lake) and organic carbon (Chongming Dongtan).  Conclusion  The total ALP significantly increased when the shoal was transformed into P. communis wetland, but the affinity between enzyme and substrate decreased. The Vmax/Km of ALP was significantly influenced by land use type and management mode after artificial reclamation. Increasing soil total nitrogen and organic carbon is beneficial to improvement of ALP catalytic efficiency no matter whether the land type is natural cover or artificial reclamation. [Ch, 1 fig. 3 tab. 43 ref.]
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Cloning and expression analysis of OfFCA gene at flower bud differentiation stages in Osmanthus fragrans
WU Qi, WU Hongfei, ZHOU Minshu, XU Qianxia, YANG Liyuan, ZHAO Hongbo, DONG Bin
2020, 37(2): 195-200.   doi: 10.11833/j.issn.2095-0756.2020.02.001
[Abstract](95) [HTML](45) [PDF](7)
Abstract:
  Objective  Sweet osmanthus (Osmanthus fragrans) is widely used in gardening as a fragrant plant. Its flower bud differentiation is significantly affected by ambient temperature. This research aims to find out the working mechanism of ambient temperature on the flower bud differentiation to help regulate flowering period of sweet osmanthus.  Method  Gene FCA (FLOWERING LOCUS CA) was studied using O. fragrans 'Yanhonggui' as the material, the process of flower bud differentiation was observed by paraffin section, and OfFCA was cloned and expression analysis was made by PCR and real-time PCR.  Result  The sequence length of OfFCA cDNA obtained by cloning was 1 319 bp, the Open Reading Frame(ORF) length was 864 bp, and 287 amino acids were encoded. Amino acid sequence alignment and evolutionary analysis showed that OfFCA was similar in FCA to Olea europaea, Oleaceae and Sesamum indicum, Pedaliaceae, with a homology of over 68%. The real time PCR demonstrated that the expression of OfFCA gene was higher at the low temperature (19℃) treatment than control temperature (25℃) in both leaves and flower buds at different flower bud differentiation stages.  Conclusion  Our work lay a foundation for the studying of regulating flowering time of O. fragrans by ambient temperature.
In vitro bulblet development and analysis of starch synthase gene(LohGBSSI) from Lilium 'Sorbonne'
MIN Ruihan, SUN Minyi, WU Yun, LI Shiqi, XIA Yiping
2020, 37(2): 201-208.   doi: 10.11833/j.issn.2095-0756.2020.02.002
[Abstract](39) [HTML](13) [PDF](2)
Abstract:
  Objective  To promote the breeding speed of Lilium spp. bulbs, a study is conducted of the metabolism of starch, a major component of lily bulbs.  Method  Taking the bulbs in vitro of oriental hybrids Lilium 'Sorbonne', the most popular variety as the research subject, observations are made of the morphological changes and starch accumulation during different development stages. Thereafter, the granule bound starch synthase gene LohGBSSI was cloned with RACE employed, and the gene expression profiles of different tissues and development stages were analyzed.  Result  (1) During the formation and development process of lily bulblets cultured in vitro, in terms of the morphological traits and source-sink transition, there are mainly three stages namely the initial swelling stage, the rapid swelling stage and later swelling stage. (2) The total length of LohGBSSI (GenBank accession number:MF101407.1) is 1 913 bp, and the open reading frame is 1 665 bp, encoding 554 amino acids, which was highly homologous to GBSSI of Lilium davidii var. unicolor (92%), suggesting that this gene might belong with the GBSSI gene family. (3) The expression of LohGBSSI gene in bulbs and leaves was significantly higher than that in stem segments and roots, indicating that the most important site for amylose synthesis was the main source-sink organs. Furthermore, the LohGBSSI expression was highest at 15 d in bulblet, suggesting that rapid starch synthesis is a necessity for the early bulblet morphogenesis.  Conclusion  This study has laid a foundation for further functional analysis of GBSS in bulb development and also provided a basis for future lily starch relevant gene modification.
Selection of pollination combinations and analysis of fruit and seed characters of excellent clones of Xanthoceras sorbifolium
NIU Yuan, AO Yan, LI Yun, TIAN Xiuming, YANG Changwen, LIU Xiaotian, LI Zhihong
2020, 37(2): 209-219.   doi: 10.11833/j.issn.2095-0756.2020.02.003
[Abstract](38) [HTML](8) [PDF](0)
Abstract:
  Objective  The present study attempts to provide reference for scientific allocation of pollination trees and superior clone popularization of Xanthoceras sorbifolium by investigating the best pollination combinations of the excellent clones to increase fruit setting rate and seed yield.  Method  Five superior clones were chosen to observe florescence phenology, stigma receptivity, and pollen viability. Control pollination was carried out to analyze the fertilization rate, fruit setting rate, and characters of each pollination combination related to seed yield.  Result  (1) The florescence stage of the 5 clones was from April 27 to May 14. (2)The stigma receptivity of female flowers was higher on the day of blooming and one day after that. (3)The pollen viability of male flowers was higher on the days of initial blooming and the complete blooming. (4)Considering fertilization rate, final fruit setting rate, seed yield, and fruit and seed characters of all pollination combinations, the optimal pollination combinations for No.10 were 10×16 and 10×119, and the recommended combinations for No.14, No.15, and No.16 were 14×15, 15×16, and 16×15 respectively. No.10, No.14, No.15 and No.16 were not suitable for pollination clone of No.119.  Conclusion  The fruit setting rate and seed yield of X. sorbifolium can be improved by scientific pollination combination.
