507 Increased spiraling lengths in urban headwater streams - potential buffering mechanisms by river networks

Thursday, May 21, 2009: 9:15 AM
Ambassador West
Wilfred M. Wollheim , Complex Systems Research Center, University of New Hampshire, Durham, NH
Bruce J. Peterson , Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA
Gretchen M. Gettel , Department of Natural Resources, Complex Systems Research Center, University of New Hampshire, Durham, NH
Charles S. Hopkinson , Georgia Sea Grant, University of Georgia, Athens, GA
Tamara K. Harms , Georgia Sea Grant, University of Georgia, Athens, GA
Nutrient spiraling metrics provide a means for understanding how urban streams and rivers are impacted by simultaneous changes in nutrient loading, runoff, riparian vegetation, channel hydraulics, and connectivity with floodplains.  Each of these changes alters the hydrological and biological characteristics governing spiraling length.  An important question is to what degree changes in spiraling length evident in urban streams are translated into altered fluxes at critical downstream points (e.g. basin mouth inputs to estuaries).  We take a river-network perspective to explore the various mechanisms by which urban impacts could be buffered in river systems.  We consider how nutrient removal in river networks responds to altered timing of runoff from urban areas (event to seasonal scales), land use change and heterogeneity, and water management.  Key processes that determine the response include non-linear removal processes, linkages with floodplains, and dilution from less impacted subbasins.  Spiraling metrics are central for understanding these responses and offer a means for assessing/mapping the dynamic importance of ecosystem services provided by river systems.  A network perspective can inform nutrient management and help prioritize stream restoration efforts.
<< Previous Abstract | Next Abstract