Wayfinding: Young Geographers Unearth Clue to Climate Change in the Andes
It was a once-in-a-lifetime opportunity for three undergraduate geographers at the University of North Carolina-Chapel Hill. In 2019, Chloe Schneider, Maribel Herrera, and Megan Raisle traveled to Ecuador with Professor Diego Riveros-Iregui and a diverse team of students, mostly undergrads. Their query: what is causing elevated CO2 emissions in the high mountains of the Andes?
Supported by funds from the National Science Foundation’s International Research Experience for Undergraduates, Schneider, Herrera, and Raisle went on to publish their findings in the Journal of Geophysical Research: Biogeosciences. Their key finding was that CO2 sheds more rapidly from streams at altitudes above 4,000m in the Andes Mountains than from waterways at lower elevation in the Amazon Basin. Emissions from high elevation streams are also greater than in the soils nearby.
This is a breakthrough finding, since for thousands of years, high-altitude ecosystems have been important accumulation sites for organic carbon. According to Jun Liang, Ph.D. of UNC-Chapel Hill, “Mountain streams are a critical part of the global carbon cycle, because they connect terrestrial and aquatic environments and have a higher proportion of stream water in direct contact with surrounding soils.”
Schneider, Herrera, and Raisle focused on the high‐altitude tropical grasslands, known as páramos, that are characterized by “high solar radiation, high precipitation, and low temperature. Páramos exhibit some of the world’s highest ecosystem carbon stocks per unit area. They may also be one source of CO2 releases to the atmosphere due to climate change. Little else has been known about the specific sources of CO2 from these areas. The trio of young researchers set about finding out more.
Among other findings, a 4‐m waterfall along the channel accounted for up to 35 percent of the total release of CO2 along a 250‐m length of stream. All in all, the students found, “[our] findings represent a first step in understanding ecosystem carbon cycling at the interface of terrestrial and aquatic ecosystems in high‐altitude, tropical, headwater catchments.”
“They had the perfect collective traits that you look for in student researchers — attention to detail, perseverance and curiosity — and they complemented each other really well,” said Professor Riveros-Iregui, Bowman.
“I’m so proud of us,” said Herrera, who is majoring in geography and environmental studies. “We all put in so much work and had our own struggles in the field, but it paid off. I came through this experience being much more confident in my own resilience.”
Adapted from Jun Liang’s 8-10-20 article for UNC-Chapel Hill Department of Geography and Schneider et al article. For a film showing the students onsite, follow this link.