Spatial Analysis of Large Wood Storage in Coastal Plain Rivers of the Southeast <scp>US</scp>

ABSTRACT Large wood (LW) is widely recognized as a significant driver of geomorphic and ecological processes in river systems, but research on LW has been focused largely on low‐order streams in high‐gradient catchments. By comparison, there have been relatively few studies examining the channel‐scale distribution of LW in higher‐order, low‐gradient river systems, such as those in the Coastal Plain of the Southeast US. Here, a field survey of LW in three Coastal Plain rivers in Alabama and North Carolina was conducted. Total wood loads were calculated, LW characteristics were examined, and Ripley's K analysis was used to investigate the channel‐scale spatial distribution of LW in the study rivers for all pieces and for subsets based on stability and decay class. Results indicate that the range of LW loads in the study rivers (9.6–20.8 m 3 per 100‐m channel length) is generally in line with loads reported for other temperate forested sites. Over half of the surveyed LW pieces were oriented perpendicular to the channel, and substantial proportions (36%–44%) were pinned, favoring the formation of jams. Ripley's K analysis showed that, on two of the three study rivers, LW was significantly clustered at short distance intervals, with higher degrees of clustering for pinned pieces, indicating the concentration of these pieces in jams. Older LW pieces (as indicated by decay class) were generally more clustered than new ones, potentially indicating the role of transport in moving pieces with longer residence time to favorable deposition locations during mobilizing flows.