The Influence of Plant Community Characteristics in Urban Parks on the Microclimate

The hot and humid feeling of the urban environment enhances residents' discomfort indices. Although the cooling and humidifying effects of plant communities in various urban parks are significant, there is still insufficient evidence for the effects of plant community characteristics on temperature and humidity. In this study, 36 typical plant communities in the Changchun Water Culture and Ecological Park in China were selected in the summer (21-23 August 2020) from 8:00 to 18:00 for three days when it was sunny and windless. We obtained plant community characteristics through field measurements and drone recordings to explore the relationship between plant community characteristics and the mechanism of temperature and humidity. The study observed that (1) the canopy density and three-dimensional green amount were significantly related to the benefits of cooling and humidification. When the canopy density is between 0.7 and 0.8 and the three-dimensional green volume is above 4 m(3)/m(2), the greatest benefit is achieved; (2) the discomfort index is between 0.6 and 0.8, and the three-dimensional green volume is 4 m(3)/m(2)-6 m(3)/m(2) minimum; and (3) the changes in temperature and humidity are different for different types of plant communities, which lead to differences in people's perceptions of environmental comfort. The tree-grassland and tree-shrub-grass types had the most apparent improvement effects on comfort. The results show that in the design process of urban park plants, emphasis is placed on plant community configuration with apparent cooling and humidification effects, which can improve the comfort of tourists in hot and humid environments. The research results provide theoretical support for sustainable urban green space development.

Automated summary

This study explores the relationship between plant community characteristics and temperature and humidity through field measurements and drone recordings. The results show that canopy density and three-dimensional green amount are significantly related to cooling and humidification effects, and different types of plant communities have different effects on comfort.