Natural population distribution pattern of Sinojackia rehderiana in an evergreen broadleaf forest
ZHOU Saixia, GAO Puxin, PAN Fuxing, LONG Jing, HU Yunan, LIU Xiangping, PENG Yansong
2020, 37(2): 220-227.   doi: 10.11833/j.issn.2095-0756.2020.02.004
[Abstract](31) [HTML](16) [PDF](2)
Abstract:
  Objective  To reveal the spatial distribution pattern in different life cycle stages, and to provide a scientific basis for protection of Sinojackia rehderiana, which was naturally distributed in Yongxiu County, Jiangxi Province.  Method  To probe causes of the spatial distribution pattern formation, the adjacent lattice sampling method, the spatial sequence method instead of time sequence, and the O-ring Completely Random Zero Model method were used to analyze the spatial distribution pattern and spatial correlation of individuals in different life cycle stages of a natural population of S. rehderiana.  Result  The DBH class structure and height class structure of S. rehderiana were complete, and the number of seedlings and saplings occupied an absolute advantage for the entire population. Population renewal, which belonged to the growth population, was in a favorable condition. In the process of development from seedling to adult tree, the population of S. rehderiana had an aggregated distribution on a small scale, and had a random to uniform distribution on a large scale. As the age class increased, the aggregated distribution receded. On a small scale, at different life cycle stages of S. rehderiana, there was a significantly positive correlation or no correlation(P=0.05); however, on a large scale there was a negative association or no correlation. The spatial association between seedlings and middle-aged trees, saplings and middle-aged trees, and saplings and adult trees was significantly negative (P=0.05).  Conclusion  In a natural state, the distribution pattern of S. rehderiana was influenced by its own biological factors, intraspecific competition, and interspecific competition; seedling and sapling growth was limited but plentiful; and the population was not currently in a stable state.
Spatial structure characteristics of close-to-nature Phyllostachys edulis forests in Zhejiang Province
YE Peng, YE Changmin, ZHOU Tongyue, LU Yujun, YANG Fan, TANG Mengping
2020, 37(2): 228-234.   doi: 10.11833/j.issn.2095-0756.2020.02.005
[Abstract](38) [HTML](10) [PDF](1)
Abstract:
  Objective  Spatial structure characteristics and differences of moso bamboo (Phyllostachys edulis) forests in different regions of Zhejiang Province were studied.  Method  The close-to-nature moso bamboo forests in different regions of Zhejiang Province were taken as the research objects, 54 sample plots were set up, and spatial structure indices (aggregation index, competition index and age mingling) were used to analyze spatial structure characteristics and differences of moso bamboo forests in different regions of Zhejiang Province.  Result  The mean competition index of moso bamboo forest in different regions of Zhejiang Province is 2.88-8.81, among which Yuyao is the largest and Qingyuan is the smallest. The mean age mingling is 0.30-0.84, the largest in Huangyan and the smallest in Wuyi. The mean aggregation index is 0.73-1.24, the largest in Ninghai area and the smallest in Yuyao area. There was no significant difference in age mingling and aggregation index among different regions in Zhejiang Province, whereas there was significant difference in competition index among different regions in Zhejiang Province(P < 0.05).  Conclusion  The spatial distribution pattern of moso bamboo forests in Zhejiang Province was mainly aggregated distribution. The spatial structure index has a certain regional variation trend, and the competition index decreases gradually from north to south.
Classification of Larix gmelini plantation based on multi-temporal characteristics
GUO Ruixia, LI Chonggui, LIU Sihan, MA Ting, QUAN Qingqing
2020, 37(2): 235-242.   doi: 10.11833/j.issn.2095-0756.2020.02.006
[Abstract](35) [HTML](11) [PDF](1)
Abstract:
  Objective  The study analyzed seasonal characteristics of Larix gmelini plantation based on multi-temporal remote sensing images, and extracted the spatial distribution of L. gmelini plantation in a forest farm located in northeast China by using various classification methods, so as to obtain the means and methods suitable for the extraction of L. gmelini plantation.  Method  Multi-temporal Landsat 8 ancillary forest resource investigation and ground plot were applied in classification process by using the maximum likelihood method, support vector machine method, spectral angle method and k nearest neighbor method, on the basis of analyzing the seasonal and phonological characteristics of L. gmelini plantations to extract information of L. gmelini plantation in the study area, and meanwhile the accuracy was verified.  Result  The L. gmelini plantation had obvious vegetation spectral features and seasonal characteristics, and the spectral differences among tree species were most obvious in the near-infrared band. The autumn image was good for information extraction of L. gmelini plantation, and the extraction precision using multi-phase data was significantly better than that of single-phase data. The classification accuracy of L. gmelini plantation could reach more than 86% with multi-temporal Landsat 8 image, among which the spectral angle method was the best, with an accuracy of 88.346 3%.  Conclusion  It is feasible and applicable to study L. gmelini plantation information extraction by using multi-temporal feature remote sensing image. The results have reference value for large-area extraction of spatial distribution of L. gmelini plantation.
Evaluation of forest ecological function based on projection pursuit classification
ZHANG Yu, CHEN Cunyou, HU Xijun
2020, 37(2): 243-250.   doi: 10.11833/j.issn.2095-0756.2020.02.007
[Abstract](32) [HTML](7) [PDF](1)
Abstract:
  Objective  The rational evaluation of forest ecological function can provide basis for formulating the corresponding measures to improve the ecological function of forests,  Method  Taking Guanyindong Nature Reserve in Nanxiong, Guangdong Province as an example, 19 indicators related to forest ecological function were selected and a forest ecological function evaluation system was established by projection pursuit classification.  Result  (1) The relatively excellent grade forest in the reserve occupied an obvious advantage, but the overall rating of the reserve was medium. (2) The forest structure in the reserve is generally good, but there are too many bamboo forests and young trees, which caused weak forest accumulation capacity and low degree of naturalness. (3) Canopy density, litter thickness, number of trees per hectare, average height and total coverage belonging to 19 indicators in the evaluation process are extremely important. Slope position, naturalness, elevation, age group, soil layer thickness, forest community structure, average DBH, and slope direction are generally important. And hectare biomass, hectare accumulation, tree species structure, health, slope, and soil type are not so important.  Conclusion  Suggestions by the preceding evaluation grade are as follows:(1) Monitoring and protecting should be implemented in the excellent and relatively excellent grade forests. Finding the symptomatic reasons, monitoring and protecting the medium grade forests emphatically. Poor and relatively poor grade forests should be closed hillsides to facilitate afforestation. (2) The reserve should control the growth and expansion of bamboo forests. (3) The functional zoning of protected areas can be adjusted appropriately according to the evaluation results.
