HR: 14:15h
AN: NB23F-04    [Abstracts]
TI: Effects of In-stream Restorations on Stream Hydrodynamics, Nutrient Uptake, and Ecosystem Metabolism at Fort Benning, GA
AU: * Roberts, B J
EM: robertsbj@ornl.gov
AF: Oak Ridge National Laboratory, Environmental Sciences Division Bldg. 1505 PO Box 2008 / Bethel Valley Road, Oak Ridge, TN 37831 United States
AU: Mulholland, P J
EM: mulhollandpj@ornl.gov
AF: Oak Ridge National Laboratory, Environmental Sciences Division Bldg. 1505 PO Box 2008 / Bethel Valley Road, Oak Ridge, TN 37831 United States
AB: Spatial variability in military training intensity results in a wide range of upland disturbance intensity at the Fort Benning Military Reservation (near Columbus, GA). We selected stream reaches within 8 catchments with contrasting levels of upland denudation and stream ecosystem disturbance. In October 2003, 4 of these streams (spanning the disturbance gradient) received in-stream restorations in the form of coarse woody debris dams every 10 m for the 100 m study reaches. Stream hydrodynamic properties, NH4+ uptake, and whole-stream metabolism were examined both prior to and after restoration for all 8 streams. In-stream restorations resulted in increases in the relative size of transient storage zones (important for biological processes) and spatial variation in water velocity (enhances habitat variability). These hydrodynamic changes corresponded to increases in both NH4+ uptake rate and velocity as the ability of stream biota to control stream NH4+ concentration increased. By monitoring stream metabolism rates for two years prior to restoration we are able to assess the impact of the restorations on these important integrative processes using a BACI-type analysis (before-after control-treatment analysis) for the first year of post-restoration.
DE: 0400 Biogeosciences
DE: 1800 HYDROLOGY
DE: 1845 Limnology
DE: 1871 Surface water quality
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly