The ebb and flow of the Bitterroot River took center stage at the Ravalli County Museum during a “Science Thursday” presentation.
Sharon Bywater-Reyes, a graduate research assistant in the University of Montana’s Geosciences Department, presented “Active Channel Zones” and discussed the relationship between vegetation and the river’s flow.
Science Thursdays are part of the “Summer of Science and Nano: The Science of Small” at the museum, sponsored by spectrUM and the Jane S. Heman Foundation.
Bywater-Reyes’ presentation gave a summation of her findings while conducting research on the Bitterroot River at the MPG Ranch just north of Florence.
“We know that the rock record changes with the evolution of land plants, and if you ask a geologist why, they don’t really know,” geologist Bywater-Reyes said. “Now I know it’s because of bank cohesion from vegetation.”
In summary, part of Bywater-Reyes’ research was designed to determine the best conditions for vegetation to grow on a sandbar in the river.
“Vegetation does actually steer stream flow,” she said.
The conditions that attribute to uprooting vegetation in a flood were swift-flowing water and the movement of sand away from the seedlings (water velocity and scours).
To determine when seedlings uproot, consider water velocity – the force within a channel – and the topography under the water’s surface.
The window of opportunity for plant growth in the Bitterroot River is just a few months.
Cottonwoods and sandbar willows have to grow their roots quickly to be deep enough before drought conditions compromise their ability to survive.
The practical use of Bywater-Reyes’ study is for planting: to be able to predict sites on a sandbar that are safe for seedlings, and to know the best place and time to plant. She said that different arrangements of plants may also make a difference, although further study is needed.
“Initially, I got into studying rivers and vegetation as a way to avoid working for an oil company,” Bywater-Reyes said. “On a personal level, I’m a vegetarian. I do that to reduce my environmental impact.”
Bywater-Reyes’ complete presentation was recorded. Contact the museum for more information.
The next Science Thursday lecture will be July 23, at 6 p.m., and will give an overview of promising medical applications and potential hazards of engineered nanomaterials – especially in inhalation. Kevin Trout and Forrest Jessop, from the Center for Environmental Health Sciences, will discuss current toxicology research in nanomaterial safety and lung disease.
Every Saturday, 10 a.m. – noon, the Summer of Science – Science Saturdays continues for youth at the Ravalli County Museum and Historical Society: July 18 – Science of Spin. Experiment with tops and gyroscopic motion and invent/design a top to take home; July 25 – Sound and how your ears hear different sounds like compression waves. Create a symphony of sounds by creating unique instruments that buzz and hum; Aug. 1 – Circuitry. Electronic circuit kits will be available to help create a circuit with light, complete a switch and see what it is like to be an electrical engineer. Play a banana piano and a variety of sensors.
The Ravalli County Museum and Historical Society is at 205 Bedford Street, Hamilton.