The Regulate Temperature Effect Of The Main Green Tree Species In Hangzhou

The"Urban Heat Island Effect"(Abbreviation UHI ) refers to the phenomenon of urban temperatures higher than that of suburbs,the city's most obvious feature of climate,reflecting the of urbanization effect of the urban environment. With the rapid development of urban construction,"UHI" has been increasing significantly in Hangzhou .As the urban heat island effect intensify the end also affect of meteorological disasters (such as local rainfall,wind,temperature,etc.),the distribution of urban air pollution,and the daily life of urban residents . Therefore,studys on the cooling effect of the main green tree species in Hangzhou is of great improtant.Based on study on tree species in Hangzhou main,16 species were selected including:Cedrus deodara,Juniperus chinensis,Koelreuteria paniculata,Sapindus mukorossi,Elaeocarpus sylvestris,Ginkgo biloba,Magnolia grandiflora,Cinnamomum camphora,Osmanthus fragrans,Pittosporum tobira,Lagerstroe miaindica,Acer palma tum,Bambusa multiplex,Prunus ceraifera,Eugenia caryophyllata,Phyllostachys nigra Munro,the cooling effect of those tree species were monitored individually 26 species combination types were designed tested and analyzed.The results showed that:The regulate temperature effects of tree were quite different when if was measured at different heighf. Generally good results were obtained at 0.5 m and 3.0 m of tree heighf.By comparison,it is founed that the differences in cooling effect among tree species was great and reached up to significant level. Generally the cooling effects of ever green tree species were the best,that of great shrubs and bushes were the Second ,and that of Coniferous species were the worst.The regulate temperature effects of 26 combination type of tree species varied greatly and significantly .The general trends of cooling effects of those 26 combination types of tree species was that:broadleaf tree species combination > broadleaf-evergreen needle > evergreen tree and shrubs > large shrubs with shrubs > conifer with conifers.The best result was obtained from evergreen breadleaf species combination.Based on the study results,some tree species and species combination types were selected and they will be used in Hangzhou city's forest. It will provied theoretical suport in city forest design of Hangzhou. However more detailed and comprehensive studies on cooling effect of tree species and needed.