Study on Age Structure and Its Dynamic Characteristics of Wild Idesia polycarpa Population in Guizhou Province

Based on the method of "replacing the age class by DBH class", the population structure, life table and survival function for Idesia polycarpa were analyzed. The results showed that the natural population structure of I. polycarpa was roughly presented as pyramidal shape. The plants were selected from the seedling stage to the juvenile stage under the natural conditions by the environment sieve with light as the leading factor. The quantitative analysis on the population dynamics showed that the I. polycarpa population was still an increasing type structure although with some fluctuation. Its population presented the quantitative fluctuation characteristics with multiple small cycles overlapped in the large cycles, and its survival curve tended to be the Deevey-Ⅲ curve.