Preliminary research on species diversity characteristics of the typical sample plots of Chimonanthus praecox community in northwest Hunan Province

Based on the field investigation on the typical sample plots of Chimonanthus praecox (L.) Link community in northwest Hunan Province, China, the species diversity indices and their characteristics of the community were calculated and analyzed. The results showed that in all layers of the community, the population quantity and the diversity indices (except dominance index) vary consistently; they increase in order from tree layer to herb layer; under the tree crown layer, the species diversity was more abundant. Comparing the synthetic diversity indices of sample plots from different regions and analyzing the DBH, it was discovered that the species diversity of the C.praecox community, disturbed by activities of human being, has gradually deteriorated, the progressive succession of the community slowed down, whereas the synthetic diversity indices of the community in natural succession were high increased distinctly, the community structure was more complicated and stable, and the community succession speeded up.