image: Ülo Mander, Professor of Physical Geography and Landscape Ecology at the University of Tartu view more
Credit: Author of the photos: Andres Tennus (University of Tartu)
Ülo Mander, Professor of Physical Geography and Landscape Ecology at the University of Tartu, received the Advanced Grant from the European Research Council to study the cycle of nitrous oxide (N2O), commonly known as the laughing gas, in fens and peatlands, its links to global climate change, and possible land-use practices that could help curb the production of this greenhouse gas in the future.
Laughing gas is one of the most dangerous greenhouse gases produced by microbial life in the soils of agricultural areas and drained peatlands. Reaching the stratosphere, it destroys the ozone layer that protects the Earth from UV radiation. It is estimated to account for 6% of the greenhouse gas impact on climate. However, this share is increasing due to changes in land use and the effects of the increasing use of fertilisers in agriculture. It is, therefore, a crucial factor in the element cycle in nature, having a long-term impact on the planet and humanity, but much is still unknown about its formation, cycle and processes of impact.
Ülo Mander and his research team at the Institute of Ecology and Earth Sciences have, for many years, studied the formation and binding of the laughing gas in the fens and drained peatlands of Estonia and the world. Their work has yielded valuable background knowledge to rely on when moving forward with this topic. The recently funded five-year research project will look into the cycle of laughing gas in three tropical wetland areas that, based on monitoring data, are N2O emissions hotspots: the northern part of Borneo Island in Malaysia, the Amazon lowlands in Peru and the world’s largest tropical wetland area in the Congo Basin, where the nitrogen cycle has not yet been studied in detail by scientists.
“There was a massive drainage of wetlands in Borneo a few decades ago to create oil palm plantations. As palm trees grow on peatland, which in turn is fertilised with nitrogen fertilisers, the world’s highest laughing gas emissions are currently measured there. In the research area in Peru, we have previously investigated the processes in natural palm swamps and areas of self-forested former agricultural land. It is an area where rapid forest growth helps to offset N2O emissions and gives hope that recovery is possible,” Mander explained the choice of sites for the project. As peatlands cover 3–4% of the land surface but store a third of all the carbon and nearly a fifth of all the nitrogen on Earth, they are critical ecosystems on the global scale.
In addition to measuring the N2O emissions from peat soils, the researchers are also interested in the role that tree trunks and crowns of peatland forests play in the cycle of the gas. The measurement devices in Borneo and Peru will be placed above tree crowns to study it. “We want to investigate what is happening in the tropical trees’ foliage that is rich in various algae, mosses, lichens and microbes and can capture some of the gases from the air and produce certain greenhouse gases to the atmosphere,” said Mander.
Incorporating the obtained data into existing N2O cycle models will also enable the researchers to assess the effects of climate change on the nitrogen cycle, predict emission peaks, propose improvements to the data underlying the International Panel on Climate Change (IPCC) reports, and adjust land-use strategies and future scenarios based on them. According to Mander, these strategies have so far been based primarily on the climate impacts of human-induced land use, but climate change has also had a significant effect on the cycles in natural ecosystems. The data on N2O emissions to be collected in the project led by Mander will be a valuable contribution to filling this gap.
The Advanced Grant received from the European Research Council is nearly €3.5 million. The grant is intended for leading top scientists who have achieved outstanding research results over the last ten years. The grant proposal was prepared with the help of the grant writing team of the University of Tartu’s Grant Office.