Factors affecting post-control reinvasion by seed of an invasive species, Phragmites australis, in the central Platte River, Nebraska.

Biological Invasions
By: , and 

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Abstract

Invasive plants, such as Phragmites australis, can profoundly affect channel environments of large rivers by stabilizing sediments and altering water flows. Invasive plant removal is considered necessary where restoration of dynamic channels is needed to provide critical habitat for species of conservation concern. However, these programs are widely reported to be inefficient. Post-control reinvasion is frequent, suggesting increased attention is needed to prevent seed regeneration. To develop more effective responses to this invader in the Central Platte River (Nebraska, USA), we investigated several aspects of Phragmites seed ecology potentially linked to post-control reinvasion, in comparison to other common species: extent of viable seed production, importance of water transport, and regeneration responses to hydrology. We observed that although Phragmites seed does not mature until very late in the ice-free season, populations produce significant amounts of viable seed (>50 % of filled seed). Most seed transported via water in the Platte River are invasive perennial species, although Phragmites abundances are much lower than species such as Lythrum salicaria, Cyperus esculentus and Phalaris arundinacea. Seed regeneration of Phragmites varies greatly depending on hydrology, especially timing of water level changes. Flood events coinciding with the beginning of seedling emergence reduced establishment by as much as 59 % compared to flood events that occurred a few weeks later. Results of these investigations suggest that prevention of seed set (i.e., by removal of flowering culms) should be a priority in vegetation stands not being treated annually. After seeds are in the seedbank, preventing reinvasion using prescribed flooding has a low chance of success given that Phragmites can regenerate in a wide variety of hydrologic microsites.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Factors affecting post-control reinvasion by seed of an invasive species, Phragmites australis, in the central Platte River, Nebraska.
Series title Biological Invasions
DOI 10.1007/s10530-015-1048-3
Volume 18
Issue 9
Year Published 2016
Language English
Publisher Kluwer Academic Publishers
Contributing office(s) Northern Prairie Wildlife Research Center
Description 12 p.
First page 2505
Last page 2516
Country United States
State Nebraska
Other Geospatial Central Platte River
Online Only (Y/N) N
Additional Online Files (Y/N) N