Noise attenuation ability and its affecting factors of green belts of 11 areas in the Yangtze River Delta
LI Yanan, HUANG Shaorong, Geriletu, YAN Lijiao
2020, 37(2): 251-258.   doi: 10.11833/j.issn.2095-0756.2020.02.008
[Abstract](37) [HTML](10) [PDF](2)
Abstract:
  Objective  Under the rapid development of urbanization, the impact of pollution caused by urban traffic noise on the living quality of urban residents has been increasingly recognized. Among many solutions to noise reduction, the green belts on the city roads enjoy the unique advantage in the reduction of traffic noise. The order is to provide references for the selection of measurement index of the noise reduction ability of the urban green belt, and give suggestions on how to achieve the optimal noise reduction effect of the urban green belt construction.  Method  This research studies the road forest belts on the major traffic roads of 11 areas (counties, cities and districts) in the Yangtze River Delta and uses the comprehensive comparative analysis of the ratio of different forest belt types, living vegetation volume and the under branch height to conduct a preliminary evaluation on the noise reduction of green belts.  Result  The noise reduction of green belts on the major traffic roads in Xuanwu District of Nanjing and Runzhou District of Zhenjiang are most effective among the 11 areas (counties, cities and districts), while those in Lianyun District of Lianyungang and Qingyuan Town of Lishui are least effective. Rationally mixed forest of arbor and shrub is better for the noise reduction. The results of the simulation model indicate a positive relationship between additional noise reduction of 11 areas (counties, cities and districts) and the living vegetation volume obtained from statistics.  Conclusion  From the comprehensive analysis of the combination of the living vegetation volume and the under branch height, it could be concluded that the effect of noise reduction within the range of 2 m of the under branch height is better.
Weathering characteristics of soil profiles from basalt in eastern Zhejiang Province
HU Zhongcheng, ZHOU Jinjie, CHEN-WU Wentao, LI Jianwu, CHENG Zhichao, WANG Xiao
2020, 37(2): 259-265.   doi: 10.11833/j.issn.2095-0756.2020.02.009
[Abstract](31) [HTML](6) [PDF](0)
Abstract:
  Objective  This study aims to explore the soil genesis of soil profiles from basalt in eastern Zhejiang Province, and to provide a comprehensive understanding of soil genesis in subtropical regions for efficient use of land resources.  Method  Four soil profiles developed from basalt in Xinchang-Shengzhou Basin were selected. The major element composition, chemical weathering indexes[chemical index of alteration(ICIA), chemical index of weathering(ICIW)] and element migration of soil were analyzed.  Result  (1) The main components in different profiles were SiO2, Al2O3, and Fe2O3, whose total content reached over 79%. (2) ICIA value was 42.81%-87.37%, and ICIW value was 45.04%-91.43%, both indicating moderate strength of chemical weathering. (3) The major element migration of most soil samples was negative. Ca, K, Mg and Na were leached out of the soil in large quantities and the mobility in the profile was significantly negative (up to a minimum value of -99%). Al, Fe and Ti elements were relatively enriched in the deposition layer (B) of some profiles, and the migration rate was over zero. The major element migration gradually decreased with soil depth.  Conclusion  (1) The chemical composition of the soil samples in different profiles was consistent. (2)The soil in the study area experienced a relatively strong chemical weathering process under the humid and hot environment. (3) The soil genesis conformed to the desilicification and allitization basic soil formation process in subtropical regions. The law of major element migration changing with soil depth in each profile suggested the gradual bottom-up weathering characteristics of the soil developed from the bedrock.
A isolation method of lignin from bamboo based on complete dissolution
WU Wenjuan, YAN Xueqing, ZOU Chunyang, WANG Bowei, HE Xian
2020, 37(2): 335-342.   doi: 10.11833/j.issn.2095-0756.2020.02.019
[Abstract](32) [HTML](6) [PDF](0)
Abstract:
  Objective  To obtain regenerated cellulolytic enzyme lignin (RCEL), ball-milled bamboo (Phyllostachys edulis) was dissolved, regenerated, and subjected to cellulose enzymatic hydrolysis in a lithium chloride/dimethyl sulfoxide (LiCl/DMSO) solvent system before the enzymatic residue is extracted and purified in the solvent.  Method  First, the chemical composition of lignin was determined with the standard method. Then, the structures and contents of the isolated lignin were analyzed by means of Fourier transform infrared(FT-IR)spectroscopy, alkaline nitrobenzene oxidation and proton nuclear magnetic resonance(1H NMR). Afterwards, gel permeation chromatography(GPC) was conducted to analyze the molecular weight and polydispersity of lignin while X-ray diffraction was used to evaluate the effect of dissolution and regeneration of bamboo on the cellulose crystallinity.  Result  (1) In terms of the chemical composition, the yield and purity of RCEL were higher. (2) The isolated bamboo RCEL lignin was GSH lignin whose condensation degree was slightly higher than that of cellulolytic enzyme lignin(CEL), the content of Syringyl structural unit was higher, almost reaching 50% (w/w), and the proportion of structural unit did not change during the separation process. (3) In terms of molecular weight and its distribution, both of the average molecular weight and weight average molecular weight of bamboo RCEL lignin were high, and there was no occurrence of lignin degradation during the separation process. (4) The crystallinity of cellulose decreased after swelling treatment of LiCl/DMSO solvent system with X-ray diffraction. (5) The thermogravimetric temperature of RCEL lignin was between 200℃ and 600℃ and different pyrolysis features are presented with different condensation degrees of lignin.  Conclusion  This separation method based on LiCl/DMSO solvent system had a good protective effect on the macromolecular structure of lignin while caused damage in carbohydrates structure. It could change the cellulose crystallization region and reduce the degree of crystallization, thus promoting the degradation of cellulose and improving the efficiency of enzyme hydrolysis, which were beneficial to the efficient separation of CEL. Compared with milled wood lignin (MWL) and CEL isolated with the traditional separation method, the RCEL lignin separated using the current separation method could better represent the protolignin of bamboo.
