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).
Evaluation of forest ecosystem service value in Wuyanling National Nature Reserve of Zhejiang Province
LI Zuoyu, DONG Hongxian, LIU Leilei, LEI Zupei
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190573
  Objective  The multi-functional ecological services provided by Wuyanling National Nature Reserve play a vital role in protecting and improving the ecological environment of Taishun and Wenzhou.  Method  Taking Wuyanling National Nature Reserve as the research area, the quality and value of the ecological services of the forest ecosystem in Wuyanling National Nature Reserve were quantitatively evaluated with reference to the Forest Ecosystem Assessment Standard (LY/T 1721−2008).  Result  The total value of forest ecosystem ecological services in Wuyanling National Nature Reserve in 2017 was 100.24 ×108 yuan·a−1, and the value of forest ecological service per unit area was 3.92×105 yuan·hm−2·a−1. The proportion of forest ecosystem service value from large to small in Wuyanling National Nature Reserve was soil conservation, water conservation, accumulation of nutrients, carbon fixation and oxygen release, biodiversity protection, and purification of the atmospheric environment. It could be seen that conservation soil, water conservation and accumulation of nutrients were the main services of Wuyanling forest ecosystem, and the sum of the three accounted for 91.92%, occupying a dominant position. The service value of different forest types in Wuyanling National Nature Reserve ranging from large to small was evergreen broad-leaved forest, Chinese fir forest, bamboo forest, Masson pine forest, coniferous and broad-leaved mixed forest, cedar forest, and economic forest. The evergreen broad-leaved forest contributed more than 50% to Wuyanling forest ecosystem service value, occupying an absolute position.  Conclusion  The ecological service value per unit area of evergreen broad-leaved forest in Wuyanling National Nature Reserve is much higher than that of other forest types. Therefore, through forest facies transformation technologies such as transforming coniferous forest into broad-leaved forest, the quality of forest stands can be improved, the structure of ecosystems can be optimized, and the output and value of ecosystem services can be increased. [Ch, 5 tab. 27 ref.]
Effects of different factors on dissolved gaseous mercury in the complexation reaction of antibiotics with mercury
YU Ninger, WU Shengchun, LIANG Peng
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190568
  Objective  To better understand the combined pollution of antibiotics and mercury, an investigation is conducted of the influence of different environmental factors on the dissolved gases mercury (DGM) formed in the liquid phase after the complexion reaction of oxytetracycline (OTC) with mercury.  Method  With OTC solution (1 μmol·L−1) and mercury chloride (HgCl2 1 μmol·L−1) selected as materials, simulation experiments were conducted in the laboratory with pH, light, salinity, and redox employed as the environmental factors to explore the changing characteristics of DGM concentration after the reaction.  Result  Environmental factors have significant impact on the formation of DGM. There is a significant decrease in DGM concentration with the increase of pH. The DGM concentration in the condition of light irradiation was slightly higher than that in the dark condition. The DGM concentration in sea water was significantly higher than that in freshwater. The DGM concentration in anaerobic condition was slightly lower than that in aerobic condition but the situation was reversed after ten days.  Conclusion  The complexation reaction of OTC with mercury occurs and is beneficial to the formation of DGM which is subject to the impact of different environmental factors. The DGM formed by the reaction of OTC and Hg is higher than that in the control group. However, the influence of OTC on the formation of DGM is not as strong as the environmental factors. [Ch, 3 fig. 27 ref.]
Calculation and correction of wood internal cavity area based on radar detection
CHEN Yongping, GUO Wenjing, TANG Qiheng
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190709
  Objective  The objective of this study is to realize the rapid recognition and quantitative characterization of the internal cavities in wood by evaluating the accuracy and precision of the cavity imaging under radar detection method.  Method  Pinus massoniana and Cunninghamia lanceolata, commonly used in ancient building timber structure, were taken as the research object. Artificial simulation was used to make special-shaped cavities at the end of the logs to simulate the internal damages, and then the radar scanner was used to detect the cavities. The differences between the visual imaging technology and the processing methods such as the Hilbert integral method, single path data extraction and synthesis, and the multi-parameter correction of the image contour were compared and analyzed. The calculation and feasible correction method of wood internal cavity area based on radar detection was proposed.  Result  The internal cavity of P. massoniana and C. lanceolata wood could be recognized rapidly by the radar nondestructive testing technology, but the visual imaging technology had a large error in quantitative evaluation, which required further relevant data processing and correction. The estimated cavity area of the unmodified radar image was smaller than that of the actual one. There was still a certain error between the actual cavity area and the estimated cavity area of the radar image calculated by Hilbert integral method or modified by dielectric constant. The distance between the wood edge and the cavity edge should be corrected according to the formula s3c=(sra)k1k2, that was to say, the dielectric constant obtained by tree species and moisture content in practical application was only one factor in the multi-parameter correction. Therefore, it was difficult for radar scanner to accurately recognize the specific shape of the cavity, regardless of data processing and correction, and further research should be carried out.  Conclusion  The radar detection and correction technology can be applied to the detection of cavities in wood and the error of cavity area identification can be less than 30% by integrating tree species and moisture content values. [Ch, 6 fig. 2 tab. 17 ref.]
A comparative study of the PhytOC sequestration potential in the trunk of Pinus massoniana of different provenances
ZHANG Yunqing, ZHANG Zhen, SUN Kai, JIANG Peikun
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190583
  Objective  As phytolith-occluded organic carbon (PhytOC) plays a unique role in the reduction of atmospheric CO2 contents and the mitigation of the greenhouse effect, this study, with a comparison conducted of the PhytOC sequestration potential of masson pines( Pinus massoniana ) of different provenances is aimed at the selection of the Masson pine with the highest PhytOC sequestration capacity.  Method  With masson pines of twenty provenances(twenty regions in 11 provinces ) chosen at Laoshan Forest Farm which is located in Chun’an County of Zhejiang Province, an analysis was conducted of the contents of total OC, phytoliths, PhytOC as well as the trunk bionass of masson pines to highlight the differences of sequestration potential of masson pines of different provenances.  Result  (1) The contents of total OC, phytoliths, PhytOC, and phytolith carbon mass fraction in the trunks of masson pines were in the range of 467.6−489.6, 0.305−0.845, 126.8−210.2, and 0.049−0.128 g·kg−1 respectively. (2) The trunk biomass and PhytOC stock in the trunks of masson pines were 76.48−295.39 kg·plant−1 and 4.83−31.58 g·plant−1, respectively. (3) As was shown in the cluster analysis, the chosen masson pines of 20 provenances can be divided into four categories: a. Hubei Tongshan 84, Guangxi Gongcheng 111, Jiangxi Jian 63 and Guangxi Cenxi 115 which demonstrate the strongest PhytOC sequestration capacity; b. 7 provenances including Henan Tongbai 21, Hunan Anhua 72 and Guangdong Xinyi 105 which demonstrate relatively strong PhytOC sequestration capacity; c. 8 provenances including Zhejiang Chun’an 56, Guizhou Duyun 123, Fujian Yongding 95; d. Zhejiang Qingyuan 54 which demonstrate the weakest PhytOC sequestration capacity.  Conclusion  Significant differences were shown in the content of phytoliths, PhytOC, and carbon content of phytolith in the trunks of masson pines of different provenances (P<0.05). Guangxi Cenxi 115 demonstrated the highest PhytOC sequestration capacity and should be promoted in plantation in the ecosystem of masson pines so as to increase the sequestration amount of PhytOC. [Ch, 3 fig. 2 tab. 35 ref.]
Optimization of camptothecin extraction process from Nothapodytes pittosporoides by Box-Behnken response surface method
LIN Jincao, XIAO Li, WU Choufei, ZHANG Shaoyong, YANG Huining, ZHANG Liqin
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190533
  Objective  This study aims to optimize extraction process of camptothecin from Nothapodytes pittosporoides by response surface method and ultrasonic wave.  Method  The content of camptothecin was determined by high performance liquid chromatography, and N. pittosporoides wood available on the market was used as the research object. Based on the single factor experiment, methanol concentration, liquid to solid ratio and ultrasonic time were taken as the influencing factors, and the extraction rate of camptothecin as the response value. Box-Behnken response surface method was used to design the experiment with 3 factors and 3 levels, so as to determine the optimal extraction process.  Result  The optimal extraction process was as follows: methanol concentration 46.4%, ultrasonic time 26.1 min, liquid to solid ratio 21.20 mL·g−1, extraction rate of camptothecin 0.084 4%, binomial fitting correlation coefficient R2 0.969 3, and deviation between the predicted value and the experimental value 3.2%.  Conclusion  Box-Behnken can be used to optimize the extraction process of camptothecin from N. pittosporoides, with high precision and good predictability. [Ch, 2 fig. 3 tab. 13 ref.]
