Streams are important landscape features because they provide an avenue for nitrogen loss from a watershed to downstream ecosystems and eventually the ocean; however, in-stream processes can control nutrient transport and export (e.g. Burns 1998). Nitrogen is an important element because it limits rates of primary production in many terrestrial and aquatic ecosystems. Alteration of the forms, timing, and concentration of nutrients is a central property of lotic systems (Fisher et al. 1998). Understanding controls on both transport and retention are central to predicting how streams influence nutrient loss from watersheds (Hedin et al. 1995, Likens and Bormann 1995, Burns 1998) and nutrient loading to downstream ecosystems (Howarth et al. 1996). With increased global nutrient loading from atmospheric sources and fertilizers, streams may play an important role in the retention, transformation and export of nutrients from the upland landscape. We know little about what controls nutrient uptake and transport in streams. There are many studies that show effects of hydrologic, biologic, and geomorphic influences on nutrient transport, but rarely have all aspects been considered in the same study. One potentially important geomorphic control is transient storage. Transient storage is water that is separated from the main channel flow and therefore, moves downstream more slowly than water in the main stream channel, which should facilitate nutrient uptake. Transient storage has been suggested to play an important role in nutrient retention in streams from both theoretical (Mulholland and DeAngelis 2000) and empirical perspectives (Valett et al. 1996, Mulholland et al. 1997). Additionally no studies have linked whole stream measures of metabolism with stream nutrient uptake, though we expect that greater C fixation or respiration will cause higher demand for nutrients. The objective of our study was to relate nutrient uptake with geomorphic and whole stream metabolism in 8 streams in Grand Teton National Park.
Contrasting Raz-Rru stream metabolism and nutrient uptake downstream of urban wastewater effluent sites
