6th Annual Judith Ramaley Celebration of Research and Creative Scholarship
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Poster #64 Total Nitrogen and Total Phosphorus Dynamics of Laurentian Great Lakes Tributaries
Joseph Kremer
Faculty Mentor: Robin Richardson
Nitrogen and phosphorus naturally limit productivity in aquatic systems and can vary spatially from headwaters to rivermouth to pelagic environments. Human alteration to the landscape (e.g. agriculture and urban development) can rapidly accelerate the addition of these nutrients and adversely affect local biota. In conjunction with the USGS at the Upper Midwest Environmental Science Center in La Crosse, WI, total N and total P data from three sites in seven tributaries dominated by agriculture and fifteen tributaries dominated by forest across the Great Lakes were collected. I sought to answer two questions: 1) Do total N and P levels in sampled Great Lakes’ tributaries dominated by agriculture differ from those dominated by forest with respect to Upstream, Rivermouth, and Lake sites? and 2) Do total N and P levels in sampled Great Lakes’ tributaries within the same dominant landscape differ between Upstream, Rivermouth, and Lake sites? For question 1, analysis revealed total N and P at Upstream and Rivermouth Agriculture sites significantly higher than all Forest sites while Lake Agriculture sites were not significantly different from any Forest sites. For question 2, results showed total N and P at Upstream and Rivermouth Agriculture sites significantly higher from Agriculture Lake but not from each other. Total N at Forest sites did not show significance from one another, but total P at Upstream and Rivermouth Forest sites were significantly higher than Lake. It was concluded that agricultural practices in these watersheds are elevating N and P inputs into their associated lake basin and that dilution and/or production within the lake account for lower Lake site values. |
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