Introduction Wildfires can alter soil structure and reduce microbial diversity, potentially affecting ecosystem resilience. Understanding the effects of wildfire on native soil microbiomes may help identify bacterial taxa relevant for ecosystem recovery. In this study, we investigated wildfire-associated patterns in soil bacterial communities across a pine–oak forest in Mexico. Methods Sixteen soil samples were categorized into three time-since-fire classes: (i) early post-fire (3 years; EPF), (ii) intermediate post-fire (3–10 years; IPF), and (iii) late post-fire (10 years; LPF), representing a site-based chronosequence rather than a replicated temporal trajectory. Bacterial communities were characterized using 16S rRNA amplicon sequencing (Illumina MiSeq) and analyzed with QIIME1. Soil physicochemical properties, including pH, moisture, texture, organic matter, and salinity, were also measured. Results Time-since-fire categories, along with pH and elevation gradients, were associated with differences in community composition. Although approximately 50% of taxa were shared among conditions, burned and unburned soils differed in the relative abundance of Actinobacteria and Acidobacteria, as well as in the occurrence of low-abundance taxa with reported thermotolerant and pollutant-degrading traits. Co-occurrence network analysis revealed differences in network structure between burned and unburned communities, although these results should be interpreted cautiously due to their correlational nature. Several genera commonly reported in post-fire environments, including Massilia, Arthrobacter , and Blastococcus , were detected. Notably, Arthrobacter and Blastococcus were part of the core microbiome, with Arthrobacter also showing differential abundance and high connectivity in unburned soil networks. Additional taxa of interest included Actinobacteria genera such as Gaiella, Jiangella, Krasilnikovia, Mycobacterium , and Rubrobacter , as well as the Proteobacteria genus Lysobacter . Discussion Collectively, these findings highlight bacterial taxa associated with wildfire-affected soils and provide insights into microbial community shifts across post-fire chronosequences. These results may support future microbiome-based approaches for the management and restoration of fire-prone ecosystems.
Rivas-Morales et al. (Wed,) studied this question.