加拿大的多伦多、蒙特利尔、温哥华等城市近来正试行在高楼的屋顶上种植绿色植物，以美化城市、改善城市的生态环境。仅多伦多就有２０家试行单位。其中一家公司在大楼顶上开辟了一块９０平方米的“花草园”，种着各种花卉绿草。该公司经理说，绿色屋顶不但降低了室外空间的温 Recently, cities such as Toronto, Montreal and Vancouver in Canada are trying to grow greenery on the roof of tall buildings to beautify the city and improve the city’s ecological environment. There are 20 pilot units in Toronto alone. One of the companies opened a 90-square-meter “flower garden” on top of the building with various flowers and green grass. The company manager said green roofs not only reduce the temperature in outdoor spaces