Plant Ecology

, Volume 206, Issue 2, pp 309–319

Reproductive interference and salinity tolerance differentiate habitat use between two alien cockleburs: Xanthium occidentale and X. italicum (Compositae)


DOI: 10.1007/s11258-009-9644-x

Cite this article as:
Takakura, KI. & Fujii, S. Plant Ecol (2010) 206: 309. doi:10.1007/s11258-009-9644-x


In recent years, reproductive interference (RI), the fitness cost of reproductive activities among species, has received much attention as a factor in competitive exclusion by alien species. In this study, we aimed to explain the distribution of two annual alien Xanthium species (X. occidentale and X. italicum) found in the northern Kinki Distinct of Japan from the viewpoint of RI. First, specimen records demonstrated that Xanthiumoccidentale was more dominant in all habitats except seaside habitats. Subsequently, using artificial patches of potted plants, we demonstrated that X. italicum suffered intense RI from X. occidentale. Finally, X. italicum was superior to X. occidentale in tolerating salinity stress. Combining these results, we concluded that the asymmetrical RI caused by X. occidentale displaced X. italicum except in seaside habitats, where X. occidentale could not establish colonies. Furthermore, we discuss the possibility that a similar RI effect caused the extinction of native species.


Competitive exclusionInterspecific pollen transferGeographical distributionReproductive interferenceSalinity stress

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.Osaka City Institute of Public Health and Environmental SciencesOsakaJapan
  2. 2.University of Human EnvironmentsOkazakiJapan