SHAO Jizhong , ZHANG Xiaosi , GUO Wenjuan , CHEN Yanrui
2023, 42(4):1-6. DOI: 10.13300/j.cnki.hnlkxb.2023.04.001
Abstract:Landscape architecture should fully play its positive role in the context of global climate change and the target of carbon peak and neutrality proposed by China government. The practical actions of landscape architecture in various countries taken to address the goals of carbon peak and neutrality were learned about through exclusively interviewing International Federation of Landscape Architects Asia Pacific Region Climate Change Working Group. The goals and prospects for the development of landscape architecture in the future were proposed from two aspects including the flexible design and low-carbon design of landscape architecture.
WU Jiaming , LIU Yining , LI Liang
2023, 42(4):7-15. DOI: 10.13300/j.cnki.hnlkxb.2023.04.002
Abstract:An intervention approach framework for landscape architecture to promote public participation in the response to climate change was proposed based on the three process dimensions of “cognition-emotion-behavior” of public participation and the theory of planned behavior to enhance the key role of landscape architecture in promoting public participation in the response to climate change.Three levels including willingness to enhance, action to stimulate, and long-term investment were covered.Seven key measures for intervention were included.In terms of enhancing awareness, the climate change information should be integrated into a multi-sensory public space design and activity system, and the spatial elements should be used to simulate possible local climate change impacts, in order to create climate change cognition and establish emotional links.In terms of stimulating action, pop-up experiences should be created and participatory low-carbon should be established.In terms of long-term guarantee mechanism, policy guarantees for public participation in the response to climate change should be promoted.The self-organization platforms in community should be built.The funding sources should be expanded.The feedback mechanisms for response actions should be improved.The sustainable public participation should be encouraged.Finally, three specific suggestions that China needs to focus on promoting public participation in the response to climate in the future were put forward based on the national conditions in China.Mainly including: changing traditional slogan promotion methods in the stage of increasing willingness, and integrating more climate change information into planning and design.Prioritize low-cost participatory low-carbon activities during the action phase to promote public participation.In the long-term investment stage, under the guidance of the government, expand funds and build self-organizing platforms, and develop sustainable evaluation feedback.
2023, 42(4):16-22. DOI: 10.13300/j.cnki.hnlkxb.2023.04.003
Abstract:A healthy living environment is an important cornerstone of all development in human society,but global climate change has plunged it into crisis.The emergence of concept of Anthropocene has laid a scientific foundation for the correct understanding of the relationship between man and nature.As a discipline connecting people,sites and environment,landscape architecture can play a key role in encouraging and leading living environment related disciplines to jointly cope with the global climate crisis.In order to meet the challenge of landscape architecture in the Anthropocene era,this article reviews the characteristics of landscape architecture in the Anthropocene.It points out that climate change,as the primary symbol of the Anthropocene,has a wide range of impacts on landscape architecture.The main objectives of landscape architecture to address climate change are summarized in depth by establishing a logical link between climate change,the human world and landscape architecture.Some feasible solutions and strategies are put forward.It will provide useful reference for the update and development of landscape architecture theories and practices.
CHEN Ruishan , CHEN Dan , WANG Yun
2023, 42(4):23-31. DOI: 10.13300/j.cnki.hnlkxb.2023.04.004
Abstract:The increasing natural disasters caused by climate change and the national carbon peak and carbon neutrality target have brought historical opportunities for the development of landscape architecture,but the voice of landscape architecture in China’s response to climate change is still insufficient.In order to enhance the significance of landscape architecture in coping with climate change,clarify its responsibilities and responsibilities in this field,and explore the innovative approaches of landscape architecture in climate design,this study,based on a comprehensive analysis of relevant domestic and foreign literature and policy measures on coping with climate change,examines the fields that landscape architecture can contribute to from two aspects of climate change mitigation and adaptation.The results show that landscape architecture needs to meet national needs such as climate change adaptation,disaster management,and carbon peak and carbon neutrality,etc.,and strengthen multi-disciplinary integration.On the one hand,carbon sequestration and sink increase in urban and rural living environment and carbon emission reduction should be achieved through climate positive design.On the other hand,it also needs to adapt to climate change through landscape planning and design,reduce disaster risk,and enhance urban and rural resilience.The innovative approaches of landscape architecture in climate design include standardization direction,spatial quantitative transformation,ecological integrity orientation,multi-scale observation and implementation,and educational reform and innovation.The above results show that landscape architecture has great potential in coping with climate change.The innovative exploration of climate design can promote the paradigm transformation and innovative development of landscape architecture disciplines and provide Chinese solutions to climate change.
ZHANG Yu , FU Yanrong , SHAO Jizhong , BAI Wanrong , Lü Xinbei
2023, 42(4):32-41. DOI: 10.13300/j.cnki.hnlkxb.2023.04.005
Abstract:The adverse effects of global climate change on the production and life of human including extreme drought, sea level rise, and reduced biodiversity are increasingly receiving attention.Landscape architecture can mitigate and adapt to the negative impacts of climate change by coordinating the relationship between humans and nature.Constructing a method and system for landscape architecture in responding to climate change has important and practical significance for better utilizing the functions of landscape architecture and promoting the development of landscape architecture disciplines.Three shortcomings in existing practices including insufficient understanding of the complexity of climate change, a disconnect between theory and practice in addressing climate change, and a lack of guarantee mechanisms for implementation were summarized by reviewing the practices and related concepts of landscape architecture in response to climate change at home and abroad.This article tentatively proposed the design of climate initiative for landscape architecture to positively address the comprehensive driving factors of climate change.The design method and technical system of climate initiative should be constructed from the perspectives of definition, characteristics, processes, methods, and implementation mechanisms.It will provide reference for the practice of designing landscape architecture with climate initiative.
