Abstract:

Clarifying the community characteristics and species diversity of ancient Ginkgo biloba communities in Nanxiong,Guangdong,a vital southern China refuge for Ginkgo biloba,can provide a reference for formulating its conservation and sustainable utilization strategies.Taking Laoweili ancient Ginkgo biloba clusters,one of the eight ancient Ginkgo biloba clusters in Guangdong Province,as the research object,typical quadrat surveys were conducted to analyze its species composition,community structure,floristic characteristics and species diversity.The results showed that:1)A total of 49 species of vascular plants belonging to 44 genera and 33 families were recorded within the community.Rosaceae,Asteraceae,and Oleaceae were the dominant families.The tree layer was dominated by Ginkgo biloba with an importance value of 66.39%,accompanied by tree species including Hovenia acerba and Osmanthus fragrans.The shrub layer contained 22 species,among which Paulownia fortunei was the dominant species with an improtance value of 19.79%.The herb layer consisted of 21 species,dominated by Miscanthus sinensis with an improtance value of 15.51%.2)The 39 plant genera were classified into 11 distribution types.At the genus level,temperate components accounted for 46.15% and tropical components accounted for 38.46%;Ginkgo was the only Chinese endemic genus.3)The species diversity indices of the shrub layer and herb layer were close to each other,and much higher than that of the tree layer.This study systematically clarifies the structural characteristics,flora,and species diversity characteristics of Laoweili ancient Ginkgo biloba community,which can provide data support for the conservation of species diversity of local ancient Ginkgo biloba communities,germplasm resource preservation and ecological landscapeutilization.

Key words: Nanxiong,Guangdong, Laoweili ancient Ginkgo biloba clusters, community structure, flora, species diversity