It has been found that deciduous such as poplar,willowand Chinese scholartrees emit chiefly isoprene, coniferous(pine and cypress)emit usually ter-penes.

• 发现北京的杨树、柳树、槐树（落叶乔木）主要排放异戊二烯化合物；松树、柏树（针叶林木）排放萜烯类化合物；