Data from: Wildfire alters nitrogen cycling to increase soil emissions of nitric oxide (NO) and the heterogeneity of nitrous oxide (N2O) in California chaparral
Data files
Apr 20, 2026 version files 180 KB
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HolyFireN_Metadata_Geoderma.csv
174.72 KB
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README.md
5.28 KB
Abstract
Wildfires drive ecosystem nitrogen (N) loss globally through combustion of plant biomass and by depositing N-rich ash onto soils to stimulate emissions of nitric oxide (NO) and nitrous oxide (N2O)—trace gases that affect air quality and climate. However, spatial and temporal variation in post-fire soil NO and N2O emissions remain under-explored, motivating our hypothesis that emissions would vary temporally with plant and microbial successional changes and spatially with burn severity, available N, soil physicochemical properties, and microbial activity. We sampled burned and unburned soils seasonally over three years after a chaparral wildfire and found that soil NO emissions significantly increased by 80 ng NO-N g−1 soil (cumulative 40-h incubations) over three years, with the highest emissions measured in year one from plots that burned at medium and high severities. No significant mean effects of burning were detectable for N2O emissions over three years (average 224 ng N2O-N g−1 soil, burned; 30 ng N2O-N g−1 soil, unburned); however, only burned soils produced statistical outlier fluxes of N2O that were up to ∼ 165 × higher than the average in unburned soils. Isotopic characterization of N2O from high-emitting soils indicated contributions from diverse processes, including nitrification and fungal and bacterial denitrification, pointing to heterogeneity in the post-fire environment that may generate hotspots of N2O production. Overall, increased soil NO and high N2O emissions post fire indicate that wildfires interact with soil N cycling to promote burn-severity-sensitive gaseous N losses years after the fires burn.
Dataset DOI: 10.5061/dryad.nk98sf87m
Description of the data and file structure
Data collected after the Holy Fire between 2018 and 2021.
Geographic location of data collection: Riverside County, California and Orange County, California.
NA indicates missing data.
Files and variables
File: HolyFireN_Metadata_Geoderma.csv
Description: Dataset for Geoderma manuscript "Wildfire alters nitrogen cycling to increase soil emissions of nitric oxide (NO) and the heterogeneity of nitrous oxide (N2O) in California chaparral"
Variables
- ID: Unique identifier for each soil sample
- TimePoint: The time point when soil samples were collected
- Subplot: Unique identifier for each plot
- soiltype: Soil Series associated with each individual plot
- Treatment: Indicates whether soil samples were collected from burned or unburned plots
- DateCollected: Date soil samples were collected in Month / Day / Year
- Latitude: Latitude associated with each plot - decimal degrees
- Longitude: Longitude associated with each plot - decimal degrees
- Elevation: Meters above sea level of each plot
- AspectDegrees: Aspect in degrees for each plot
- Aspect: Aspect in cardinal directions (NESW) for each plot
- DistanceRoad: Meters from Road for each plot
- BAERSBS: Burned Area Emergency Response categorization of soil Burn Severity at the 30 m2 scale
- ASHSBS: Classification of soil burn severity based on ash depth at the 1 m2 scale
- InitialAshDepth: Ash depth in cm measured two weeks after fire
- Wind Speed: m/s from El Cariso weather station
- Precipitation: Total monthly precipitation in mm from El Cariso weather station
- Air Temp: Average monthly air temperature in °C from El Cariso weather station
- Soil Moisture: g water g soil−1 measured from soils in the field
- Bulk Density: Soil bulk density in g cm−3
- % Sand: Soil sand % content
- % Clay: Soil clay % content
- % Silt: Soil silt % content
- pH: Soil pH
- mgC/gsoil: Bulk soil C in mg C g soil−1
- mgN/gsoil: Bulk soil N in mg N g soil−1
- C:N: Bulk soil C to bulk soil N ratio
- Mg-C/ha-1: Bulk Soil C stocks in Mg C ha−1
- Mg-N/ha-1: Bulk Soil N stocks in Mg N ha−1
- d13C: Bulk soil δ13C in ‰
- d15N: Bulk soil δ15N in ‰
- Phosphate: Soil Extractable Phosphate in µg PO43- -P g soil−1
- Nitrate: Soil extractable Nitrate in µg NO3--N g soil−1
- Ammonium: Soil extractable Ammonium in µg NH4+-N g soil−1
- Nitrite: Soil extractable Nitrite in µg NO2--N g soil−1
- Microbial Biomass C: µg C g soil−1
- Microbial Biomass N: µg N g soil−1
- Vegetation Richness: Total number of plant species per plot
- VegNfixer%cover: % cover of N-fixing plants at each plot
- Fungal Species: Fungal Richness, or total number of fungal species in each soil sample
- Bacterial Species: Bacterial Richness, or total number of bacterial species in each soil sample
- Bacterial biomass: Bacterial abundance as gene copy number g soil -1
- Fungal biomass: Fungal abundance as gene copy number g soil -1
- field_netmin: Net mineralization rate measured in the field in µg N g soil−1 day−1
- field_netnitr: Net nitrification rate measured in the field in µg NO3**–-N g soil−1 day−**1
- field_netNH4: Net NH4+ production rate in the field in µg NH4**+-N g soil−1 day−**1
- lab_netmin: Net mineralization rate measured in laboratory incubations in µg N g soil−1 day−1
- lab_netnitr: Net nitrification rate measured in laboratory incubations in µg NO3**–-N g soil−1 day−**1
- lab_netNH4: Net nitrification rate measured in laboratory incubations in µg NH4**+-N g soil−1 day−**1
- cumulative NO: Cumulative NO emissions measured in laboratory incubations over 48hrs in ng NO-N g-1soil
- cumulative N2O: Cumulative N2O emissions measured in laboratory incubations over 48hrs in ng N2O-N g-1soil
- cumulative CO2: Cumulative CO2 emissions measured in laboratory incubations over 48hrs in ng CO2-N g-1soil
- startWC: Starting water content of incubations for gases in g water g soil−1
- endWC: Water content at the end of incubations for gases in g water g soil−1
- start.NH4: Starting soil concentrations of NH4+ in µg NH4+-N g soil−1
- start.NO3: Starting soil concentrations of NO3- in µg NO3--N g soil−1
Code/software
Files are comma-delimited .csv files.
Access information
Other publicly accessible locations of the data: