Estimating metabolic responses to carbon, nitrogen and phosphorous additions in different stream compartments.
Abstract
For over a decade, the resazurin "smart" tracer has been used to understand metabolic interactions between stream channels and their transient storage zones in the surface and shallow subsurface (<10 cm). Understanding processes occurring in these zones are critical to the health and functioning of stream ecosystems. We present an analysis of metabolic responses inferred from the transformation of resazurin after the addition of nitrogen, carbon and phosphorus (N, C and P) in the Boulder Creek Critical Zone Observatory (CZO), a snowmelt-driven catchment located in Front Range of the Rocky Mountains, Colorado. We performed constant-rate tracer experiments that included the co-injection of a conservative tracer (sodium chloride), resazurin, and combinations of N, C and P throughout snowmelt recession. We analyzed tracer breakthrough curves measured in the stream thalweg, side pools, and at multiple depths (2 to 10 cm) in the hyporheic zone to quantify transport and reactivity in all of these stream compartments. With these data, we compared transport and processing as a function of changing discharge and C, N, P concentrations in multiple stream compartments to develop a hierarchical classification of metabolic activity based on non-dimensional Damköhler numbers.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H13N1935D
- Keywords:
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- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0496 Water quality;
- BIOGEOSCIENCES;
- 1830 Groundwater/surface water interaction;
- HYDROLOGY;
- 1839 Hydrologic scaling;
- HYDROLOGY