Investigation on plant diversity of middle-aged and near mature Cunninghamia lanceolata plantation

Cunninghamia lanceolata is one of important fast growing species in southern China, and plays an important role in forestry production. In order to study the effects of different age structure on plant diversity of Chinese fie plantation growing in hilly area, the plant diversity of C. lanceolata near mature forest and middle-age forest were investigated and studied by adopting Simpso's diversity index and species richness method. The results indicate that the stand age of Chinese fir plantation had a great influence on species diversity of plant community, the species abundance near mature plantation was higher than middle-age plantations, while in middle aged forests, plant species was relatively few; With the gradual increase tree age, the plant community types in the forests gradually increased, after the stand entering the near-mature stage, the plant community types changes of plant species was not a very obvious; Plantation species richness generally showed a trend that the species richness of near-mature forest was higher than that of middle-age forest, especially in shrubs and herbs; Chinese FIR plantation management should reasonably adjust population structure based on different forest-ages, creat a good forest growth conditions, thus helping protect and restore species diversity.