Preparation and properties of bamboo leaf/HDPE composites
ZHA Yao, RAO Jun, GUAN Ying, ZHANG Liping, GAO Hui
2020, 37(2): 343-349.   doi: 10.11833/j.issn.2095-0756.2020.02.020
[Abstract](29) [HTML](7) [PDF](0)
Abstract:
  Objective  The research aim is to improve add value of bamboo leaves.  Method  Novel composites were prepared from ethanol treated bamboo leaves(Phyllostachys edulis) by both hot press molding and injection molding, using high density polyethylene (HDPE) as reinforcing agent and appropriate amount of additives. The structure and properties of the composite were characterized by fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA), and the effects of different contents of bamboo leaves on the properties of composites by the two different molding processes were investigated.  Result  Thermal analysis results showed that the thermal stability of the composites prepared by the two different molding processes increased with the increase of the relative content of bamboo leaves. Mechanical property results indicated that the tensile modulus of composite prepared by injection molding also increased with the increase of the content of bamboo leaves, while the tensile strength decreased. When the content of bamboo leaves increased, the bending strength of the composite increased first and then decreased. The maximum bending strength of the composites obtained by hot press molding and injection molding reached 28.72 and 30.20 MPa when the bamboo leaf content was 40%. The bending modulus of composites obtained by hot press molding and injection molding increased with the increase of the content of bamboo leaves, and the maximums reached 1 564.92 and 1 696.15 MPa, respectively. The impact strength gradually decreased with the increase of the bamboo leaf content.  Conclusion  In contrast, the hot pressed bamboo leaf/HDPE composite had more stable thermal properties, and could be a new environmentally friendly material.
Dimensional stability and mold resistance to bamboo treated in gaseous phase fluorination
LIU Tingsong, WANG Hui, WANG Tongshu, JIANG Jun, WANG Jie, SUN Fangli, YANG Xianjin
2020, 37(2): 350-356.   doi: 10.11833/j.issn.2095-0756.2020.02.021
[Abstract](37) [HTML](9) [PDF](0)
Abstract:
  Objective  The strong permeability and reactivity of gaseous fluorine supposedly helps form chemical bonds between fluorine and bamboo. This aim is to increase the leaching resistance of gaseous fluorine  Method  The four-year-old bamboo (Phyllostachys edulis) was heated in a tubular reactor at 150℃ and treated with 25% fluorine for 4 h. To improve the fluorination effect, bamboo was pretreated with sulfuric acid at different concentrations before the fluorine thermo treatment. Analysis included fourier transformed infrared spectra and X-ray photoelectron spectroscopy. Tests on mold resistance for fluorinated bamboo with mixed fungi of Trichoderma viride, Penicillium citrinum, and Aspergillus niger were conducted.  Result  The chemical analysis and testing of fluoride bamboo showed obvious changes in lignin. Fourier transformed infrared spectra demonstrated that the new peaks at 739 cm-1 were C-F (carbon-fluorine) monosubstituted bonds; whereas, concentrated sulfuric acid pretreated fluorinated bamboo showed double C-F peaks at 878 and 1 088 cm-1 caused by the polysubstitution of C-F bonds on the benzene ring of lignin. Binding energies of 687.8 eV (C-F) and 689.2 eV (C-F2) in X-ray photoelectron spectroscopy confirmed the presence of the C-F bond in fluorinated bamboo. The dimensional stability of treated bamboo was tested under three moistening-drying cycles and water soaking-drying cycles, respectively. The average anti-shrink efficiency (ASE) for three cycles of thermo fluorinated bamboo was 19.1% for moistening-drying and 7.5% for water soaking-drying. Sulfuric acid pretreatment further improved dimensional stability of thermo fluorinated bamboo where 20 g·kg-1 sulfuric acid pretreatment behaved the best with a corresponding ASE of 31.0% for moistening-drying and 15.8% for water soaking-drying. Tests on mold resistance for fluorinated bamboo with mixed fungi of T. viride, P. citrinum, and A. niger, showed no obvious anti-mold efficacy; whereas, for fluorinated bamboo pretreated with sulfuric acid there was slight improvement.  Conclusion  Thus, with gaseous-phase thermo fluorination, a new way of bamboo modification with strong permeability and high reactivity, dimensional stability and mold resistances of treated bamboo were better than the controls making them effective for inner modification of bamboo.
Effect of agricultural structural adjustment on the growth of agricultural total factor productivity
CAO Zhuang, YU Kang
2020, 37(2): 357-365.   doi: 10.11833/j.issn.2095-0756.2020.02.022
[Abstract](54) [HTML](28) [PDF](4)
Abstract:
[Objective] Under the common constraints of the law of diminishing marginal returns and the resource environment, relying on factor inputs to promote agricultural growth is not sustainable. Therefore, continuous improvement of agricultural total factor productivity (TFP) is particularly important for the sustainable growth of China's agriculture.[Method] Using the multiplicatively complete Hicks-Moorsteen TFP index, China's agricultural total factor productivity growth is completely decomposed into technological progress, technological efficiency changes, scale efficiency changes and mixed efficiency changes. The adjustment of agricultural structure affects the growth of agricultural TFP by changing mixed efficiency.[Result] From the time dimension, only the change of mixed efficiency between 1992-1997 contributed 0.5 percent to the growth of agricultural TFP, that is, the adjustment of agricultural structure during this period promoted the growth of agricultural TFP. From the regional perspective, only the mixed efficiency change in the eastern region contributed 0.4 percent to the growth of agricultural TFP in the eastern region, that is, the adjustment of agricultural structure in the eastern region promoted the growth of agricultural TFP in the eastern region. The growth of agricultural TFP in China mainly comes from technological progress. The effects of agricultural restructuring on the growth of agricultural TFP are comparatively different by time and space.[Conclusion] The agricultural structure should be adjusted according to market demand, resource endowment and comparative advantage, in order to improve the mixed efficiency and promote the growth of agricultural TFP.
