Influence of Bank Afforestation and Snag Angle-of-fall on Riparian Large Woody Debris Recruitment

A riparian large woody debris (LWD) recruitment simulator (Coarse Woody Debris [CWD]) was used to test the impact of bank afforestation and snag fall direction on delivery trends. Combining all cumulative LWD recruitment across bank afforestation levels averaged 77.1 cubic meters per 100 meter reach (both banks forested) compared to 49.3 cubic meters per 100 meter reach (one side timbered). Both bank afforestation and snag fall patterns generated significant differences in riparian LWD delivery, but there was no noticeable interaction. Scenarios with only one bank forested delivered 15 to 50 percent less LWD than their two bank counterparts. Snag fall patterns also produced statistically different LWD recruitment, with some registering only 35 to 52 percent of the most productive fall patterns. These results suggest testing the assumptions of random snag fall from two forested banks before modeling riparian LWD recruitment.