Urban Trees and Elderly Well-Being: Species-Specific Strategies for Thermal Comfort in Heat-Stressed Cities

Abstract

The dual challenges of global aging and intensifying urban heat demand innovative, evidence-based strategies to foster thermally and psychologically comfortable environments for vulnerable populations, particularly the elderly. Despite the documented benefits of urban greenery, the species-specific impacts of urban trees on thermal comfort and well-being remain underexplored. This study investigates how distinct tree species—Camphora officinarum (camphor), Platanus acerifolia (London plane), and Ginkgo biloba (ginkgo)—regulate urban microclimates and support elderly well-being during hot summer days. Conducted at five sites in Shanghai, including a control site and four vegetated plots, this study engaged 210 elderly participants. Microclimatic variables were measured using the physiological equivalent temperature (PET) alongside air temperature, humidity, and wind speed. Physiological responses, assessed through heart rate variability (HRV), and psychological outcomes, evaluated via validated self-report scales, were analyzed. The results revealed that dense-canopy trees significantly reduced PET, enhanced thermal comfort, and improved ROS and SVS scores, while lower LF/HF ratios indicated reduced physiological stress. Correlation analyses underscored the pivotal role of canopy density (SVF) in fostering psychological and physiological well-being. Camphor and London plane trees consistently provided the greatest benefits, emphasizing the importance of species selection in urban greening strategies. These findings underscore the critical role of species selection in urban forestry to mitigate heat stress and foster age-friendly resilience. Practical implications emphasize integrating dense-canopy species into urban landscapes to enhance microclimate regulation and public health.