中文摘要：

根据野外60个样方的调查数据，应用Levins、Shannon-Wiener生态位宽度指数和Levins生态位重叠指数分析了巨桉人工林草本层13个主要种的生态位宽度和生态位重叠特征。结果表明，里白和芒的生态位宽度最大，主要是由于其具有广泛的适应性。生态位宽度较大（或较小）的种群，它们所构成的种对间生态位重叠既有较大的，也有较小的，生态位宽度与生态位重叠程度无相关性。总体上看，巨桉人工林草本层物种间生态位重叠相对较低。从生态响应速率来看，里白发展性最强，可能形成少数种独占巨桉人工林草本层的格局。

英文摘要：

Based on the data of 60 plots obtained from investigation, the niche breadth and niche overlapping of 13 main herbage populations in Eucalyptus grandis plantation were studied by using Levins and Shannon-- Wiener niche breadth index and Levins niche overlapping index. The niche breadths of Hicriopteris glauca and Miscanthus sinensis were bigger than that of the others because these two species had extensive adaptation to environment. The species with big niche breadth didn＇t always have big niche overlapping, and the niche breadth and niche overlapping did not have a positive direct liner relation. In conclusion, relatively lower niche overlapping between species were apparent in herb layer of E. grandis plantation. From the eco-response rate, aggression of H. glauca was strongest, and few species would monopolize the herb layer of E. grandis.