Application and development of quartz crystal microbalance (QCM)
ZOU Chunyang, WANG Bowei, YAN Xueqing, HE Xian, WU Wenjuan
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190570
As a surface sensitive analysis technique based on the piezoelectric effect of quartz crystal, quartz crystal microbalance (QCM) is a highly sensitive on-line interface process analysis tool featured with the sensitivity of Nanogram level and a in-situ and real-time reflection of the surface quality change of the crystal wafer. The strengths of QCM in real-time monitoring, characterization of (biological) membrane deposition, detection of specific antigens and research on cell adhesion have been widely explored in the fields of chemistry, physics and biology. This paper, with an introduction of the technical principles of QCM and an overview of its applications in cells, environmental monitoring, enzymatic hydrolysis, electrochemistry and other fields in recent years, is aimed to prospect the research direction of QCM in the future. [Ch, 40 ref.]
Dynamic characteristics of soil respiration of Savanna ecosystem in dry hot valley of Yuanjiang
YANG Kaiye, GONG Hede, LI Jing, LIU Yuntong, SHA Liqing, SONG Qinghai, JIN Yanqiang, YANG Daxin, LI Peiguang, WEN Guojing, CHEN Aiguo, PANG Zhiqiang, ZHANG Yiping
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190647
  Objective  Soil respiration plays an important role in regulating CO2 concentration in the atmosphere. Soil respiration in the Savanna ecosystem is one of the main sources of global greenhouse gas emissions, but its emission characteristics and main influencing factors are not clear.  Method  Taking the Savanna ecosystem in dry hot valley of Yuanjiang inYunnan Province as an example, the soil respiration was measured from June 2014 to June 2015 by static chamber method, and the dynamic characteristics and its influencing factors in the Savanna ecosystem in Yuanjiang were studied.  Result  Soil temperature, soil moisture and soil respiration had obvious seasonal variations, and as expected, they were significantly (P<0.01) higher in rainy season than in dry season. The relationship between soil respiration and soil temperature and soil moisture are exponential and parabola. The temperature Q10 at 5 and 10 cm of soil was 1.73 and 1.98 respectively, which was less than the global average of 2.0. Therefore, using 10 cm soil temperature could better simulate soil respiration. Fitting analysis of soil temperature, water content and soil respiration showed that the soil respiration of Savanna ecosystem in Yuanjiang was mainly restricted by water condition. The annual emission of soil respiration in the ecosystem was 4.20 t·hm−2·a−1, including 2.71 t·hm−2 in rainy season, accounting for 64.5% of the total annual carbon emission, and 1.49 t·hm−2 in dry season, accounting for 35.5% of the total annual carbon emission. The average value of soil respiration in global Savanna ecosystem is 8.16 t·hm−2·a−1.  Conclusion  Compared with the global Savanna ecosystem, the total amount of soil respiration in Yuanjiang was in a lower position, which could be attributed to the lower rainfall in the Savanna ecosystem in Yuanjiang. There exists a significant positive correlation between rainfall and soil respiration in the Savanna region (R2=0.61, P<0.001). [Ch, 4 fig. 1 tab. 72 ref.]
Post occupancy evaluation of rural complex in the rural of large cities
LIN Qiqi, XU Bin, ZHANG Yaping
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.2020.20190580
  Objective  Txplore the comprehensive requirements of users in the planning design of rural complexes.  Method  A case study of the rural complex in Raocheng village of West Lake District in Hangzhou, starting with the rural scenery and the perception of rural life in the suburbs rural village of big cities, post occupancy evaluation (POE) method was used for survey and information feedback, and correlation analysis was made on POE conclusions, spatial participation and landscape preference of each landscape node in the rural surroundings complex.  Result  ①The users mainly come from the villagers around Raocheng village and residents of Hangzhou city; ②The Raocheng village rural complex is an important place for users’ daily relaxation, however only 9.26% for short-term or long-term vacations; ③The main factors affecting user’s satisfaction level with the rural complex are rural experience, landscape features, cultural features and supporting service facilities, and the rural experience and landscape features are the dominant ones; ④The rural perception of landscape nodes has a positive correlation with user preference and user density.  Conclusion  Landscape planning design should not only retain and translate the native elements, but also need to consider the source of users and the needs of behavior patterns. [Ch, 2 fig. 4 tab. 14 ref.]
Dynamic changes of capsaicinoids and vitamin C contents in Hangzhou pepper during the harvesting period
GONG Xiangyu, RAO Shuaiqi, LÜ Xiaohan, YANG Jing, ZHU Biao
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.2019-0577
  Objective  This study is aimed to determine the dynamic changes of capsaicinoids, vitamin C and dry matter contents in the fruit of Hangzhou pepper (Capsicum annuum 'Hangzhou Jizhua' × 'Jilin Zaojiao') during the harvest period.  Method  Contents of capsaicin, dihydrocapsaicin, vitamin C and dry matter in the fruit of four common cultivars of Hangzhou pepper harvested at different times (14, 21, 28, 35, 42, 49, 56 days after flowering) were measured by HPLC.  Result  Content of capsaicinoids fluctuated during the harvest period and varied among four cultivars, while the contents of vitamin C and dry matter increased with fruit ripening.  Conclusion  Around 49 days after flowering is the best pepper harvest time in terms of fruit maturity, and the contents of capsaicinoids, vitamin C and dry matter. Since the dynamic changes of capsaicinoids content varied among cultivars, the optimum harvesting planning should take into consideration various factors such as pepper varieties, market demand and supply-demand relationship. [Ch, 4 fig. 3 tab. 27 ref.]
Plant community characteristics of natural secondary forest with different restoration years in karst area of Xichuan County, Henan Province
WANG Lei, CUI Ming, ZHOU Mengling, ZHAO Xiaodong, YAN Weipeng, WU Jianhong, LIU Yuguo
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190498
  Objective  This study aims to investigate the species composition, biological diversity and structural characteristics of natural secondary forest communities with different restoration ages in the karst area at the head of canal in the middle route of the South-to-North Water Diversion Project, and to understand the vegetation status in the karst area, so as to provide scientific basis for regional vegetation protection and restoration, biodiversity protection and comprehensive management and evaluation of rocky desertification.  Method  Using the research method of “space instead of time”, and taking 6 kinds of natural secondary forests (20, 28, 35, 40, 53, 70 a) in the karst area of Xichuan County as the research object.The tree layer, shrub layer and herb layer were investigated according to the method for forest community survey, and the important value of community species, diversity index, community structure and community similarity coefficient were calculated.  Result  A total of 63 species of vascular plants belonging to 40 families and 58 genera were found in 18 fixed plots of 10 800 m2. With the increase of recovery years, the species richness increased continuously, and most of the increased species belonged to single family, single genus and single species. The species diversity index of each layer showed different characteristics with the increase of recovery years, but the overall trend was slowly rising. Shannon diversity index, Simpson diversity index and Pielou evenness index of tree layer were the highest in P5 plots (recovery time 53 a), and the lowest in P1 plots (recovery time 20 a). Shannon diversity index and Simpson diversity index of shrub layer and herb layer increased slowly. The results of Jaccard similarity coefficient showed that there was a very different level of similarity between plots with different recovery years, and the species composition was quite different. Except for the density, there were significant differences in community average height, coverage, DBH and other structures between 20 and 70 a after restoration (P<0.05), and there was no significant difference among the others.  Conclusion  Compared with the karst areas in southwest China, the species richness in the karst area at the head of canal in the middle route of the South-to-North Water Diversion Project is relatively low, and Quercus variflora is the dominant species in the communities, with single family, single genus and single species being the majority, and the difference between communities is large. In the later period of vegetation restoration in the karst area, vegetation grows slowly, and the tree height and DBH are mainly concentrated in grade Ⅱ and Ⅲ. [Ch, 2 fig. 5 tab. 34 ref.]