ZHU Liqing , GAO Chi , ZHU Chunyang
2023, 42(4):42-52. DOI: 10.13300/j.cnki.hnlkxb.2023.04.006
Abstract:Flood disasters are the main risk faced by coastal cities due to climate change. Based on the IPCC's definition of risk, this article constructed an assessment model of flood risk index based on hazard, vulnerability, and exposure. 11 evaluation indicators were used to calculate the flood risk index with scenario simulation and GIS spatial overlay methods. The Huangpu River waterfront space in Shanghai was selected as the study area for empirical analysis. Scenarios in 2030, 2050, and 2100 were simulated. The spatial pattern of flood risk under climate change goals in the Huangpu River waterfront area was obtained based on the results of evaluation. Furthermore, a single-factor overlay evaluation was conducted based on population density to identify the “Three Zones and Three Policies” for landscape renewal in the Huangpu River waterfront space through scenario simulation. The results of assessing the flood-prone area showed that the risk level is increasing year by year according to the spatial pattern of flood risk under the objective of climate change in the Huangpu River waterfront. Both upstream and downstream parts of Huangpu River show high flood risk sections in the scenario simulation in 2050 and 2100. The coastline that adopts resistance (flood control) strategies has been increasing year by year, posing an increasing threat to areas with high urban population density. The number of shorelines adopting evacuation strategies has been increasing year by year, and the livability of water banks has decreased. The number of shorelines adopting coexistence (flood carrying) strategies is decreasing year by year, and more resistance and evacuation strategies are needed. According to the flood risk zoning policy of Huangpu River waterfront from the perspective of climate change, the flood area is located to the east of Baoshan District and the Northwest Angle of Pudong New Area. The Huangpu River waterfront space needs to adopt a retreat and evacuation strategy, implement population evacuation, plan the “estuary protection plan”, and construct ecological wetlands in the middle reaches of the Songjiang District. The flood-resistant area is located in the central urban area, and the waterfront space needs to continue to adopt flood-resistant strategies, with increasing risks. The assessment of the flood bearing area is located in most of the Huangpu waterfront spaces, and the strategy of coexisting with the flood can be adopted, but the potential is increasingly shrinking.
CHEN Chongxian , FANG Yan , LIU Jingyi
2023, 42(4):53-63. DOI: 10.13300/j.cnki.hnlkxb.2023.04.007
Abstract:In the context of global climate change and sea level rise, coastal disasters will have a significant impact on the landscape and socio-economic development of coastal cities. Guangzhou, a coastal city in the Pearl River Delta, was used to construct a “sensitivity adaptabilit” vulnerability assessment framework based on the land use and socio-economic data in the area. The vulnerability characteristics of urban landscape system in Guangzhou under three different scenarios of sea level rise superimposed with storm surge risk in the short-term (2030), the medium-term (2050) and the long-term (2100) were assessed. The results showed that the agricultural landscape, park green space, and wetland landscape had the largest inundation area under different risk scenarios in the future, while the industrial landscape and commercial and public service landscape had the most severe economic losses from the perspective of inundation scope and economic losses. The areas with high landscape vulnerability in the short-term were mainly concentrated in Liwan District, Baiyun District and Huangpu District in the central part of Guangzhou from the perspective of the overall spatial distribution of vulnerability. In the medium and long term, the risk of landscape vulnerability in Haizhu District in the central part of Guangzhou gradually increased. From the perspective of spatial distribution of various landscape vulnerability, the most vulnerable areas of agricultural landscape in the short-term are Panyu District and Nansha District in southern Guangzhou compared with other landscapes including the transportation landscape and residential landscape. In the mid-term and long-term stages, the vulnerability risks of various landscapes have increased to varying degrees, with significant changes in the vulnerability levels of park green spaces and wetland landscapes. This article systematically assessed the impact of sea level rise combined with storm surge on different types of urban landscapes in Guangzhou. It will provide decision-making reference for the risk management and prevention of coastal disasters in the future, and the construction of urban resilience in Guangzhou.
ZHANG Xiaosi , SHAO Jizhong , LIN Runze , LI Kunyang , TAN Yanran , ZHANG Xueyin
2023, 42(4):64-73. DOI: 10.13300/j.cnki.hnlkxb.2023.04.008
Abstract:Quantitative analyses were conducted on the extreme temperatures and urban ecological spatial patterns with cooling effects in Wuhan in 2000, 2010, and 2020 by constructing indexes, functional models, and mathematical statistics to analyze the evolutionary characteristics of climate change and the cooling effect of urban ecological spatial pattern and the coordination mechanism between them. The results showed that the comprehensive index of extreme temperatures in Wuhan in 2000, 2010, and 2020 showed a trend of first increasing and then decreasing, while the overall index of urban ecological spatial pattern showed a trend of decreasing. The pattern indices including CA, NP, PLAND, LPI, LSI and AI, that were positively correlated with cooling effects, all exhibited linear or fluctuating decline characteristics within 20 years. It is indicated that the cooling effect of ecological space in Wuhan has gradually been weakened. The coordination degree between the comprehensive index of extreme temperature and the comprehensive index of urban ecological spatial pattern in 2000, 2010, and 2020 gradually decreased from intermediate coordination to severe imbalance, indicating that the cooling effect of ecological space in Wuhan on alleviating extreme temperature is gradually decreasing.
CHANG Mingxin , ZENG Chen , XIE Peng , LIU Shumi
2023, 42(4):74-85. DOI: 10.13300/j.cnki.hnlkxb.2023.04.009
Abstract:Land use change is an important factor that affects the carbon cycle process of terrestrial systems and climate change.In order to seek the optimal carbon emission reduction path for terrestrial space and realize the optimization of low-carbon green national land spatial pattern,this study selected Wuhan as a case study area.Based on linear programming and Markov model,the land use structure of Wuhan in 2035 under different scenarios was formed.The cellular automata model incorporating spatial autocorrelation effect was used to simulate the land use spatial layout based on different land use structures,then the carbon emissions in the future under different land use structures and spatial layouts was analyzed,and finally a low-carbon land use pattern that meets the future development goals of the city was proposed.The results showed that in the natural development scenario and the economic priority scenario,the construction land and cultivated land area will change significantly,and the total carbon emissions will increase by 8.25% and 29.06%,respectively.Under the low-carbon oriented scenario,the growth rate of construction land slowed down,the forest land increased significantly,and the total carbon emissions increased by 5.46%.From the perspective of spatial form,under the natural development scenario and the economic priority scenario,the construction land expands outward around the central urban area obviously,and the scattered construction land in the far urban area was gradually merged.Under the low-carbon oriented scenario,the increase of construction land was limited,the increase of forest land in the far urban area was obvious,and the ecological framework of multi-ecological green wedges and ecological corridors was gradually formed.The above results showed that the simulation results under different scenarios can all show the impact of different development strategies on the territorial spatial pattern of Wuhan.The carbon emissions situation of the economic priority scenario that emphasizes the maximization of economic benefits is not optimistic.The new pattern of national land space development and protection integrated with the low-carbon concept can achieve the goal of green carbon reduction while taking into account the speed of economic growth.
