Pinus sylvestris as a missing source of nitrous oxide and methane in boreal forest

0458795 - ÚVGZ 2017 RIV GB eng J - Journal Article
Macháčová, Kateřina - Bäck, J. - Vanhatalo, A. - Halmeenmäki, E. - Kolari, P. - Mammarella, I. - Pumpanen, J. - Acosta, Manuel - Urban, Otmar - Pihlatie, M.
Pinus sylvestris as a missing source of nitrous oxide and methane in boreal forest.
Scientific Reports. Roč. 6, mar (2016), s. 23410. ISSN 2045-2322. E-ISSN 2045-2322
R&D Projects: GA MŠMT(CZ) LO1415; GA MŠMT EE2.3.20.0246
Research Infrastructure: CzeCOS II - 90061
Institutional support: RVO:67179843
Keywords : CH4 * N2O * greenhouse gas * emission * gas flux * tree emission * tree * stem * shoot * forest floor * Scots pine * soil moisture * ecosystem exchange
Subject RIV: EH - Ecology, Behaviour
Impact factor: 4.259, year: 2016

Boreal forests comprise 73% of the world’s coniferous forests. Based on forest floor measurements,they have been considered a significant natural sink of methane (CH4) and a natural source of nitrous oxide (N2O), both of which are important greenhouse gases. However, the role of trees, especially conifers, in ecosystem N2O and CH4 exchange is only poorly understood. We show for the first time that mature Scots pine (Pinus sylvestris L.) trees consistently emit N2O and CH4 from both stems and shoots. The shoot fluxes of N2O and CH4 exceeded the stem flux rates by 16 and 41 times, respectively. Moreover, higher stem N2O and CH4 fluxes were observed from wet than from dry areas of the forest. The N2O release from boreal pine forests may thus be underestimated and the uptake of CH4 may be overestimated when ecosystem flux calculations are based solely on forest floor measurements. The contribution of pine trees to the N2O and CH4 exchange of the boreal pine forest seems to increase considerably under high soil water content, thus highlighting the urgent need to include tree-emissions
in greenhouse gas emission inventories.
Permanent Link: http://hdl.handle.net/11104/0259027