Effects of enclosure duration on litter and soil water holding capacity of Phyllostachys edulis forest
JIANG Zhonglong, YE Liuxin, LIU Jun, LIN Song, XÜ Minyu, WU Jiasen, LIU Juan, LIU Haiying
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190603
  Objective  This study aims to explore the effects of natural enclosure on forest litter and soil water holding capacity of Phllostachys edulis forest and provide scientific basis for evaluating water conservation function of different types of Ph. edulis forests.  Method  Using the method of space-for-time, and taking Ph. edulis stands in Yuhang District, Hangzhou City of Zhejiang Province as the research object, effects of different enclosure periods (10, 20, 30 years) and conventional management (control) on water holding capacity of litter layer and soil layer of Ph. edulis forest were studied.  Result  Compared with ck, the litter reserves, maximum water holding capacity and effective retention capacity after natural enclosure increased by 85.7%−300.7%, 92.0%−402.8%, 87.7%−377.6%, respectively (P<0.05). After natural enclosure, the soil non-capillary porosity increased by 27.52%−137.74% (P< 0.05), the bulk density of top soil (0−30 cm) decreased by 16.53%−26.52%(P<0.05), and the water holding capacity of non-capillary pores in soil (0−60 cm) increased by 50.2%−106.3% (P<0.05). The maximum water holding capacity of surface soil (0−30 cm) after 20 years of natural enclosure increased by 18.1%−33.2% (P<0.05).  Conclusion  Natural enclosure can significantly improve the water holding capacity of litter and the water retention efficiency of surface soil, and the water conservation function is enhanced with the extension of enclosure period. [Ch, 4 fig. 4 tab. 24 ref.]
Optimization of microwave-assisted extraction of anthocyanins from Bletilla striata flowers
WANG Zhen, WANG Jie, XIANG Haiping, FAN Zepeng, SUN Chengman, XING Bingcong, SHAO Qingsong
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190581
  Objective  This study is aimed at the optimization of microwave-assisted extraction of anthocyanins from Bletilla striata flowers.  Method  With anthocyanins in B. striata flowers determined and extracted via microwave-assisted extraction and pH Differential Method and the optimum parameters of the four single factors of microwave power, methanol concentration, extraction time and solid-liquid ratio obtained, the study has managed to obtain the optimal extraction parameters of anthocyanins with the quadratic regression equation model established using the Response Surface Methodology (RSM).  Result  (1) The conditions of the optimal model fit well with actual extraction; (2) The pH differential method was adjusted to a measured wavelength of 530 nm and a solution equilibration time of 80 min; (3) The impact of the four factors of microwave power, material to liquid ratio, methanol concentration and microwave time on the amount of extraction decrease in a progressive order; (4) With the microwave power at 640 W, the methanol concentration as 90%, the microwave time set for 22 min, and the ratio of material (g) to liquid (mL) adjusted as 1∶48, the total anthocyanin extraction in B. striata flower was 6.68 mg·g−1, which was basically consistent with the theoretical prediction value of 6.83 mg·g−1.  Conclusion  The optimized method can be employed for the extraction and preparation of anthocyanins in B. striata flowers, providing a basis for the comprehensive development and utilization of B. striata flowers. [Ch, 8 fig. 2 tab. 22 ref.]
BN-PAGE analysis of thylakoid membrane protein complex during rapid growth of Phyllostachys edulis
FU Lucheng, BU Keli, WANG Lingjie, LI Qingli, GAO Peijun, GAO Yan, ZHANG Rumin
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190398
  Objective  The objective of this research is to reveal the photosynthetic characteristics and the development of photosystem of the stem of Phyllostachys edulis.  Method  Blue-greengel electrophoresis (BN-PAGE) was used to analyze the thylakoid membrane proteins in stems and leaves, and the changes in pigment content and the 77 K low temperature fluorescence emission spectrum were measured.  Result  The content of chlorophyll and carotenoid in stems was significantly lower than that in leaves (P<0.01), and with the development of stems, the pigment content increased significantly. The core complex of PSⅡ in the thylakoid membrane of stems and leaves was relatively complete and there were more light-catching pigments. PsaA/B and PsaD subunits were mainly isolated from PSI core complex in leaves and the stem base, and PsaA/B was obtained from the middle of stem, but no PsaA/B was found at the top of stem. There were two obvious main peaks at 685 and 745 nm in the 77 K low temperature fluorescence emission spectrum of leaves and stems, and six maximum values in the fourth derivative spectrum, which were mainly the fluorescence emission peaks of the core complex of PSⅡ and PSⅠ, and the shoulder peak caused by the emission fluorescence peak of the PSⅡ peripheral light catching antenna (LHC Ⅱ), PSⅡ inner peripheral light catching antenna (CP47), PSⅡ inner peripheral light catching antenna (CP43), PSⅠ reaction center complex (RCI), and PSI light catching antenna (LHC Ⅰ). The characteristic emission peak of LHC Ⅱ and PSⅡ core complex at the top of stem had obvious blue shifts compared with that of leaves.  Conclusion  The core complex of PSⅡ in stems of P. edulis has been formed. With the development of stems, the bamboo shoot coat gradually falls off, the pigments are synthesized in large amount, the inner antenna proteins CP47 and CP43 and the peripheral light-catching complex are formed gradually. Meanwhile, the PSⅠ core proteins PsaA and PsaB begin to form after the stems are exposed to light, and the core complex of PSⅠ is gradually assembled and synthesized. [Ch, 4 fig. 2 tab. 45 ref.]
Relationship between site and structure and its influence on biomass in Phyllostachys edulis forest
YANG Fan, TANG Mengping
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190572
  Objective  The objective of this study is to find out dominant factors affecting the biomass of moso bamboo(Phyllostachys edulis) forest from site factor and stand structure factor, and to analyze the relationship between dominant factors and their effects on stand biomass.  Method  In 10 counties (cities) of Zhejiang Province, 52 sample plots of moso bamboo forest less disturbed by human beings were selected and the dominant factors were obtained by random forest. On this basis, the structural equation model was constructed to analyze the direct, indirect and total effects of each dominant factor on stand biomass.  Result  The results of random forest showed that culm density, average DBH, competition index, soil thickness and altitude were main factors affecting biomass of moso bamboo forest. The results of structural equation model analysis showed that the preset path in the model could be accepted and the collected data could be well reflected. The total effect of culm density, average DBH, competition index and soil thickness was positive, which had positive effect on the biomass of moso bamboo forest. The total effect of altitude was negative, which had negative effect on the biomass of moso bamboo forest. The total effect of average DBH was biggest, which was 0.739. The direct effect of bamboo degree on the biomass of moso bamboo forest was greater than indirect effect. The direct effect of culm density was greater than indirect effect. The indirect effect of soil thickness was biggest, reaching 0.492. Among the site factors, the total effect of soil thickness on the biomass of moso bamboo was greater than that of altitude. The indirect effect of soil thickness, altitude and competition index was greater than the direct effect.  Conclusion  The main component factors of moso bamboo forest, such as culm density and average DBH, are most closely related to the biomass of moso bamboo forest. Altitude, soil thickness and competition index indirectly affect the biomass of moso bamboo forest through the component factors of moso bamboo forest. In the management of moso bamboo forest, the influence of site factors, non-spatial structure, spatial structure and their interrelations on the biomass of moso bamboo forest should be considered comprehensively, and the structure of moso bamboo forest should be adjusted on the basis of making full use of the site potential in order to improve the productivity of moso bamboo forest. [Ch, 3 fig. 3 tab. 40 ref]
Lightweight plant disease recognition model for edge computing
WANG Guan, WANG Jianxin, SUN Yu
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190595
  Objective  The traditional deep learning model is not suitable for edge deployment because of too many parameters and too much calculation. Automatic identification of plant diseases on the edge of the network is urgently needed to realize long-term and large-scale low-cost crop monitoring.  Method  By using multiple model compression methods, a light weight deep convolution neural network was obtained, which could be deployed in the embedded system with limited computing power to realize intelligent identification of plant diseases at edge nodes. The model compression was divided into two stages. The first stage used the channel pruning method based on L1 norm to compress the MobileNet model. In the second stage, simulation learning and quantization were combined to restore the recognition accuracy while the model was quantized, and a high-precision lightweight end model was obtained.  Result  Experimental results of 58 kinds of plant diseases in PlantVillage dataset showed that channel pruning compressed MobileNet by 3.6−14.3 times, and quantization reduced the parameter accuracy of the model from 32 bit to 8 bit. The overall compress rate reached 14.4−57.2 times, and the recognition accuracy was only reduced by 0.24% to 1.65%. Compared with the pruning method trained by common learning, and pruning with quantization trained by common learning, this method achieved higher compression rate and recognition accuracy.  Conclusion  The combination of multiple model compression methods can compress the artificial intelligence models in depth with only tiny loss of accuracy, and provide plant disease recognition models for agriculture and forestry based on edge computing. [Ch, 3 fig. 2 tab. 23 ref.]
