Damming the wood falls

Rivers historically transported unquantified volumes of driftwood to the ocean. Driftwood alters coastal sediment dynamics and provides food and habitat for diverse organisms. Floating driftwood supports open-ocean organisms. Sunken wood sustains seafloor communities. Centuries of deforestation, flow regulation, and channel engineering have substantially reduced riverine large wood fluxes to the oceans. Here, we use contemporary records of wood flux to reservoirs and coastal regions to estimate the magnitude of potential contemporary global wood fluxes. We estimate that 4.7 million m(3) of large wood could enter the oceans each year (the 95% prediction interval range is similar to 300,000 to 70 million m(3)). This represents an upper bound for contemporary wood fluxes to the oceans because of wood removal from rivers and reservoirs and a lower bound for historical wood fluxes because of deforestation and river engineering. Substantial reduction of this wood flux likely negatively affects coastal and marine environments.

Automated summary

In the past, rivers transported significant amounts of driftwood to the oceans, benefiting coastal and marine environments. However, with the increase in deforestation and river engineering, a large amount of driftwood is prevented from entering the oceans, negatively impacting coastal and marine ecosystems.