UV-induced N2O emission from plants

• Published in: Atmospheric environment (1994) Vol. 99; pp. 206 - 214
• Main Authors: Bruhn, Dan, Albert, Kristian R., Mikkelsen, Teis N., Ambus, Per
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2014; Elsevier
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Climatology. Bioclimatology. Climate change; Earth, ocean, space; Epicuticular wax; Exact sciences and technology; External geophysics; Fundamental and applied biological sciences. Psychology; Greenhouse gas; Meteorology; Nitrous oxide; Plant; Synecology; Terrestrial ecosystems; Ultra violet radiation; Vegetation; Plant; Nitrous oxide; Epicuticular wax; Greenhouse gas; Vegetation; Ultra violet radiation; Terrestrial environment; Photosynthetically active radiation; UVA radiation; UVB radiation; Interspecific comparison; Nitrogen compounds; Environmental factor; solar radiation; Plant leaf; greenhouse gas; Air biosphere interaction; ecosystems; irradiance; Emission measure; Nitrogen protoxide
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2014.09.077

Nitrous oxide (N2O) is an important long-lived greenhouse gas and precursor of stratospheric ozone-depleting mono-nitrogen oxides. The atmospheric concentration of N2O is persistently increasing; however, large uncertainties are associated with the distinct source strengths. Here we investigate for the first time N2O emission from terrestrial vegetation in response to natural solar ultra violet radiation. We conducted field site measurements to investigate N2O atmosphere exchange from grass vegetation exposed to solar irradiance with and without UV-screening. Further laboratory tests were conducted with a range of species to study the controls and possible loci of UV-induced N2O emission from plants. Plants released N2O in response to natural sunlight at rates of c. 20–50 nmol m−2h−1, mostly due to the UV component. The emission response to UV-A is of the same magnitude as that to UV-B. Therefore, UV-A is more important than UV-B given the natural UV-spectrum at Earth's surface. Plants also emitted N2O in darkness, although at reduced rates. The emission rate is temperature dependent with a rather high activation energy indicative for an abiotic process. The prevailing zone for the N2O formation appears to be at the very surface of leaves. However, only c. 26% of the UV-induced N2O appears to originate from plant-N. Further, the process is dependent on atmospheric oxygen concentration. Our work demonstrates that ecosystem emission of the important greenhouse gas, N2O, may be up to c. 30% higher than hitherto assumed. •Plants released N2O in natural sunlight, mostly due to UV.•The emission rate is temperature dependent.•The N2O formation appears to be at the surface of leaves.•Ecosystem emission of N2O may be up to c. 30% higher than hitherto assumed.