Abstract: A survey was conducted with the belt-sample method on distributions of weeds in various habitats where alien plants grow. Through the use of Principal Component Analysis (PCA), the authors find that light condition and human disturbance are key factors for wild weeds distribution in samples of Herb of Annual Fleabane, which take up 28. 84% and 23. 95%. By using Cluster Analysis and then comparing index of Simpson, Shannon-Wiener and Pielou, the results are verified that Erigeron annuus adapts to grow in quite drought environment with human intensive disturbance. The analysis of relationship between the importance value of this alien specie and the species richness of samples shows that the latter increases firstly and then decreases with the rise of the former, according withy = -0.1799x2 + 0. 2678x + 0. 7651( R2 = 0. 9209) , demonstrating a significant correlation between them, which suggests that the invasion of Erigeron annuus is harmful to species diversity. The results contribute to the prevention and control of alien invasive weeds.

Key words: biological invasions, spatial pattern, species diversity

摘要： 通过样带样方法, 调查了雾灵山外来入侵植物一年蓬(Erigeron annuus (L.) Pers.)在不同生境中的分布和空间格局。主成分分析表明: 影响一年蓬样方内杂草分布的两个主要因素是光照和人为干扰, 贡献率分别为28. 84% 和23. 95% 。经聚类分析, 将不同聚类型的 Simpson 优势度、Shannon-Wiener 多样性和 Pielou 均匀度指数进行比较, 验证了一年蓬适合生长于人为干扰较强的干旱环境。物种多样性随着一年蓬重要值( > 0. 74) 的增加而减小(y = - 0. 1799x2 + 0. 2678x + 0. 7651), 相关性显著(R2 =0. 9209)。研究表明一年蓬对群落内物种多样性存在不利影响。研究结果有助于当地管理部门对外来入侵杂草实施防控、监测与综合治理。

关键词: 生物入侵, 空间格局, 物种多样性