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Street trees are essential to urban ecological benefits and human well-being. The canopy morphology relates to the green view index (GVI), which needs to be calculated based on specific tree species. This study conducts a field study on 760 street trees of 3 species from the pedestrian perspective, and explores the differences in canopy GVI and its factors of different specifications of street trees using DBH grading. The results indicate that (1) street trees can provide 20% of the GVI in unilateral streets, with 13% of the GVI in a single canopy. (2) A flat oval crown with a wider canopy width is more effective in providing GVI than a long oval crown, and a CW with a higher canopy GVI highlights this advantage. (3) DBHs of 30 and 40 can be used as grading indicators for Cinnamomum camphora, and the specification requirements can be reduced for Southern magnolia and Chinese privet. (4) The concept of DE is introduced, and new parameters related to the central crown have significant impacts on GVI. The conclusions can improve the GVI application in urban greenery planning as well as have certain implications for the cost management of future seedling cultivation. [ABSTRACT FROM AUTHOR]

Urban parks are public green spaces which have a direct impact on the daily outdoor activities of residents and visitors due to their landscape and functionality. To enhance the spatial vitality and services of urban parks to meet the needs of urban residents and visitors, managers and planners should focus on people's perceptions and preferences of park landscape characteristics. This study aimed to investigate the relationship between visitors' landscape preferences and environmental factors in urban parks. Fixed-point photography and mobile measurements were used to quantify the environmental factors of urban parks. Unmanned aerial vehicle observations and ground observations were used to examine physical activities and spatial behaviors of visitors to quantify their landscape preferences. Second, the differences in visitors' landscape preferences in various types of landscape spaces were analyzed based on descriptive statistics and significance tests. Finally, a correlation analysis and principal component analysis were introduced to explore the relationship between urban park environmental factors and visitors' landscape preferences. The results showed that visitors' physical activities and spatial behaviors were affected by many environmental factors, especially accessibility and visible green index. Our findings also shed new light on the significant differences in visitors' physical activities and spatial behaviors of different genders and age groups. It was observed that most male visitors were sitting, whereas female visitors preferred to take photographs. Exploring the relationship between urban parks and visitors' landscape preferences is of great significance for improving park satisfaction, people's happiness, and urban sustainability. [ABSTRACT FROM AUTHOR]

Urban parks reduce air temperatures within parks and surroundings by exerting the cooling island effect, significant for mitigating the urban microclimate. However, the park cooling effect may be influenced by the surrounding building configuration, and this needs to be studied in more detail, in particular, to explore how to maximize the cooling effect of parks by adjusting the surrounding building configuration. Thus, in this study, the effects of building height, building interval, and building orientation on the cooling effect of a small urban park were investigated using field measurements and ENVI-met numerical simulations. The results demonstrated that (1) building height, building interval, and building orientation all impact the park cooling effect, but their impacts vary. (2) Building height had the strongest effect on the park cooling intensity, and adjusting building height provided the maximum park cooling intensity (1.2 °C). (3) Building orientation had the most effect on the park cooling distance, 100 m downwind of the park. (4) The park cooling effect is best when the surrounding buildings were parallel to the prevailing wind direction, and the park cool island has the greatest intensity and range. This study can guide decision-makers in optimizing building configuration to maximize the park cooling effect. [ABSTRACT FROM AUTHOR]

Urban greening is the most effective way to regulate the microclimate environment and thermal discomfort. However, despite being an important type of vegetation, relatively few studies have investigated the effect of bamboo on microclimate characteristics and thermal comfort. In this study, the microclimate characteristics and the differences in the thermal comfort provided by common bamboo communities in East China were investigated in summer and winter, and the effects of canopy structure characteristics on microclimate and thermal comfort were analyzed. The results showed that there were significant differences in microclimate between bamboo communities and the control check in summer, but the differences in air temperature in winter were not obvious. In the daytime during summer, the maximum daily average temperature of the bamboo community decreased by 2.6 °C, and the maximum temperature–humidity index (THI) decreased by 1.1 °C. In the daytime during winter, the maximum daily average temperature increased by 0.5 °C and the maximum THI increased by 0.8 °C. Among the different bamboo communities, Sinobambusa tootsik var. laeta and Pseudosasa amabilis had better effects on improving microclimate and thermal comfort, while the effects of Phyllostachys nigra and Phyllostachys heterocycla 'Pubescens' were relatively small. Aspects of canopy structure, especially leaf area index and canopy coverage, had the greatest influence on the microclimate environment, while air temperature made the greatest contribution to thermal comfort. The goal of our study is to quantify the data to confirm the role of bamboo in improving urban climate problems and human comfort and to further select the appropriate bamboo species for urban green spaces and to utilize the ecological benefits of bamboo to optimize the human living environment. [ABSTRACT FROM AUTHOR]

