Wednesday, March 6, 2013
Ancient Landslides Shape Oregon's Coho Habitat
A new study published in the journal Geology documents the impact of large, ancient, deep-seated landslides in forming productive coho habitats in the Oregon Coast range. The paper, published by a group of researchers at the University of Oregon found that wide, low gradient areas of river valleys associated with large, ancient landslides produced hotspots for coho habitat in the Elk Creek drainage, a tributary of the Umpqua River. While we have long understood that coho thrive in low gradient areas with large intact floodplains, the importance of ancient geologic events in the formation of these habitats reminds us that many of the processes that create and sustain healthy salmon habitat are driven by the local geological history. Indeed, one might consider geology the canvas upon which ecological communities and fish populations are drawn.
Further north, in areas with a recent glacial history, the processes that have formed valleys and the factors which contribute to the formation of high quality coho habitat are likely to differ. However the fundamental message remains the same, rivers are defined by their geology.
More information in a press release from the University of Oregon: