Research data_Catena20251101

We hypothesized that: (i) post-fire SOC accumulation would depend more strongly on fungal necromass content and stabilization than on CUE, and (ii) restoration dominated by leguminous species would strengthen necromass–mineral associations through improved nitrogen availability, while non-leguminous restoration would decrease mineral protection and SOC stability. Across seasons and soil depths, SOC and mineral-associated organic carbon (MOC) increased significantly in naturally restored forests but declined in plantations, particularly in those dominated by Michelia macclurei. Although CUE determines the potential for microbial residue production, SOC accumulation was more strongly associated with the stabilization of microbial necromass, especially of fungal origin. Plant inputs, including litter quality and root contributions, further modulated the interactions between necromass and minerals, thereby shaping SOC trajectories. Our findings highlight that necromass stabilization, rather than microbial metabolic efficiency alone, is the dominant driver of post-fire SOC recovery. This study fills a critical gap by linking plant inputs, microbial physiology, and mineral stabilization, and it underscores the importance of species-specific restoration strategies for long-term carbon retention. UF, unburned forests; NRF, naturally restored forests; ARF1, artificially restored forests planted with Acacia mangium; ARF2, artificially restored forests planted with Michelia macclurei.