N2O isotopic composition and soil microclimate for grassland monoliths subjected to an experimental drought

DOI

Publication abstract: Nitrous oxide is a powerful greenhouse gas whose atmospheric growth rate has increased rapidly over the past decade. Causes of N2O emission dynamics from terrestrial ecosystems and their responses to climate change remain poorly understood. Based on high-resolution isotopic measurements we found that microbial functional gene abundances and soil moisture were the main drivers of variability in baseline emissions and pathways. After fertilization and, surprisingly, under drought, denitrification dominated grassland N2O production and dynamics, contributing 70% of emissions. Drought responses of N2O emissions were supported by a clear reversible enrichment in nitrogen-bearing organic matter compared to oxygen on the surface of soil microaggregates. We observed hysteresis for both total N2O flux and denitrification contribution during rewetting, which were higher than control and drought for the same soil moisture range. These results illustrate that the magnitude of feedbacks between climate change and N2O emission pathways is sufficient to account for increases in atmospheric growth rate in the past decade. We expect these effects will be amplified in the coming decades as climatic extremes are expected to increase in severity.

Supplement to: Harris, Eliza (submitted): Denitrification dominates drought and post-drought dynamics of nitrous oxide emissions.

Identifier
DOI https://doi.org/10.1594/PANGAEA.907601
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.907601
Provenance
Creator Harris, Eliza ORCID logo
Publisher PANGAEA
Publication Year 2019
Rights Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International; https://creativecommons.org/licenses/by-nc-sa/4.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 3 datasets
Discipline Earth System Research
Spatial Coverage (11.291 LON, 47.126 LAT)
Temporal Coverage Begin 2018-05-22T14:00:00Z
Temporal Coverage End 2018-11-05T12:30:00Z