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| NCED Researchers Investigate Nutrient Cycling | | NCED researchers from St. Olaf College, the College of St. Catherine, the University of Minnesota, and the University of California-Berkeley (UCB), including current and former NCED postdoctoral research associates, graduate students, and undergraduate students, are working with a collaborator from the University of Nebraska on an NSF-funded project entitled "Coupling Consumer-Resource Interactions and Nutrient Spiraling in a Stream Network." This project has researchers working to understand feedbacks between food web structure and nutrient cycling in streams, including how location within a stream network mediates those effects. Results from the first two summers of field work suggest that there are some important links between an increase in drainage area along stream networks and an increase in biological activity in terms of nutrient flux. Initial results from both whole stream nutrient uptake measurements and small recirculating chamber experiments suggest that the biological uptake of inorganic nitrogen does not change as drainage area increases despite an increasing biomass. In contrast, phosphate uptake does increase with drainage area. We hypothesize that this pattern is the result of higher nitrogen fixation in large, sunny streams, which leads to an increase in nitrogen relative to phosphate availability. This pattern is an interesting example of how a biological response to a physical gradient (light in this case) can influence the flux of multiple nutrients. |  | | Left: Measurements of nutrient uptake in Elder Creek, one of the study sites used in the project, at UCB's Angelo Coast Range Reserve in northern California (C. McNeely photo). Right: NCED researchers prepare a tracer addition to measure metabolism and hydrologic exchange in a stream at the Angelo Reserve (C. McNeely photo). | | | | | Sandy River Flows Again | | On October 19, 2007, fall rains brought flows on the Sandy River, OR, to a sufficient level for Portland General Electric (PGE) to notch the temporary coffer dam (video), allowing the river to start redistributing reservoir sediment. Read the full story. In addition, a documentary film crew that visited St. Anthony Falls Laboratory (SAFL) this past June shot footage of a model study located in the basement of the lab: NCED created a model of the Marmot Dam with colleagues from the US Forest Service (USFS), Oregon State University, and dam owners PGE to help predict and document this exciting event. View a clip of this video, "Scale Model Demonstrates Coffer Dam Washout," to learn more about how a river removes a coffer dam. | | USIP Students Present at SACNAS | | NCED's 2007 Undergraduate Summer Internship Program (USIP) students, using travel scholarships, attended the Society for Advancement of Chicanos and Native Americans in Science (SACNAS) national conference held this month in Kansas City, Missouri. These students, along with an NCED graduate student, presented their research. In addition, Science Museum of Minnesota President Eric Jolly delivered the keynote address, and NCED Diversity Director Diana Dalbotten led a session ("Getting Our Hands Dirty! New Approaches, Tools, and Techniques for Understanding Our Environment") with other NSF Science and Technology Centers. | | |
