亚热带城市乡土树种小叶榕的蒸腾、降温及其减碳效益研究

Study on Characteristics of Transpiration,Cooling Effect and Carbon-Reduction Effect of Ficus concinna,a Native Tree Species in Subtropical Cities

基于蒸腾扩散系数,对几种亚热带城市典型植物的蒸腾降温潜力进行评估,并对小叶榕进行持续观测,定量地研究其蒸腾降温特征和节能减碳效益,得到如下结论。(1)在研究区域内的几种典型植被中,小叶榕作为乡土树种,在相同的环境条件下表现出最强的蒸腾降温潜力。(2)单株小叶榕的日均蒸腾水量为32.48 kg,总体上呈现夏秋高、春冬低的特点;同时,小叶榕能有效地缓解热岛效应,尤其是在热岛效应严重的夏季夜间,其蒸腾降温作用使得观测区域86%的时间为无热岛状态。(3)单株小叶榕每年通过蒸腾降温作用间接减少的二氧化碳排放量达到1442.10 kg。

Based on the transpiration transfer coefficient(hat),the cooling potential of several typical subtropical urban vegetations was evaluated.A Ficus concinna was continuously observed to quantitatively study its characteristics of transpiration,cooling effect and carbon-reduction effect.The results showed that (1)among several typical vegetations in the study area,Ficus concinna,as a native tree species,showed the strongest cooling potential in the same environment.(2)The average daily transpiration volume of Ficus concinna was 32.48 kg per tree,which was generally high in summer and autumn and low in spring and winter.At the same time,Ficus concinna could effectively alleviate the heat island effect,especially at night in summer when the heat island effect was severe,its cooling effect made the observation area no heat island state for 86%of the time.(3)The annual carbon emission reduction from the cooling effect of individual Ficus concinna reached 1442.1 kg.