Effects of exogenous gibberellin on growth of Carya illinoensis and its metabolic gene expression
YAN Zepu, ZHANG Jiaqi, LIANG Bi, WEI Guangli, ZHANG Qixiang, WANG Zhengjia
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190566
  Objective  This study attempts to explore the effect of gibberellin(GA3) on plant height and discuss the feedback regulation mechanism of GA20ox, GA3ox and GA2ox in the process of GA3 synthesis.  Method  The leaves of Carya illinoensis seedlings were sprayed with 100 mg·L−1 GA3. The plant height, internode length and main root length of C. illinoensis and the spatiotemporal variation of CiGA20ox, CiGA3ox and CiGA2ox were studied.  Result  After 28 days of GA3 application, the internode length and the elongation of the main root length of C. illinoensis seedlings were significantly different from those of the control(P<0.05), but the number of internodes did not change. The average plant growth was 2.9 cm, which was 1.93 times that of the control, and the difference was extremely significant (P<0.01). The results of real-time PCR showed that there were spatial-temporal differences in the expression of GA20ox, GA3ox and GA2ox during the growth period of C. illinoensis. Exogenous GA3 could continuously reduce the expression of CiGA20ox. After 28 days, the expression level of CiGA20ox was only 38.6% of the initial value. The expression level of CiGA3ox dropped to a low point of 55.4% of the initial value on day 7 and rose to 350% of the initial value on day 28. The expression level of CiGA2ox in general showed a wavy change, reaching the peak after 7 days, then falling back to the initial level after 21 days, and rising to 220% of the initial value after 28 days. However, CiGA3ox accumulated in the stem of C. illinoensis seedlings, which changed in transcription level compared with CiGA20ox and CiGA2ox.  Conclusion  The exogenous GA3 could promote the stem elongation of C. illinoensis and cause the temporal and spatial variation of the key gene expression patterns of GA3 metabolism in C. illinoensis. [Ch, 6 fig. 1 tab. 29 ref.]
Effect of Larix gmelinii proportion on soil chemical properties and enzymatic stoichiometry in mixed coniferous and broad-leaved forest
WANG Bo, ZHOU Zhiyong, ZHANG Huan, ZHU Yong, CAO Yusong, ZHAO Hongtao
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190525
  Objective  The objective of this research is to study the chemical properties and enzyme stoichiometry of soil under different proportions of Larix gmelinii forests.  Methods  The investigated L. gmelinii forests were classified into six groups according to its volume proportion in the community (70%, 75%, 80%, 85%, 90%, 95%), and its soil samples were monitored for the nutrient content and biochemical properties in 0-5 cm soil layers and 5−20 cm soil layers.  Results  Among the five enzymes analyzed, the activity of acid phosphatase was the highest, and the mean value of 0−5 and 5−20 cm soil layers were 463.74 and 312.91 nmol·g−1·h−1. In 0−5 cm soil layer, the activity of leucine aminopeptidase (LAP) was promoted by the increase of L. gmelinii proportion, and the leucine aminopeptidase activity of L. gmelinii community with 95% proportion significantly increased by 57.44% and 59.40%, compared with that of L. gmelinii community with 75% and 85% proportion. The proportion of L. gmelinii in the community also affected the chemometric characteristics of soil enzymes. When the proportion of L. gmelinii reached 95% in 5−20 cm soil layer, the ratio of nitrogen-acquiring enzyme to phosphorus-acquiring enzyme was much higher than that of L. gmelinii communities with the proportion of 80% and 85% (P95%-80%=0.02, P95%-85%=0.02). However, the ratio of carbon-acquiring enzyme to nitrogen-acquiring enzymewas lowest in forest community with 95% proportion of L. gmelinii. There existed a complex correlation between soil enzyme activity and soil nutrient content, which also changed with the increase of soil depth. In 0−5 cm soil layer, soil pH negatively correlated with the activities of glucosidase (BG), and acetylglucosaminidase (NAG) (PpH-BG=0.01, PpH-NAG=0.03). In the 5−20 cm soil layer, there existed a positive correlation between soil total nitrogen (TN) content and the activities of leucine aminopeptidase (LAP) and NAG (PLAP-TN=0.02, PNAG-TN=2×10−4), and a negative correlation between acid or alkaline phosphatase (AP) and soil total phosphorus (TP) content (PAP-TP=0.02). Through the redundancy analysis of the above variables, it was found that the enzymatic stoichiometry was greatly influenced by soil pH in 0−5 cm layer, while in 5−20 cm layer it was mainly affected by the mass fraction of soil total nitrogen and available nitrogen.  Conclusion  The proportion of L. gmelinii in the mixed coniferous and broad-leaved forest in warm temperate zone is an important biological factor for regulating soil nutrient dynamics, and its regulation largely relies on the activity and stoichiometric characteristics of soil enzymes. [Ch, 4 fig. 4 tab. 41 ref.]
Effects of sanitation cutting pine wilt diseased trees on the stand structure of pure Pinus massomiana plantation
ZHANG Huafeng, CHEN Siyu, LIU Gang, WANG Yixiang
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190487
  Objective  This study aims to explore the effects of sanitation cutting of the diseased pine trees infected by Bursaphelenchus xylophlius on the stand structure of pure Pinus massomiana plantation and provide a reference for the management of P. massomiana invaded by B. xylophlius.  Method  Field plots were selected of both a pure P. massomiana plantation infected by B. xylophlius and its neighbouring plantation uninfected to be investigated in Lin’an, Zhejiang, China.  Result  After 12 years of sanitation cutting, compared with the uninfected pure P. massomiana plantation, it is shown that the importance values of P. massoniana significantly decreased from 100.00% to 38.41%. The stand diameter distribution followed an inverse J-shaped curve. In terms of height stricture, single storied stand changed into multi-storied stand. The individual size inequality significantly increased. The distribution pattern of trees changed from uniform distribution to random distribution. The competitive index of trees significantly increased, and that of trees at 6 cm diameter class was the highest.  Conclusion  The sanitation cutting accelerated the succession speed of the infected pure P. massoniana, with significant changes in several stand structure indicators and the single-storied even-aged pure P. massoniana stand succeeded by the mixed multi-storied uneven-aged P. massoniana and broad-leaved trees stand. [Ch, 2 fig. 4 tab. 18 ref.]
Estimation of genetic parameters for juvenile growth of half-sib seedlings of Torreya grandis
YE Shuyuan, DONG Leiming, DONG Ang, YU Weiwu, DAI Wensheng, ZENG Yanru
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190542
  Objective   To provide rationale for the selection and breeding of natural superior individuals of Torreya grandis, this research is intended to study the inheritance of the growth traits of T. grandis seedlings which are generally used as the rootstock for grafting from T. grandis ‘Merrillii’ in production.   Method   With half-sib seedlings of T. grandis open pollinated in the natural forests as material, the height, basal diameter and number of branches were measured for two consecutive years while the relevant genetic parameters were fitted and estimated employing conventional linear mixed model (LMM) and generalized linear mixed model (GLMM) so as to calculate the genetic and phenotypic correlation coefficients.   Result   The coefficient of variation of seedling height was greater than that of basal diameter and decreased with the seedling ages. Every growth trait parameter displayed a very significant difference among families (P<0.01), and a relatively high heritability. The heritability of one-year-old seedlings for each parameter was higher than that of two-year-old seedlings and the genetic correlation was greater than that of phenotypic correlation. In terms of genetic gain, the seedling height was bigger than the basal diameter and the number of branches, and the genetic gain of the annual branch was the highest. The correlation analysis of growth phenotypic traits showed that there was a significant correlation between genotype and phenotype of the same batch tree seedlings in all the parameters except the number of branches.   Conclusion  Natural T. grandis populations have displayed the great potential for selection and breeding in growth traits. Seed-bearing trees could be selected based on the height of one-year-old seedlings for the purpose of stock cultivation. [Ch, 3 tab. 24 ref.]
