Abstract: In order to explore the secondary succession mechanism of evergreen broad-leaved forests in subtropical zone, an investigation was made on a secondary forest having been restored for 40 years after clear-cutting on Laoshan island of Qiandao Lake region, Zhejiang Province, China, with the population structure, survivorship curve, and spatial distribution pattern of the dominant tree species in this community analyzed. Pinus massoniana population had the highest importance value (50.47%), followed by Lithocarpus glabra, Castanopsis sclerophylla,and Cyclobalanopsis glauca populations. The population structure of P. massoniana was of spindle type, the number of the individuals at agesize classes 1 and 2 was very few, and juvenile individuals were defective, representing a declining trend; while the population structure of L. glabra, C. sclerophylla, and C. glauca was of pyramid type. Based on the analysis of static life table, the mortality of the P. massoniana individuals at small age-size classes was negative, which also suggested that the seedlings in P. massoniana population were defective, and the population had a declining trend. The survivorship curve of P. massoniana population was convex, while that of L. glabra, C. sclerophylla and C. glauca populations was approximately linear. The entirety and the individuals at different agesize classes of the four dominant populations all presented a clumping distribution. In sum, P. massoniana population was of stable type with a declining trend, while L. glabra, C. sclerophylla, and C. glauca populations were of stable type with a developing trend. During the succession process, the community would develop to conifer-broadleaved forest, and finally, to evergreen broadleaved forest.

Key words: Secondary plant metabolites, Plutella xylostella, Repellent, Antifeedant, Bioactivity