红薯对薇甘菊的竞争效应

在外来入侵生物的生态管理中,利用具有较高经济价值的本地植物或伴生的本地物种进行替代控制是治理入侵植物的有效途径之一。本研究以本地作物红薯(Ipamoea batas)和入侵植物薇甘菊(Mikania micrantha)为试验对象,田间试验条件下采用deWit取代法,研究了红薯对薇甘菊的竞争效应。结果表明:薇甘菊单种时,主茎长、分枝长、节间长和分枝数大于红薯,而主茎节数、不定根节数、叶柄长、叶面积均明显小于红薯,使薇甘菊在与红薯争夺养分和光照时处于劣势;在薇甘菊与红薯共存条件下,各个混种比例中薇甘菊的株高、分枝、叶、茎节不定根和生物量等均受到显著抑制,且受到的抑制率普遍高于其对红薯的抑制率;薇甘菊和红薯的相对产量(RY)、相对产量总和(RYT)均显著小于1.0,说明2物种的种间竞争大于种内竞争;红薯对薇甘菊的竞争平衡指数,只有在薇甘菊所占比例高时(1:3)竞争平衡指数显著小于0,其余各个混种比例下竞争平衡指数均显著大于0,说明红薯与薇甘菊之间存在很强的竞争作用,红薯对薇甘菊的竞争力强于薇甘菊。本研究表明,无论是从形态特征还是生物量来看,红薯都可以作为一种对薇甘菊进行替代控制的理想竞争植物。

Competitive effect of Ipamoea batas to Mikania micrantha

In the ecological management of invasive alien species,replacement control with valuable native species or associated native species is an effective approach to control the invasive species.In this paper,a field experiment was conducted to study the competitive effect of native crop Ipamoea batas using to invasive plant Mikania micrantha by the method of de Wit replacement series.In monoculture,the main stem length,branch length,internode length,and branch number of M.micrantha were higher,but the node number of main stem,node number of adventitious root,leafstalk length,and leaf area were obviously lower than those of I.batas,suggesting that I.batas had higher competitive ability on soil nutrients and light than M.micrantha.In multi-culture,the plant height,branch,leaf,stem node,and adventitious root,and biomass of M.micrantha were suppressed significantly,and the suppressed rates were higher than those of I.batas.The relative yield(RY) and the relative yield total(RYT) of M.micrantha and I.batas were obviously lower than 1.0,showing that the intraspecific competition between M.micrantha and I.batas was more intense than their interspecific competition.The competitive balance index of I.batas vs.M.micrantha in various proportions(except 1:3) of multi-culture was greater than zero,showing that I.batas had a stronger competitive ability than M.micrantha.All the results suggested that it could be a promising strategy to replace M.micrantha by I.batas.