Effects of human disturbance on species diversity and soil physiochemical properties of Schima superba community in Mengding Mountain
ZHANG Rong, LI Tingting, JIN Suo, YU Shunyao, WANG Yu, LI Yujiang, QI Jinqiu, HAO Jianfeng
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190554
  Objective  The objective of this study is to explore the impact of tourist development on the ecological environment and to investigate the response of the secondary forest community of Schima superba to human disturbance in Mengding Mountain, Sichuan Province.  Method  The species diversity and soil physiochemical properties of S. superba community with mild, moderate and severe human disturbance were studied using typical plot sampling.  Result  (1)A total of 155 species of vascular plants were recorded in the study area, belonging to 72 families and 115 genera. (2)Human disturbance had a negative impact on the level of species diversity in the community. With the increase of disturbance intensity, the species richness index (D) , the Shannon-Wiener diversity index (H), the Simpson diversity index (H′) and the Pielou index (Jsw) of S. superba community all decreased. (3)The soil physiochemical properties varied under different disturbance intensity. Human disturbance significantly reduced soil water content, total nitrogen, total potassium, available phosphorus, and soil organic matter mass fraction (P<0.05), increased soil bulk density value, and had no significant effect on soil total phosphorus, available potassium and pH (P>0.05). (4)Correlation studies showed that soil total potassium, water content and organic matter were the most important factors affecting the species diversity of S. superba community.  Conclusion  The impact of human disturbance on the biodiversity and soil physiochemical properties of S. superba community is negative.[Ch, 2 fig. 4 tab. 27 ref.]
Soil fertility of Pinus massoniana forests under different near-natural management measures
JIANG Shikun, ZHOU Yunchao, TAN Wei, CHEN Zhu, HUANG Jianfeng
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190549
  Objective  The research aims to study the effects of different near-natural management measures on soil fertility under Pinus massoniana forests.  Method  In Kaiyang near-natural management project area of Guiyang City, the near-natural selective cutting, near-natural thinning, near-natural tending, and the control group were selected to comprehensively evaluate the impact of different management measures on soil fertility under P. massoniana forests.  Result  The mass fractions of organic matter, soil total nitrogen, alkali-hydrolyzed nitrogen, total potassium, total phosphorus, available phosphorus, urease, alkaline phosphatase in near-natural selective cutting were higher than those of the control group, showing an up-going trend. The mass fractions of organic matter, total nitrogen, alkali-hydrolyzed nitrogen, total potassium, total phosphorus, and available phosphorus were significantly different(P<0.05). The mass fraction of soil organic matter, total nitrogen, alkali-hydrolyzed nitrogen, total potassium, available potassium, total phosphorus, available phosphorus, and sucrose in near-natural thinning was higher than that in the control group, showing an increasing trend, among which the mass fraction of total nitrogen, alkali-hydrolyzed nitrogen, total potassium, available potassium, total phosphorus and available phosphorus had significant differences (P<0.05), but the mass fraction of urease showed a decreasing trend. The mass fraction of alkali-hydrolyzed nitrogen, total potassium, available phosphorus and urease in near-natural tending showed a decreasing trend, among which the difference between alkali-hydrolyzed nitrogen and total potassium was significant (P<0.05), and the mass fraction of sucrose showed an increasing trend. The comprehensive evaluation scores of soil fertility in the P. massoniana stands with near-natural thinning and selective cutting were significantly different from those of the control group (P<0.05), but the difference in tending was not significant (P>0.05). The effect of different near-natural management measures on soil physical indexes was not significant (P>0.05).  Conclusion  Near-natural thinning and selective cutting can significantly promote soil fertility of Pinus massoniana forests, which is of great significance for maintenance and improvement of soil fertility of P. massoniana forests. The effect of near-natural tending on forest stands is not significant. The near-natural management theory plays an important role in improving forest soil fertility and sustainable forest management in Guiyang.[Ch, 1 fig. 6 tab. 19 ref.]
Effects of volatile components of three evergreen plants on air anion and microorganism
ZHAO Yahong, XU Cuixia, MA Ling, WANG Bin, WEI Saijun, LÜ Jiaxin, GAO Yan, ZHANG Rumin
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190521
  Objective  The objective is to study the effects of volatile organic compounds (VOCs) from three evergreen plants on air microorganism inhibition and air purification.  Method  The composition and content of VOCs in Myrica rubra, Vatica mangachapoi, Camellia sinensis in single tree and open field were analyzed using thermal desorption system/gas chromatography/mass spectrometry (TDS-GC-MS) technique. The effect of VOCs on airborne microorganism was investigated by natural sedimentation method, and the number of air anion was measured.  Result  The main VOCs of M. rubra were α-oxalene, parsley alcohol, rolene, limonene and nonaldehyde, in which terpenes accounted for 78.5% of the total. The main VOCs of V. mangachapoi were acetyl acetate, octyl butyrate, cis-3-hexenol, pinocarvone, nonanal, decanal, and octanal, in which ester compounds accounted for 54.1% of the total. Acetyl acetate, octyl butyrate, methyl salicylate, nonanal, decanal, limonene were the main VOCs of C. sinensis, and ester compounds accounted for 40.8% of the total. The VOCs in open space were benzene, accounting for 74.2% of the total. The VOCs in M. rubra garden were benzene and terpene, accounting for 54.8% and 35.6%, respectively. The VOCs in V. mangachapoi garden were benzene and terpene, accounting for 35.4% and 52.2%, respectively. The VOCs in C. sinensis garden were benzene and terpene, accounting for 50.1% and 36.5%, respectively. The daily average number of air anion in M. rubra garden, V. mangachapoi garden, C. sinensis garden, and the open space was 2 559.2、2 660.0、1 878.4、1 078.8 per cubic centimeter, respectively. In M. rubra garden, V. mangachapoi garden, and C. sinensis garden, daily average bacterial inhibition rate was 45.5%, 48.7% and 39.3%, respectively, daily average inhibition rate of fungi was 39.0%, 35.8% and 34.6%, respectively, and that of actinomycetes was 42.3%, 42.2% and 39.7%, respectively.  Conclusion  Plant VOCs can inhibit the growth of airborne microorganism, promote the formation air anion and improve the air quality. [Ch, 5 fig. 2 tab. 38 ref.]
Classification, ordination and correlation analysis of dominant species of ecological non-commercial forests in Songyang, Zhejiang
YE Sentu, JIN Chao, WU Chuping, YANG Tangliang, JIANG Bo, YUAN Weigao, HUANG Yujie, JIAO Jiejie, SUN Jiejie
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190514
  Objective  This study aims to reveal the distribution of forest community and species diversity on the gradients of complex environment by classifying and sorting the community of ecological non-commercial forest in Songyang County, Zhejiang Province, and discussing the change law of diversity and interspecific relationship.  Method  Taking 128 monitoring plots as research projects, two-way indicator species analysis (TWINSPAN), canonical correspondence analysis (CCA), species diversity index and interspecific association analysis were used to study the community characteristics of non-commercial forest in Songyang County.  Result  TWINSPAN results showed that the forest community could be divided into 6 types. CCA results demonstrated that the community distribution and types of non-commercial forest in Songyang County showed obvious differentiation on environmental gradient, which was mainly affected by altitude, soil type and slope aspect. The results of multiple comparison of species diversity showed that the Shannon-Wiener index and Simpson index of associations with mixed forest or broad-leaved forest were significantly higher than those of other associations, and the diversity of association dominated by Phyllostachys edulis was significantly lower than that of other associations. Interspecific Association Analysis illustrated that most tree species in sample plots had no significant correlations. The positive and negative correlation ratio was 1.9, indicating the overall stability of the community.  Conclusion  Differential management should be carried out for the non-commercial forest in Songyang County, and mixed and broad-leaved forests should be actively promoted. It is possible to consider different supplementing measures for the non-commercial forests with different site conditions and different stands. The edge control of bamboo forests and community combinations that can adapt to various environments should be properly promoted. [Ch, 4 fig. 3 tab. 37 ref.]
