Biological Invasions

, Volume 18, Issue 8, pp 2325–2332 | Cite as

Propagule quality mediates invasive plant establishment

  • James A. EstradaEmail author
  • Chris H. Wilson
  • Julienne E. NeSmith
  • S. Luke Flory
Original Paper


Propagule pressure is commonly considered a primary driver of invasive plant establishment and spread. However, the physical size or condition (i.e., quality) of propagules may also affect establishment, particularly under unfavorable habitat conditions such as low light environments. We used an outdoor mesocosm experiment to test the relative contribution of propagule size (number of individuals introduced) and quality (number of rhizome nodes) to the establishment and performance of the highly invasive cogongrass (Imperata cylindrica) under experimental sun and shade treatments. We found that the introduction of higher quality propagules (rhizome segments ≥3 nodes in length) significantly enhanced establishment across both light treatments, and increased final tiller count in the sun treatment. The sun treatment also enhanced rhizome growth, an effect that could increase spread rates and invasion success. Thus, while cogongrass is likely to establish in both sun and shade, introductions of large propagule sizes or large rhizomes in high light environments likely poses the greatest threat to native habitats. Our results demonstrate that propagule quality promoted both establishment and performance of a highly invasive grass species and suggest that propagule quality may play an important but underappreciated role in the invasion process.


Cogongrass Propagule pressure Imperata cylindrica Invasion Mechanism 



We thank Deah Lieurance, Christina Alba, and members of the Flory Lab for helpful discussions and revisions on earlier versions of the manuscript. Support was provided in part by the Florida Fish and Wildlife Conservation Commission.

Supplementary material

10530_2016_1163_MOESM1_ESM.pdf (32 kb)
Fig. A1 Online Resource 1: Coefficient plot for contrasted tiller count predictions for three and five node as opposed to single node rhizome segments. Each coefficient represents positive or negative treatment effects as compared to a reference level of one propagule (p) with one node (n). We consider coefficients with confidence intervals (95 %) excluding zero to be significantly positive or negative, with those above zero being positive and below being negative. (PDF 31 kb)
10530_2016_1163_MOESM2_ESM.pdf (253 kb)
Fig. A2 Online Resource 2: Raw data for tiller counts over the course of the experiment. Symbols represent mean ± SE. (PDF 252 kb)


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Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  • James A. Estrada
    • 1
    Email author
  • Chris H. Wilson
    • 2
  • Julienne E. NeSmith
    • 2
  • S. Luke Flory
    • 1
  1. 1.Agronomy DepartmentUniversity of FloridaGainesvilleUSA
  2. 2.School of Natural Resources and EnvironmentUniversity of FloridaGainesvilleUSA

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