Study on Environmental Effects of Tree Species in Cities Green Space - Case on China

The urban heat island (UHI) effect, caused by the rapid development of cities and urban anthropogenic heat emissions, has gradually become an important factor that seriously affects the urban living environment and people health. Studying the environmental effects of different green space tree species can provide data support for preventing the UHI effects. The results revealed significant differences regarding the cooling effect, humidifying effect, as well as the discomfort reduction rate among different tree species. To be more specific, the cooling effect of each tree species was found as Ficus microcarpa (the large crown) > Terminalia neotaliala > Ficus microcarpa (the middle crown) > Roystonea regia ? lawn. Moreover, the humidification effect was found as Ficus microcarpa (the large crown) > Terminalia neotaliala > Ficus microcarpa (the middle crown) > lawn> Roystonea regia. Lastly, the discomfort reduction rate was found as Ficus microcarpa (the large crown) > Terminalia neotaliala > Ficus microcarpa (the middle crown) > Roystonea regia > lawn. The results showed that tree species with high canopy density and dense foliage can reduce people’s discomfort and the risk of heat stroke outdoors. The same tree species, the larger the crown width, the better the effect of reducing temperature and humidity and reducing discomfort.