Age estimation and spatial distribution characteristics of ancient and famous trees in Guang’an City, Sichuan Province
ZHANG Yanli, YANG Jiajun
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190585
  Objective  To better protect and preserve the ancient and famous trees in Guang’an City, this study is focused on the geographical distribution characteristics of them and the relationship between tree age, growth environment and ecological factors, which is of vital importance.  Method  First, the standard deviation ellipse was used to summarize the distribution characteristics of ancient and famous trees. Then, the geographically weighted regression model(GWR) and multivariable linear regression model (MLR)were employed to simulate the regression intensity of tree height, chest circumference, average crown width, altitude and slope to tree age.  Result  (1) The ancient and famous trees in Guang’an are distributed in a linear pattern along the water system, mountains and traffic lines while in a circular structure along the government residence and the red tourist destinations; more are distributed in the countryside than in the city with flat land as the dominant habitat; there are more normal plants than weak ones with a moderately favorable growing environment; more are distributed in the high-altitude areas than in the low-altitude areas with a significant vertical difference. (2) GWR works better than the ordinary least squares model (OLS); the average crown width, chest circumference and tree height are the key factors that affect tree age; the slope has little effect on tree age and altitude has a negative correlation with tree age. (3) The correlation coefficient of MLR is 0.297 higher than that of GWR. The coefficient intensity of each explanatory variable and regression variable is highly consistent with that of GWR, and the accuracy of estimating the age of ancient trees under 300 a is higher.  Conclusion  With the employment of standard deviation ellipse, geographically weighted regression model and multivariable linear regression model, the distribution characteristics of ancient and famous trees are better summarized, providing decision-making basis for the estimation of the age of ancient trees and the protection of ancient and famous trees. [Ch, 4 fig. 3 tab. 21 ref.]
Diameter-height model for Pinus massoniana plantations based on BP neural network
MAO Guangxian, TAN Wei, CHAI Zongzheng, ZHAO Yang, YANG Shenjun
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190486
  Objective  To provide theoretical guidance for the management of the plantation of Pinus massoniana, a wood widely used in the south, this study is aimed at the establishment of a high-efficiency diameter-height Model.  Method  With 4 284 P. massoniana plants from 82 sample plots in central Guizhou Province as the study subjects, 6 generalized nonlinear models were selected to fit the diameter-height relationship. After the determination of the optimal number of hidden layer nodes, repeated training was conducted to establish the BP neural network-based model of diameter-height relationship for P. massoniana plantation.  Result  Among the 6 generalized nonlinear models, the model that fits the best is Korf function (R2=0.650) while the two hidden layers for BP neural network model were suitable for P. massoniana plantation with 1∶2∶1 as the appropriate model structure (number of input layer nodes∶number of hidden layer nodes∶number of output layer nodes) was and the model prediction accuracy reaching 0.717.  Conclusion  The generalized nonlinear model can fit the diameter-height relationship of P. massoniana plantation pretty well, yet in comparison, the BP neural network works better in that it’s not reliant on empirical models and has better fitting accuracy for the high R2 yet lower root mean squared error. [Ch, 5 fig. 5 tab. 35 ref.]
Correlation between fruit quality and soil fertility and leaf nutrients of Zizyphus jujuba ‘Lingwuchangzao’
YAN Liangliang, YUE Kun, SONG Lihua
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190462
  Objective  To establish a scientific fertilization system for Zizyphus jujuba ‘Lingwuchangzao’, the current study is aimed to figure out the correlation of soil, leaves and fruit nutrients with the quality of the above mentioned jujube.  Method  With the soil, leaves and fruit nutrients of 5 Z. jujuba ‘Lingwuchangzao’ as the study subjects, by using the multiple linear stepwise regression analysis the relationship between fruit quality with the soil fertility and leaf nutrients was established.  Result  The soil fertility properties of different planting bases were significantly different, and Mn was generally lacking in planting bases. The longitudinal diameter of fruit was negatively correlated with the soil total K, the fruit hardness and the fruit N content. The fruit titration acid content was positively correlated with the content of soil available K, leaf P and fruit N, but negatively correlated with the content of fruit Fe. The content of fruit N was positively correlated with the content of soil organic matter, leaf Fe and fruit Zn, but negatively correlated with the content of soil Se. The K content of fruit was negatively correlated with the effective Fe content of soil, but positively correlated with the total P content of soil. The content of Zn in fruits was positively correlated with the content of available K in soil, Zn in leaves and N in fruits.  Conclusion  The application amount of organic fertilizer and trace element fertilizer should be increased in the planting bases of Z. jujuba ‘Lingwuchangzao’, especially that of Mn, while that of Fe should be reduced. [Ch, 11 tab. 24 ref.]
Community characteristics of the wild Phoebe and Machilus plants in Yuan’an County, Hubei Province
HU Shengke, LIU Chang, WEI Pujie, LI Mengxi, HU Die
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190428
  Objective  This study aims to explore the species composition, structure and characteristics of wild Phoebe and Machilus communities in Yuan’an County, Hubei Province, and improve the distribution record of wild Phoebe and Machilus resources in Yichang area.  Method  The field investigation of the wild Phoebe and Machilus communities in Mingfeng Town, Hualinsi Town and Leizu Town of Yuan’an County was carried out by using quadrat method to record the habitat conditions and species distribution of Phoebe and Machilus plants, and the method of Community Ecology was used for statistical analysis.  Result  (1) There were 2 species of Phoebe and 3 species of Machilus plants in the survey area, including Phoebe neurantha and Ph. faberi in Ph. genera, and M. ichangensis, M. pauhoi and M. ultinervia in Machilus genera. M. pauhoi and M. multinervia were identified as new distribution record species in Yuan’an County. (2) There were 73 species of vascular plants belonging to 35 families and 61 genera, among which 21 families were single genera and single species. The high bud plants had the largest distribution in the community, while the underground and surface buds had the least. The DBH levels of most species were in grade Ⅲ (5.0 cm ≤ DBH<7.5 cm)and Ⅳ(7.5 cm ≤ DBH<22.5 cm), with a few species in grade Ⅴ(DBH≥22.5 cm). Shannon-Kiener diversity index H′, Simpson dominance index Ds and evenness index Jsw showed no significant difference among the three townships(P>0.05), but Margalef richness index R did(P<0.05).  Conclusion  Yuan’an County is rich in wild Phoebe and Machilus resources, with high species diversity index and reasonable community structure. However, the protection of local wild Phoebe and Machilus resources should be further strengthened.[Ch, 3 fig. 3 tab. 28 ref.]
Coupling effects of soil water and fertilizer application on the growth of Quercus variabilis seedlings
JU Jiao, LI Yingchao, WANG Libing, LI Dongxing, CHEN Mengyuan, HE Sanjun, ZHENG Lei, YU Haiyan
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190456
  Objective  The aim is to investigate the response of stem height, ground diameter, leaf area, root weight and biomass accumulation of the seedlings of Quercus variabilis to the coupling of water and fertilizer, and to establish optimal combination of irrigation and fertilization.  Method  The four-factor-five-level quadratic regression general rotatable central composite design(RCCD) was employed to establish the regression model of each index and soil moisture (W), nitrogen (N), phosphorus (P) and potassium (K), with an analysis conducted of the main effect, monofactor and coupling effect of each factor on growth.  Result  (1)With the variance analysis of the stem height, ground diameter, leaf area, root weight and biomass, it was found that there is a significant divergence in the treatment of various factors (P<0.05) and the growth of seedling 8,16 and18 is the most favorable. (2) The model test results show that W and N have significant positive effect on all 5 indexes, P has no significant effect on ground diameter, K has no significant effect on any indexes, and there is a decrease of the main effect: W>N>P>K. (3) In terms of monofactor effect, it was shown that all the indexes presented a trend of first increase and then decrease with the increase of fertilizer application, in the path of a parabola. There was a gradual growth of the seedling with the increase of W before the a drop occurred in the growth rate. (4) With the anlaysis of the coupling effect, it was found that W×N has significant positive effects on stem height, root weight, biomass and leaf area, W×P has significant positive effects on stem height, ground diameter, root weight and biomass, W×K has significant positive effects on biomass, and N×P has significant positive effects on root weight, leaf area and biomass, N×K has significant negative effects on the ground diameter and the coupling effect between water and fertilizer is greater than that between fertilizers.  Conclusion  In conclusion, the water and fertilizer demand in the seedling stage of Q. variabilis is W>N>P>K, and suitable water and fertilizer ratio can promote the growth of seedlings. Seedlings grow better with conditions of high water, high nitrogen, high phosphorus and low potassium fertilizer. The optimal combination of water and fertilizer regulation was as follows: soil water content was 79% of the maximum field moisture capacity, nitrogen application was 215.3 mg·plant−1, phosphorus application was 46.0 mg·plant−1, potassium fertilizer application was 18.1 mg·plant−1, with seedling height reaching 45.14 cm, ground diameter reaching 4.40 mm, root weight reaching 6.30 g·plant−1,biomass reaching 11.70 g· plant−1, and leaf area reaching 460.83 cm2. [Ch, 3 fig. 2 tab. 30 ref.]
