Organic Carbon Concentrations in Hyporheic Zone Sediments: A Tool for Measuring Stream Integrity

John M. Stofleth, F. Douglas Shields, Jr., Garey A. Fox
2004 Critical Transitions in Water and Environmental Resources Management   unpublished
Effects of channel incision on sand-bed stream carbon reservoirs were examined. Channel incision may deplete hyporheic zone C stores due to bed erosion, less frequent hydrologic exchanges between stream and floodplain, and paucity of riparian vegetation and large woody debris. Presented are organic C concentrations found in hyporheic sediments before and after an incised stream rehabilitation project and in three adjacent streams in northern Mississippi. The sampled streams comprise a spectrum
more » ... omprise a spectrum of physical conditions corresponding to the conceptual channel evolution model (CEM). Carbon concentrations in the upper 10 cm of the bed ranged from 0.24 + 0.36% for a nonincised reference site to only 0.01 + 0.02% for aggradational incised channels. Carbon concentrations generally declined with increase in stage of the CEM, increased with increasing percent canopy over the study reach and were not directly related to large woody debris (LWD) density. These findings suggest factors linking ecological degradation to channel incision and prospective pathways for stream rehabilitation design.
doi:10.1061/40737(2004)416 fatcat:6qbkpaevinh23jp7bm5izwhqiq