Tuesday, June 5, 2007 - 9:30 AM
92

Stream Denitrification Potential- Where and How Much?

Stuart Findlay1, Patrick J. Mulholland2, Robert O. Hall3, Stephen K. Hamilton4, Bruce J. Peterson5, Jennifer L. Tank6, Cliff N. Dahm7, Walter K. Dodds8, Nancy B. Grimm9, William H. McDowell10, H. Maurice Valett11, Jackson R. Webster12, Chelsea Crenshaw7, Jody Potter10, Melody J. Bernot13, and Daniel J. Sobota14. (1) Inst. of Ecosystem Studies, Millbrook, NY 12545, (2) Environmental Sciences Division, Oak Ridge National Laboratory, Bethel Valley Road, PO Box 2008, Oak Ridge, TN 37831-6036, (3) Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, (4) Kellogg Biological Station, 3700 East Gull Lake Drive, Hickory Corners, MI 49060, (5) Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA 02543, (6) Department of Biological Sciences, University of Notre Dame, Galvin Life Sciences, Notre Dame, IN 46556, (7) Department of Biology, University of New Mexico, Albuquerque, NM 87131, (8) Division of Biology, Kansas State University, 116 Ackert Hall, Manhattan, KS 66506, (9) School of Life Sciences, Arizona State University, Tempe, AZ 85287, (10) Department of Natural Resources, University of New Hampshire, Durham, NH 03824, (11) Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, (12) Department of Biological Sciences, Virginia Tech, 2119 Derring Hall, Blacksburg, VA 24061, (13) Department of Biological Sciences, Murray State University, Murray, KY 42071, (14) Department of Fisheries and Wildlife, Oregon State University, 104 Nash Hall, Corvallis, OR 97331

Small streams have a demonstrated ability to denitrify a portion of their nitrate load but there has not been an extensive consideration of where in a stream this process is occurring and how various habitats contribute to total capability.  As part of the Lotic Intersite Nitrogen Experiment (LINX II) we measured denitrification potential from 65 streams spanning eight regions of the US and three landcover types.  In each stream, potentials were measured in habitats found across many streams as well as likely hot spots.  Overall, streams in urban and agricultural land covers showed higher potentials than reference streams (largely forested catchments).  Within streams, different habitats showed high activity per unit mass versus high activity per unit area.  Consequently, both hot spots and the cooler matrix contributed significantly to whole stream performance.

See more of Microbial Ecology
See more of Contributed Sessions

See more of The NABS 55th Annual Meeting