Landers, D. H. U.S. EPA, Landers@mail.cor.epa.gov
Andrus, C. W. Dynamac Corporation, andrusc@mail.cor.epa.gov
Erway, M. M. Dynamac Corporation, morrison@mail.cor.epa.gov
Cline, S. U.S. EPA, cline@mail.cor.epa.gov

 
SPATIAL AND TEMPORAL DIMENSIONS OF OFF-CHANNEL HABITAT DIVERSITY AND FUNCTION IN THE WILLAMETTE RIVER, OREGON, USA
 
Over the last 150 years the main channel of the Willamette River has been drastically altered by human activity from a generally meandering and anastamosing river with extensive reaches of broad, active flood plain to a river with 13 major dams, extensive revetments, encroaching urban and agricultural landuse and limited riparian forest corridors. These alterations have reduced the amount of off-channel features by over 80% and by changing the magnitude and duration of high flow events, have limited the regeneration of these features. During the last three years we have sought to characterize the ecological functions of the remaining off-channel habitats over a ~70 km reach of the river and to distinguish their spatial and temporal characteristics. We have used physico-chemical parameters of the water to examine connections between off-channel habitats and the main channel via hyporehic and river flow. For selected sites, these attributes have been tracked daily and seasonally. We have also examined landform maturation processes on a decennial timeframe to determine the change in ecological function (e.g. macrophyte and periphyton production) as it relates to landform age. Finally, we have related these characteristics to the use of off-channel habitats by fish and postulate important considerations for future management actions.
 
Day: Monday, Feb. 1
Time: 04:45 - 05:00pm
Location: Hilton of Santa Fe
 
Code: SS47MO0445H