Large Wood Distribution and Influence on Channel Morphology in Headwater Valleys of the Ozark Highlands

Keywords: large wood, Ozark Highlands, headwater streams, fluvial geomorphology, channel morphology
Abstract Type: Poster Abstract

Abstract

The role of large wood in fluvial environments is well documented with effects ranging from increased biodiversity to controlling channel morphology. However, few studies of large wood occurrence and geomorphic impacts have been completed within the Ozark Highlands. This study investigates large wood loads in two small headwater tributaries (2.5 km2) draining the Mark Twain National Forest in the Ozark Highlands, Missouri. The objectives of this study are to explore the distribution of large wood across different valley floor landforms and compare wood loads between the two watersheds based on differences in channel network, valley characteristics, and land management practices. Large wood loads were tabulated at 9 – 12 reaches in each watershed in August 2022. Large wood distribution across channel, bench, floodplain, and terrace features were quantified and their effect on channel morphology was examined. Additionally, large wood and standing tree basal area were compared between the two watersheds as one of the watersheds is managed through prescribed burning and the other is not. This study quantifies large wood loads in ephemeral karst streams within forested watersheds and contributes to our understanding of how large wood effects channel morphology.