Needs and expectations of German and Chinese children for livable urban green spaces revealed by the method of empathy-based stories

One of the important features of cities is to provide high-quality outdoor environments for various groups of citizens. Although children are frequent users of green spaces, the knowledge and perspectives applied in planning and design of urban green spaces are mostly defined by adults. This results in spaces and practices that may limit the daily lives and creativity of urban children. Promoting child-friendly cities benefits from knowledge produced by children themselves, regarding their perceptions and experiences, as well as ideas and suggestions. This study provides empirical results concerning children’s needs and mental images for urban green spaces in two urban areas in two countries (Chengdu, China, and Ruhr Region, Germany). 765 children, ages 8–10 were surveyed through the method of empathy-based stories (MEBS). Participants were asked to use their imagination to write stories according to given scenarios. Our study shows that MEBS can be used to gather meaningful data with children, and that children are an important stakeholder group in urban planning, landscape design and management with an ability to express their diverse needs and preferences towards green spaces. Both designed green spaces (e.g. gardens, parks) and wild nature (e.g. forests, meadows) can offer a range of activities and experiences for children in their everyday lives: opportunities for play, socializing, contact with nature, aesthetic and restorative experiences, learning and exploration. Our findings include indications of children’s awareness of the diverse ecosystem services that green spaces provide, as well as of urban sustainability and livability. While we found German and Chinese children to have corresponding needs and expectations regarding urban green spaces and nature, we also found some variation. We suggest that the use of, and experiences in green spaces are linked not only to the landscape but also to conceptual-cultural contexts.     

Park and neighbourhood environmental characteristics associated with park-based physical activity among children in a high-density city

Constructing and renovating urban parks is an effective strategy for high-density cities to satisfy residents’ needs for recreation in nature. Using Hong Kong as an example of a high-density city, the purpose of this study was to examine the associations of park and neighbourhood environments with park-based physical activity (PA) among children and examine the moderating effect of neighbourhood income in their relationships. A cross-sectional study was conducted in 32 urban parks in Hong Kong. Park-based PA and the park and neighbourhood environments were measured using systematic observation tools and the geographic information system. Neighbourhood income was extracted from the 2011 Hong Kong Population Census data on median household income. A total of 7,753 children were observed using urban parks for PA during the study. Children’s park-based PA was positively associated with the quality of supporting amenities, park safety, neighbourhood walkability, and neighbourhood quality, while the associations of park-based PA with the diversity of active facilities and park size were not significant. In addition, neighbourhood income moderated the associations of park-based PA with the diversity of active facilities, the quality of supporting amenities, neighbourhood walkability, and neighbourhood quality. These findings provide empirical evidence on the moderating role of neighbourhood socioeconomic status on the associations between park and neighbourhood environments and children’s park-based PA in a high-density city. With children’s needs for using parks for PA, our findings are beneficial for urban planners to renovate existing urban parks to enhance their utility for children living in high-density cities.     

Using best-worst scaling to reveal preferences for retrofitting raingardens in suburban streets

Raingardens are increasingly common in sustainable stormwater management in cities around the world. Implementing raingardens will change the appearance of conventional urban streetscapes and this is especially important when retrofitting raingardens into existing streets. Raingardens need to fulfil both technical and aesthetic functions. Aesthetic function, assessed as landscape preference, must be understood to ensure that retrofitted raingardens are appropriately designed and managed. Scholars have long adopted a Likert rating scale- to determine landscape preference. Limitations of this method led market researchers to develop choice-based ranking, including best-worst scaling, to assess preference. Thus, this study uses best-worst scaling to assess landscape preference by residents for pairs of streetscapes with and without raingardens in four suburbs of Melbourne, Victoria, Australia. These preference data, and attitudes towards raingardens, stormwater harvesting and own streetscapes, inform guidelines for design and management of retrofitted raingardens. Findings revealed respondents’ overwhelming support for harvesting and reuse of stormwater, though support for fit-for-purpose stormwater reuse decreased as personal proximity increased. While attitudes towards raingardens were positive and most respondents liked the raingardens in their own street, less than one-quarter helped to maintain them. Across all respondents, maintenance of raingardens in streetscapes was regarded as the responsibility of local government. Nevertheless, many would install raingardens in their own property. Overall, streetscapes with raingardens were preferred to those without. Residency in a street with or without raingardens did not influence preference, however, residency in a particular street did. Indeed, context was important: preference for one’s own streetscape varied statistically significantly between residents of inner- and outer-Melbourne suburbs. Drawing on these results, four guidelines for design and management of retrofitted raingardens are proposed: 1. Understand context; 2. Consider how the street is used; 3. Select appropriate plants and planting style; 4. Ensure adequate maintenance.     