2023, 42(4):86-97. DOI: 10.13300/j.cnki.hnlkxb.2023.04.010
Abstract:Global climate change has led to a gradual intensification of heat island effects and a significant increase in events of extreme high temperature at summer in urbans. How to effectively improve the cooling effect of urban blue-green spaces is an important way to adapt to the climate change and build a living environment with high-quality. The Landsat-8 data and radiative transfer equation was used to retrieve land surface temperature in Kunshan City. The correlation analysis and boosted regression tree (BRT) model of the urban blue-green spatial pattern and the measurement index of summer cooling effect were established constructed at the scale of urban and block to identify the key factors and their importance ranking of urban blue-green spatial patterns that affect summer cooling effects in the Jiangnan water network area and to explore the differences in spatial scale of cooling effect with comparative study. Results showed that there were four indicators with a relative contribution rate of over 10% for the impact of the blue-green spatial pattern on the summer maximum surface temperature at the scale of urban. The decreasing order of impact degree was as follows: index of water body shape > proportion of blue-green space > width of waterfront green space > aggregation index of water body. There were three indicators with a relative contribution rate of over 10% for the impact of the blue-green spatial pattern on the average intensity of cold island at the scale of urban. The decreasing order of impact degree was as follows: width of waterfront green space > index of water body shape > proportion of blue-green space. At the scale of block, there were five indicators with a relative contribution rate of over 10% for the impact of the blue-green spatial pattern on the summer maximum surface temperature at the scale of urban. The decreasing order of impact degree was as follows: index of water aggregation > average patch index of water > ratio of green space > ratio of water surface > index of water body shape. There were two indicators with a relative contribution rate of over 10% for the impact of the blue-green spatial pattern on the average intensity of cold island at the scale of urban. The decreasing order of impact degree was as follows: aggregation index of green space > proportion of blue-green space. It is indicated that the spatial pattern characteristics of urban blue-green space have significant scale effects on the correlation degree and contribution level of summer cooling. The optimization strategies of planning and design were proposed. It will provide a practical reference for creating a comfortable urban living environment at different scales.
LIU Huosheng , LI Sitao , WAN Haokai , YU Qianhui , WU Changguang
2023, 42(4):98-106. DOI: 10.13300/j.cnki.hnlkxb.2023.04.011
Abstract:The air temperature in the central urban area of Wuhan City was observed based on the local climate zone (LCZ) scheme to accurately evaluate the spatial-temporal differentiation characteristics of urban heat island (UHI) in Wuhan City and assist in the design of climate adaptability. The spatial-temporal variation of urban heat island intensity (UHII) in six types of architectural spaces and three types of natural spaces during three consecutive summer and winterperiods were analyzed. Explored the daily average UHII differences, hourly UHII variation, and UHII differences within the same LCZ type among different LCZ types, as well as their influencing factors were investigated. The results showed that each LCZ maintained stable daily average inter-type differences of UHII in summer and winter. The LCZ type with more high-rise building had a higher UHII, especially the open high-rise (LCZ 4) and open mid-rise (LCZ 5). However, sparse forests (LCZ B), dense forests (LCZ A), open low-rise (LCZ 6), and scattered buildings (LCZ 9) remained below 0 ℃ in general. There was a significant difference in the hourly variation of UHII between LCZ A and other LCZ types. LCZ A showed a rapid increase followed by a decrease within 8 hours after sunrise, while other LCZ types showed a rapid decrease followed by a stable increase. Within a single day, the UHII of each LCZ exhibited a characteristic of “strong in summer and weak in winter, weak in day and strong at night”. LCZ 9 and LCZ A were able to maintain the urban cold island effect for a long time to alleviate local heat environment, while LCZ 4 was the only type maintaining UHII above 0 ℃ in both summer and winter. Both LCZ 2 and LCZ 5 with mid-rise characteristics exhibited significant intra-type UHII differences. Similar LCZ plots located in the central part of the urban area were affected by the obstruction of urban canopy ventilation, and their UHII was higher than those on the urban boundary plots. The results indicated that UHII difference among LCZs were stable in summer and winter, while intra-class significant differences of the same LCZ were mainly driven by the spatial structure of Wuhan City, with densely urban core area being more prone to localized high temperatures due to poor ventilation performance and frequent anthropogenic heat emissions.
TAN Jing , CHEN Zhenghong , CHEN Yingying , XIAO Mei , JIA Wenqian
2023, 42(4):107-115. DOI: 10.13300/j.cnki.hnlkxb.2023.04.012
Abstract:The observation data of the initial flowering period of Japanese cherry trees in the cherry blossom garden at Wuhan University and the meteorological data of the same period were used to analyze the temporal and spatial response characteristics of the flowering period of cherry blossoms to the urban heat island effect in Wuhan to improve the accuracy of the model for predicting the flowering period of cherry blossom in Wuhan and to better predict the flowering period of cherry blossom. The results showed that the urban heat island effect in Wuhan has been significantly enhanced since the late 1980s. The warming rate and contribution rate of urban heat island in winter have increased significantly since 1988. The urban heat island effect was the highest in the central urban areas of Wuhan, spreading and radiating from the urban core areas to the suburban areas. Huangpi and Xinzhou in the northern areas of Wuhan City were almost unaffected by the heat island effect. The flowering period of cherry blossom in Wuhan had obvious temporal and spatial response to the urban heat island effect in winter. The 5-year sliding average UHII of average winter temperature increased by 1 ℃, leading to an early flowering period of cherry blossoms by about 2.8 days. The Hankou River Beach, Holiday Inn Riverside and other places in the central urban areas of Wuhan were the first places where cherry blossoms bloomed, 1?2 days earlier than the flowering period of Wuhan University. The flowering period of cherry blossom garden in East Lake and Dijiao Park was 1?2 days later than that of Wuhan University. It is indicated that the urban heat island effect significantly advances the flowering period of cherry blossoms in Wuhan, and the flowering period of in the areas with strong urban heat island effect was earlier than that in the areas with weak urban heat island effect.
