Coupling Consumer-Resource Interactions and Nutrient Spiraling in a Stream Network

Dr. Jill Welter has received NSF funding via a subcontract with St. Olaf College in Northfield, MN for her research on Nutrient Spiraling in a Stream Network. The goal of this project is to understand feedbacks between stream consumer community composition and nutrient cycling, and how these feedbacks change with stream size and stream network position. Stream networks comprise gradients in light and temperature from small shaded headwater streams to large open rivers. These gradients coincide with a shift in the energy source to aquatic organisms from terrestrial detritus to algal production. These changes may alter food quality (nutrient content) and consumer community composition that ultimately feedback on nutrient cycling. As a result of the tight linkage between nutrient availability, food quality and consumer nutrient use efficiency, the effects of consumer-resource interactions may be transmitted downstream, with potential consequences for receiving systems. Dr. Welter's work provides a more realistic foundation for understanding the impact of human activities on watershed communities and nutrient fluxes.

This project builds upon previous work in the South Fork Eel River in northern California, and as a result, fieldwork is conducted in this watershed during the summer months. Dr. Welter and her student research assistants make measurements of nutrient spiraling, collect dominant organisms for analysis of biomass and nutrient content, and complete a series of manipulative experiments to determine the underlying feedbacks between consumer communities and nutrient cycling in streams throughout the network.

Students are a critical component of this project. A number of St. Kate's students, including Lyna Menezes, Carrie Booth, Maria Moenkedick, Shawna Handshug and Michaela Swanson have had the opportunity to travel to California to conduct field studies during the summer. Students who travel to California conduct independent projects, learn a variety of field and lab methods and have great opportunity to interact with researchers from various institutions at the Angelo Coast Range Reserve. Students attend seminars and assist researchers from these institutions and get an appreciation for the diversity of work conducted at the Reserve.