Resilience and turnover of soil mycobiota following fire-prevention interventions in Mediterranean scrublands

The abandonment of rural areas across the Mediterranean has led to widespread shrub encroachment, increasing fuel loads, and the risk of high-intensity wildfires under current and future climate conditions. Fuel management practices, such as prescribed burning and mechanical clearing, are necessary to mitigate this threat. However, these interventions may also alter soil fungal communities, which play a key role in ecosystem functioning and support non-timber forest products of socio-economic interest. In this study, we assessed the effects of prescribed burning and total mechanical clearing on soil fungal communities in Cistus ladanifer -dominated shrublands in northern and southern Spain. Soil samples were collected before and after the fire-prevention treatments were performed, and fungal DNA was extracted and sequenced to characterize taxonomic and functional shifts. Prescribed burning triggered a strong, initial shift in the fungal community: five months post-fire, ectomycorrhizal (ECM) fungi significantly decreased while saprotrophs increased. However, one year after management, the relative abundances of both guilds returned to pre-fire levels, suggesting important insights on the functional resilience. Comparisons among prescribed burning, total clearing, and control plots revealed no significant differences in fungal richness or diversity. Although compositional changes were detected, no evidence of significant trophic functional disruption was found. These results indicate that both prescribed burning and mechanical clearing are effective biomass reduction strategies that cause only transient but not significant disturbances to soil fungal communities, supporting their use in fire-prone Mediterranean landscapes. • Prescribed burning maintains fungal richness over short-term periods. • Burning promotes resilient saprotrophic and ectomycorrhizal fungi one year after. • No differences in fungal diversity between treatments or versus the control. • Prescribed fire and total clearing preserve trophic functions.