Abstract
Riparian forests are known as hot spots of N cycling in landscapes and climate warming speeds up the cycle. Here we present results from the first multi-annual high temporal-frequency study of soil, stem and ecosystem (eddy covariance) fluxes of N2O from a typical riparian forest in Europe.
Hot moments (extreme events of N2O emission) last a quarter of the study period but contribute more than a half of soil fluxes. For the first time we demonstrate that high soil emissions of N2O do not reach the ecosystem level. During the drought onset, soil N2O emission peaks at intermediate soil water content. Rapid water content change is the main determinant of the emissions. The freeze–thaw period is another hot moment. However, according to the eddy covariance measurements the riparian forest is a modest source of N2O. We propose photochemical reactions and dissolution in canopy-space water as consumption mechanisms.
Hot moments (extreme events of N2O emission) last a quarter of the study period but contribute more than a half of soil fluxes. For the first time we demonstrate that high soil emissions of N2O do not reach the ecosystem level. During the drought onset, soil N2O emission peaks at intermediate soil water content. Rapid water content change is the main determinant of the emissions. The freeze–thaw period is another hot moment. However, according to the eddy covariance measurements the riparian forest is a modest source of N2O. We propose photochemical reactions and dissolution in canopy-space water as consumption mechanisms.
Original language | English |
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Publisher | Research Square |
Number of pages | 33 |
DOIs | |
Publication status | Published - 7 Oct 2020 |
Bibliographical note
This study was supported by the Ministry of Education and Science of Estonia (SF0180127s08 grant), the Estonian Research Council (IUT2-16, PRG-352, and MOBERC20), the Czech Science Foundation (17-18112Y) and project SustES - Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797), the EU through the European Regional Development Fund (Centres of Excellence ENVIRON, grant number TK-107, EcolChange, grant number TK-131, and the MOBTP101 returning researcher grant by the Mobilitas Pluss programme) and the European Social Fund (Doctoral School of Earth Sciences and Ecology). This work was also supported by Academy of Finland (294088, 288494), and from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme under grant agreement No [757695]. We would like to thank Marek Jakubík for his technical supportKeywords
- automated chambers
- eddy covariance
- grey alder
- QCLAS
- soil ux
- stem ux