OU professor studies how decreasing glacial cover affects mountain river ecosystems

Gabrielle Abdelmessih, Staff Reporter

Oakland University professor Dr. Scott Tiegs Ph.D. co-authored a study in the journal, “Nature Climate Change” published on March 15.

The study found that melting glaciers have an impact on carbon cycle processes and vital glacier-fed river ecosystem functions, which could further global warming.

Dr. Tiegs, a professor in OU’s Department of Biological Sciences, elaborated by saying, “One of the key findings is this idea that in a warming world, the activity of microbes is going to be enhanced because of higher temperatures. These microbes will degrade more organic matter, convert it to greenhouse gases, and that can further have a positive feedback loop on the global climate.”

The study was conducted on a global scale, with other researchers/co-authors from across the globe, led by the University of Leeds (United Kingdom). The study sites were regions located in Austria, Ecuador, France, New Zealand, Norway and the United States.

The Finse Alpine Research Centre (Norway), Obergurgl Alpine Research Centre (Austria), Design School at the University of Leeds, and the School of Life Sciences molecular ecology facilities at the University of Essex (United Kingdom) were the facilities used in the study.

“It took a couple of years to plan. These are colleagues that we’ve already had, so we had a pretty good working relationship with all these different people in different countries around the world,” Tiegs said.

Decomposition rates of organic matter were measured in mountain rivers spanning six countries on four continents, using a standardized organic-matter assay developed at Oakland University.

For approximately one month, the cotton strips were incubated in the rivers and later tested to determine the degree of decomposition. Organic matter incubated in warmer waters with less glacial flow decomposed more quickly.

Tiegs, who worked to develop the assay, highlighted its efficiency, portability, and global usage.

“It’s a standardized means of quantifying the ability of an ecosystem to process organic matter. Because it’s standardized, we can have decomposition rates that are directly comparable in whatever ecosystem we decide to deploy the assay in,” he said. “It’s quite portable. You can stick it in an envelope and ship it to anybody in the world in just a matter of days. It really lends itself to this sort of collaborative endeavor.”

As ecosystems change due to melting glaciers, this study will help researchers predict how global warming will impact these systems in the future.

“When we think of greenhouse gas emissions, we typically think of emissions that come from tailpipes, power plants, etc. But it’s important to keep in mind that natural ecosystems: lakes, forests, oceans, they release CO2 and other greenhouse gases as well,” Tiegs said.

Other co-authors of the research study include Sarah Fell, Lee Brown and Jonathan Carrivick at the University of Leeds — Kate Randall, Kirsty Matthews Nicholass and Alex Dumbrell at the University of Essex — Verónica Crespo-Pérez at Pontifical Catholic University of Ecuador—Sophie CauvyFraunié at INRAE, France — and Eran Hood at University of Alaska Southeast.

The study can be found here.