Characteristics and driving factors of nocturnal water consumption of Eucalyptus urophylla plantations in Leizhou Peninsula
WANG Zhichao, XU Yuxing, ZHU Wankuan, DU Apeng
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190531
  Objective  This research aims to explore the water consumption characteristics of Eucalyptus urophylla at night and its driving factors, and provide data support for improving the estimation accuracy of water consumption in large scale eucalyptus forests.  Method  Using thermal dissipation probe(TDP) technique, E. urophylla, a common eucalyptus from Leizhou Peninsula, was chosen as the research object to continuously observe its nocturnal sap flow and simultaneously measure the main environmental factors such as atmospheric temperature, humidity, rainfall and photosynthetically active radiation. The characteristics and the driving mechanism of sap flow at night were discussed in depth.  Result  The results indicated that the average water consumption contribution rate of E. urophylla at night during the observation period was 6.62%, and the first half of the night consumed significantly more water than the second half (P<0.05). The nocturnal flow rate was significantly higher in the rainy season than in the dry season (P<0.05). The average nocturnal flow rate was extremely significantly higher on sunny days than on rainy days (P<0.01). The nocturnal water consumption contribution rate in the dry season is 1.4 times that in the rainy season. Nocturnal flow rate was significantly and positively correlated with vapor pressure deficit(P<0.01)during the dry and rainy seasons, and the fitting equation was of high statistical significant. However, the coefficient of determination was only 0.37 and 0.35 for the dry season and the rainy season, respectively. Meanwhile, there was an extremely significant positive correlation between the nocturnal water consumption and the daytime transpiration (P<0.01), and there was a power function relationship with a determination coefficient of 0.33.  Conclusion  Nocturnal water consumption accounts for a small proportion of the total transpiration volume. However, if nocturnal sap flow is fully ignored, total water consumption of the E. urophylla plantation ecosystem based only on the daytime sap flow can be underestimated. Nocturnal transpiration and trunk hydration together drive the E. urophylla’s nocturnal water consumption. [Ch, 4 fig. 2 tab. 28 ref.]
Plant community structure and ecological benefits of Qianwangling Park in Lin’an
WANG Ying, CAI Jianguo, ZHANG Zheqi, LIU Yanwei, WANG Yi
Accepted Manuscript doi: 10.11833/j.issn.2095-0756.20190464
  Objective  This research aims to analyze the plant community structure of Qianwangling Park in Lin’an District of Hangzhou City, Zhejiang Province, and evaluate its ecological benefits.  Method  Taking Qianwangling Park as the research object, the structure of 32 plant communities in the park was investigated, and the i-Tree model was used to evaluate the ecological benefits of community including energy conservation, carbon dioxide absorption, air quality improvement and rainwater interception.  Result  (1) There were 1 613 trees in the community, belonging to 39 families 62 genera and 74 species. The community structure was mainly of the multi-layer type, dominated by the landscape style of the mixed forest of needles and broads. (2) The annual ecological benefit of the community was 208 588.16 yuan·a−1, and the average benefit per tree was 129.25 yuan·plant−1·a−1, among which the benefits of energy conservation, carbon dioxide absorption, air quality improvement and rainwater interception were 48 188.80, 98 447.36, 4 019.84 and 57 932.16 yuan·a−1, accounting for 23.10%, 47.20%, 1.93% and 27.77% respectively. The highest total value of ecological benefits reached 12 777.60 yuan·a−1, found in sample L21 (Cinnamomum camphora+Magnolia grandiflora-Camellia japonica community), accounting for 6.13%. This community had the highest benefits in saving energy, absorbing carbon dioxide and intercepting rainwater. The mixed community contributed the most to ecological benefit values, accounting for 35.47%. (3) The deciduous broad-leaved and coniferous trees had higher average benefits per plant, and deciduous broad-leaved trees had more advantages in energy conservation, CO2 absorption, air quality improvement and rainwater interception.  Conclusion  The ecological benefit of plant community in Qianwangling Park is mainly determined by the number of tree species, growth type and average diameter at breast height. The coniferous and broad-leaved mixed community has obvious advantages in ecological benefit value.[Ch, 2 fig. 4 tab. 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
2020, 37(3): 397-406.   doi: 10.11833/j.issn.2095-0756.20190335
[Abstract](2851) [HTML](1255) [PDF](109)
  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. 32 ref.]
Characteristics and impact factors of space utilization of young and middle-aged natural Larix gmelinii forests
YU Bao
2020, 37(3): 407-415.   doi: 10.11833/j.issn.2095-0756.20190382
[Abstract](1212) [HTML](557) [PDF](24)
  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.]
Biomass allocation and allometric growth of Picea schrenkiana in Tianshan Mountains
LAN Jie, XIAO Zhongqi, LI Jimei, ZHANG Yutao
2020, 37(3): 416-423.   doi: 10.11833/j.issn.2095-0756.20190384
[Abstract](1692) [HTML](669) [PDF](45)
  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-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.]
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
2020, 37(3): 424-431.   doi: 10.11833/j.issn.2095-0756.20190461
[Abstract](1148) [HTML](436) [PDF](18)
  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.]
Quality evaluation of Shajiabang National Wetland Park from the perspective of coordinated development
ZHU Ying, WU Yingqian, LI Xin
2020, 37(3): 432-438.   doi: 10.11833/j.issn.2095-0756.20190448
[Abstract](1298) [HTML](384) [PDF](29)
  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.]
Forests landscape pattern changes and driving forces in Mount Tianmu
YU Fei, LI Zhiyong
2020, 37(3): 439-446.   doi: 10.11833/j.issn.2095-0756.20190306
[Abstract](1142) [HTML](471) [PDF](48)
  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.]
Community structure characteristics for landscape-recreational forests in the urban parks of Foshan City
ZHAO Qing, HU Rouxuan, XU Dongxian, WEI Yuhan, TANG Honghui
2020, 37(3): 447-455.   doi: 10.11833/j.issn.2095-0756.20190396
[Abstract](856) [HTML](369) [PDF](22)
  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.]
Characteristics and influencing factors of plant diversity in riverside rural settlement in Guangzhou
WANG Ziyan, WANG Cheng, TANG Sainan, ZHANG Chang, HAN Dan
2020, 37(3): 456-464.   doi: 10.11833/j.issn.2095-0756.20190391
[Abstract](995) [HTML](399) [PDF](26)
  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.]
Diversity and flora of wetland plants of Changxing County, Zhejiang Province
LIU Zheng, LI Ying, ZHU Pei, CHU Xudong, HE Guoqing, SUN Yong
2020, 37(3): 465-471.   doi: 10.11833/j.issn.2095-0756.20190436
[Abstract](991) [HTML](466) [PDF](33)
  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.]
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
2020, 37(3): 472-479.   doi: 10.11833/j.issn.2095-0756.20190343
[Abstract](1024) [HTML](385) [PDF](14)
  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.]
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
2020, 37(3): 480-488.   doi: 10.11833/j.issn.2095-0756.2020.20190485
[Abstract](1918) [HTML](441) [PDF](20)
  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.]
Effects of shading and fertilization on growth and nitrogen accumulation of Phoebe zhennan seedlings
DENG Bo, YAN Lipeng, LIU Guihua, XU Mengyuan
2020, 37(3): 489-495.   doi: 10.11833/j.issn.2095-0756.20190399
[Abstract](1852) [HTML](562) [PDF](31)
  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. 22 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
2020, 37(3): 496-505.   doi: 10.11833/j.issn.2095-0756.20190370
[Abstract](1365) [HTML](569) [PDF](46)
  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.]
Effect of low temperature on photosystem Ⅱ in Nothofagus antarctica
ZHAI Yu, ZHOU Shuai, HAO Xiangchun, HAN Lijun
2020, 37(3): 506-513.   doi: 10.11833/j.issn.2095-0756.20190366
[Abstract](384) [HTML](148) [PDF](4)
  Objective  Nothofagus antarctica PSⅡ photochemical performance under low temperature was assessed and its results were used in calculation integrated biomarker response (IBR) to assess the synthetical indicator of chlorophyll fluorescence under low temperature stress.  Method  The environment temperature of N. antarctica was changed gradually (from 25 ℃ to −25 ℃). After exposed, relative chlorophyll content (SPAD value) and fast chlorophyll fluorescence were measured and analysed, IBR were calculated, to assess the effect of low temperature PSⅡ photochemical activity.  Result  15 ℃ hardly affects the PSⅡ photochemical activity. Oxygen-evolving complex and energy flow between PSⅡ units were disturbed under −5 ℃. Under the low temperature of −5, −15 and −25 ℃, SPAD value was remarkably reduced, and the PSⅡ donor side, electron transport of PSⅡ, energy flow between PSⅡunits were all disturbed seriously; heat dissipation was remarkably increased. IBR under different temperature treatments have a significant negative correlation with SPAD value and temperature.  Conclusion  The damage of PSⅡ photochemical activity by low temperature (below −5 ℃) was serious, and IBR can be used as a comprehensive parameter to evaluate the effect of low temperatures on PSⅡ photochemical activity and SPAD value. [Ch, 7 fig. 1 tab. 24 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
2020, 37(3): 514-521.   doi: 10.11833/j.issn.2095-0756.20190259
[Abstract](2083) [HTML](310) [PDF](14)
  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.]
Effects of wetland reclamation on kinetic characteristics of soil alkaline phosphatase
XU Chuanhong, LU Mingxing, FAN Diwu, CHENG Hu, HAN Jiangang
2020, 37(3): 522-530.   doi: 10.11833/j.issn.2095-0756.20190388
[Abstract](1247) [HTML](472) [PDF](8)
  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.]
Differences and influencing factors of soil moisture in karst microhabitats in southeast Yunnan
KUANG Yuanyuan, FAN Tao
2020, 37(3): 531-539.   doi: 10.11833/j.issn.2095-0756.20190383
[Abstract](945) [HTML](413) [PDF](21)
  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.]
Imaging rules in chlorophyll fluorescence of soybean pods in response to Fusarium verticillioides
LONG Xiyang, XIAO Xinli, ZHANG Qihui, YANG Wenyu, LIU Jiang, ZHANG Jing
2020, 37(3): 540-546.   doi: 10.11833/j.issn.2095-0756.20190325
[Abstract](922) [HTML](413) [PDF](22)
  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.]
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
2020, 37(3): 547-555.   doi: 10.11833/j.issn.2095-0756.20190339
[Abstract](1775) [HTML](446) [PDF](13)
  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 5 mL 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
2020, 37(3): 556-562.   doi: 10.11833/j.issn.2095-0756.20190337
[Abstract](1054) [HTML](483) [PDF](19)
  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.]
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
2020, 37(3): 563-570.   doi: 10.11833/j.issn.2095-0756.20190379
[Abstract](1286) [HTML](512) [PDF](23)
  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.]
Drying characteristics and drying schedule developed of Acacia melanoxylon wood
ZHOU Fan, ZHOU Yongdong, GAO Xin, FU Zongying, HOU Junfeng, WENG Xiang, LIN Shaohui
2020, 37(3): 571-577.   doi: 10.11833/j.issn.2095-0756.20190394
[Abstract](1026) [HTML](446) [PDF](12)
  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 technique.  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 0.620 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 final average moisture content, drying evenness, moisture content deviation in thickness, residual drying stress, and drying defects of the dried lumber all come to the requirements of the second grade drying quality of sawn timber in the Chinese National Standard. 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.]
Automatic navigation of production platform in greenhouse based on wireless positioning
ZHAO Chenyan, YAO Lijian, YANG Zidong, YAN Song, CAI Cuncheng
2020, 37(3): 578-586.   doi: 10.11833/j.issn.2095-0756.20190364
[Abstract](1051) [HTML](435) [PDF](20)
  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.]
Rural landscape planning of northern Zhejiang based on industrial development orientation
XIANG Ying, ZHANG Jianguo
2020, 37(3): 587-592.   doi: 10.11833/j.issn.2095-0756.20190635
[Abstract](514) [HTML](114) [PDF](4)
  Objective  This aim is to explore the industry-oriented rural landscape planning in northern Zhejiang and a rural development pathway that combines increased quality of rural landscape with optimized rural industrial structure.  Method  With three villages (Rongxing, Hongxing, and Hexing) of different industrial types in Tongxiang City of northern Zhejiang as empirical case studies, this paper integrates theoretical analysis with empirical studies.  Result  The complex industrial structure and intensive industrial operations have posed significant impacts upon the rural development of the region and presented three major problems: a rural industrial development that is confronted with challenges, a rural social development that is inadequately driven, and a grim situation for ecological protection. In light of the reciprocal causation and mutual influence between rural landscape and rural industrial structure, this paper proposes three principles of planning: combining production development with ecological protection, historical remains with cultural promotion, and ruins protection with cultural landscape.  Conclusion  The strategies include constructing some particular planning development strategies, namely, the construction of tourism sites by coupling industrial landscapes optimization, historical relics protection and cultural benefits for people based on the combination of agricultural production and ecological protection, and the shaping of cultural and creative landscapes based on the integration of skill inheritance and cultural innovation. [Ch.1 fig. 1 tab. 19 ref.]
Research progress of CO2 flux in forest ecosystem based on eddy covariance technique: a review
GONG Yuan, JI Xiaofang, HUA Yuting, ZHANG Yinlong, LI Nan
2020, 37(3): 593-604.   doi: 10.11833/j.issn.2095-0756.20190412
[Abstract](554) [HTML](263) [PDF](11)
Forest ecosystem is an important part of carbon cycle in terrestrial ecosystem. Forests can regulate CO2 concentration in the atmosphere and it is of great scientific significance and application value to conduct carbon cycle research of forest ecosystem for better understanding of biogeochemical processes and coping with global climate change. The eddy covariance technique is currently the most widely used CO2 flux observation technique in forest ecosystem. This paper summarizes the main achievements of CO2 flux in forest ecosystem and discusses some representative results of CO2 flux in forest ecosystem based on this technique. Current studies on CO2 flux in forest ecosystem mainly focus on the following 5 aspects: carbon source/sink estimation of forest ecosystem, calculation of source area/footprint of CO2 flux observations, dynamic characteristics of CO2 flux and its environmental impact factors, extraction of phenological parameters of forest ecosystem based on statistical model, and impact of climate system based on mechanism model on carbon cycle of forest ecosystem. The main conclusions are as follows: The forest ecosystem is an important carbon sink of terrestrial ecosystem. During CO2 flux observation of forest ecosystem, the spatial representativeness of the flux source area needs to be tested. The carbon source/sink status of the forest ecosystem is affected by tree age, precipitation and soil water content. Air temperature is an important factor influencing carbon cycle of forest ecosystem. Future studies on CO2 flux in forest ecosystem should focus on improving the accuracy of flux footprint model, discussing the contributions of different stands to CO2 emissions, and establishing a parametric model of plant physiological process by combining climate system model and ecophysiological model to predict the impact of climate change on forest carbon exchange. The study of CO2 flux in forest ecosystem at the regional-global scale will focus on multi-site flux and integrated analysis of long-term sequence of meteorological and flux data, and discuss the climatology characteristics of CO2 flux and the spatial pattern of carbon source/sink to better understand the carbon cycle of terrestrial ecosystem.[Ch, 1 tab. 64 ref.]
Scientific note
Resistance of Phoebe sheareri to anthracnose induced by salicylic acid
HOU Panpan, CHEN Anliang, FEI Libin, MA Liangjin
2020, 37(3): 605-610.   doi: 10.11833/j.issn.2095-0756.20190342
[Abstract](1204) [HTML](505) [PDF](35)
  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 P. sheareri and produce disease resistance.[Ch, 3 fig. 23 ref.]

Bimonthly, Start in 1984

Supervisor:Department of Education of Zhejiang Province

Sponsor:Zhejiang A&F University

Editor-in-Chief:YING Yibin

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


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