Analysis On The Spring Phonology Variation Characteristics Of The Introduced Woody Plants In Beijing Botanical Garden

Plant phenplogy as being a sensitive reactor to climate change,it has play an important roles in agricultural production activities,forest ecosystem,climate change and environmental pollution monitoring.However,most of the phenological studies has carried before focused on long term climatic change and plants response to this change,by using the responses of plants towards climate change has taken place over past several decades to predict the trends on plant phenology and growing seasons;Even the impact of the environmental factors on plant phenology at an erea or large-scale ereas.Then the Botanical garden being as a gathering place of all introduced plant species from different climatic regions could reflect well the influences of environmental factors on plant phenology.Therefore,In this paper the phenological change of introduced species in Beijing Botanical Garden and their native habitat along the latitudinal gradient were discussed,then the phenological change of 58 introduced species explained by analyzing the environmental effect on them.Through energy model,precipitation model and habitat heterogeneity model which are established by multiple regression method to explain the flowering phenology and leafing phenology variance.All the species were classified for a better understanding of the spring phenology of them.Finally a further clustering analysis carried on according the flowering and leafing phenological indicators were chosen.The result shows that:(1)With the change of latitude plant phenology changes accordingly,that latitudinal increase leads delay on the appearance time of phenology.The phonological change of introduced species is more significant while the latitudinal span is bigger.(2)The interaction effect of three models together up to32.5%,three models totally could explain 70.9%of the flowering phenology variance.In terms of average leafing phenology,the function of the precipitation model(7.6%)is bigger than the single function of energy model(4.3%)and the habitat heterogeneity model(0.1%),respectively.The interaction effect of the energy model and precipitation model is the highest(33.7%),the interaction effect of the three models reaches 30.7%.(3)Most of the introduced trees,in the Beijing Botanical Garden,are accomplish their flowering phenology in 7 to 20 days.Then,for the leafing phenology most of the introduced species are only needs about 4 to 7days.