A recent study done by the University of Eastern Finland and published in Atmospheric Chemistry and Physics found that isoprene and terpenes, a class of highly reactive organic chemicals that have a considerable impact on the Earth’s climate, are a significant source in boreal wetlands.
The study was conducted in collaboration between the University of Eastern Finland, the University of Helsinki, the Finnish Meteorological Institute, the Institute of Environmental Assessment and Water Research in Spain, and the University of California Irvine in the US.
The emission rates of isoprene and terpenes from boreal wetlands were examined using a mix of field observations and modeling. The majority of the area in the northern latitudes, from northern Europe to Siberia and Canada, is covered with boreal wetlands.
The research team discovered that these emissions are substantially higher than previously believed and that they have a particularly strong exponential temperature response, which suggests that boreal wetlands could be a key source of these compounds owing to global warming.
Our results suggest that boreal wetlands could have a significant impact on the Earth’s climate system, especially as temperatures continue to rise. It is important that we continue to study and monitor these emissions to better understand their impacts on a larger, global scale.
Professor Siegfried Schobesberger
“Our study shows that boreal wetlands are a large source of isoprene and terpenes, which contribute to the formation of secondary organic aerosol and ozone. The isoprene and terpene emissions from these wetlands have been understudied. We used an ecosystem-scale eddy covariance measurement technique to quantify the emissions from a boreal wetland during the unusually warm early summer of 2021,” says first author, Doctoral Researcher Lejish Vettikkat of the University of Eastern Finland.
The emission rates of isoprene and terpenes from boreal wetlands are dependent on temperature, solar radiation, and vegetation leaf area (i.e., wetland grasses and shrubs). Most strikingly, the measurements revealed a much stronger response of these emissions to unusually high temperatures (above 30 °C).
The fact that this response remained for some time after the incident also suggests that the plants, which are not accustomed to this high temperatures, were experiencing heat stress.
The scientists also discovered the emissions of a hitherto unknown type of bigger terpenes known as diterpenes, which could build aerosols particularly effectively and have a cooling effect on the Earth’s radiation balance.
“Our results suggest that boreal wetlands could have a significant impact on the Earth’s climate system, especially as temperatures continue to rise. It is important that we continue to study and monitor these emissions to better understand their impacts on a larger, global scale,” notes Associate Professor Siegfried Schobesberger of the University of Eastern Finland.
The researchers anticipate that their findings will contribute to the improvement of methods for calculating emissions from boreal wetlands and their effects on the climate. This work emphasizes the need for more investigation into the intricate linkages between these little-studied ecosystems and the climate system of the Earth.
