紫茎泽兰与黑麦草苗期相对竞争力和生长特征的研究

为探究替代物种黑麦草（Lolium perenne）抑制外来人侵杂草紫茎泽兰（Eupatorium adenophorum）的潜力，采用de Wit取代系列设计，在野外小区内设置3水平多年生黑麦草栽植时间、4水平种植密度以及3水平混种比例等不同种植处理，于12周后收获，分别测量黑麦草与紫茎泽兰的地上生物量和地下生物量，用单株相对产量分析其竞争力。结果表明，种植密度、混种比例和黑麦草栽植时间显著影响紫茎泽兰的地上生物量，紫茎泽兰的竞争力在低种植比例情况下，随黑麦草栽植时间的推迟而明显增强，随种植密度的降低而增强。种植密度、混种比例、黑麦草栽植时间以及这些因素的互作等对黑麦草的地上生物量与地下生物量均具有显著影响；栽植时间越晚、密度越大，黑麦草的竞争力就越弱（尽管不存在直线关系）。在大多数种植处理条件下，紫茎泽兰经历的种间竞争明显大于种内竞争，表现出较弱的竞争力；而黑麦草在与紫茎泽兰同时栽植的情况下，经历的种内竞争大于种间竞争，表现出较强的竞争力。

Relative Competitive Ability and Growth Characteristics of Eupatorium adenophorum and Lolium perenne Seedlings

The competitive ability and growth characteristics of the perennial ryegrass (Lolium perenne) and the alien invasive weed (Eupatorium adenophorum) were studied by using de Wit replacement series method. The density, mixture proportion, and ryegrass-transplant time had significant effects on the aboveground biomass of E. adenophorum. The competitive ability of E. adenophorum was increased with postponing ryegrass-transplant, and planted at low density. The aboveground and belowground biomasses of L. perenne were significantly affected by density, mixture proportion, ryegrass-transplant time, and their interactions. The competitive ability of L. perenne was decreased with postponing ryegrass-transplant, and with density increasing. The results indicated that there were more interspecific competition of E. adenophorum experienced than that of L. perenne, while L. perenne had more intraspecific competition than interspecific competition when transplanted at the same with E. adenophorum, it indicated that L. perenne was a stronger competitor.