PRIMARY CONTROLS ON NUTRIENT USE: ECOSYSTEM METABOLISM AND DISTURBANCE IN A SMALL HEADWATER STREAM, WESTERN MONTANA
Ecosystem metabolism and disturbance can alter nutrient retention in aquatic systems. During summer and fall months of 2018, nitrate concentrations followed consistent diel swings in Miller Creek of western MT. Research addressing the interacting determinants of nitrate retention was conducted with a single-station method in November 2018. Fine-scale temporal measurements collected from a suite of in-situ sensors placed in the stream revealed significant daily trends. Generalized linear models were used to determine the relative roles of physicochemical characteristics and stream metabolism on daily changes in nitrate retention. Average declines in nitrate concentrations from night to day (-0.03 mg/L) corresponded with elevated average rates of gross primary production (0.02 mg O2 m-2 s-1). Rates of GPP may reflect discharge influences on sediment stability, given fine-grained bed materials introduced by past land use. Further research is needed to address how reduced sediment stability and metabolism may change nitrate retention at a whole-system scale over multiple seasons in Miller Creek.
H. Maurice Valett (Co-Presenter/Co-Author), University of Montana, Division of Biological Sciences, firstname.lastname@example.org;
Kim Bray (Primary Presenter/Author), University of Montana, email@example.com;