Impact of climate change on soil nitric oxide and nitrous oxide emissions from typical land uses in Scotland

• Published in: Environmental research letters Vol. 16; no. 5; pp. 55035 - 55044
• Main Authors: Medinets, S, White, S, Cowan, N, Drewer, J, Dick, J, Jones, M, Andrews, C, Harvey, D, Skiba, U
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01-05-2021
• Subjects: Air quality; Ammonia; Anthropogenic factors; atmospheric N deposition; Climate change; Climatic conditions; Deposition; Drought; Ecosystem management; Emission analysis; Emissions; Environmental impact; Global warming; Grasslands; Human influences; Land use; Lowlands; Moorland; N2O; Nitric oxide; Nitrogen oxides; Nitrous oxide; Rainfall; Soils; United Kingdom > UK; Scotland
• ISSN: 1748-9326; 1748-9326
• DOI: 10.1088/1748-9326/abf06e

Abstract
Soil emissions of NO and N
2
O from typical land uses across Lowland and Highland Scotland were simulated under climate change conditions, during a short-term laboratory study. All locations investigated were significant sources of N
2
O (range: 157–277
µ
g N
2
O–N m
−2
h
−1
) and low-to-moderate sources of NO emissions (range: 0.4–30.5
µ
g NO–N m
−2
h
−1
), with a general tendency to decrease with altitude and increase with fertiliser and atmospheric N inputs. Simulated climate warming and extreme events (drought, intensive rainfall) increased soil NO pulses and N
2
O emissions from both natural and managed ecosystems in the following order: natural Highlands < natural Lowlands < grazed grasslands < natural moorland receiving high NH
3
deposition rates. Largest NO emission rates were observed from natural moorlands exposed to high NH
3
deposition rates. Although soil NO emissions were much smaller (6–660 times) than those of N
2
O, their impact on air quality is likely to increase as combustion sources of NO
x
are declining as a result of successful mitigation. This study provides evidence of high N emission rates from natural ecosystems and calls for urgent action to improve existing national and intergovernmental inventories for NO and N
2
O, which at present do not fully account for emissions from natural soils receiving no direct anthropogenic N inputs.