By Blake Jackson
Peatlands cover only 3% of the Earth’s land surface but store more than 30% of the world’s soil carbon, preserving organic matter and sequestering carbon for thousands of years. A new study warns that extreme drought events could dramatically accelerate carbon loss from peatlands in a warming climate.
Researchers found that under conditions simulating future climates with higher temperatures and elevated carbon dioxide severe droughts increased carbon release from peatlands by nearly three times.
This means that these ecosystems, typically valuable carbon sinks, could become carbon sources, potentially erasing 90 to 250 years of stored carbon in just months.
“As temperatures increase, drought events become more frequent and severe, making peatlands more vulnerable than before,” said Yiqi Luo, senior author and Liberty Hyde Bailey Professor in the School of Integrative Plant Science’s Soil and Crop Sciences Section, College of Agriculture and Life Sciences (CALS).
“We add new evidence to show that with peatlands, the stakes are high. We observed that these extreme drought events can wipe out hundreds of years of accumulated carbon, so this has a huge implication.”
While drought effects on reducing ecosystem productivity and increasing carbon release in peatlands are well-known, this study is the first to examine how warming and higher carbon dioxide exacerbate these impacts.
The Intergovernmental Panel on Climate Change estimates extreme drought will become 1.7 to 7.2 times more likely in the near future, underscoring the urgency of the findings.
Luo and his team, including postdoctoral researcher Quan Quan, conducted experiments at a boreal spruce bog in northern Minnesota using 10, 20-meter-wide chambers to control temperature and carbon dioxide levels.
They studied the 2021 extreme drought, finding that higher temperatures and elevated carbon dioxide slowed water table recovery, leading to greater carbon emissions.
“Previous studies indicated that elevated carbon dioxide can usually make extreme events less impactful, but our results indicate the opposite,” Luo said. Elevated carbon dioxide alone boosted productivity, but combined with a 9°C temperature rise, carbon emissions surged. Quan’s analysis showed that higher carbon dioxide increased dissolved carbon in the bog, which releases more carbon dioxide when exposed to oxygen during drought.
Since 2015, Luo’s team has integrated field data with models to better understand peatland responses to environmental changes, highlighting the critical role of peatlands in climate mitigation.
Photo Credit: gettyimages-karen-massier
Categories: New York, General, Weather