Moving Bedforms Control CO ₂ Production and Distribution in Sandy River Sediments

Streams and rivers play an important role in the global carbon cycle. The origins of CO2 streams are often poorly constrained or neglected, which is especially true for originating from heterotrophic metabolism streambeds. We hypothesized that sediment movement will have a direct effect on stream metabolism, thus, aim this study was to quantify moving bedforms production sandy conducted flume experiments where we used planar optodes measure distributions O2 under various streambed celerities. combined these measurements with assessment bed morphodynamics modeling calculate consumption rates. Our results indicate transport can strongly influence production. found bedform celerity controls shape hyporheic zone exchange flux, directly linked spatial temporal CO2. It also most pronounced change occurred when changed stationary conditions slowly bed. A more gradual increase rates observed further celerity. points out causes hydraulic isolation between non-moving fraction lead transient storage deeper sediments, may be released bursts during scour.