Abstract: Session B 9:20 am (Back to Session B)
Biological Drivers: Restoring the Biological Processes that Maintain Stage 0 in Rocky Mountain Headwaters Streams
Authors: Jessica Doran and Mark Beardsley
Anastomosing multi-channel streams dominated unconfined alluvial valleys in the Rocky Mountains for most of the Holocene, and the current preponderance of incised single-thread channels in these environments is a consequence of human activity in the Anthropocene (Polvi and Wohl 2012, 2013; Kramer et. al. 2010, Laurel and Wohl 2018). The native anastomosing stream type is characterized by geomorphic and ecological dynamicity; extreme habitat complexity; sediment, carbon, nutrient, and water retention; tight floodplain connectivity; aquifer recharge; flood peak dampening; and resilience to natural and artificial disturbance such as flood, drought, and fire.
The conversion of anastomosing streams to a single-thread channels, a shift from Stage 0 to Stage 1 in the stream evolution model (Cluer and Thorne 2013) is caused by disruption of the natural self-sustaining biophysical feedback loops involving beaver dams, beavers, and willows (Laurel and Wohl 2018). This talk introduces a practical approach for converting these streams back to their native form and function by restoring these keystone biological drivers. We discuss how mountain meadow streams are assessed, prioritized, restored, adaptively managed, and monitored using examples from Colorado and Montana.