FENG Xianhui , ZENG Zhilin , JING Meixi , GAO Kechang , XIAO Yiqiang
2023, 42(4):116-124. DOI: 10.13300/j.cnki.hnlkxb.2023.04.013
Abstract:To investigate whether differences in the representations of the two commonly used vegetation indices, NDVI and EVI, affect vegetation-related studies under different index representations. This study is based on the use of two different remote sensing vegetation indices, MODIS-NDVI and MODIS-EVI, from 2005 to 2020 to characterize the spatial features of vegetation in the Guangdong-Hong Kong-Macao Greater Bay Area. Using 17 natural and anthropogenic factors from the same time period as the driving factor, the effect of the 17 driving factors on the spatial features of the vegetation based on the different indices NDVI and EVI is calculated separately using Geo-detector. The results show that although there are differences in the results of the southern subtropical-tropical vegetation in the Guangdong-Hong Kong-Macao Greater Bay Area as characterized by different vegetation indices in NDVI and EVI, the quantitative and ranking results of the influence of driving factors under different indices calculated by the Geo-detector module are consistent, and are not affected by the differences in index representation. Among the drivers, land use type and elevation are the dominant drivers. Their effect on the spatial distribution of vegetation is greater than 50% under different metrics. Most of the factors have a two-factor enhancement effect on the spatial features of vegetation under different representation metrics. Synergies in population distribution and land use type have the strongest effect on NDVI-based vegetation cover; however, the synergistic effect of the population distribution and elevation has the strongest effect on the vegetation cover based on the EVI index. This study concludes that while the NDVI and EVI indices differ in representing vegetation cover characteristics, the results of the quantitative analysis of drivers remain consistent.
LI Xuexue , LING Lin , WANG Kangxu , CAI Mingli , CAO Cougui , JIANG Yang
2023, 42(4):125-131. DOI: 10.13300/j.cnki.hnlkxb.2023.04.014
Abstract:The conventional japonica rice and its Cry2A* transgenic rice lines, and the conventional indica rice and its Cry2A* transgenic rice lines were used to conduct the pot experiment. The root characteristics of Cry2A*transgenic rice lines under nitrogen application and no nitrogen application were investigated to study the root characteristics of Cry2A* transgenic rice lines and provide technical support for the cultivation and regulation of insect-resistant transgenic rice. The results showed that the root length, root surface area and root volume of the Cry2A* transgenic rice lines were significantly lower than those of the parents under no nitrogen application at the stage of mature, but there was no significant difference between them and the parental control under the nitrogen application. The root active absorption area of KY(Cry2A*) was significantly higher than that of the parents at the stage of flowering, while the root active absorption area of MH86(Cry2A*) was not significantly different from that of the parents. Compared with no nitrogen application, nitrogen application significantly increased the root diameter of KY(Cry2A*), but had no significant effect on the root diameter of MH86(Cry2A*). It is indicated that there was a certain difference in the root characteristics between the Cry2A* transgenic rice and its parents, and this difference was more obvious under no nitrogen application.
YANG Lirong , Lü Na , ZHANG Zhao , LIU Anda , MA Xuefeng , YANG Guozheng
2023, 42(4):132-139. DOI: 10.13300/j.cnki.hnlkxb.2023.04.015
Abstract:After sowing winter wheat from 2018 to 2020, the cotton stalk was mechanically crushed and covered before returning to the field to study the decomposition dynamics of cotton stalk returning to the field and the impact of different amounts of cotton stalk returning to the field on the yield of wheat. Three treatments including zero stalk returning (ZS), half stalk returning (HS) and all stalk returning (AS) were set up with the randomized block. The decomposition, nutrient release, and structural component changes of cotton straw with different returning amounts were analyzed. The results showed that the decomposition rate of straw was first fast and then slow, with the fastest decomposition occurring 20 days after returning to the field, and then gradually decreasing. After 170 days of returning to the field, the decomposition rates of HS and AS were 73.4% and 66.8% respectively from 2018 to 2019, and 77.6% and 60.4% respectively from 2019 to 2020. There were differences in the release rates of different structural components in straw. After 170 days of decomposition, the release rate of soluble sugars in cotton culms was 70.7%-81.38%, followed by cellulose (57.3%-60.7%) and lignin (44.1%-50.3%). There were also differences in the release rates of N, P, and K in cotton stalk, with K release rates ranging from 83.1% to 87.9%, P release rates ranging from 71.4% to 80.5%, and N release rates ranging from 66.5% to 74.7%. Returning cotton stalk to the field increased the number of spikes per unit area of wheat, thereby increasing the yield of wheat. It is indicated that returning cotton stalk to the field is beneficial for improving soil nutrient status and increasing the yield of winter crop (wheat), with all stalk returning (AS) being better.
PAN Yifan , LIU Yongzhong , HUANG Yuxuan , CHEN Huan , LI Yanting , LUO Yin
2023, 42(4):140-149. DOI: 10.13300/j.cnki.hnlkxb.2023.04.016
Abstract:A questionnaire survey was conducted on 306 planting entities in main citrus planting provinces (cities) in China regarding techniques including winter sanitation,weed control,and management of fertilizer and water to understand the cultivation situation and management techniques of citrus in China.The results showed that 96.7% of planting entities conducted winter sanitation for citrus orchards.The annual average times of weed control,fertilization,irrigation and pesticide application were 3.2,4.9,6.7 and 11.5,respectively.57.5%,56.2%,and 47.4% of the planters used herbicides,knapsack mowers,and manual weed control,respectively.65.5% and 63.9% of the planters used broadcasting and foliar spraying methods.53.1% and 39.3% of the planters used pipe irrigation and drip irrigation methods.71.2% of the planters used pipeline injection,and the proportion of air-sent mechanical injection was relatively low (14.7%).Only 34.5% of the planters had regular pruning during the growing season,and the pruning was mainly done by manual methods (accounting for 86.6%).The application of citrus cultivation and management techniques is related to the area,type,and distribution of citrus orchards.The annual average number of weed control and fertilization,the proportion of drip irrigation and fertilization,is higher in large area or gentle slope flat orchards than that in small area or mountainous orchards,but the annual average number of pesticide applications is the opposite.In central China,the ratio of irrigation,fertilization and fruit holding operation at maturity were the least among different planting regions.Based on the results of investigation,suggestions for the development of citrus cultivation and management technologies have been proposed.Firstly,it is necessary to continue to pay attention to the research and development of citrus cultivation and management technologies that meet the needs of the times.Secondly,it is important to attach importance to the research and development of cultivation technologies and equipment that combine agronomy and agricultural machinery.Thirdly,the research and development of cultivation technologies and equipment with ease,simplicity and high quality should focus on systematicity.
