Another unexpected finding on the Puca Glacier was how microbes stabilized the soil and prevented erosion on the slope by using their filament-like structure to weave soil particles together in a matrix, Schmidt said. The CU-Boulder researchers also found the microbes excrete a glue-like sugar compound to further bond soil particles.
In addition, they discovered that nitrogen fixation rates -- the process in which nitrogen gas is converted by bacteria into compounds in the soil like ammonia and nitrate -- increased by about 100-fold in the first five years. "Overall, our results indicate that photosynthetic and nitrogen-fixing bacteria play important roles in acquiring nutrients and facilitating ecological succession in soils near some of the highest-elevation receding glaciers on Earth," wrote the team in Proceedings of the Royal Academy.
Global climate change has accelerated the pace of glacial retreat in high latitude and high-elevation environments, exposing lands that have been devoid of vegetation for centuries or millennia, said Schmidt. He likened the high Andes to the harsh Dry Valleys of Antarctica, under study by researchers from NASA's Astrobiology Institute because of hostile conditions believed to be similar to those on portions of Mars.
"This kind of research should help us understand how the cold regions of Earth function, and how the biosphere will respond to future climate change," said Schmidt. The research also could lead to the discovery of new antibiotics, as well as industrial enzymes
|Contact: Steve Schmidt|
University of Colorado at Boulder