Analysis of Natural Population Dynamics of Davidia involucrata in Bayuelin Nature Reserve

Based on the comprehensive investigation in Bayuelin Nature Reserve,the age structure mas analyzed and the specific time sdedule of the natural population of Davidia involucrata was prepared by diameter class and the piecewise leveling technique instead of age range.The survival curve and the mortality curve were drawn together with the rate of disappearance curve.By the way of time series,the dynamic changes in the number of populations were predicted.Results showed that the age structure of D. involucrata population fluctuated,and the number of juvenile and adult individuals was relatively rich.Considering the disturbance of ambient environment,V'_pi=2.50%,the survival curve tended to Deevey-Ⅲtype;The trend of death rate curve and disappearance rate curve were basically the same.The time series prediction showed that the population had some potential for recovery.