128-9 Evaluating River Corridor Geomorphic Response to Large Wood Augmentation in the Southern Appalachian Mountains

Session: Riverscapes in transition: Advances in fluvial geomorphology, sediment transport, deposition, river health, and urban rivers (Posters)

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Authors:

Abstract:

Large wood is a fundamental driver of channel complexity, sediment storage, and aquatic habitat in river systems. However, human activities have substantially altered natural wood regimes in many watersheds, reducing geomorphic complexity and disconnecting physical and ecological processes. Large wood restoration is increasingly used to enhance channel complexity and ecological function in degraded rivers, yet relatively few studies have quantified how logjam characteristics influence geomorphic adjustment over time. This gap is especially pronounced in Appalachia, where a legacy of deforestation and channel wood removal has constrained observations of wood dynamics in streams. Here, we assess the geomorphic response to wood augmentation in two tributary stream channels within the Citico Creek Watershed of the Cherokee National Forest in southeastern Tennessee. The Citico Creek Watershed is a highly diverse area that has experienced historic wood removal from timber harvests, degrading and disconnecting aquatic habitats, making it a priority for restoration. We examined two restored tributary streams within the Citico Creek watershed - the Little Citico Creek and Caney Branch - where large wood has been installed over the past several years. The streams differ in wood installation age, providing an opportunity to assess how both logjam characteristics and time since installation influence geomorphic response. We tested whether the older restoration site of the Little Citico exhibits greater geomorphic development than the recently augmented reach of Caney Branch. We quantified logjam geometry, porosity, blockage ratio, spatial distribution, and associated pool morphology to evaluate how logjam characteristics influence channel complexity and local geomorphic processes. Preliminary results suggest that the older restoration site has more variation in logjam characteristics and associated channel complexity than the recently restored stream, suggesting that geomorphic adjustment increases through time following wood augmentation. These results provide early evidence that logjam design and restoration age influence geomorphic adjustment following wood augmentation. Continued monitoring will improve understanding of restoration trajectories and inform process-based river restoration in mountain watersheds.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-20244

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