Abstract:

Aesculus wilsonii,a rare tree species and endemic to China,usually sporadically distributes in the evergreen and deciduous broadleaved mixed forest in China,and there are very few natural Aesculus wilsoniiommunities with considerable area in the nature.In the present study,the biodiversity,space distribution pattern,size class of population and community structure of an infrequent natural  Aesculus wilsonii community,which was found at the Qizimei Muontain in Xuan'en of Hubei Province,were analyzed by using the methods of community ecology and contiguous grid.The results showed that: (1)  Aesculus wilsonii  was a dominant species in the community,and its importance value was 22.7,far larger than that of  Meliosma oldhamii, whose importance value was 13.7 and was the second largest one in the community;(2) Species in the community were very abundant.Abundance index and evenness index of the tree layer were much lower than those of the shrub layer and the herb layer,while dominance index of the tree layer was far larger than that of the shrub layer and the herb layer,which illuminated that the species in the tree layer were fewer than in the shrub layer and the herb layer.In addition,most of the dominant populations displayed an uneven distribution pattern,and the role of the dominant species in the tree layer was marked and the stratification was evident in the  Aesculus wilsonii community;(3) According to the age structure, Aesculus wilsonii  community was presently stable,but the seedlings and saplings of all the five dominant populations were severely insufficient in the  Aesculus wilsonii  community,which would make the community considerably susceptible to the potential influences on its survival and development.As a result,some measures should be taken to protect the community.

Key words: Aesculus wilsonii/the Qizimei Mountain/community characteristics/distribution pattern