Biology professor studies global river ecology

One of Oakland University’s own was the leader of a recently published global study of river ecology in the journal, Science Advances.

In the study, Dr. Scott Tiegs, associate professor of biology at OU, observed and analyzed the decomposition of organic matter in rivers across 40 countries. This study took place on every continent, and in different ecosystems with help from 152 other researchers.

Mark Isken, associate professor of management information systems for the School of Business; Dave Szlag, associate professor of environmental science; and undergraduate student Diana Ethaiya also contributed to the study.

Rivers play key roles in our global carbon cycle and help regulate our climate,” Tiegs said. “One of the ways this is done is through the decomposition of organic matter as it is transported downstream.”

According to National Geographic, rivers are a crucial part of our water cycle and help transport groundwater and precipitation down to oceans where the water then evaporates, and create clouds to repeat the cycle. Although rivers are vital to societies, humans have only a basic knowledge of them.

“Despite the central importance of decomposition in rivers, we have only a rudimentary understanding of how their capacity to decompose organic matter varies from river to river,” Tiegs said.

Tiegs’ study aimed to gather information on how decomposition in rivers varies across the world in different ecosystems. The speed and severity of rivers decaying across the world can tell a lot about the environment.

“By having field sites distributed on each continent, we were able to understand how rivers function across Earth’s major climatic zones such as deserts and rainforests,” Tiegs said.

About 500 rivers were examined in the global study Tiegs led. The rivers studied are known as reference streams, or streams that are not heavily impacted by humans. The methods used in each site were standardized from river to river, which made this study unique and more useful than others that have been done previous to it.

“Some of my field sites were in Ecuador, one of my favorite places to do research,” Tiegs said. “It was a treat for me to get to take OU students there last month during a tropical field ecology class.”

In the future, Tiegs plans to use the same assessment used in this study, but on rivers that experience human activity in ways of agriculture and industrialization. This will allow for a comparison between rivers that are relatively untouched by humans and those that are impacted.

This will enable us to quantify how these two land uses impact the role of rivers in our global carbon cycle,” Tiegs said.

These findings will lead to discovering more on how humans have an impact on our ecosystems and our environment. Temperature and moisture, which were both evaluated by this study, are climatic variables that are increasingly impacted by humans.

The data collected in the study will allow researchers to know how these factors can affect the world in the long-run.

The full research article can be found on the Science Advances website.