Of wood and rivers: bridging the perception gap: Fid-Bau Portal

Of wood and rivers: bridging the perception gap

Wohl, Ellen

Wood and beaver dams were historically much more abundant along river corridors from the tropics to the boreal zone. An extensive scientific literature documents the physical and ecological functions created by instream and floodplain wood. By enhancing physical diversity, wood mediates fluxes of water, solutes, organic matter, and sediment; enhances habitat abundance and diversity; promotes retention and biogeochemical uptake of nutrients; and increases biodiversity. Perceptions of wood in rivers, however, remain largely negative and wood is seldom incorporated in river management and restoration plans outside of the U.S. Pacific Northwest. People are unused to seeing wood in river corridors as a result of a long history of deliberate wood removal from rivers, combined with altered land cover and river engineering that reduced quantities of wood in rivers. Negative perceptions of wood in rivers may also reflect hazards, including damage to infrastructure from mobile wood or wood accumulations at bridges that enhance flood damages. People are also unused to seeing beavers in river corridors because of a long history of beaver trapping and substantially reduced beaver populations throughout Eurasia and North America. Extensive and sustained removal of wood and beavers from river corridors has created substantial changes in the appearance and function of rivers. As river restoration increasingly emphasizes re-creation of processes rather than static forms, the river science community has an opportunity to increase public recognition of the vital role played by wood and beavers in sustaining physically and biologically diverse and resilient river ecosystems.