Stream nutrient sampling during winter baseflow conditions in the Andrews Forest and Willamette River Basin, February 2009

To better understand the impact of land use on stream nutrient export, a synoptic sampling of streams draining 57 sub-basins within the Willamette River basin was conducted during winter baseflow conditions. The objective of the study was to assess how streamwater values of stream dissolved organic carbon (DOC), NO3- and Cl- and specific ultra-violet absorbance (SUVA) were related with the proportion of land in the watershed in urban areas, agriculture, and forest. Stream water samples were collected during baseflow conditions in February 2009 throughout the Willamette River basin, including the experimental watersheds (1,2,6,7,8,9,10), Lookout and Mack Creeks at the HJ Andrews Forest. Land use for each point-delineated watershed were determined from published values from the PNWERC dataset (http://www.fsl.orst.edu/pnwerc/wrb/access.html).