Among seven studied forest types in Me Linh Station for Biodiversity, the old secondary forest naturally regenerated after exploition has the highest number of tree species and its species composition is similar to that of primary forest. The main structure parameters are as follows: DBH of 17.5cm, H of 16.2m and 784 individuals/ha. Four vegetation types with younger secondary forest naturally regenerated after exploition and dominated by one tree species (Captanopsis indica, or Knema globularia, or Aquylaria crassna, or Styrax tonkinensis), are similar in species composition, structure of forest layers, individual distribution along diameter and hight classes, and structure parameters (with DBH of 9.8-15.5cm, H of 9.414.2m and 663-1002 individuals/ha. The other vegetation types, such as the secondary forest naturally regenerated after shifting cultivation and the secondary forest naturally regenerated after exploition and dominated by Neohouzeana dulloa, have not yet clear structure due to short recovery time
the main tree species are pioneer species.