The Role of Riparian Vegetation in Protecting and Improving Chemical Water Quality in Streams


We review the research literature and summarize the major processes by which riparian vegetation influences chemical water quality in streams, as well as how these processes vary among vegetation types, and discuss how these processes respond to removal and restoration of riparian vegetation and thereby determine the timing and level of response in stream water quality. Our emphasis is on the role that riparian vegetation plays in protecting streams from nonpoint source pollutants and in improving the quality of degraded stream water. Riparian vegetation influences stream water chemistry through diverse processes including direct chemical uptake and indirect influences such as by supply of organic matter to soils and channels, modification of water movement, and stabilization of soil. Some processes are more strongly expressed under certain site conditions, such as denitrification where groundwater is shallow, and by certain kinds of vegetation, such as channel stabilization by large wood and nutrient uptake by faster-growing species. Whether stream chemistry can be managed effectively through deliberate selection and management of vegetation type, however, remains uncertain because few studies have been conducted on broad suites of processes that may include compensating or reinforcing interactions. Scant research has focused directly on the response of stream water chemistry to the loss of riparian vegetation or its restoration. Our analysis suggests that the level and time frame of a response to restoration depends strongly on the degree and time frame of vegetation loss. Legacy effects of past vegetation can continue to influence water quality for many years or decades and control the potential level and timing of water quality improvement after vegetation is restored. Through the collective action of many processes, vegetation exerts substantial influence over the well-documented effect that riparian zones have on stream water quality. However, the degree to which stream water quality can be managed through the management of riparian vegetation remains to be clarified. An understanding of the underlying processes is important for effectively using vegetation condition as an indicator of water quality protection and for accurately gauging prospects for water quality improvement through restoration of permanent vegetation. (KEY TERMS: assessment; biogeochemistry; buffers; legacy effects; nonpoint source pollution; resilience; restoration; rivers ⁄ streams; soils; watershed management.) Dosskey, Michael G., Philippe Vidon, Noel P. Gurwick, Craig J. Allan, Tim P. Duval, and Richard Lowrance, 2010. The Role of Riparian Vegetation in Protecting and Improving Chemical Water Quality in Streams. Journal of the American Water Resources Association (JAWRA) 1-18. DOI: 10.1111 ⁄ j.1752-1688.2010.00419.x Paper No. JAWRA-09-0035-P of the Journal of the American Water Resources Association (JAWRA). Received February 17, 2009; accepted July 23, 2009. a 2010 American Water Resources Association. No claim to original U.S. government works. Discussions are open until six months from print publication. Respectively, Research Ecologist (Dosskey), Southern Research Station, USDA Forest Service, Lincoln, Nebraska; Assistant Professor (Vidon), Department of Earth Sciences, Indiana University-Purdue University at Indianapolis, Indianapolis, Indiana; Post-Doctoral Fellow (Gurwick), Department of Global Ecology, Carnegie Institution for Science, Stanford, California, currently Senior Scientist, Union of Concerned Scientists, Washington, D.C.; Associate Professor (Allan), Department of Geography and Earth Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina; Ph.D. Candidate (Duval), School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario, Canada; and Research Ecologist (Lowrance), USDA Agricultural Research Service, Southeast Watershed Research Laboratory, Tifton, Georgia (E-mail ⁄Dosskey: JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION 1 JAWRA JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION AMERICAN WATER RESOURCES ASSOCIATION

3 Figures and Tables

Cite this paper

@inproceedings{Dosskey2010TheRO, title={The Role of Riparian Vegetation in Protecting and Improving Chemical Water Quality in Streams}, author={Michael G. Dosskey and Philippe G F Vidon and Noel P. Gurwick and Craig J. Allan and Tim P. Duval and Richard R . Lowrance}, year={2010} }