The foundation under our feet has a reputation for being an inhospitable place. In contrast, soil is known to be rich in life, from bacteria to plant roots to bugs.
From this point of view, soil has been established as the most potent source of carbon dioxide by forests: CO2: being a natural by-product of the life within it. But according to a study by the University of Texas at Osting, the prevailing view is simply scratching the surface.
The study found that CO2: It can also be produced in deeper underground fractures, which can be up to 29% of the average daily CO2: released from the soil depending on the season.
This finding does not mean that landscapes emit more CO2 into the atmosphere, but it does challenge the conventional wisdom of where CO2 is produced. It can also help improve climate change models, as understanding how carbon dioxide is produced is an important part of making accurate predictions.
The study linked CO2: Seasonal absorption of water with deep tree roots in the rock at a depth of many meters above the water surface, which shows that the roots of the tree, the bacteriological communities around them are a source of CO2, that the fractures of the foundations have flourished
“This is a paradigm shift in terms of where the action is,” said Daniela Rempe, an assistant professor at UT Jackson Geosciences School of Science who co-authored the study. “Land can be the only potential player in forests.”
The study was published in the December 6, 2020, issue of the journal JGR Biogeosciences:,
The study was led by Alison Tune, a graduate student at the Ison Exxon School. Other co-authors include Philip Bennett, a professor at the Acks Exxon School, Iaa Wang, a PhD student at the University of Illinois at Urbana-Champaign, and Jennifer Druhan, an Urban-Champagne Assistant at the University of Illinois at Urbana-Champaign, who was instrumental in designing and conducting the research. ,
The soil does not settle on a solid foundation. Instead, between these two extremes lies the transitional zone of the broken atmospheric base. This modified rock is known to be difficult to sample. The study was based on a special sampling tool buried on a hillside in Northern California that stretched from the top of a broken foundation to the floor, about 44 feet.
This tool quickly revealed that this region is an active CO site2: production
“There is a big CO2: “The source is under the ground,” said Tune. “It simply came to our notice then [CO2] We were quite excited by what we found in the concentration profiles in the sector. ”
Analyzing thousands of samples collected in 2017-2019, the researchers found that CO2: did not stay in place. During the dry season CO:2: First, it made its way to the ground where it was released into the atmosphere. During the wet season, when groundwater rose to fill fractures, almost 50% of CO2: dissolved in water, which eventually flows into streams and rivers.
The researchers found that it dissolved CO2: Due to the atmospheric weather of the rock, 80% of the carbon dissolved in the groundwater, coming from the study area, comes from the broken base. Rempe says the discovery is significant because it is the first time that scientists have been able to pinpoint the location of the ongoing rocky weather on the hillside.
This study is based on a growing body of knowledge that shows the broken ground as an ecologically viable region. For example, in a 2018 study, Rempen և and his colleagues found evidence of moisture in broken rock storage trees during droughts.
Mark Torres, an associate professor at Rice University who studies how carbon circulates in the environment, said the study was important because it sheds light on a part of the landscape that is considered a “black box” of soil and groundwater.
“During my work I usually collect river water, I have to conclude what is happening under the hill,” he said. “What’s impressive about the work is how they look at things that are incredibly difficult to see.”
Researchers plan to investigate the fractured cornerstone elsewhere, including the local research site of the Exxon School’s White House Outdoor Learning Center, a 266-acre site in Dexing Springs, Texas.
“Broken cornerstones are really common in Texas, where the soil is really thin, there are very deep roots,” Tune said. “It could be an important part of the carbon cycle in these ecosystems. It’s possible to understand that as we move forward, the climate changes over time.”
Reference. “Carbon Dioxide Production in Underground Stones Significantly Contributes to Forest Carbon Cycling” Alison K. Tun, enn enifer L. Druhan, ia ia Wang, Philip S. Bennett և Daniela M. Rempe, November 27, 2020 JGR Biogeosciences:,
DOI: 10.1029 / 2020JG005795:
The Department of Energy, the National Science Foundation, and the American Geological Survey supported the study.