Analysis of tourists' perception of forest cultural value in Mount Tianmu
YU Fei, LI Zhiyong
2020, 37(2): 366-373.   doi: 10.11833/j.issn.2095-0756.2020.02.023
[Abstract](42) [HTML](12) [PDF](1)
Abstract:
  Objective  To explore the differences of touristsundefined perception of the value in different forest cultures and the causes of the differences.  Method  Forest cultural value is an important part of forest ecosystem. On the basis of defining the connotation and extension of forest cultural value, eight categories of forest cultural values are determined, and a questionnaire is designed to study tourists' perception of the forest cultural values in Mount Tianmu.  Result  The results show that 71.2% of the tourists recognize the eight categories of forest cultural values in Mount Tianmu, among which the physical and mental health (95.5% with an average score of 1.62) and aesthetic (95.5% with an average score of 1.48) are the most recognized and score the highest. Leisure and recreation (85.6%, average score 1.39), education and scientific research (87.1%, average score 1.32), sense of locality (87.9%, average score 1.25), cultural heritage (83.0%, average score 1.17). Inspiration (75.8%, with an average score of 0.97), religion and spiritual service (71.2%, with an average score of 0.88) have the lowest number of people with the lowest score. The background of tourists also has a certain impact on their perception of forest cultural value. The tourists under 40 years old have a significantly lower perception of leisure and recreation value than other age groups, and the tourists between 40 and 60 years old have a higher perception of leisure and recreation, aesthetics and sense of place than other age groups. Tourists' perception of Mount Tianmu's aesthetic core sense of locality will first rise and then decline with the extension of their stay time, and the perception of visitors staying from one week to one month is the highest.  Conclusion  Therefore, in the construction process of Mount Tianmu spot, it is necessary to avoid excessive development of physical and mental health and aesthetic value, and strengthen the excavation of inspiration, religion and spiritual service value.
Spatial distribution features and influence factors of forest towns in Zhejiang Province
GE Yang, ZHANG Jianguo
2020, 37(2): 374-381.   doi: 10.11833/j.issn.2095-0756.2020.02.024
[Abstract](36) [HTML](13) [PDF](1)
Abstract:
  Objective  To explore the spatial layout features of forest towns in Zhejiang Province and conclude the human and natural factors that affect the spatial layout, this research is conducted of the geographic data of 73 forest town and 121 provincial or national forest parks in Zhejiang as well as the indicators of the natural and social conditions of their respective cities.  Method  With the nearest neighbor index, Gini coefficient, correlation analysis and kernel density method adopted, ArcGIS 10.2 and SPSS 19.0 software are employed to study the main spatial distribution features and influencing factors of these forest towns and forest parks.  Result  (1) The 73 forest towns in Zhejiang Province are concentrated. Specifically, forest towns are evenly distributed in the north of Zhejiang, eastern Zhejiang and southern Zhejiang, yet they are concentrated in the west of Zhejiang; (2) The distribution of forest towns in different cities is relatively balanced; (3)In terms of kernel density estimation values(from high to low), the towns can be divided into three main echelons, the ones in the western and northern parts of Huzhou, the ones in the northern and central part of Quzhou, and the ones in Lishui, Wenzhou and Taizhou, subject to factors such as resources endowment, policies, distribution of mountains, transportation and neighboring cities.  Conclusion  Concentrated in economically underdeveloped areas along foothills and valleys, forest towns are designed to facilitate the green and sustainable development of the local economy. The fast development of the highway network is conducive to the development of forest towns though the influence of the respective cities on the layout of forest towns is very limited. On the other hand, the high correlation between the location of the forest town and that of the spatial distribution of the forest park is indicative of the dependence of forest towns on the abundant forest resources around as the vital guarantee for development. Given the huge potential of developing forest towns in other parts of Zhejiang, on the basis of the above results, this research has put forward some feasible suggestions on rationalizing the spatial layout of forest towns.
Research advances in non-destructive detection methods of seed vigor
QU Zhijie, JIA Liangquan, QI Hengnian, WANG Ruiqin, ZHAO Guangwu
2020, 37(2): 382-390.   doi: 10.11833/j.issn.2095-0756.2020.02.025
[Abstract](28) [HTML](13) [PDF](1)
Abstract:
Seeds are the most fundamental means of agriculture production, and their vitality will directly affect the production and development of agriculture. The detection methods of seed vigor are mainly divided into two categories:non-destructive testing and lossy testing. With advantages of no damage to seed samples, high detection efficiency, online detection, good repeatability and less experimentation pollution, non-destructive seed vigor testing methods include near-infrared spectroscopy, hyperspectral detection, electronic nose detection, and machine vision detection. Based on the development status of non-destructive testing technology for seed vigor at home and abroad, this paper comprehensively reviews methods, techniques and detection results of non-destructive testing of seed vigor, and summarizes the characteristics, application status, research progress, advantages and disadvantages in practical application, summarizes the current methods of non-destructive testing of seed vigor at home and abroad, and forecasts the development trend.
Optimization of regeneration system of stem segments of Nandina domestica 'Firepower' in vitro culture
YE Wen, YUAN Chaoqun, QIN Wei, WANG Zhentao, ZHU Yuqiu
2020, 37(2): 391-396.   doi: 10.11833/j.issn.2095-0756.2020.02.026
[Abstract](31) [HTML](16) [PDF](4)
Abstract:
  Objective  To realize the large-scale production of Nandina domestica 'Firepower', this research is focused on the optimization of the regeneration system of the stem segments of 'Firepower' in vitro.  Method  With stem segments of 'Firepower' as the explant, a study is conducted of the key factors such as the basic medium, 6-BA and NAA concentration, sugar concentration and pH that affect the adventitious bud induction, proliferation and rooting.  Result  (1) The ideal medium for adventitious bud induction was WPM+0.50 mg·L-1 6-BA+0.10 mg·L-1 NAA, with an induction rate of adventitious bud of 93.8%, and a robust growth rate; (2) The medium for adventitious bud multiplication was WPM+0.75 mg·L-1 6-BA+0.10 mg·L-1 NAA, with a proliferation cofficient of 3.3 and favorable growth of the new bud; (3) The rooting medium was 1/2 WPM+0.50 mg·L-1 NAA + white sugar 30.0 g·L-1(pH 6.0), with a rooting rate of 95.0%.  Conclusion  The regeneration system of the stem segments of 'Firepower' in vitrothat has been optimized in the current study will provide reliable technical support for large-scale production of 'Firepower'.
