Skip to main content

Advertisement

Log in

Temporal and nonlinear dispersal patterns of Ludwigia hexapetala in a regulated river

  • Original Paper
  • Published:
Wetlands Ecology and Management Aims and scope Submit manuscript

Abstract

Rivers are vulnerable to biological invasion due to hydrologic connectivity, which facilitates post-entry movement of aquatic plant propagules by water currents. Ecological and watershed factors may influence spatial and temporal dispersal patterns. Field-based data on dispersal could improve risk assessment models and management responses. Ludwigia hexapetala, an invasive emergent macrophyte, provides a case study for understanding dispersal patterns throughout a watershed. The species spreads via hydrochory and is increasingly imposing detrimental ecological and economic impacts within watersheds of the United States and Europe. We investigated morphology of shoot fragments and their dispersal in the Russian River watershed of California, capturing shoot fragments of L. hexapetala during repeated summer surveys at five locations in the river and quantifying their morphological traits that predict establishment success. Highly variable capture counts suggest the importance of pulse disturbance events in local dispersal of L. hexapetala. Unexpectedly, dispersing propagule pressure was nonlinear, with more shoot fragments captured in the middle rather than lower river. Captured fragments in the middle river were twice the length of fragments captured in the lower river and bore 83% more stem nodes, characteristics associated with greater establishment success. Our results support development of spatially targeted management, outreach, and prevention efforts that could lead to decreased propagule pressure in the watershed.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

References

Download references

Acknowledgements

This research was supported by the US Army Corps of Engineers, Engineer Research and Development Center, Aquatic Plant Control Research Program, Vicksburg, Mississippi, USA. M. Skaer Thomason received support from the USDA-ARS Pathways program for graduate student development, and a subsequent USDA post-doctoral appointment. We thank Rebecca Drenovsky, Eric Wolanski and anonymous reviewers for comments that improved the manuscript. We thank Caryn J. Futrell for chemical laboratory analyses, and Sonoma County Water Agency for technical input and access to sites. We thank Shannon Burke, Malia Forbert, Caryn J. Futrell, Alex Pluchino, and Rachel Stump for assistance in the field and laboratory.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Brenda J. Grewell.

Electronic supplementary material

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Skaer Thomason, M.J., McCort, C.D., Netherland, M.D. et al. Temporal and nonlinear dispersal patterns of Ludwigia hexapetala in a regulated river. Wetlands Ecol Manage 26, 751–762 (2018). https://doi.org/10.1007/s11273-018-9605-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11273-018-9605-z

Keywords

Navigation