Effects of crown closure changes in broad-leaved forests on thermal comfort and human responses according to season

The aim of this study is to investigate the effects of crown closure seasonal changes in broad-leaved forests on the thermal comfort and the human responses. The participants were a total of 146 male and female university students. The participants sat in a chair and rested in forests with a high and low crown closure, and then closed their eyes and rested for 5 min. The thermal comfort (predicted mean vote, predicted percentage of dissatisfaction) and the physiological (forehead temperature, blood pressure, pulse rate, heart rate variability, heart rate) and psychological (thermal sensation vote, comfort sensation vote) responses were measured. The comparisons of thermal comfort and the physiological and psychological responses in forests with high and low crown closure were performed in each season. As a result, forests with high crown closure had higher thermal comfort than forests with low crown closure in summer, fall, and winter, and results related to physiological and psychological responses were more relaxed in all seasons. In conclusion, this study found that forests with high crown closure is more effective to enhance thermal comfort and relax human responses according to season.