The main objective of this study is to understand how stream network position influences feedbacks between nutrient cycles, stream metabolism, and consumer-resource interactions. The overall question is where and when are biotic interactions and biological chemical makeup important determinants of nutrient flux in river networks, and what are the consequences for downstream ecological communities? Recent theory addressing consumer-driven nutrient recycling suggests that shifts in elemental content of stream consumers, such as insects, are driven in part by resource availability and in part by the emergence of specific life history traits in response to changing environmental conditions along gradients of physical variables. The effects of resulting shifts in chemical imbalances between consumers and resources on nutrient fluxes is an exciting frontier in the study of streams. The investigators will examine feedbacks between stream metabolism, consumer-resource interactions and biogeochemical cycling at several network positions and during algal succession. They will use these measurements to estimate whole-system effects of changes in algal and dead organic matter and consumer-resource interactions on fluxes of multiple nutrients by exploring their specific effects on nutrient uptake and regeneration. This project and its science partnerships will provide liberal arts students with new and unique opportunities to explore ecosystem science and access to philosophies and lab facilities of large research groups.
