生物多样性 ›› 2005, Vol. 13 ›› Issue (2): 130-136.  DOI: 10.1360/biodiv.040122

• 论文 • 上一篇    下一篇

互花米草与海三棱藨草的生长特征和相对竞争能力

陈中义1,2, 李博1, 陈家宽1*   

  1. 1 (复旦大学生物多样性科学研究所,教育部生物多样性与生态工程重点实验室,上海200433)
    2 (长江大学园艺园林学院,湖北荆州434025)
  • 收稿日期:2004-08-21 修回日期:2005-01-30 出版日期:2005-03-20 发布日期:2005-03-20
  • 通讯作者: 陈家宽

Some growth characteristics and relative competitive ability of invasive Spartina alterniflora and native Scirpus mariqueter

Zhongyi Chen1, 2, Bo Li1, Jiakuan Chen1*   

  1. 1 Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai 200433
    2 College of Gardening and Horticulture, Yangtze University, Jingzhou, Hubei 434025
  • Received:2004-08-21 Revised:2005-01-30 Online:2005-03-20 Published:2005-03-20
  • Contact: Jiakuan Chen

摘要:

外来物种互花米草(Spartina alterniflora)已对我国特有种海三棱藨草(Scirpus mariqueter)发生了竞争取代。作者通过在长江口崇明东滩湿地取样和盆栽竞争实验,比较了二者的主要生长特征和种间相对竞争能力。结果表明:无论是先锋种群还是成熟种群,互花米草的高度、盖度、地上生物量、地下生物量和平均每花序种子数都显著大于海三棱藨草;海三棱藨草的密度和单位面积结实枝条数显著大于互花米草。两种植物成熟种群的单位面积种子产量和种子的萌发率没有显著差异。种内竞争和种间竞争显著降低了两种植物的平均每株产生的无性小株数、结实株数、地上生物量和地下球茎数(海三棱藨草产生球茎),互花米草的种间竞争能力(相对邻里效应指数)显著大于海三棱藨草。互花米草在生长上的优势可能导致其在种间竞争上的优势,从而使互花米草能够在海三棱藨草群落中成功入侵。

Abstract

Spartina alterniflora,originating in North America, has been introduced to China and has now invaded many inter-tidal zones of gulfs and estuaries in China. With its spread, Scirpus mariqueter,a native grass species, has experienced a concurrent decrease in area. Based on field investigation at Chongming Dongtan Wetland and potted plant competition experiments at Fudan University, we compared growth characteristics and relative competitive ability between the two species. The results indicated that in terms of height, coverage, above-ground biomass, below-ground biomass, and mean seed number per spike, values for Spartina alterniflora were all significantly higher than those of Scirpus mariqueter.However, the density and number of flowering tillers per square meter for Spartina alterniflora were significantly lower than those of Scirpus mariqueter.In terms of seed output per square meter and seed germination rate, there were no significant differences between the mature populations of the two species. Both interspecific and intraspecific competition between Spartina alterniflora and Scirpus mariqueter remarkably reduced the number of ramets, the proportion of fruiting ramets, the above-ground biomass and the number of corms (only Scirpus mariqueter has corms). The interspecific relative competitive ability (measured as relative neighbour effect index, RNE) of Spartina alterniflora was significantly greater than that of Scirpus mariqueter. The obvious growing advantage of Spartina alterniflora compared with Scirpus mariqueter might explain its greater interspecific competitive ability, which might explain its successful invasiveness into the native Scirpus mariqueter community in the Yangtze River estuary.