Fire-resistance of major tree species in the Beijing area

In this study,we selected 17 major tree species widely planted in the Beijing area in order to evaluate their fire-resistance,using principal component analysis.Four physicochemical indices(absolute moisture content,calorific value,ash content and extract content) and nine bio-ecological characteristics(phenology,crown density,leaf characteristics,bark condition,germination ability,juvenile growth rate,degree of natural pruning,ground litter structure and forest health) were investigated.The results show that the order of fire-resistance of 17 tree species from strong to weak is:Ulmus pumila,Koelreuteria paniculata,Syringa amurensis,Salix matsudana,Juglans mandshurica,Robinia pseudoacacia,Populus tomentosa,Tilia mandshurica,Betula devurica,Celtis bungeana,Prunus sibirica,Acer truncatum,Quercus liaotungensis,Pyrus bretschneideri,Pinus armandii,Pinus tabulaeformis and Larix principis-rupprechtii.The fire-resistance of Ulmus pumila,Koelreuteria paniculata,Syringa amurensis,Salix matsudana and Juglans mandshurica was the strongest,in Quercus liaotungensis,Pyrus bretschneideri,Pinus armandii,Pinus tabulaeformis and Larix principis-rupprechtii the weakest,while Robinia pseudoacacia,Populus tomentosa,Tilia mandshurica,Betula devurica,Celtis bungeana and Prunus sibirica occupied a medium position in fire resistance.