Dynamics of Large Wood in Urban Streams

Keywords: Large wood, fluvial geomorphology, riparian vegetation
Session Type: Virtual Paper Abstract
Day: Saturday
Session Start / End Time: 2/26/2022 05:20 PM (Eastern Time (US & Canada)) - 2/26/2022 06:40 PM (Eastern Time (US & Canada))
Room: Virtual 52

Abstract

Large wood (LW) has important physical and ecological functions, such as reinforcing streambanks and retaining organic material. Historically, riparian vegetation, which is a significant source of LW in streams, was extensively removed during urban expansion. A pilot study was conducted in Audubon Natural Area (semi-natural site), Lake Daniel Park (revegetated riparian vegetation), and Latham Park (very little riparian vegetation) of North Buffalo Creek located in Greensboro, North Carolina. The diameter, length, channel orientation, pool formation, and sediment storage function of LW were recorded in multiple 100-meter segments at each site. The results showed that the Audubon Natural Area had the highest frequency of wood pieces compared to the two other sites (χ2 = 8.55, df = 2, p = 0.01). The volumes of individual pieces at the three different sites were compared using the Kruskal-Wallis rank sum test and no significant difference was found (χ2= 1.41, df = 2, p value = 0.49). However, both the differences in length and diameter of individual pieces were close to the threshold (χ2 = 5.27, df = 2, p = 0.07 and χ2 = 5.3667, df = 2, p = 0.068, respectively), suggesting that the increase in riparian vegetation increases the frequency of wood loads, and each individual piece’s diameter and length are also bigger, not the volume. However, further research is required to establish the relationship between riparian buffer and wood load frequency and dimensions.