Enhancing pollination ecosystem service in urban green areas: An opportunity for the conservation of pollinators

The rapid growing urbanization is one of the main threats to urban biodiversity and the ecosystem services (ES) that they provide. Pollination is one of the most affected ES in urban areas mainly due to the decline in urban green areas (UGAs) and other factors derived from urbanization itself. Considering this and the already existing global pollinator crisis, the aim of this work is the evaluation of urban green infrastructure as an opportunity for pollinator conservation. For that purpose, the ornamental vegetation of a medium-sized Mediterranean city (Granada, south-eastern Spain) was determined. The floral origin, phenology and floral traits of the conforming species and the pollinator species that they attract were analysed. Additionally, NMDS analysis were performed in order to determine if the “Pollination Syndromes” are a useful tool to actually predict the pollinator group attracted to a certain plant species. It was found that UGAs have huge potential for pollinator conservation as the major part of its ornamental species have an entomophilic pollination strategy. However, there is an imbalance in the availability of flower resources throughout the year. Hence, the addition of species flowering out of the main flowering season would be advisable in order to get a continuous supply of floral resources for pollinators. A current disproportion in the potentially attracted pollinator groups was also found out, being bees the predominantly attracted ones. However, results showed that the “Pollination Syndromes” are a tool with limitations at the moment and needs to be used with considerations. Thus, the specific plant-pollinator relationship should be determined through field work in each case-study. Further studies considering key factors such as urban connectivity and fragmentation would be desirable to ensure a comprehensive management for urban pollinators.     

Characterizing green and gray space exposure for epidemiological studies: Moving from 2D to 3D indicators

The presence of green spaces has been associated with improved physical health and better mental health and wellbeing. In contrast, the presence of gray features including build-up areas might have a negative impact on the health and wellbeing of citizens. To date, the available evidence on the health effects of green and gray spaces have mainly relied on 2-dimensional (2D) indicators of these spaces such as land use maps or, more recently, satellite derived indices (e.g., green space indices such as normalized difference vegetation index (NDVI) or gray space indices such as imperviousness). Although they are acceptable proxies of these exposures, 2D indicators could have inaccuracies when characterizing diverse set of vegetation types in combination with different types of gray spaces, which is typical of urban environments. To overcome this gap, we developed a set of three-dimensional (3D) indicators derived mainly from airborne LiDAR (Light Detection and Ranging) acquired in 2008 and 2010 over the metropolitan area of Rome (Italy). In particular, we extracted volume of green features such as shrubs and trees (Green volume [m3/ha]), volume of buildings (Gray volume[m3/ha]), a novel index called Normalized Difference Green-Gray Volume index (NDGG) as well as indicators of the tree count. We compared the 3D indicators with two widely used 2D indicators for characterizing green and gray spaces (i.e., NDVI and imperviousness) in different buffers around 79140 address points in the city. For the green indicators, we found that the Pearson correlations between NDVI and Green Volume were 0.47 (50 m buffer) and 0.33 (300 m buffer) while the correlations between NDVI and number of trees were 0.56 (50 m buffer) and 0.58 (300 m buffer). For gray indicators, the correlations between imperviousness and gray volume were 0.62 (50 m buffer) and 0.79 (300 m buffer). For NDGG, the correlations were higher with both NDVI (0.76 and 0.83 for 50 m and 300 m buffers) and imperviousness (−0.75 and −0.83 for 50 m and 300 m buffers). Our results showed that the use of 3D indicators can have potential benefits, especially regarding green features which can be highly heterogeneous in complex urban landscapes such as the city of Rome.     