An urban agglomeration is a highly developed spatial area formed by integrated cities. While previous studies have analyzed green space allocation at the provincial and city scales, there is insufficient information on green space allocation in urban agglomerations. For this research, a database of green spaces in eight urban agglomerations (133 cities) in China from 2002 to 2019 was constructed to better understand the equity of green space distribution among land resources. A green space equity index (GEI) was established based on the Theil index and combined with GeoDetector to analyze the differences in urban agglomeration green spaces. The main conclusions are as follows: The sum of the GEI of China's urban agglomerations has increased significantly, rising from 3.74 in 2002 to 6.34 in 2019. The GEI value for each of the eight urban agglomerations was kept under 0.01. Polarized development has occurred within urban agglomeration cities, and the allocation of green space in megacities is relatively weak, especially in the more economically developed Yangtze River Delta and Guanzhong urban agglomerations. The average temperature, humidity, and precipitation have dominant influences in determining the GEI values. This paper provides a new perspective on the management and allocation of urban agglomeration green spaces. [ABSTRACT FROM AUTHOR]

Soil temperature plays an important role in soil respiration, which is related to the atmospheric carbon cycle. In addition to its own physical and chemical properties, soil temperature is also influenced by external environmental factors, including plants. Therefore, it is relevant to explore the relationship between plant characteristics and soil temperature. This study was conducted in Hangzhou, China. The influence of canopy structural characteristics of bamboo communities on soil temperature was investigated in detail by means of field measurements. In summer, the canopy structure of bamboo communities reduced the soil temperature by up to 3.0–3.8 °C, 2.4–3.4 °C, and 2.3–3.0 °C at 5 cm, 10 cm, and 20 cm, respectively. In winter, the canopy structure of bamboo communities increased soil temperature by up to 0.1–0.4 °C, 0.1–0.6 °C, and 0.2–0.7 °C at 5 cm, 10 cm, and 20 cm, respectively. The leaf area index and canopy cover significantly affected the soil temperature, while the effect of the sky view factor was minimal compared to other factors. We also discovered that soil temperatures at different depths interact and are influenced by the air temperature. These findings provide a more reasonable bamboo canopy plan to improve the urban environment effectively. [ABSTRACT FROM AUTHOR]

Forest walking is a popular, healthy, and light outdoor activity. The potential comprehensive relationships between the vertical structures, thermal comfort, negative air ions (NAI), and human physiological stress in forest walking spaces have not been determined. We performed an experiment in the Baishuihe National Nature Reserve, Sichuan Province, China. Thirty-two college students recruited as subjects completed a forest walk (approximately one kilometer) on the same trail divided into three vertical structure type subsections, namely: A (dense herb and shrub layers with a sparse tree layer), B (dense tree, herb and shrub layers), and C (dense tree and herb layers with a sparse shrub layer). When the subjects passed preset environmental measurement points, staff measured climatic indexes (air temperature, relative humidity, wind velocity, surface temperature and global radiation) and NAI levels, and these data were input into the Rayman model to form a comprehensive thermal comfort index, the physiologically equivalent temperature (PET). PET and NAI differences and dynamic data among the subsections were analyzed. The subjects' brain waves, heart rates (HRs), and walking speed (S) were digitally recorded. We selected brain wave θ, γ and β-high/α rates, neuroemotional indexes (stress and relaxation) and HR as physiological indicators, and S as an auxiliary indicator. The correlations between PET and NAI with physiological and auxiliary indexes were analyzed. Forest type C showed the lowest PETs and highest NAIs along with the most stable dynamic changes. PET was negatively correlated with HR and positively correlated with γ (12 channels). NAI was positively correlated with S and relaxation and negatively correlated with γ (two channels) and the β-high/α ratio (five channels). These comprehensive relationships suggest that dense tree, sparse shrub, and high-coverage herb layers combined with optimal temporal conditions (before noon or after a light rain) form the best thermal comfort and NAI conditions conducive to reducing human physiological pressures during summer daytime forest walking. These results provide theoretical references for forest walking and spatial regulation. [ABSTRACT FROM AUTHOR]

• Thermal behavior of living walls is both affected by modular system and plants. • LWS can improve indoor by around 0.6–1.7 ℃ on average during insulation time in a day. • Indoor thermal benefits of north-facing LWS is better than north- and south-facing LWS. • Insulation of living walls is positively correlated to plant height and leaf coverage. As eastern China rapidly urbanizes, living walls are spreading swiftly across cities and consequently resulting in its stronger influence on the urban thermal environment. The objective of this study is to assess the effect of external living wall systems (LWSs) on indoor thermal environments in winters with low temperatures and high humidity levels. Four containers with different outer facades were arranged in Hangzhou and a comparative analysis was conducted on changes in the internal and external thermal environments of these containers. Results reveal that both the soil-filled planter pots and plants positioned on the LWSs play a role in indoor insulation while pots have a more stable effect. Good thermal performance of living walls can improve the energy efficiency of buildings. When the north-facing walls of the containers were equipped with planter pots, a bamboo living wall or a living wall with other plants, the internal temperatures were 0.4 °C, 1.7 °C and 1 °C higher during the insulation period, respectively, relative to those of the reference container, and the all-day insulation period of the north-facing LWSs lasted more than 20 h a day. By contrast, thermal benefit of the north-and south-facing LWSs was weaker. Compared to more widely used plant species, dwarf bamboo increased insulation and wind resistance levels on the living walls, creating significantly higher temperatures on living wall surfaces and within containers in winter, indicating that plant features have a strong positive impact on the insulating features of living walls. This study not only makes up for the lack of research on the thermal performance of LWSs in the researched area during the winter, but also is of great significance to the development and application of living walls with better thermal benefits, such as orientation setting, plant selection, building energy saving, etc. Image, graphical abstract [ABSTRACT FROM AUTHOR]