黑麦草与入侵杂草紫茎泽兰苗期的相对竞争力

为研究利用黑麦草(Lolium perenne)替代种植治理外来入侵杂草紫茎泽兰(Eupatorium adenophorum)再入侵或新入侵丢荒地,采取复合deWit取代试验设计方法用盆栽植物研究了黑麦草和紫茎泽兰在苗期的相对竞争力,观察在若干密度梯度每密度下不同比例条件下两种植物的相对产量、相对产量总和以及竞争攻击力等参数,并比较其表型特征在不同竞争格局下的异同.黑麦草与紫茎泽兰在所有密度及其比例下的相对产量总和(RYT)均近似于1.0,说明这两种植物面临着对相同资源的直接竞争.竞争的结果是,在所有密度及其比例下,紫茎泽兰混种时的生物量均显著小于单种时的生物量(即相对产量RY小于1.0);而黑麦草的相对产量(RY)变化则恰恰相反.黑麦草的株高和地上生物量并不受混种竞争的显著影响(与单种无显著差异),分蘖数反而高于单种,表现出很强的竞争性;而紫茎泽兰在混种竞争下的株高、分株数和地上生物量均显著低于单种(无竞争),表现出较弱的竞争性.对利用黑麦草替代种植治理紫茎泽兰在机械防治后再入侵以及对丢荒地新入侵问题的可行性进行了讨论.图1表3参18

Relative Competitive Ability of Lolium perenne and the Alien Invasive Weed, Eupatorium adenophorum (Compositae) at Seedling Stage

To study the revegetation by Lolium perenne for managing the problems with recolonization of Eupatorium adenophorum after uprooted or its colonization to wasteland,the multiple de Wit design was performed with a regime of densities and proportions to evaluate the relative competitive ability of the two plants at seedling stage. The competition was measured by using the relative yield (RY), relative yield total (RYT), mean aggressive index (A) and phenological traits. The RYT was close to 1.0, which implied that the two plants competed for the same resources. At all densities and proportions the yield of E. adenophorum in mixture was significantly less than that in monoculture but L. perenne manifested in contrary to E. adenophorum, indicating that L. perenne was a better competitor than E. adenophorum. The conclusion was also supported by phonological performances. The plant height and above-ground biomass of L. perenne were not affected by mixture with E. adenophorum compared with monoculture and even more ramets were produced in mixture. On the contrary, E. adenophorum in mixture grew smaller with fewer ramets and less biomass than in monoculture. The possibility of using L. perenne for revegetation to control E. adenophorum is disscused in this paper. Fig 1, Tab 3, Ref 18