Nitrous oxide emission and isotopic composition data from four dryland sites in Southern California

This data publication includes in-situ nitrous oxide and nitric oxide emissions measured in four dryland sites in Southern California between June 2019 and August 2020. Emissions were measured from eight locations within each site every 15 minutes after experimentally adding water and ¹⁵N labeled nitrate or ammonium to the soils. We report nitrous oxide and nitric oxide emissions from two of the sites in 2019, and nitrous oxide from all four sites in 2020. Dry soils from three of the sites were used to measure the abundance of nitrate reducing genes and transcripts using quantitative polymerase chain reaction (qPCR). We also collected soils from the most arid site to conduct two lab experiments in 2022. In July 2022, we incubated a subset of the dry soils with chloroform to inhibit microbial activity. Then we added ¹⁵N labeled nitrate tracer to chloroform fumigated and control soils and measured the isotopic composition of nitrous oxide emitted from these soils every 20 minutes in response to experimental rewetting. In December 2022, we conducted a second lab experiment to measure the natural abundance isotopic composition of nitrous oxide produced in the lab. Data are provided as individual tabular files containing: field nitrous oxide fluxes, field nitric oxide fluxes, field nitric oxide isotopes, qPCR gene and transcript abundance, chloroform inhibition nitrous oxide data, and natural abundance isotope data.The purpose of this study was to identify the processes that produce nitrous oxide (a potent greenhouse gas) and nitric oxide (an air pollutant) emissions from dryland ecosystems in Southern California.For more information about this study and these data, see Krichels et al. (2023). These data were originally published on 09/07/2023. On 12/07/2023, metadata was updated to include reference to the newly publishedKrichels et al. (2023).