Articles
Planting densities and vertical soil nutrients in a Populus tomentosa stand
BO Huijuan, ZHU Jialei, WEN Chunyan, NIE Lishui, SONG Lianjun
2020, 37(2): 266-272.   doi: 10.11833/j.issn.2095-0756.2020.02.010
[Abstract](29) [HTML](12) [PDF](0)
Abstract:
  Objective  To explore the effects of planting densities on soil nutrients of different soil layers for a Populus tomentosa plantation.  Method  10-year-old S86 clones were used to study the soil nutrient characteristics with three planting densities (T1:2 m×2 m; T2:4 m×3 m; and T3:4 m×5 m) for six soil layers (0-5, 5-10, 10-20, 20-40, 40-60, and 60-100 cm). In mid-October 2016, soil samples were collected, and the contents of carbon (C), available nitrogen (N), available phosphorus (P), and available potassium (K) were determined and in total there were 3 treatments with 3 replicates, then one-way ANOVA and Duncan's multiple comparison tests were used to determine significant differences.  Result  The proportions of nutrients in the 0-20 cm layer compared to the 0-100 cm layer were:C(69%), N(79%), P(71%), and K (74%). The content of soil nutrients varied for the three planting densities. The highest C content found in T2 (15.44 g·kg-1 in the 0-5 cm layer) was significantly higher (P < 0.05) than T1; the C content in the 5-20 cm layer was significantly different (P < 0.05) than other densities in the order of T3 > T2 > T1; and in the 40-100 cm layer, the T1 content was significantly lower (P < 0.05) than other densities. The N content in T2 was 14.5-142.7 mg·kg-1. The P content was 1.3-12.4 mg·kg-1 with the content of T2 being significantly higher (P < 0.05) than other layers from 5-40 cm; however, in the 40-100 cm layers the content was T3 > T2 > T1. Planting density, though, had no significant effect on K content (P>0.05).  Conclusion  Nutrient content varied according to planting density and soil layers with the soil nutrient content of 10-year-old P. tomentosa clone S86 gathered in the 0-20 cm layer for the 2 m×2 m density having a lower nutrient content than the 4 m×3 m and 4 m×5 m densities.
Effects of applying limestone powder and microbial fertilizer on soil chemical properties and microbial community in the diseased Carya cathayensis woodland
FANG Wei, YU Xiao, WANG Jing, XU Qiufang, LIANG Chenfei, QIN Hua, CHEN Junhui
2020, 37(2): 273-283.   doi: 10.11833/j.issn.2095-0756.2020.02.011
[Abstract](38) [HTML](10) [PDF](2)
Abstract:
  Objective  This study attempts to determine the efficacy of applying limestone powder and microbial fertilizer to enhance soil chemical properties and microbial communities in the diseased Carya cathayensis woodland.  Method  Soil from dead C. cathayensis woodland was collected for culture experiment. The four treatments tested included a control (ck) with no amendment and three amendment treatments:limestone powder (LP), Bacillus fluid (SL), microbial compound fertilizer (MCF). Soil samples were collected at day 20, 40, 60 and 120, and analyzed for chemical properties. Additionally, the abundances and community structures of soil bacteria and fungi were examined using quantitative PCR and PCR-DGGE, respectively.  Result  The LP greatly improved the soil pH, but had no significant effect on other soil chemical properties or microbial community structure or abundances. Both SL and MCF treatments significantly(P < 0.05)increased soil organic carbon content as well as alkali-hydrolysable nitrogen and available phosphorus and potassium. The SL treatment increased soil pH, and in the short term(60 d)increased the abundance of bacteria and fungi, but decreased microbial diversity. In contrast, MCF treatment reduced the soil pH, significantly (P < 0.05) increased the abundance of soil fungi, and in the short term (40 d) increased bacterial abundances, but the bacterial community diversity reduced significantly (P < 0.05) and the diversity of fungi did not increase significantly. The DGGE profiles analysis showed that the effective time for the MCF and SL treatments with adding of beneficial microbes was about 120 days, which could play a good role in promoting growth, increasing the beneficial bacteria proportion and adjusting the soil microbial community structure.  Conclusion  MCF, SL and LP can significantly improve the soil chemical traits of C. cathayensis woodland and increase the number of beneficial bacteria in soil. It can be used as a soil amendment for degraded C. cathayensis woodland.
Effects of two cultivation environments on diversity of bacterial symbionts in Dendrobium catenatum
YU Wangyin, YAO Guan, Tashi Lhamo, Phur Qiong, LIU Jingjing, ZHOU Xiang
2020, 37(2): 284-290.   doi: 10.11833/j.issn.2095-0756.2020.02.012
[Abstract](30) [HTML](13) [PDF](1)
Abstract:
  Objective  Aimed to discover the effect of different cultivation measures on endophytic bacterial communities and polysaccharides accumulation in Dendrobium catenatum, this research is conducted to compare D. catenatum in two environments of soil cultivation in green house and truck-attaching cultivation in open field.  Method  With the Miseq high-throughput sequencing on Illumina platform conducted, efforts are made to discover the community structures, diversity, and potential functions of bacterial symbionts in different tissues such as roots, stems and leaves of D. catenatum. Besides, the correlation of polysaccharide content with bacterial community was also analyzed employing the stepwise method.  Result  (1) There is significant difference (P < 0.05) in bacterial communities in different tissues with different cultivation environments; (2) The bacterial richness was higher in truck-attaching cultivation than that in greenhouse, and the operational taxonomic units (OTUs) in root tissues are the largest in number (112-630 OTUs) while those in leaf tissues (28-73 OTUs) are the smallest in number. Comparatively, the OTUs in phyla of Firmicutes (16.7%-34.9%), Bacteriodetes (8.7%-35.6%) and Proteobacteria (15.9%-42.0%) dominate in tissues; (3) Physiologically, OTUs of nitrogen-fixation related bacteria such as Frankiaceae are larger in number in truck-attaching cultivation environment, reflective of the influence of nitrogen-lacking environment. The stepwise procedure results have shown that the relative abundance of Acinetobacter has the highest correlation with the polysaccharide contents in different tissues of root, stem and leaf, followed by Pseudomonas.  Conclusion  D. catenatum are rich in endophytic bacteria, cultivation measures exert effect on the bacterial community and some bacteria are correlated with the polysaccharides contents. These results shall shed light on further exploration of endophytic bacterial resources in D. catenatum.
