Soil Chemistry and Exotic Plant Invasions in Riparian Corridors of Varying Width

Research Issue

In cities and suburbs, riparian corridors provide at least two important services— they help protect running water from being contaminated by pesticides, herbicides, and silt; and they provide wildlife with refuge and a place to forage for food.  As these areas become increasingly degraded by nonnative plants, these benefits may be negatively affected. Four of the most important invasive plants in this system are Japanese honeysuckle, Oriental bittersweet, garlic mustard, and multiflora rose.

 Our Research

Our research was designed to explore relationships between the width of riparian corridors in human-dominated landscapes and their ability to buffer streams from runoff and invasion. To this end, we are investigating the effect of riparian corridors on native biodiversity on two fronts. (1) We are using soil chemistry profiles to investigate the efficacy of forested riparian corridors of various widths as buffers against non-point-source nutrient pollution. (2) We are measuring the ability of riparian buffers to minimize the negative influence of invasive plants on wildlife habitat. Because these plants invade from the edge of forested riparian corridors and can spread into the corridor itself (where vital wildlife habitat still may exist), we are trying to determine what width of buffer effectively excludes invasive plants from the corridor's interior. 

Expected Outcomes 

The data collected at these sites will be used to help cities and landowners manage riparian corridors to optimize ecosystem services; to predict areas that are most likely to be invaded and mitigate invasion; and to make decisions on optimal width and species composition when possible.

Research Results

Significant correlations between the width of buffers and invasion have been seen for several species of invasive plants. Results of this study are currently being prepared as a manuscripts for refereed journals. Meanwhile, papers and posters have been presented at conferences.

Ferris, G.; Williams, C.; D’Amico, V. 2009. Green armor and cul-de-sac corridors. In: McManus, K.A.; Gottschalk K.W., eds.  Proceedings, 20th U.S. Department of Agriculture Interagency Research Forum on Invasive Species, 2009. Gen. Tech. Rep. NRS-P-51. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station.

Ferris, G.; Morgan, J.; Williams, C.; D'Amico, V. 2009 Riparian corridors as potential biodiversity refugia. In: McManus, K.A.; Gottschalk, K.W., eds. Proceedings, 19th U.S. Department of Agriculture Interagency Research  Forum on Invasive Species, 2008. Gen. Tech. Rep. NRS-P-36. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station.

Morgan, J.; Ferris, G.; Williams, C.; D’Amico, V. 2008. Excluding invasive plants with riparian corridors. In: McManus, K.A; Gottschalk, K.W., eds. Proceedings, 19th U.S. Department of Agriculture Interagency Research  Forum on Invasive Species, 2008. Gen. Tech. Rep. NRS-P-36. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station.

Ferris, G.; D’Amico ,V.; Williams, C. 2007. Preserving biodiversity in riparian corridors.  In: Proceedings of the Conference on Emerging Issues Along Urban/Rural Interfaces, 2007 April 12. Auburn University, GA: 38.

Research Participants

Principal Investigator

• Vincent D’Amico, Research Entomologist, U.S. Forest Service, Northern Research Station 
• Christopher K. Williams, Department of Entomology and Wildlife Ecology, University of Delaware 

Research Partner

• Gavin Ferris, Department of Entomology and Wildlife Ecology, University of Delaware
• Jessica Morgan, Department of Entomology and Wildlife Ecology, University of Delaware

For further details log on website :
https://www.nrs.fs.fed.us/disturbance/invasive_species/invasive_plants_riparian_corridors/