Abstract: To ascertain the invasion characteristics of field sandbur (Cenchrus pauciflorus Benth.), field sandbur population dynamics and community diversity in the artificially sand-fixation forest such as Populus simonii and Salix gordejevii were studied using quadrat survey method. Results showed that field sandbur appeared in early June, and its height, population coverage, frequency, biomass achieved maximum values then become the dominant apecies of the grass communities in sand-fixation forest in July. The species completed its life cycle at the end of August. The invasion of field sandbur reduced community diversity. Community Shannon-Wiener index, Simpson index and Pielou index reached the largest in July, were 2.23, 0.89 and 0.50 in Populus simonii grass communities and 1.89, 0.84 and 0.41 in Salix gordeievii grass communities, respectively. It was concluded that the invasion of field sandbur had negative effects on community diversity and affected community structure.

Key words: Cenchrus pauciflorus Benth., Population dynamics, Community diversity, Khorchin sandy land

摘要： 为明确少花蒺藜草(Cenchrus pauciflorus Benth.)的入侵特征,采用样方调查法对科尔沁沙地人工小叶杨(Populus simonii)和黄柳 (Salix gordejevii)2个固沙林群落中少花蒺藜草种群动态及群落多样性进行分析研究。结果表明:少花蒺藜草于6月初开始出现于2个群落中,7月份种群高度、盖度、频度、生物量均达到最大值,成为固沙林草本群落中的优势种,8月底完成生命周期;少花蒺藜草入侵地物种稀少,7月份群落的Shannon-Wiener指数、Simpson指数和Pielou指数达到最大,仅为2.23,0.89,0.50(小叶杨草本群落)和1.89,0.84,0.41(黄柳草本群落)。分析认为少花蒺藜草的入侵对群落的多样性产生不利影响,影响了整个生物群落的结构组成。

关键词: 少花蒺藜草, 种群动态, 群落多样性, 科尔沁沙地