不同间作绿肥替代化肥模式对木薯性状和产量的影响

通过探讨秸秆还田与化肥减施下间作绿肥对木薯产量性状的影响,着力解决连作木薯土壤肥力提高与改良相关技术的协调增效。于2019-2020年,以木薯品种“南美1号”为供试材料,设置8个处理,调查每个小区的木薯茎径、叶绿素（SPAD）、块根直径、块根长、单株茎秆鲜重、单株块根鲜重、株高、单片叶重、单株块根数以及小区产量等农艺性状。结果表明,处理5（木薯秆还田+化肥减量12.5%+12.5%营养元素当量黑豆绿肥还田）的木薯产量最高,并得到拟合方程。绿肥秸秆还田以及间作绿肥从整体上改良了土壤肥力,并通过显著影响木薯块根、单片叶重以及单株块根数而影响最终产量。     

不同覆膜处理下春玉米叶面积指数高光谱估算

为实现快速、无损、实时监测不同覆膜处理下春玉米的叶面积指数(Leaf area index,LAI),研究覆膜因子对LAI及冠层反射率的影响,借助高光谱遥感技术获取了各生育期春玉米的冠层反射率,在对光谱数据进行预处理后,经相关性分析提取各覆膜处理LAI的敏感单波段、敏感植被指数和特征指数,据此构建了全生育期各覆膜处理下...     

基于卷积神经网络马铃薯叶片病害识别和病斑检测*

针对自然环境下马铃薯叶片病害识别率低和晚疫病斑定位难的问题,基于大田环境中采集的马铃薯叶片图像,首先对马铃薯叶片病害进行识别,对比AlexNet、VGG16、InceptionV3、ResNet50、MobileNet五种神经网络模型,结果表明InceptionV3模型的识别效果准确率最高,可达98.00%。其次对马铃薯叶片的晚疫病斑进行检测,提出一种改进型的CenterNet-SPP模型,该模型通过特征提取网络获取对象的中心点,再通过中心点回归获得中心点偏移量、目标大小等图像信息,训练后的模型在验证集下的mAP可达90.03%,以F₁为评价值分析对比其它目标检测模型,CenterNet-SPP模型的效果最好,准确率为94.93%,召回率为90.34%,F₁值为92.58%,平均检测一张图像耗时0.10 s。为自然环境下马铃薯叶片病害识别和检测提供较为全面的深度学习算法和模型研究基础。     

苦荞VQ基因家族的全基因组鉴定及其在叶斑病原与激素处理下的表达谱分析

[目的]VQ基因家族在植物生长、发育以及对生物或非生物胁迫反应中发挥重要功能.在全基因组尺度上,全面鉴定苦荞(Fagopyrum tataricum L.Gaertn.)VQ(FtVQ)基因家族,分析其在苦荞叶斑病原——互格链格孢(Alternaria alternata)和黑孢霉(Nigrospora osmanth...     

有机肥替代部分化肥结合外源硒对白术的促生作用

为探讨有机肥替代部分化肥结合喷施外源硒对白术生长的影响及其可能作用机理,采用大田试验,设置喷施清水（CK）、有机肥替代部分化肥结合喷施清水（OM）、有机肥替代部分化肥结合喷施5 mg·m^-2硒肥（OM+5Se）、有机肥替代部分化肥结合喷施10 mg·m^-2硒肥（OM+10Se）和有机肥替代部分化肥结合喷施15 mg·m^-2硒肥（OM+15Se）五个处理,考察不同处理对白术叶功能性状、产量和土壤理化性质的影响。结果表明,OM、OM+5Se、OM+10Se和OM+15Se显著增加白术的叶面积,增幅分别为12.3%、25.3%、22.5%和10.4%。OM+5Se和OM+10Se处理显著增加白术叶干质量,增幅分别为10.7%和13.0%。OM+5Se处理显著增加白术叶片比叶面积,增幅为13.0%。OM+5Se和OM+10Se处理显著降低白术叶片长宽比,降幅分别为15.6%和18.4%。OM、OM+5Se、OM+10Se和OM+15Se显著增加白术产量,增幅分别达到37.3%、121.7%、91.7%和65.2%。在施用有机肥的基础上,外源喷施硒肥对白术生长整体表现为促进作用,但促生效果呈现低浓度上升、高浓度下降的趋势。相关性分析表明,通过测定白术的叶功能性状可初步了解白术的生长情况。与对照相比,其他四种处理显著增加白术根际土壤的有机质、碱解氮、有效磷和速效钾含量。综上表明,有机肥替代部分化肥或有机肥替代部分化肥结合喷施外源硒肥均能促进白术生理生长,提高白术产量,且以有机肥替代部分化肥结合喷施5 mg·m^-2硒肥对白术的促生效果最好。