广西中部7种典型灌丛群落的物种多样性特征

为揭示广西中部典型灌丛群落的结构和物种多样性特征,运用样方法调查分析了广西中部7种典型灌丛群落的物种、区系组成、生活型谱和物种多样性指数。结果表明,7个群落中共有85种灌木,隶属37科68属,以大戟科(Euphorbiaceae)和豆科(Leguminosae)为主,分别有10种和9种,占灌木种数的11.76%和10.59%;还有74种草本植物,隶属35科61属,以禾本科(Gramineae)和菊科(Asteraceae)为主,分别有13种和11种,占草本物种数的17.57%和14.87%。龙须藤(Bauhinia championii)群落的物种丰富度指数(S)、Simpson优势度指数(D)、Shannon-Wiener多样性指数(H′)和Pielou均匀度指数(J)均最高,而光荚含羞草(Mimosa sepiaria)、老虎刺(Pterolobium punctatum)、桃金娘(Rhodomyrtus tomentosa)群落的相对较低。由于研究区域地处中亚热带南缘,灌丛群落的区系组成以泛热带分布最多,占43.94%,生活型以高位芽植物为主,占37.50%。因此,广西中部灌丛群落的区系组成和生活型谱的热带性质强于温带性质,且接近于南亚热带植被的组成特征。

Species Biodiversity of Seven Typical Shrub Communities in the Middle of Guangxi Zhuang Autonomous Region

In order to understand the biodiversity characteristics of shrub communities in the middle of Guangxi, the species composition, floral, life-form and species biodiversity of seven typical shrub communities were investigated and analyzed. The results showed that there were 85 shrubs belonging to 37 families and 68 genera, and 74 herbs belonging to 35 families and 61 genera in the seven shrub communities. The shrub species were dominant by Euphorbiaceae and Leguminosae, which contained 10 and 9 species, accounting for 11.76% and 10.59% of the total shrub species, respectively. The herb species were dominant by Gramineae and Asteraceae, which contained 13 and 11 species, accounting for 17.57% and 14.87% of the total herb species, respectively. Among the seven shrub communities, Bauhinia championii community had the highest species richness, Shannon-Weiner, Simpson and Pielou indexes, followed by Mimosa sepiaria, Pterolobium punctatum, Rhodomyrtus tomentosa communities. The areal-type was dominant by Pantropical element accounting for 43.94%, and the phanerophytes was dominant in the life form accounting for 37.50%. Therefore, it was suggested that the tropical floral and life-form of shrub communities in middle Guangxi was stronger than temperate, and closed to the vegetation in southern subtropics.