Secret of missing source of nitrous oxide (N2O) and methane (CH4) in boreal forest


Scots pine trees as a missing source of nitrous oxide (N2O) and methane (CH4) in boreal forest have been revealed by an international research team led by Dr. Kateřina Macháčová (CzechGlobe) and published in Scientific Reports belonging to the Nature publishing group in March.


Both CH4 and N2O are important greenhouse gases contributing to global climate change. In addition to the well-known fluxes from soils, N2O and CH4 can be emitted also from different plant organs. However, these emissions are only poorly understood. For example, the N2O and CH4 fluxes from boreal trees have not been previously studied neither included into total gas exchange inventories, although the boreal forests comprise 73% of the world’s coniferous forests. The article shows for the first time that Scots pine, a typical representative of boreal forests, emits significant amounts of N2O and CH4 into the atmosphere. Moreover, these emissions increase with increasing soil water content. This can be crucial as the future climatic scenarios predict frequent extreme precipitation events in this climatic zone. The results clearly show that current inventories of N2O and CH4 emissions, which are mostly based on soil fluxes, are underestimated and an inclusion of tree emissions will lead to a substantial improvement of calculations of greenhouse gases net ecosystem exchange.

The article Machacova K, Bäck J, Vanhatalo A, Halmeenmäki E, Kolari P, Mammarella I, Pumpanen J, Acosta M, Urban O, Pihlatie M (2016) Pinus sylvestris as a missing source of nitrous oxide and methane in boreal forest. Scientific Reports, 6, 23410. DOI: 10.1038/srep23410 to download is here