Oecologia

, Volume 159, Issue 4, pp 803–815

Novel weapons and invasion: biogeographic differences in the competitive effects of Centaurea maculosa and its root exudate (±)-catechin

  • Wei-Ming He
  • Yulong Feng
  • Wendy M. Ridenour
  • Giles C. Thelen
  • Jarrod L. Pollock
  • Alecu Diaconu
  • Ragan M. Callaway
Community Ecology - Original Paper

DOI: 10.1007/s00442-008-1234-4

Cite this article as:
He, WM., Feng, Y., Ridenour, W.M. et al. Oecologia (2009) 159: 803. doi:10.1007/s00442-008-1234-4

Abstract

Recent studies suggest that the invasive success of Centaurea maculosa may be related to its stronger allelopathic effects on native North American species than on related European species, one component of the “novel weapons” hypothesis. Other research indicates that C. maculosa plants from the invasive range in North America have evolved to be larger and better competitors than conspecifics from the native range in Europe, a component of the “evolution of increased competitive ability” hypothesis. These hypotheses are not mutually exclusive, but this evidence sets the stage for comparing the relative importance of evolved competitive ability to inherent competitive traits. In a competition experiment with a large number of C. maculosa populations, we found no difference in the competitive effects of C. maculosa plants from North America and Europe on other species. However, both North American and European C. maculosa were much better competitors against plants native to North America than congeners native to Romania, collected in areas where C. maculosa is also native. These results are consistent with the novel weapons hypothesis. But, in a second experiment using just one population from North America and Europe, and where North American and European species were collected from a broader range of sites, competitive interactions were weaker overall, and the competitive effects of C. maculosa were slightly stronger against European species than against North American species. Also consistent with the novel weapons hypothesis, (±)-catechin had stronger effects on native North American species than on native European species in two experiments. Our results suggest that the regional composition of the plant communities being invaded by C. maculosa may be more important for invasive success than the evolution of increased size and competitive ability.

Keywords

Allelopathy(±)-CatechinCompetitionEvolution of increased competitive ability (EICA)InvasionNovel weapons hypothesis

Supplementary material

442_2008_1234_MOESM1_ESM.doc (80 kb)
MOESM1 (DOC 81 kb)
442_2008_1234_MOESM2_ESM.doc (462 kb)
MOESM2 (DOC 462 kb)

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Wei-Ming He
    • 1
  • Yulong Feng
    • 2
  • Wendy M. Ridenour
    • 3
  • Giles C. Thelen
    • 3
  • Jarrod L. Pollock
    • 3
  • Alecu Diaconu
    • 4
  • Ragan M. Callaway
    • 3
  1. 1.State Key Laboratory of Vegetation and Environmental Change, Institute of BotanyChinese Academy of Sciences (CAS)BeijingChina
  2. 2.Xishuangbanna Tropical Botanical GardenChinese Academy of Sciences (CAS)MenglaChina
  3. 3.Division of Biological SciencesThe University of MontanaMissoulaUSA
  4. 4.Institute of Biological ResearchIasiRomania