Amplified fragment length polymorphism(AFLP)was used to analyze 2 populations: Schima superba Gardn. et Champ. and Castanopsis chinensis Hance. across three different communities representing three succession stages, in Dinghu Mountain, China. These two were middle succession species in the lower subtropical broad_leaved forest. Four AFLP primer combinations using total 48 individuals of S. superba provided 24, 40, 27 and 27 reliable bands, of which 15, 23, 23 and 16 were polymorphic, respectively. Similarly, total 48 individuals of C. chinensis provided 27, 20, 33 and 39 reliable bands, of which 12, 5, 15 and 13 were polymorphic respectively. These bands were used as presence/absence data to assess the levels of genetic variation and population structure of those species. From average heterozygosity, S. superba possessed higher molecular variation than C. chinensis . Analysis of molecular variance(AMOVA)indicated that most of the genetic variation of S. superba was due to the differences within population(95.99%, P <0.001), with 4.01% ( P <0.001)genetic variation among population. Similarly, AMOVA indicated the most of the genetic variation of C. chinensis was due to the differences within population(75.36%, P <0.001), with 24.64%( P <0.001)genetic variation among communities(24.64%). DCA(Detrended Correspondence Analysis) analysis showed that the individuals of S. superba from the same community did not cluster together, while the individuals of C. chinensis from the same community roughly cluster together. The above results reflected the biological characteristics of the two different species suggesting the significant effect of microenvironment of different community on population differentiation and its relationship of which to forest succession resulted in genetic divergence.
