DOI: 10.5061/dryad.1zcrjdg5t
title: Data from: Fall prescribed burns deplete surface soil C pools more than spring burns in a young mixed-conifer forest

description: Wildfires burn as much as 3% of Earth’s surface annually and remove carbon
 (C) stored in surface soils. Prescribed burns may offer an opportunity to
 preserve soil C stocks by limiting the extent and severity of wildfires.
 However, there is a limited number of days that are dry enough to conduct
 prescribed burns but wet enough to prevent the unintentional spread of
 fire. While prescribed burns mostly occur during the historical fire
 season—late summer and fall—burning during other favorable seasons, like
 spring, would facilitate forest management. Yet, it is not clear how
 burning in the spring versus the fall affects soil C stocks. To assess how
 burn season affects soil C dynamics, we measured bulk soil C,
 mineral-associated organic C (MAOC), particulate organic C (POC),
 pyrogenic organic matter (PyOM), microbial respiration, and extracellular
 enzyme activity in surface soils for two years after burning young
 mixed-conifer forest stands in either the fall or spring. We found that
 fall burning, which tended to consume more surface fuels, immediately
 combusted soil organic matter, lowering POC from 37 ± 14 to 14 ± 8.3 g C
 kg-1 three days after burning. Furthermore, fall burning stimulated
 microbial respiration, preventing bulk C from increasing above 43 ± 14 g C
 kg-1 for two years. Spring burning did not decrease soil C, and MAOC
 increased by 36%. Taken together, our results suggest that spring
 prescribed burns preserved soil C stocks relative to fall burns in young
 mixed-conifer forest stands.
description: # Data from: Fall prescribed burns deplete surface soil C pools more than
 spring burns in a young mixed-conifer forest **GENERAL INFORMATION** Data
 for: "Fall prescribed burns deplete surface soil C pools more than
 spring burns in a young mixed-conifer forest" which includes data on
 soil carbon, microbial respiration, ash depth, and extracellular enzyme
 activity for the manuscript submitted to Forest Ecology and Management.
 Cells with "n/a" indicate that data were not collected or did
 not pass quality control measures. Please refer to the publication for
 methodologies used to generate these data and for the experimental design.
 Title of Dataset: Data for: Fall prescribed burns deplete surface soil C
 pools more than spring burns in a young mixed-conifer forest Authors:
 Alexander H. Krichels, Chloe L. Reid, Basubi B. Zhilik, Jacob Kemner,
 Robert A. York, Sydney I. Glassman, Peter M. Homyak Corresponding author:
 Alexander H. Krichels, Rocky Mountain Research Station,
 [alexander.krichels@usda.gov](mailto:alexander.krichels@usda.gov),
 [ahkrichels@gmail.com](mailto:ahkrichels@gmail.com) Data collected between
 2019 and 2025 Geographic location of data collection: Riverside County,
 California and El Dorado County, California. **DATA & FILE OVERVIEW**
 File list (file names and brief description of all data files):
 **C_Fractions.csv**: | **Column name** | **Description** | **Units** |
 **Data format** | **Missing data code** | | :-------------- |
 :---------------------------------------------------------------------------------- | :---------- | :-------------- | :-------------------- | | Sample Name | Unique identifier for each soil sample | - | Category | 
 
 | | Plot | Unique identifier for each plot | - | Category | 
 
 | | Sub | Unique identifier for each subplot. Corresponds to cardinal
 direction and distance. | - | Category | 
 
 | | Timepoint | When soil samples were collected | - | Category | 
 
 | | Treatment | Whether samples were burned or not | - | Category | 
 
 | | Season | Season when burn was conducted | - | Category | 
 
 | | Date | Date when sample was collected | M/D/YR | Date | 
 
 | | Fraction | Whether sample reflects POM, MAOM, or Sand | - | Category
 | 
 
 | | gN/kgsoil | how much nitrogen is present in the sample | g-N/kg soil
 | Number | 
 
 | | gC/kgsoil | how much carbon is present in the sample | g-C/kg soil |
 Number | 
 
 | | Moisture | Soil moisture | ‰ | Number | 
 
 | **Respiration.csv**: | **Column name** | **Description** | **Units** |
 **Data format** | **Missing data code** | | :---------------- |
 :---------------------------------------------------------------------------------- | :---------- | :-------------- | :-------------------- | | Sample Name | Unique identifier for each soil sample | - | Category | - | | Plot | Unique identifier for each plot | - | Category | - | | Sub | Unique identifier for each subplot. Corresponds to cardinal direction and distance. | - | Category | - | | Timepoint | When soil samples were collected | - | Date | M/D/YR | | Season | Season when burn was conducted | - | Category | - | | Treatment | Whether samples were burned or not | - | Category | - | | Total Respiration | Amount of CO2 respired during a 96-hour lab incubation | mg-C/g soil | Number | - | **EEA.csv**: | **Column name** | **Description** | **Units** | **Data format** | **Missing data code** | | :-------------- | :---------------------------------------------------------------------------------- | :-------- | :-------------- | :-------------------- | | Sample Name | Unique identifier for each soil sample | - | Category | 
 
 | | Plot | Unique identifier for each plot | - | Category | 
 
 | | Sub | Unique identifier for each subplot. Corresponds to cardinal
 direction and distance. | - | Category | 
 
 | | Season | Season when burn was conducted | - | Category | 
 
 | | Treatment | Whether samples were burned or not | - | Category | 
 
 | | Timepoint | When soil samples were collected | - | Category | 
 
 | | Enzyme | What enzyme was measured | - | Category | 
 
 | | Activity | Potential extracellular enzyme activity | nmol/g/hr |
 Number | 
 
 | **Ash_Data.csv**: This file shows the depth of ash (cm) measured 17
 days after the Holy Fire. | **Column name** | **Description** | **Units**
 | **Data format** | **Missing data code** | | :-------------- |
 :---------------------------------------------------------------------------------- | :-------- | :-------------- | :-------------------- | | Plot | Unique identifier for each plot | - | Category | 
 
 | | Sub | Unique identifier for each subplot. Corresponds to cardinal
 direction and distance. | - | Category | 
 
 | | Season | Season when burn was conducted | - | Category | 
 
 | | Ash1 | Measured ash depth. First replicative measurement | cm |
 Number | 
 
 | | Ash2 | Measured ash depth. Second replicative measurement | cm |
 Number | 
 
 | | Ash3 | Measured ash depth. Third replicative measurement | cm |
 Number | 
 
 |