Biological Invasions (2016) 18, 2325-2332

James A. Estrada, Chris H. Wilson, Julienne E. NeSmith and S. Luke Flory (2016)
Propagule quality mediates invasive plant establishment
Biological Invasions 18 (8), 2325-2332
Abstract: 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.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): S. Luke Flory

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Imperata cylindrica (weed)		U.S.A. (SE)