Assessing the Influence of Large Wood on Channel Morphology in Coastal Plain Rivers

Large wood—pieces of wood at least 10 cm in diameter and 1 m in length—is a significant driver of physical and ecological processes in river systems. How large wood exerts control on a river depends greatly on that river's geomorphologic setting and changes as a river flows through varying types of terrain. This study examines large wood distribution and its effects on channel morphology in two higher-order, low-gradient rivers with fine-grained substrates, the Sipsey River, Alabama and the Lumber River, North Carolina. Using field-collected wood measurements and sonar-derived bathymetric data, multiple interpolation methods, weighted overlay analyses, and spatial correlation tests were conducted to assess how large wood interacts with deposition, transition, and erosion zones. Results indicate that large wood is primarily concentrated in transition zones, with less presence in deposition zones and minimal occurrence in erosion zones. Weak correlations between large wood characteristics and channel morphology suggest that other environmental factors, such as flood events and riparian conditions, may influence sediment transport processes more strongly in this context. These findings highlight the complexity of wood–river interactions and the need for further research to better understand these dynamics in different geomorphic settings, ultimately informing more effective river management and restoration strategies.<p></p>