Transgenetic expression coat protein of Chinese wheat mosaic virus(CWMV) enhances resistance of Nicotiana benthamiana to CWMV
YANG Jin, JIN Peng, LIU Peng, YANG Jian, WANG Yang, DAI Liangying, CHEN Jianping
2020, 37(2): 291-295.   doi: 10.11833/j.issn.2095-0756.2020.02.013
[Abstract](33) [HTML](17) [PDF](1)
Abstract:
  Objective  Chinese wheat mosaic virus (CWMV) is an important virus causing wheat mosaic virus disease. The objective of this study is to obtain expression transgenic tobacco (OECP) of CWMV coat protein (CP) gene and analyze its disease resistance, which lays a foundation for the cultivation of wheat disease resistance materials.  Method  The expression vector containing the coat protein gene of CWMV was constructed by in vitro recombinant DNA technology and OECP was obtained by Agrobacterium-mediated transformation assay. Western Blot and PCR analysis showed that the CP gene of CWMV was correctly expressed in OECP.  Result  Some transgenic positive plants displayed dwarf phenotype. The quantitative analysis in OECP showed that expression level of CWMV motor protein gene was significantly reduced 7 days after inoculation with CWMV.  Conclusion  Expressing CP protein gene could significantly enhance resistance of Nicotiana benthamiana to CWMV.
Leaf structure and chlorophyll content in Torreya grandis 'Merrillii' with Nalepella abiesis infestation
QIAN Yuting, XUE Xiaofeng, ZENG Yanru, CHEN Wenchong, YE Xiaoming, YU Weiwu, DAI Wensheng
2020, 37(2): 296-302.   doi: 10.11833/j.issn.2095-0756.2020.02.014
[Abstract](34) [HTML](6) [PDF](1)
Abstract:
  Objective  The aim is to provide a theoretical basis for the prevention and control of Nalepella abiesis and to study the damage mechanism and chlorophyll content from N. abiesis on leaves of Torreya grandis 'Merrillii'.  Method  Dynamic changes in leaf tissue structure, stomatal structure, chloroplast ultrastructure, and chlorophyll content were studied using the fluorescence microscope, transmission electron microscope (TEM), scanning electron microscope (SEM), and spectrophotometer.  Result  The palisade cells changed in shape and decreased in number for an increase in days after inoculation (DAI) with mites. By the 40th day, thickness of the palisade tissue decreased considerably; spongy cells shrank; spongy tissue became looser; around stomata the cuticular peg was destroyed; guard cells shrank; and stomata shrank revealing obvious injury. Mesophyll cells gradually swelled and became deformed with the gap between cells becoming larger and larger. Also, the number of chloroplasts gradually decreased with the appearance of starch grains. By the 12th day, the number of osmiophilic granules within the chloroplast had increased with grana lamellae becoming more and more irregular in structure, especially on the 25th day, and finally disintegrating and disappearing on the 40th day. There was no significant difference in chlorophyll content between ck and the treatment with mite infection from 0 to 12 d, but a significant difference occurred from 25 to 40 d(P < 0.05). Compared to the ck, the decrease in chlorophyll content continued as time increased.  Conclusion  N. abiesis infestation could destroy the structure of the mesophyll cells and leaf stomata of T. grandis 'Merrillii' leading to a decreased chlorophyll content that could affect photosynthesis.
Sequence analysis of COⅠ, COⅡ, Cytb and 28S gene fragments from Apriona swainsoni larvae
YE Bihuan, LI Haibo, YE Weibang, CHEN Youwu
2020, 37(2): 303-310.   doi: 10.11833/j.issn.2095-0756.2020.02.015
[Abstract](33) [HTML](8) [PDF](1)
Abstract:
  Objective  Based on molecular biological methods, this research was intended to explore the the target genes that could identify Apriona swainsoni larvae from other Cerambycidae larvae, so as to provide a guarantee for the food and drug use of A. swainsonias larvae.  Method  Four different gene fragments were cloned using the general primers of COⅠ, COⅡ, Cytb and 28S genes before the homologous sequence retrieval, multiple comparison, sequence analysis and molecular phylogenetic tree construction were carried out.  Result  (1) The fragments of the four gene sequences obtained by gene cloning were 817, 545, 434 and 1 088 bp, respectively. (2) In light of the distribution of special loci, 28S had the highest proportion of conserved sites, followed by Cytb, COⅠ and COⅡ, while the variability rate was just the opposite. The base composition and replacement of the COⅠ, COⅡ and Cytb gene fragments were all shown as A+T contents> G+C contents, with the rate of translocation higher than that of the conversion. However, when it came to the 28S gene fragment, it was A+T cotents <G+C cotents, with the rate of translocation lower than that of the conversion. (3) There existed differences in the sequence structure between mitochondrial genes and nuclear genes with the latter more conservative than the former. (4)The molecular phylogenetic relationship based on those four gene sequences could distinguish A. swainsoni larvae from other Cerambyeidae larvae, such as A. germari.  Conclusion  COⅠ, COⅡ, Cytb and 28S genes could be used as the molecular reference for the identification of A. swainsoni larvae.