SUN Yi , HU Yibo , YE Junli , CHAI Lijun , DENG Xiuxin , XIE Zongzhou
2023, 42(4):150-157. DOI: 10.13300/j.cnki.hnlkxb.2023.04.017
Abstract:To screen the rootstock resources for superior traits of convergent parents,94 individual plants of F1 hybrid population with Red tangerine as the female parent and Trifoliate orange as the male parent were used as test materials to observe their defoliation period and flowering period for two consecutive years,and the fruit quality,seed embryo types and germination rate of 37 individual plants with high fruition rates were analyzed. The results showed that the phenology of 94 individual plants was similar to that of their parents,but there was a significant difference in the defoliation period between hybrid progenies. The fruit shape of the hybrid population was more inclined toward paternal inheritance,mainly oval in shape. The average fruit weight of the offspring populations was 58.63 g,average number of seeds was 14,and 1000-grain weight was 153.73 g.The soluble solid content was 10.7%?16.5%,which was not significantly different from that of the female parent,and the titratable acid content of fruit was 2.00%?5.56%,which was significantly higher than that of the female parent. The flavedo of the hybrid population mainly includes red peel (female parent preferred) and yellow peel (male parent preferred). The contents of β-cryptoxanthin were significantly higher than those of the parents,and the contents of violaxanthin lutein and zeaxanthin were between those of parents,while the contents of β-carotene in the peel of parents and hybrid offspring were relatively low. The contents of violaxanthin,lutein and β-carotene showed continuous changes,which showed quantitative characteristics. The ratio of monoembryoid to polyembryoid types in the hybrid progeny was close to 1∶3,which indicated that the character was determined by a single gene. In summary,the results showed that the progeny No. 3,No. 6 and No. 24 had the characteristics of polyembryony ,more seeds per fruit and a high germination rate,and could be used as excellent rootstock candidates for further evaluation.
LI Dasui , RUAN Siqi , HU Qingqing , ZHANG Jinzhi , ZHANG Yahao , DIAN Yuanyong , HU Chungen , LIU Yongzhong , LEI Hongwei , ZHOU Jingjing
2023, 42(4):158-166. DOI: 10.13300/j.cnki.hnlkxb.2023.04.018
Abstract:One hundred and twenty citrus trees under three cultivation patterns including wide row and narrow plant,wide row and narrow plant fence pattern and traditional cultivation were used to measure the content of nitrogen in the canopy and extract the texture index and vegetation index from the multispectral images data of UAV remote sensing to quickly and accurately obtain the content of nitrogen and spatial distribution characteristics of plant canopy,and to manage the large-scale orchard accurately and dynamically.The random forest (RF) algorithm was used to establish the inversion model of nitrogen in the citrus canopy based on vegetation index,texture index,and the integration of vegetation index and texture index.The inversion accuracy of support vector machine (SVM),BP neural network algorithm (BP),and RF models that integrate vegetation index and texture index was compared.The results showed that the integration of vegetation index and texture index predicted the content of nitrogen in citrus canopy more accurately than the single vegetation index or texture index in the random forest algorithm.The training sets R2 and the test sets R2 of the vegetation index,texture index,and integration of vegetation index and texture index were0.710 and 0.430,0.761 and 0.349,0.775 and 0.533,respectively.The training sets R2 and the test sets R2 of the integration of vegetation index and texture index in the SVM algorithm and BP neural network were0.511 and 0.371,0.651 and 0.204,respectively.The results of using the RF model of vegetation index and texture index to inverse the content of nitrogen in citrus orchards under three cultivation patterns showed that the average content of nitrogen in citrus canopy in wide row and narrow plant werethe highest,followed by the wide row and narrow plant fence pattern,and the traditional cultivation pattern was the lowest,with the average content of nitrogen being 31.33,30.20,and 27.82 mg/g,respectively.It is indicated that the random forest algorithm combining UAV remote sensing with vegetation index and texture index can effectively predict the content of nitrogen in citrus canopy.It will provide a reference for the quantitative fertilization of large-scale citrus orchards.
LIU Yonghong , ZHENG Wentao , ZHANG Jintian , MA Zhonghua , KUAI Jie , WANG Bo , ZHOU Guangsheng
2023, 42(4):167-176. DOI: 10.13300/j.cnki.hnlkxb.2023.04.019
Abstract:The slow/controlled-release technology has been widely applied in the agricultural production with the rapid development of green, efficient, and intensive modern agriculture.The use of slow/controlled release fertilizers (SRFs or CRFs) can reduce environmental pollution, restore soil ecology, improve the utilization efficiency of fertilizer, and reduce labor costs.However, there are also some shortcomings in the application of slow/controlled release fertilizers.This article summarized the development, classification, preparation methods, and applications of SRFs or CRFs in recent years based on reviewing literatures.The advantages and disadvantages of slow/controlled release fertilizers in application were summarized.The problems and countermeasures in the application of slow/controlled release fertilizers were sorted out.It is proposed that systematic studies should be conducted on the application technology and evaluation system of slow/controlled release fertilizers in the future, focusing on the development of green materials, production processes, and equipment innovation, to form the integration and demonstration of industrial technology for slow/controlled release fertilizers, and to develop efficient, environment friendly, and low-cost slow/controlled release fertilizers that meet the requirements of production.
