The evolution of increased competitive ability, innate competitive advantages, and novel biochemical weapons act in concert for a tropical invader

Authors

  • Rui-Min Qin,

    1. Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China
    2. Graduate University, Chinese Academy of Sciences, Beijing, China
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    • These authors contributed equally to this work.
  • Yu-Long Zheng,

    1. Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China
    2. Graduate University, Chinese Academy of Sciences, Beijing, China
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    • These authors contributed equally to this work.
  • Alfonso Valiente-Banuet,

    1. Instituto de Ecología, Departamento de Ecologôa de la Biodiversidad, Universidad Nacional Autônoma de Mexico, México D.F, México
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  • Ragan M. Callaway,

    1. Division of Biological Sciences, University of Montana, Missoula, MT, USA
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  • Gregor F. Barclay,

    1. Department of Life Sciences, University of the West Indies, St. Augustine, Trinidad and Tobago
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  • Carlos Silva Pereyra,

    1. Instituto de Ecología, Departamento de Ecologôa de la Biodiversidad, Universidad Nacional Autônoma de Mexico, México D.F, México
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  • Yu-Long Feng

    Corresponding author
    1. College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, Liaoning Province, China
    • Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China
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Author for correspondence:

Yu-Long Feng

Tel: +86 24 88487163

Email: yl_feng@tom.com; fyl@xtbg.ac.cn

Summary

  • There are many non-mutually exclusive mechanisms for exotic invasions but few studies have concurrently tested more than one hypothesis for the same species.
  • Here, we tested the evolution of increased competitive ability (EICA) hypothesis in two common garden experiments in which Chromolaena odorata plants originating from native and nonnative ranges were grown in competition with natives from each range, and the novel weapons hypothesis in laboratory experiments with leachates from C. odorata.
  • Compared with conspecifics originating from the native range, C. odorata plants from the nonnative range were stronger competitors at high nutrient concentrations in the nonnative range in China and experienced far more herbivore damage in the native range in Mexico. In both China and Mexico, C. odorata was more suppressed by species native to Mexico than by species native to China. Species native to China were much more inhibited by leaf extracts from C. odorata than species from Mexico, and this difference in allelopathic effects may provide a possible explanation for the biogeographic differences in competitive ability.
  • Our results indicate that EICA, innate competitive advantages, and novel biochemical weapons may act in concert to promote invasion by C. odorata, and emphasize the importance of exploring multiple, non-mutually exclusive mechanisms for invasions.

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