Can we estimate biogeochemical uptake rates in sediments from reach-scale data or vice versa?
Abstract
Hydrologists and stream ecologists want to understand how reactive transport processes from sub-meter to reach scales aggregate to determine nutrient and carbon export across watersheds. Mesocosm (sub-meter) scale experiments offer the advantage of being tractable and affordable but may be spatially and temporally irrelevant for describing watershed-scale processes. While reach scale experiments sample larger heterogeneities, they provide aggregated information that does not allow for easy detection of hot-spots and hot-moments, and might still be irrelevant for describing watershed processes if they are not conducted under varying flow conditions. We conducted mesocosm (column) and reach-scale experiments along a first-to-eight stream order continuum using nutrient and resazurin tracers to investigate how information collected at the sub-meter scale (mesocosom experiments) compares to that collected at the reach scale, and vice versa. Our work highlights the difficulty of finding useful patterns not only across stream orders (i.e., for the same type of experiment) but also across experiments. Our results offer quantitative perspective on why hydrologists and stream ecologists must depart from the status quo of conducting solute-specific (e.g., only N), site-specific (primarily headwaters) and single-season (mainly summer) experiments to understand controls on nutrient retention.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFM.H23D1717G
- 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