Effects of host plants and temperatures on digestive enzyme activities in Heterolocha jinyinhuaphaga larvae
XIANG Yuyong, SUN Xing, YIN Peifeng
2020, 37(2): 311-318.   doi: 10.11833/j.issn.2095-0756.2020.02.016
[Abstract](29) [HTML](6) [PDF](0)
Abstract:
  Objective  This research aims to study the effects of host plants and temperatures on digestive enzyme activities in Heterolocha jinyinhuaphaga larvae, and lay a foundation for further research on their physiological and biochemical mechanism of environmental adaptation.  Method  Effects of these factors on digestive enzyme activities in H. jinyinhuaphaga larvae were studied through ultraviolet spectrophotometry and burette in laboratory by using 3, 5-dinitrosalicylic acid method, fulin-phenolic method, and standard sodium hydroxide solution titration method.  Result  Digestive enzyme activities of each H. jinyinhuaphaga larva differed after feeding on 'Jiufeng No. 1', 'Xiangshui No. 1', 'Xiangshui No. 2' and a wild variety of Lonicera japonica. The H. jinyinhuaphaga larvae feeding on the wild variety had the highest amylase, sucrase and protease activities, and the lowest lipase activity. The activities in the 1st instar larva were 18.37, 26.45, 22.31 and 5.54 mmol·g-1·min-1 respectively. The four digestive enzyme activities all increased with larval ages. Compared with the 1st instar larvae, the 5th instar larvae, after feeding on the four cultivars, displayed an increase in amylase activities by 33.39%, 27.48%, 33.31% and 45.29%, an increase in sucrase activities by 19.12%, 15.02%, 14.64% and 29.64%, an increase in protease activities by 25.55%, 18.69%, 21.69% and 41.46%, and an increase in lipase activities by 84.95%, 68.04%, 68.41% and 77.80%. In the range of 16-34℃, the activities of the four digestive enzymes all showed a tendency of first increasing and then decreasing with the rise of temperature. The highest amylase activities were observed at 22℃ in the larvae of the 1st-5th instar, which were 19.95, 20.57, 21.79, 23.64 and 25.86 mmol·g-1·min-1. The sucrase activities of the 1st-5th instar larvae were the highest at 22℃, which were 27.65, 28.89, 29.85, 31.45 and 32.89 mmol·g-1·min-1. The protease activities of the 1st-5th instar larvae were the highest at 25℃, which were 21.65, 22.76, 23.43, 25.71 and 26.98 mmol·g-1·min-1. The lipase activities of the 1st-5th instar larvae were the highest at 28℃, which were 7.38, 8.49, 9.81, 11.33 and 13.21 mmol·g-1·min-1. Two-way ANOVA showed that the interaction between host plants and larval ages, as well as the interaction between temperatures and larval ages, had no significant effect on the four digestive enzyme activities.  Conclusion  Host plants and temperatures can affect digestive enzyme activities of H. jinyinhuaphaga larvae.
Effects and mechanism of multi-walled carbon nanotubes on the bacterial toxicity of cadmium
FU Yong, PEI Jianchuan, LI Mei, WANG Pengcheng, WANG Jiejie
2020, 37(2): 319-324.   doi: 10.11833/j.issn.2095-0756.2020.02.017
[Abstract](30) [HTML](7) [PDF](0)
Abstract:
  Objective  This study aims to explore the combined toxicity of multi-walled carbon nanotubes(MWCNTs) and heavy metals.  Method  Three types of MWCNTs[Short-MWCNTs(S-M), Short-carboxyl-MWCNTs(SC-M), Short-hydroxyl-MWCNTs(SO-M)]were selected to conduct the toxicity tests. Single and combined toxicity of MWCNTs and Cd2+ to Escherichia coli with different mass concentrations was studied, and the underlying toxicity and its influencing mechanism were revealed by zeta potential determination, sedimentation and adsorption experiments.  Result  Under the same conditions the bacterial toxicity of the three types of MWCNTs ranging from strong to weak was S-M, SC-M and SO-M. In the presence of MWCNTs (100 mg·L-1) and Cd2+(0, 1, 2, 4, 8, 10 mg·L-1), the combined toxicity ranging from strong to weak was S-M + Cd2+, SC-M + Cd2+ and SO-M + Cd2+. All the combined toxicity was lower than additive toxicity accordingly. In the presence of MWCNTs (10, 20, 50, 100, 200 mg·L-1) and Cd2+(1 mg·L-1), the combined toxicity ranging from strong to weak was S-M + Cd2+, SC-M + Cd2+ and SO-M + Cd2+.  Conclusion  The influence of MWCNTs on the bacterial toxicity of Cd2+ mainly depends on the adsorption capacity of MWCNTs to Cd2+.
Biochar derived from waste newspapers for removing copper ions from aqueous solution
HU Die, LI Wenqi, ZHANG Liping, GUAN Ying, GAO Hui
2020, 37(2): 325-334.   doi: 10.11833/j.issn.2095-0756.2020.02.018
[Abstract](34) [HTML](7) [PDF](0)
Abstract:
  Objective  A series kinds of biochar were produced from waste newspapers by pyrolysis at different temperatures (400, 500 and 600℃). The ability of removing copper ions from an aqueous solution of these biochar will be testified and the corresponding adsorbing mechanism also will be discussed.  Method  The following techniques have been utilized to characterize the structure and properties of biochar, which are elemental analysis, Brunauer-Emmett-Teller method (BET), Fourier transform-infrared spectroscopy (FTIR), X-ray photoelectron spectrometry (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and atomic absorption spectroscopy (AAS).  Result  The fabricated biochar (WBC-600) exhibits a typical porous structure and its specific surface area is high as 211 m2·g-1. This structure will be beneficial for removing Cu2+ from aqueous solution. Furthermore, physical and chemical properties of biochar varied significantly based on the pyrolysis temperatures. It is revealed that the aromaticity, specific surface area, pH, and ash content of the biochar increased gradually with the increasing pyrolysis temperature, while the hydrogen, nitrogen and oxygen contents decreased. Batch adsorption experiments were performed to examine the effects of initial pH, contact time, Cu2+ concentration, and temperature on the adsorption capacity of Cu2+. The maximum adsorption capacities of waste newspapers biochar, WBC-400, WBC-500, and WBC-600 were 107, 115 and 138 mg·g-1 at 30℃ (pH 5.0), respectively. The pseudo-second-order kinetics model and Langmuir adsorption isotherm model were suitable for describing the adsorption process, indicating that chemical sorption was a rate-limiting step and adsorption took place at specific homogeneous sites within the adsorbent (monolayer adsorption). The calculated ΔHo values indicated that the adsorption process was endothermic. Furthermore, the adsorption mechanism for WBC was attributed to precipitation, ion exchange, π-π interactions, and complexation.  Conclusion  The biochar fabricated from waste newspapers by the process suggested in our study meets the criterion of being an effective adsorbent for removing Cu2+ from an aqueous solution. Moreover, since the original material, waste newspaper, is a typical solid waste disposal, the manufacturing of the biochar will have benefits both to reduce cost and protect environment.

Bimonthly, Start in 1984

Supervisor:Department of Education of Zhejiang Province

Sponsor:Zhejiang A&F University

Editor-in-Chief:Zhou Guomo

Editor:Editorial Department of Journal of Zhejiang A&F University

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E-mail:zlxb@zafu.edu.cn

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