Lake State biologist, class collaborate to answer global change questions
SAULT STE. MARIE — Sampling of Eastern Upper Peninsula rivers by Lake Superior State University professor Ashley Moerke and her limnology students has helped set a standard on how climatic factors affect river ecosystems.
The ﬁndings are published in the latest issue of the journal Science Advances.
The study, which involved the work of 153 ecological researchers from 40 countries, found that climatic factors — such as temperature and moisture — influenced carbon-cycling rates of river ecosystems. Carbon-cycling, or rather the cycle that carbon takes through the Earth’s river and streams, is a critical function of ecological systems across the world touching everything from food webs to global climate.
“River ecosystems play significant roles in the global carbon cycle by regulating rates of decomposition and transporting organic matter to the oceans, but we have only a rudimentary understanding of how decomposition rates vary from river to river,” said Scott Tiegs, a biology professor at Oakland University in Michigan, who led the study.
Unlike most previous studies on carbon-cycling in streams and rivers, the methodology in this study was identical across all field sites. The study made use of standardized, easy-to-use field sampling kits that enabled a large number of researchers to participate in the study.
“As a result, we were able to quantify decomposition rates in over 500 rivers across the globe, including every continent,” Tiegs said.
Moerke incorporated the field sampling kits into her undergraduate limnology class so students could contribute to this important large-scale study.
“Not only did this research provide critical information on global differences in carbon cycling, but it also engaged LSSU undergraduates in real-world research that illustrates how rivers function,” said Moerke.
“Carbon-cycling is the conversion of organic matter from form one to another. Leaves that fall into streams are converted into carbon,” Tiegs said in an interview with the Oakland Press. “This process of decomposition is necessary to maintain the productivity of ecosystems. If this stopped, our forests would stop growing. It’s basically the recycling of energy.”
The paper notes that climatic factors that govern decomposition rates are increasingly impacted by human activities. These findings will help researchers establish baselines to quantify environmental impacts to the functioning of ecosystems on a global scale.
In addition to providing fundamental information on how river ecosystems function, our results provide baseline data that will enable future researchers to evaluate large-scale ecological responses to warming and other dimensions of global climate change,” said Tiegs.
The research was sponsored by the Ecuadorian Science Foundation. To view the article, “Global Patterns and Drivers of Ecosystem Functioning in Rivers and Riparian Zones.”
When she is not teaching students in the field, classroom or laboratory, Dr. Ashley Moerke is director of LSSU’s Center for Freshwater Research and Education – CFRE — slated for completion by summer 2020.
CFRE is actually two undertakings in one. LSSU’s existing Atlantic salmon hatchery will remain open, while just to the east, a new two-story building will be built in what is now the city of Sault Ste. Marie’s Alford Park.
The new 20,000 square-foot building — named for project benefactors Richard and Theresa Barch — will anchor community, educational, and research activities. This includes a public Great Lakes Visitor Center that will be free and open to the public with interactive displays to highlight Great Lakes issues and LSSU research.