CSU geomorphologist awarded Fulbright grant to study afforestation and bank cohesion along rivers in Iceland

Sara Rathburn (left), Þorsteinn Sæmundsson (middle) and Greta Wells at the volcano in Geldingadalir. Photo: Sara Rathburn

Beginning in the ninth century, the once lush and thick forests across Iceland were cleared by Vikings, settlers, and livestock. In just 150 years, nearly all the trees in Iceland were removed. Since the 1940s, the Icelandic Forest Service and Soil Conservation Service has been replanting trees to help limit widespread soil erosion across the country.

In 2020, Sara Rathburn, a professor in the Department of Geosciences at Colorado State University, was awarded a U.S Fulbright Scholar grant  to study the relationship between afforestation and  bank stability along rivers in Iceland.  Due to the COVID-19 pandemic, Rathburn’s travels to Iceland were postponed until March of 2021. Rathburn was hosted by the University of Iceland and conducted field research from March through July of this year.

“Iceland is a geologist’s dream, ” Rathburn said. “I visited the erupting volcano four times, an amazing benefit of my delayed Fulbright.”  My Fulbright research explores how putting vegetation back influences channel stability, and the role of river expansion and extension in  landscape erosion in Iceland.

Without vegetation in and around watersheds, rivers are incredibly mobile and can lead to increased meander migration, soil erosion and degraded aquatic and riparian habitat. Rathburn’s research explores the characteristics of roots of these newly-planted trees to determine what afforested species contribute the greatest bank cohesion.

“No one in Iceland is investigating the effects of afforestation on channel stability so the results will be unique,interesting, and useful” Rathburn said. “Another important factor for afforestation efforts moving forward is how Icelanders think about rivers and that promoting healthy riparian corridors will help create a river ethic for these communities.”

In Reykjavík, Rathburn worked with Þorsteinn Sæmundsson at the University of Iceland and the Director of the Icelandic Forest Service, Þröstur Eysteinsson. Rathburn’s research on vegetation-channel interactions is highly interdisciplinary and has geologists talking to ecologists and botanists, which is a new direction of geomorphological research in Iceland.

Rathburn said the experience abroad gave her the special opportunity to learn about the Icelandic culture, including its traditions and myths.

“I could not have completed my research without understanding some of the history, culture and myths associated with the landscapes in Iceland,” Rathburn said. “Learning about the early settlers and how they dealt with various types of natural disasters and my interactions with current Icelanders gives me insight into their perspectives on landscapes in the context of a rich cultural history.”

Rathburn said she is careful to not appear as an outsider with all the answers but instead takes the time to learn and appreciate the stories associated with the people and their rivers. With this mindset, she believes her work will be respected and fill knowledge gaps in understanding the mechanisms of added cohesion of afforested vegetation. Her results will also be useful for management decisions regarding continued afforestation of rivers in Iceland.