The Population Structure and Dynamics of Davidia involucrata——A Case Study of Heizhugou National Nature Reserve

To understand the future development trend of the population, the main endangered factors were discussed for Davidia involucrata in Heizhugou National Nature Reserve, and some theoretical references were provided for the protection and restoration. The population structure and dynamics of D. involucrata were studied by plotting its distribution map, population structure map, static life table, survival curve and time series model.The hierarchical structure of the population was spindle-shaped, which was similar to that of the height structure. The number of seedlings, young trees and old individuals was small, and the development of the population depended mainly on the middle-aged individuals. The standard survival curve of the population was Deevey I type, i.e. Convex type, belonging to a descending type. The individual mortality rate and individual loss degree of the population are basically consistent, showing the characteristics of fragility in the early and late period and stability in the middle period. Time series predictions showed a significantly decrease in the total number of surviving individuals in next five years. The seedlings mainly sprouted from roots.It indicated that the population was a descending type in a rapid decline stage, which would be a serious aging problem with the passage of time,. The poor regeneration ability of seeds had become the most serious problem in the development of this population.Protection strategies were proposed according to the results of the study.