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.

本研究提出如下假说：(i) 火灾后土壤有机碳（SOC, soil organic carbon）的累积更显著地依赖于真菌残体的含量与稳定过程，而非碳利用效率（CUE, carbon use efficiency）；(ii) 以豆科物种为主的生态修复模式可通过提升土壤氮素有效性强化残体-矿物结合作用，而非豆科修复模式则会削弱矿物保护能力与土壤有机碳稳定性。
在不同季节与土壤深度梯度下，自然恢复林（NRF, naturally restored forests）的土壤有机碳与矿物结合态有机碳（MOC, mineral-associated organic carbon）均显著升高，而人工林则出现显著下降，尤以火力楠（Michelia macclurei）人工林最为显著。
尽管碳利用效率决定了微生物残体的生成潜力，但土壤有机碳的累积与微生物残体（尤其是真菌来源残体）的稳定过程关联更为紧密。植物输入过程（包括凋落物质量与根系贡献）进一步调控了残体与矿物间的相互作用，进而塑造了土壤有机碳的动态变化轨迹。
本研究结果表明，残体稳定过程而非单纯的微生物代谢效率，是火灾后土壤有机碳恢复的主导驱动因子。本研究通过联结植物输入、微生物生理特性与矿物稳定过程填补了关键研究空白，并强调了物种特异性修复策略对长期碳固存的重要意义。
缩写说明：UF：未火烧林；NRF：自然恢复林；ARF1：以马占相思（Acacia mangium）营造的人工恢复林；ARF2：以火力楠营造的人工恢复林。