桂西北喀斯特地区不同退化程度植被群落物种组成及多样性特征

Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Plant Protection submitted time 2018-07-18 Cooperative journals: 《广西植物》

俞月凤 何铁光 杜虎 韦彩会 蒙炎成 李忠义 张野 王瑾 胡钧铭 苏天明 范适

Abstract： Many natural ecosystems have been suffering from degradation across the world. Karst ecosystems are known for susceptibility and sensitivity to disturbance. So far, little information is available on the characteristics of vegetation communities suffering from different levels of degradation in Karst areas. Therefore, this study investigated species composition, community structure and species diversity of vegetation communities suffering from different levels of degradation in Karst areas. The results showed that: (1) There were significant differences in species composition and life form composition of communities suffering from different levels of degradation. Numbers of plant families and species were highest in potential degraded communities. Along degradation, tree species gradually reduced and ultimately disappeared. The proportion of shrubs increased first and then decreased. The proportion of herbal increased gradually along degradation. (2) There is a total of 217 vascular plant species belonging to 86 families and 165 genera across 45 explored plots, and Euphorbiaceae, Meliaceae, Rosaceae, Verbenaceae, Gramineae, Nephrolepidaceae were the dominant species. Along degradation, the important values of dominant species gradually decreased, i.e., their dominance in the community gradually weakened while the important values of the companion species gradually increased. (3) Community structure tended to simplify along degradation, as density, height and coverage of community decreased. (4) There were significant differences in species diversity indexs of arbor, shrub and herb layers of communities suffering from different levels of degradation. The species richness index, Shannon-Wiener index and Simpson index decreased along degradation. In sum, characteristics of vegetation community substantially changed along degradation, which has important implication for further studies on degradation and vegetation restoration in Karst areas.

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