几种绿化树种降低城市热岛效应的研究

A Study on Reduction of the Heat Island Effect by Three Urban Tree Species

选择华北地区3种常见的城市绿化树种国槐(Sophora japonica)、元宝枫(Acer mono Maxim)、法桐(Plata-nus orientalis),测定其光合速率及蒸腾强度,据此估算其固碳量、释氧量和降温增湿量,并量化评价3种绿化树种的生态学效应及对城市“热岛效应”的减缓作用,时间尺度为日。结果表明:法桐的固碳量、释氧量比国槐、元宝枫大,分别为5.153和3.75g.m-2.d-1;国槐、元宝枫固碳量分别为5.153和2.244g.m-2.d-1,释氧量分别为3.75和1.63g.m-2.d-1。3种植物的降温增湿作用以法桐最明显,国槐次之,元宝枫最低。国槐、元宝枫、法桐3种植物每平方米叶面积对其周围1 000 m3空气柱的降温作用分别为0.26℃、0.17℃、0.31℃,对空气相对湿度的增加分别为0.40%、0.27%、0.47%。

By measuring diurnal photosynthesis and transpiration, three urban tree species in Northern China of Sophora japonica, Acer mono Maxim and Platanus orientalis were studied so as to appraise theirs alleviative effect on urban heat island and their ecological benefits of carbon dioxide absorbing capacity, oxygen producing, and cooling and humidification. The result showed that the capacities of carbon dioxide absorbing and oxygen producing ofP. orientalis, S. japonica, A. mono Maxim were 5. 153 and 3.75, 5. 153 and 3.75, and 2.244 and 1.63 g·m^-2·d^-1, respectively. Moreover, the effects of cooling and humidification were different among the three tree species S. japonica, A. mono Maxim and P. orientalis, which were 0.26℃, 0.17℃ and 0.31℃, and 0.40% , 0.27% and 0.47% respectively.