Abstract: Isoprene emission fluxes were investigated for 12 tree species in and around Bei極ng city. Bag-enclosure method was used to collect the air sample and GC-PID was used to directly analyze isoprene. Ginkgo and Magnolia denudata had negligible isoprene emissions, while ignificant emissions were observed for Platanus orientalis, Pendula loud, Populus simonii, and Salix matsudana koidz, and other remaining trees showed no sign of isoprene emission. Variations in isoprene emission with changes in light, temperature and season were investigated for Platanus orientalis and Pendula loud. Isoprene emission rates strongly depended on light, temperature and leaf age. ....... click the url {下載全文（PDF文檔)} download the file ,at the page top EW-4400型便攜式光離子化氣體檢測(cè)儀