中文摘要：

通过调查,将西安市片状绿地按种植结构分为乔灌草、乔草、灌草、乔木、灌木和草坪6种类型,并定点定时测定绿地中心和对照点的光强、湿度、温度、噪音、空气中细菌数.结果表明,在片状绿地中,除草坪外,其他绿地均具有一定的遮荫效应,不同结构绿地遮荫效应依次为灌木＞乔灌草＞乔草＞灌草＞乔木＞草坪;各绿地也有明显的降温效应,降温效应依次为乔灌草＞乔木＞灌木＞乔草＞灌草＞草坪;各绿地还有一定的增湿效应,增湿效应依次为乔草＞乔灌草＞乔木＞灌木＞灌草＞草坪;各绿地也具有降噪效应,降噪效应依次为乔灌草＞乔草＞乔木＞灌草＞灌木＞草坪;各绿地在灭菌方面也有明显的作用,灭菌效应依次为乔灌草＞乔草＞乔木＞灌草＞灌木＞草坪.相同种植结构的绿地中复层结构绿地的生态效益均大于单层结构的绿地.最后,根据以上结论提出了提高城市绿地生态功能的措施.

英文摘要：

Through investigation, this paper classified the green lands in Xi＇ an into six planting structures, i. e., trees ＋ shrubs ＋ herbs （T ＋ S ＋ H）, trees ＋ herbs （T ＋ H）, shrubs ＋ herbs （S ＋ H）, trees （T）, shrubs （S）, and lawn （L）. After determining the photosynthetically active radiation, relative humidity, temperature, noise, and bacteria in the air in the center and outside of the green lands, the ecological functions of the green lands on regulating urban microclimate were analyzed. All kinds of these green lands had the function of shading, which was decreased in order of S 〉 T ＋ S ＋ H 〉 T ＋ H 〉 S ＋ H 〉 T 〉 L. Green lands also had obvious effect on lowering temperature, with the order of T ＋ 8 4- H 〉T 〉 8〉T ＋ H 〉 S ＋ H 〉 L. The effect of increasing humidity was in order of T＋ H 〉 T＋ S＋ H〉T〉S〉S＋ H〉 L, that of lowering noise was in order of T＋ S＋ H〉T＋ H 〉T〉S＋ H〉S〉 L, and that on killing bacteria was in order of T＋ S＋ H〉T＋ H〉T〉S＋ H〉S〉 L. Green lands with multi-layer structure had greater ecological functions than those with single layer. According to above results, the measures of increasing ecological functions of urban green lands were put forward.