Abstract:In order to understand the age structure and dynamic changes of Pseudotsuga gaussenii population, four survival functions were used to discuss the dynamic changes of P. gaussenii population in Ningguo, Anhui province by replacing age classes with size classes and establishing static life table with smoothing technique. The results showed that P. gaussenii in Ningguo was declining population. The number of individuals at juvenile stage was very small, accounting for 3.78% with low survival, while the number of individuals at middle-age stage was high, accounting for 80.04%. The life expectancy of P. gaussenii decreased with the increment of age. The survival curve of P. gaussenii population belonged to Deevey-Ⅱ type. The seed germination rate was low and there were few seedlings, which were related to the high canopy density, the insufficient light intensity and the poor individual competitiveness in the community. The young individuals were insufficient, individuals at middle-and high-age could not be supplemented in time, and human disturbance was too serious, which caused to unstable population structure of P. gaussenii. Therefore, it was recommended that small reserve would be established to protect P. gaussenii population.
