Cooperative Fish and Wildlife Research Units Program: Minnesota
Education, Research and Technical Assistance for Managing Our Natural Resources

Large wood performs many important ecosystem functions in streams, including diversifying instream flow environments (e.g., plunge pools, and backwater habitat), creating overhead cover for fish, and providing a stable substrate for invertebrates and periphyton. Few instream studies of large wood dynamics have been completed in the Midwest, rather the majority of studies have been from mountainous areas with steeper gradients and narrower floodplains. We will use individual logs to investigate instream wood dynamics in streams flowing through second-growth forest to improve our understanding of instream wood processes in the Midwest. We will relate mobilization and retention of individual pieces to geomorphic conditions and piece characteristics. We hypothesize that shorter, smaller, and more buoyant pieces will be mobilized more readily than large dense pieces, and that channels that are steeper, wider, and more entrenched will retain less wood than narrow, shallow, nonentrenched channels. Information gained from this study will be broadly disseminated and used to improve riparian management policies, wood removal regulations, and stream restoration practices.