The Ecology and Management of Wood in World Rivers

Dynamics of Wood in Rivers in the Context of Ecological Disturbance

Futoshi Nakamura and Frederick J. Swanson


Abstract.—Disturbance relevant to dynamics of wood in rivers can take many forms. We consider effects of ecosystem disturbance related to wood in river systems in geographic settings, which include high-gradient, boulder-dominated streams, braided, gravel-bed streams, and low-gradient, sand-bed streams. Disturbances of forests affect delivery of wood to streams and rivers directly by causing wood input or wood removal and indirectly by limiting source material. Disturbance of the fluvial system, either the channel form or flow regime, alters the transport and standing crop of wood. Change in wood distribution by processes of deposition, transport, and removal can disturb riparian, benthic (streambed), hyporheic, and water-column habitat. Human actions, such as harvesting trees, building roads, and regulating water flow, can substantially alter the types, frequencies, spatial patterns, and severity of the natural disturbance regime. We summarize the current status of knowledge on these points and identify knowledge gaps in studies of wood in rivers within the context of ecological disturbance. Finally, we offer a framework for future work and management that integrates processes that shape the spatial and temporal dynamics of wood at a series of scales.