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Ecological Functions of Off-Channel Habitats of the Willamette River, Oregon, Database and Documentation (1997-2001)
Citation:
ERWAY, M., C. ANDRUS, S. FERNALD, S. P. CLINE, AND D. H. LANDERS. Ecological Functions of Off-Channel Habitats of the Willamette River, Oregon, Database and Documentation (1997-2001). U.S. Environmental Protection Agency, Washington, DC, EPA/620/R-03/004, 2008.
Impact/Purpose:
The goals were to evaluate the functions of alcoves and side channels in a large river ecosystem, determine factors that currently affect their ecological functions, and identify future management options to improve these functions.
Description:
The database from the Ecological Functions of Off-Channel Habitats of the Willamette River, Oregon project (OCH Project) contains data collected from 1997 through 2001 from multiple research areas of the project, and project documents such as the OCH Research Plan, Quality Assurance Plan, a summary of quality assurance data, data dictionaries, maps, and figures with cumulative frequency distributions of the water chemistry data. This project was part of the Pacific Northwest Alternative Futures Research Consortium, and studied the role of off-channel habitats, or alcoves, in large river ecosystems. The goals were to evaluate the functions of alcoves and side channels in a large river ecosystem, determine factors that currently affect their ecological functions, and identify future management options to improve these functions. The largest component of the database is the water chemistry data collected over the five years from alcoves, the main channel, and groundwater wells, and includes hourly in situ data of basic water chemistry variables (temperature, dissolved oxygen, pH, turbidity, and specific conductance) collected at different locations for variable time periods and distances from the main channel. Other types of data in the database are physical data from the alcoves such as surface area, volumes, water depths, and tree ages, and data from sampling fish, alcove herbaceous cover, periphyton, substrates, and macrophytes. The database is in Microsoft Access, but also includes data exported into Excel spreadsheets. Data documentation includes descriptions of sampling locations, and sampling and analysis methods. Some of the key findings from this project are that the off-channel habitats of the Willamette River between Corvallis and Eugene have been reduced by approximately 80% due to human-induced land use changes and dam management, and the remnant ecological functions of the hyporheic zones suggest that significant amounts of summer cooling occurred in these off-channel habitats that benefited the main channel as well as the off-channel areas.