LIU Zeqin , LIU Ning , LI Shujuan , HUANG Guoqin , ZHOU Quan
2023, 42(4):177-184. DOI: 10.13300/j.cnki.hnlkxb.2023.04.020
Abstract:A pot experiment was designed to plant winter crops in the Science and Technology Park of Jiangxi Agricultural University from 2020 to 2021 to study the interaction mechanism between root exudates and the changes of soil microbial community under the intercropping pattern of Chinese milkvetch (Leguminous cruciferous) and rapeseed .The results showed that there were significant differences in the characteristics of root exudates under different planting patterns of Chinese milkvetch and rapeseed compared with the single cropping of Chinese milkvetch, intercropping significantly increased the content of monosaccharides and decreased the content of neurotransmitter compounds. Amino acids, monosaccharides, neurotransmitters, and other compounds were significantly correlated with soil microorganisms. Among them, monosaccharide compounds were significantly positively correlated with Acidobacteriota, Chloroflexi and other microorganisms.Neurotransmitter compounds were significantly positively correlated with Chloroflexota, Firmicutes, Gemmatimonadota, Myxococcota, Cyanobacteria and other microorganisms. The individual correlation results of the three models including the single cropping of Chinese milkvetch (A), the single cropping of rapeseed (R), and the intercropping of Chinese milkvetch and rapeseed oil (AR) showed that the difference in the correlation between root exudates and microorganisms and the overall result was the maximum under the single cropping of rapeseed.There was no significant correlation between monosaccharides and Acidobacterium and Chlorobacterium under A and R. Under AR, there was a significantly positive correlation between monosaccharides and Acidobacterium and Chlorobacterium. The relative abundance of Acidobacteriota communities under AR was significantly higher than that under A, and the index of microbial coverage was also significantly higher than that under A. It is indicated that root exudates are likely to be an important factor in changing the structure of soil microbial community in the intercropping of Chinese milkvetch and rapeseed, and monosaccharide compounds play a major role in this process.
HE Lang , LI Hongying , XIONG Qizhong , ZHANG Hongmei , LIU Wangbing , YE Xinxin
2023, 42(4):185-191. DOI: 10.13300/j.cnki.hnlkxb.2023.04.021
Abstract:A soil culture experiment was conducted to study the effects of two sulfur fertilizers including sulfur and sodium sulfate combined with calcium magnesium phosphate on the changes in Cd availability and the transformation of Cd morphology in paddy soil to investigate the immobilization effect of sulfur fertilizer combined with phosphorus fertilizer on cadmium (Cd) in paddy soil. Six treatments including control (CK), calcium magnesium phosphate (P), sulfur (S1), sodium sulfate (S2), calcium magnesium phosphate + sulfur (PS1), and calcium magnesium phosphate + sodium sulfate (PS2) were set up. The relationship between the Cd availability in soil and the available sulfur, available phosphorus, pH, and Eh was analyzed. The results showed that the Cd availability in soil decreased significantly after applying different immobilization materials in the soil. Among them, PS1 treatment had the lowest content of available Cd, which decreased by 49.8% compared to CK. P treatment increased soil pH by 0.39 compared to CK. S1 treatment significantly reduced the soil Eh value, which was 23.2% lower than CK, and promoted the reduction of SO42- to S2-. PS1 treatment significantly increased the content of available phosphorus in soil. Compared with CK, the available phosphorus in PS1 treatment increased by 81.9%. PS1 treatment synergistically promoted the Cd transformation of exchangeable fraction to residual fraction in soil due to the regulation of soil Eh, available sulfur and available phosphorus. It is indicated that the combination application of sulfur and calcium magnesium phosphate has potential in alleviating Cd pollution in paddy soil.
MA Ziyu , MA Wenlin , JIA Xiaohong , WANG Shengtao , ZHANG Lei
2023, 42(4):192-198. DOI: 10.13300/j.cnki.hnlkxb.2023.04.022
Abstract:By analyzing and predicting the changes in soil organic carbon content of maize fields in Qianqiaozi Village,Huairou District,we reveal the key influencing factors affecting organic carbon changes and provide a scientific basis for achieving carbon sequestration and emission reduction targets in Beijing,China. In this study,the DNDC model was validated using the actual measured organic carbon data from 2016 to 2019 in the maize fields,and then the main influencing factors such as climate,soil and material return were selected to conduct sensitivity analysis on the validated DNDC model,and finally the future (to 2100) organic carbon changes under different typical concentration pathways (RCP8.5,RCP4.5) were simulated. The results showed that: the calibrated DNDC model can simulate the soil organic carbon changes in this maize field well; the initial organic carbon content and straw return rate are the main influencing factors of organic carbon changes; the organic carbon content increases significantly under RCP8.5 and RCP4.5,and the soil carbon pool reaches equilibrium at about 77 years,and the organic carbon content reaches 27.70 g/kg and 29.03 g/kg by 2100,respectively. The DNDC model can be used to study organic carbon changes in maize fields in this study area,and this management approach can be used to sustain carbon sequestration in the future.
XIONG Hao , ZHAO Yuexiu , CHEN Dake , CHEN Yaru , CHEN Gaogui , LI Feng’e
2023, 42(4):199-206. DOI: 10.13300/j.cnki.hnlkxb.2023.04.023
Abstract:In order to investigate the regulatory mechanisms of the interferon-induced transmembrane protein 1 gene (Ifitm1) in mammalian follicle development, Ifitm1 was overexpressed and suppressed in mouse granulosa cells (mGCs). The effects of Ifitm1 on the growth of mGCs were detected by flow cytometry, qRT-PCR and EdU method, the effects of Ifitm1 on the expression of ovulation-related genes in mice were detected by qRT-PCR and Western blot, and the mGCs were treated with related pathway inhibitors to investigate the mechanisms by which Ifitm1 affectes follicle development and ovulation in mice. The results showed that the Ifitm1 gene was successfully overexpressed and suppressed in mGCs. Further studies revealed that interference with Ifitm1 gene expression reduced the expression of cell cycle protein Ccnd1 by 63.5%, decreased the percentage of cells in G0/G1 phase, blocked the cells in G2/M phase, thus inhibiting the proliferation of granulosa cell. Ifitm1 interference also resulted in 1.95-6.76 fold increase in the expression levels of the ovulation marker genes Lhr, Ereg and Cyp19a1 (P<0.05), and inhibited the expression of p-AKT (Ser473), a key protein in the PI3K/AKT signalling pathway, blocked the PI3K/AKT signalling pathway, and then inhibited the expression of Ifitm1 gene, but the mRNA levels of Lhr, Ereg and Cyp19a1 remained unchanged in mGCs, suggesting that the Ifitm1 gene affects ovulation through inhibiting the activity of PI3K/AKT signalling pathway. In summary, Ifitm1 plays an important role in mGC growth and follicular ovulation through the PI3K/AKT pathway.
Lü Mingrui , WANG Ping , ZHAO Yuhua , GAO Jian
2023, 42(4):207-214. DOI: 10.13300/j.cnki.hnlkxb.2023.04.024
Abstract:In order to explore the optimum spectrum for largemouth bass (Micropterus salmoides) larvae,four treatments including full spectrum (FS),red light (RL),green light (GL) and blue light (BL) were set up under the industrial recirculating aquaculture system. Hoping to find suitable spectral range for largemouth bass breeding,the growth performance,activities of superoxide dismutase (SOD),catalase (CAT),lysozyme (LZM),alkaline phosphatase (AKP),contents of glutathione (GSH) and malondialdehyde (MDA),the relative expression levels of growth hormone (gh),insulin-like growth factors-1 (igf-1),thyroid stimulating hormone (tsh),heat shock protein 70 (hsp70),corticotropin releasing factor (crf),caspase-3 of largemouth bass larvae in different treatments were compared and analyzed. The results showed that the final body length and weight,specific growth rate (SGR),weight gain rate (WGR) and LZM activity of larvae in the full spectrum,green light and blue light groups were significantly higher than those in the red light group (P<0.05),while the contents of MDA,GSH and activities of SOD and CAT were significantly lower than those of the red light group (P<0.05). The activity of AKP and mRNA expressions of gh,igf-1 and tsh in the full spectrum and green light groups were significantly higher than those in the red light group (P<0.05),and the mRNA expressions of hsp70,crf and caspase-3 were significantly lower than those of the red and blue light groups (P<0.05). The survival rate (SR) of larvae in the full spectrum group was significantly higher than that in other groups (P<0.05),and showed good cluster phototaxis behavior. In conclusion,full spectrum light source is the most beneficial for largemouth bass larvae cultivation under the industrial recirculating aquaculture.
GUO Wei , YIN Heng , MO Aijie , ZHAI Yuxiang , YI Linyuan , YANG Huijun , YUAN Yongchao
2023, 42(4):215-224. DOI: 10.13300/j.cnki.hnlkxb.2023.04.025
Abstract:To determine the dietary protein requirement of mandarin fish (Siniperca chuatsi) with different sizes,mandarin fish with initial body weight of (11.58±1.34) g (G1),(94.77±2.59) g (G2) and (245.26±3.59) g (G3) were selected to investigate the effects of different dietary protein levels on growth performance,feed utilization rate,morphological indexes,digestive enzyme activity,antioxidant capacity and ammonia nitrogen excretion.The results showed that when the protein content was 500 g/kg,the specific growth rate (SGR),final body weight (FBW) and weight gain rate (WGR) of mandarin fish in G1 and G2 groups were the highest,while when the protein content was 450 g/kg,those in group G3 were the highest.The feed coefficient showed an opposite trend.Based on the analysis of SGR’s broken-line regression model,the optimal protein requirements of three different sizes of mandarin fish were 497.1 g/kg,451.9 g/kg and 446 g/kg,respectively.The survival rate of mandarin fish with small and middle sizes fed with low protein level (350 g/kg and 400 g/kg) diet was significantly lower than that of other groups (P<0.05),but dietary protein level had no significant effect on survival rate of mandarin fish in G3 group (P>0.05).Condition factor,hepotasomatic index and viscerasomatic index of mandarin fish in G1 and G2 groups decreased significantly with the increase of dietary protein level (P<0.05).With the increase of dietary protein level,the dry matter apparent digestibility coefficient (ADC) of mandarin fish was first increased and then stabilized in G1 and G3 groups,while that in G2 group was first increased and then decreased.With the increase of dietary protein level,the crude protein ADC of mandarin fish with three different sizes increased significantly (P<0.05) and decreased slightly after reaching the highest value at 500 g/kg protein level.A similar trend was observed in trypsin activity of the foregut.The activities of glutamic-pyruvic transaminase and glutamic-oxalacetic transaminase in liver of mandarin fish at three different growth stages increased dramatically as dietary protein level elevated (P<0.05).The ammonia nitrogen excretion rate of mandarin fish with three different sizes reached the peak at 6 h after feeding and increased significantly with the increase of dietary protein level (P<0.05).When feeding with high protein level diet,the ammonia nitrogen excretion rate of mandarin fish in G3 group was noticeably higher than that in G1 group (P<0.05).The above results showed that dietary protein content had significant effects on the growth performance,digestion and metabolic indexes of mandarin with three sizes,and the optimal protein requirement could be determined to achieve the optimal healthy breeding effect for mandarin fish.
LAN Jie , LIANG Xufang , ZHANG Yanpeng , ZHAI Lijuan , WAN Gongwei
2023, 42(4):225-235. DOI: 10.13300/j.cnki.hnlkxb.2023.04.026
Abstract:Neuropeptide Y receptors (YR) are thought to mediate multiple physiological functions of teleost NPY family peptides,such as feeding. However,the structure and signaling of fish NPY receptors have not been fully elucidated. In this study,the gene structure,tissue expression and signaling of YR in grass carp (Ctenopharyngodon idellus) were reported. The sequences of seven YR genes of Y1R,Y2R,Y2-2R,Y4R,Y7R,Y8Ra and Y8Rb were obtained in the grass carp genome. Homology analysis of grass carp YR revealed that the amino acid sequences encoded by seven YR isoforms were highly conserved in teleost fish. The results of tissue expression showed that grass carp YR was mainly expressed in central tissues,but also in peripheral tissues,including eyes,gills and intestines. NPY can activate the expression of Y2R,Y4R and Y8Rb in HEK293t cells. Y2R is coupled to the cAMP/PKA signaling pathway and Y4R is coupled to the MAPK/ERK signaling pathway. Y8Rb can activate both cAMP/PKA and MAPK/ERK signaling pathways. Intracerebroventricular injection of NPY could significantly increase the expression of Y1R,Y2R,Y4R and Y8Rb. This study shows that grass carp Y2R,Y4R and Y8Rb are functional and can transmit signals efficiently,and NPY action is likely mediated by these receptors.
