Wildfire-induced losses of soil particulate and mineral-associated organic carbon persist for over four years in a chaparral ecosystem

Wildfires are increasing in frequency and severity with changes in the climate. Increases in fire activity may lower soil carbon (C) stocks if photosynthetic C inputs are outpaced by microbial decomposition in burned ecosystems. However, fires may preferentially deplete particulate organic carbon (POC, which is more susceptible to microbial decomposition) over mineral-associated organic carbon (MAOC, which is protected from decomposers), potentially slowing microbial C losses after wildfires. Yet it remains unclear how plants, microorganisms, and soil organic matter pools interact to control the fate of C after wildfires. To assess how wildfires affect the persistence of soil C, we measured POC, MAOC, pyrogenic organic C, plant cover, extracellular enzyme activity (EEA), soil microbial abundance, and microbial community composition 17 days, 1, 3, and 4 years after the Holy Fire burned 94 km2 of a fire-adapted chaparral. We found that the fire immediately decreased POC by 50% (from 50.9 ..., Site description
This study was conducted within the Holy Fire burn scar in the Cleveland National Forest. The Holy Fire burned 94 km2 of manzanita-dominated chaparral shrubland between August 6 and September 13, 2018. Seventeen days after the fire was extinguished, we established 9 plots; 6 of these plots were within the burn scar of the Holy Fire, while the other 3 served as control unburned plots (Figure S1; Pulido-Chavez et al. 2022). Each plot (~25 m2) consisted of four 1 m2 subplots located 5 m from the center of the plot in each cardinal direction (i.e., N, S, E, W; Figure S1). All nine plots had similar aspects, slope, elevation, and pre-fire vegetation dominated by manzanita (Arctostaphylos glandulosa) and chamise (Adenostoma fasciculatum) shrubs.
The climate at the site is Mediterranean with hot, dry summers (average 9.2 mm precipitation per month since 1990) and cool, wet winters (average 101 mm precipitation per month since 1990). Annual temperature averages 17 °C, and total..., , # Data from: Wildfire-induced losses of soil particulate and mineral-associated organic carbon persist for over four years in a chaparral ecosystem

Authors: Alexander H. Krichels, Elizah Z. Stephens, Chloe Reid, M. Fabiola Pulido-Chavez, Maria Ordonez, Jennie R. McLaren, Meg Kargul, Loralee Larios, Sydney I. Glassman, Peter M. Homyak

Corresponding author: Alexander H. Krichels, Rocky Mountain Research Station, [[e-mail]](mailto:[e-mail]), [[e-mail]](mailto:[e-mail])

Data collected between 2018 and 2024

Geographic location of data collection: Riverside County, California and Orange County, California.

Empty cells indicate missing data.

#### DATA & FILE OVERVIEW

File list (file names and brief description of all data files):

**Compiled_Open_Data.csv**:

| **Column name** | **Description** | **Units** | **Data format** | **Missing data code** |
| :-...,