Comparisonon Species Composition and Spatial Structure of Different Aged Secondary Forest of Castanopsis eyrei-Schima superba

During October and December of 2017, three sample plots with 50 m × 50 m were set up in 20-25, 35-40 and 55-60-year secondary Castanopsis eyrei-Schima superba forest in Suichang, Zhejiang province. Complete enumeration was made in the sample plot. The results showed that treenumbers of overstory increased and that of understory decreased with increase of forest age. Species number maintained stable while species composition of different storey changed evidently. The proportion of three dominant species of the over story such as C. eyrei, S. superba and Cyclobalanopsis glauca increased from 20.41% at 20-25-year forest to 73.53% at 55-60-year forest. The analysis demonstrated that 20-25-year stand was aggregated distribution, 35-40-yearsemi-aggregated one, and 55-60 year uniform distribution.