LIU Yiwei , WANG Wei , ZHANG Shuyu , SUN Junyang , LI Shuangshuang
2023, 42(4):236-243. DOI: 10.13300/j.cnki.hnlkxb.2023.04.027
Abstract:To address the issues of low prediction accuracy and slow convergence rate of ammonia nitrogen concentration model under small sample data, a method of establishing ammonia nitrogen concentration prediction model by using long short-term memory (LSTM) and optimizing the model by using Bayesian optimization algorithm and Meta-learning mechanism was proposed. The Bayesian optimization algorithm was used to optimize the superparameters of the prediction model, and the initial values of the model parameters were given. Then the Meta-LSTM algorithm was used to learn the model gradient and allow the parameter sharing and updating among the optimizers, and finally the optimization of the prediction model of ammonia nitrogen concentration was realized. Compared with LSTM, GRU and RNN models, the result shows that the root-mean-square error, mean absolute error and mean square error of the proposed model are 0.027 6, 0.023 9 and 0.000 76, respectively, which are better than other prediction models. It is further indicated that the prediction model of ammonia nitrogen concentration based on Bayesian and Meta-learning is effective for modeling small sample data, and can achieve convergence in rapid training. The accuracy of the model meets the prediction requirements of ammonia nitrogen concentration for aquaculture.
2023, 42(4):244-253. DOI: 10.13300/j.cnki.hnlkxb.2023.04.028
Abstract:As a high-value carotenoid, lycopene has many physiological functions, such as anti-oxidation, scavenging free radicals and preventing heart cerebrovascular disease. It is widely used in fields such as food and medicine. At present, lycopene mainly comes from natural tomato extraction, and its market application is limited due to the limited production capacity. While the biotechnology represented by synthetic biology has brought the dawn for the innovative production of lycopene. In this paper, the physicochemical properties, physiological functions and production methods of lycopene were summarized according to the relevant domestic and foreign research literature. In particular this paper focuses on the recent research progress in the metabolic engineering, fermentation and extraction of lycopene by biotechnology. The research status of lycopene synthetic biology was systematically reviewed. Finally, the future direction and problems of lycopene production by biotechnology are prospected, so as to provide reference for the related research on the biosynthesis of lycopene.
YI Lin , AN Yueqi , ZHANG Hanwei , XIONG Shanbai
2023, 42(4):254-261. DOI: 10.13300/j.cnki.hnlkxb.2023.04.029
Abstract:In order to explore the impact of TGase from different species of freshwater fish on gel properties, the effect of silver carp transglutaminase (STG) or black carp transglutaminase (BTG) on the solubility, protein aggregation, rheological properties, puncture properties, and microscopic morphology of myosin after low-temperature gelation were evaluated. Results showed that the addition of STG/BTG promoted formation of more ε-(γ-Glu)-Lys covalent bonds in myosin heavy chain (MHC) of silver carp or black carp compared with the group without enzyme addition, resulting in more aggregation of MHC. The turbidity and average particle size of myosin, the elastic modulus(G'), breaking force, and breaking distance of myosin gel increased significantly, and the protein network structure was enhanced. In terms of enhancing the gel properties of the same myosin, the catalytic cross-linking effect of BTG was stronger than that of STG, while the activity of BTG (12.67 U/mg) was lower than that of STG (14.34 U/mg), and the myosin gel properties of black carp were always higher than those of silver carp regardless of TGase addition. In conclusion, the essential reason for the differences in gel properties of surimi from different freshwater fish species was the source of myosin rather than the differences in TGase activity.
CHEN Renfan , XIE Zhi , LIN Chen
2023, 42(4):262-269. DOI: 10.13300/j.cnki.hnlkxb.2023.04.030
Abstract:An improved YOLOv5s-based method for rapidly detecting strawberry ripeness was proposed to solve the problem of rapid and accurate identification of strawberry fruits in greenhouse. The Shuffle_Block was introduced as a feature extraction network in the backbone to lightweight the model.Meanwhile,the omni-dimensional dynamic convolution (ODConv) module was used in the neck structure to enhance the information mining ability of model for strawberry targets,reduce computational complexity,and further achieve lightweight.The results showed that the average precision of the improved YOLO-ODM model reached 97.4%.The model size is 7.79 Mb.The average detection time on the GPU is only 11 ms per image,and the floating-point operations are 6.9×109 FLOPs.Compared with the original network,the lightweighted YOLO-ODM method improved the accuracy of detection while reducing model size by 43% and floating-point operations by 52%.It is indicated that the lightweighted method can rapidly and accurately detect the ripeness of strawberry fruit in greenhouse,monitor the growth status of strawberries.
TU Ming , CAO Tao , WAN Zhihua , MO Hongtao , ZHANG Guozhong
2023, 42(4):270-278. DOI: 10.13300/j.cnki.hnlkxb.2023.04.031
Abstract:To address the problem of the lack of effective discrete element models in the design and simulation analysis of water caltrop dehulling primary processing equipment, this paper carries out the research work of water caltrop discrete element parameter calibration and prototype test. The 3D inverse technique was used to obtain the water caltrop profile model, and the water caltrop intrinsic parameters and basic contact parameters were measured by physical tests. The average shearing force of the water caltrop was obtained from the uniaxial compression test as 352.95 N, and this was used as the calibration target. Based on the Hertz-Mindlin with bonding model, a water caltrop discrete element model was established to carry out virtual calibration tests on bonding parameters, and the calibration range of each parameter was initially screened by single-factor tests. The two-level analysis factor test and the steepest climb test were used to quickly screen the significant factors and their calibration intervals, and the Central composite response surface test was designed to solve the bonding parameters to determine the optimal combination of parameters in the discrete element model, and a rotary shear water caltrop simulation model was established to study the effects of different tools on water caltrop shear at different rotational speeds, which was used as a basis to design a shear vibration-type water caltrop sheller to carry out prototype tests to verify the reliability of the model. The results show that,the significant effect on the shearing force of the factor normal stiffness per unit area is 4.818×107 N/m3, shear stiffness per unit area is 5.343×108 N/m3, the remaining insignificant factors are taken as the middle level, that is, the normal stress per unit area is 1×107 Pa, shear stress per unit area is 1×107 Pa, bond radius of 1.6 mm. The shearing force of the simulated test is 352 N, with an error of 0.269%; the minimum shearing force of the rectangular tool screened from the rotary shear test is 93.20 N at 230 r/min, with an error of 0.215% from the predicted value of 92.99 N; the prototype test shows that the rectangular tool has better performance than other rotational speeds in shearing water caltrop angles at 230 r/min; the comprehensive demonstration shows that the established discrete element model of water caltrop can provide a reference basis for the design of dehulling tools and the determination of key parameters for water caltrop primary machining equipment.
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