中文摘要：

研究了紫茎泽兰与非洲狗尾草、本地狗尾草、佩兰和小藜在野外单、混种条件下根系形态特征,并对相对竞争能力进行了分析.结果表明：紫茎泽兰与非洲狗尾草混种条件下,紫茎泽兰根系长度、体积和表面积比单种时减小,而非洲狗尾草增大;紫茎泽兰混种时生物量比单种时降低了77.1%,而非洲狗尾草增加了80.4%;非洲狗尾草相对产量和竞争平衡指数高于紫茎泽兰,相对产量总和约为1.0,说明非洲狗尾草地下竞争能力强于紫茎泽兰.紫茎泽兰与本地狗尾草混种条件下,两物种根系长度、体积和表面积低于单种,生物量分别比单种降低了45.3%和22.8%;竞争效应参数表明两物种具有较强的竞争效应.紫茎泽兰与佩兰混种时,两物种根系长度、体积和表面积与在单种时无显著差异,生物量分别低于单种;竞争效应参数表明紫茎泽兰具有竞争优势.紫茎泽兰与小藜混种时,紫茎泽兰根系形态和竞争能力均占优势。从地下根系竞争来看,可以利用非洲狗尾草替代控制紫茎泽兰以及对紫茎泽兰入侵迹地进行生态修复。

英文摘要：

A field experiment was conducted to explore the root competitive effects of Ageratina adenophora and Setaria sphacelata, S. yunnanensis, Eupatorium fortunei, Chenopodiurn serotinum in monocuhure and mixture, and the relative competitive abilities were evaluated. The results showed that the root length, superficial area and volume of A. adenophora in mixture were lower than in monoculture, but those of S. sphacelata were higher in mixture than in monocuhure. The biomass of A. adenophora in mixture decreased by 77.1% and that of S. sphacelata increased by 80.4% compared with those in monocuhure. The relative yield and competitive balance index of S. sphacelata were significantly higher than those of A. adenophora, and the relative yield was about 1.0, suggesting that the underground competitive ability of S. sphacelata was higher than A. adenophora. The root morphology of S. yunnanensis in monoculture and mixture was higher than those of A. adeno- phora, but the root morphology of two species in mixture was lower than in monocuhure. The biomass of A. adenophora and S. yunnanensis in mixture decreased by 45.3% and 22.8% compared with those in monoculture, respectively. Competition effect parameters showed that A. adenophora was a mutual antagonism with S. yunnanensis. The root morphology of E. fortunei and A. adenophora in mixture showed no significant difference compared with that in monoculture. The biomass of A. adenophora and E. fortunei was lower than that in monocuhure, respectively. Competition effect parameters showed that A. adenophora was a superior competitor. In the mixture of A. adeno- phora and C. serotinum, the root morphology parameters and competitive ability of A. adenophora were superior to those of C. serotinum. Above all, S. sphacelata is a preference plant material to control the A. adenophorum invasion and recover biodiversity in A. adenophorum invasion fields.