Human activities shape global patterns of decomposition rates in rivers

A study published in the journal Science uses a global experiment and predictive modeling to illustrate how human impacts to aquatic ecosystems are contributing to the global climate crisis.

The study estimates rates of organic-matter decomposition in freshwater ecosystems (a source of carbon emissions) across the world, including areas such as the tropics that have been underrepresented in prior studies.

ESS Professor, Jenn Follstad Shah, along with a team of researchers collected field data from sites around the world and used predictive modeling and machine-learning algorithms to fill in those gaps. The field study involved 550 rivers from around the globe. More than 150 researchers in 40 countries contributed samples using a standardized field assay based on the decomposition of small pieces of cotton fabric.

The study reported the highest decomposition rates among densely populated, agricultural areas, including parts of the United States, Europe and Southeast Asia. Agricultural and urban runoff, the authors point out, is a major contributor to the increase in carbon emissions responsible for climate change.

Read the full research article featured in the journal Science. Check out a Q&A with Dr. Jenn Shah featured in @theU, and an interview on KUER News' All Things Considered program.