Effect of Plant Community on Temperature Lowering and Humidity Increasing in Residential Areas of Shanghai

Observation of effects of 23 different types of plant communities commonly found in the residential areas of Shanghai on temperature and humidity revealed that all plant communities,regardless of type,could lower temperature and increase humidity in the residential areas,but their effects varied significantly.The effects were the highest and differed the most sharply from that of lawns during 13:00-14:00,while during 16:00-17:00,the effects differed slightly.About 18% of the plant communities were lower than lawns in temperature-lowering effect and about 45% in humidity-increasing effect.Among the types of plant communities,coniferous forest,coniferous-broad-leaf mixed forest and bamboo forest were the highest in the two effects,lowering the temperature by>2.3 ℃ and increasing the humidity by 12.4% on a daily mean basis.