Key Laboratory of Green Utilization of Critical Non-metallic Mineral Resources, Ministry of Education, Wuhan University of Technology, Wuhan 430070, China.
School of Environment, Tsinghua University, Beijing 100084, China.
Environ Sci Technol. 2024 Oct 22;58(42):18744-18755. doi: 10.1021/acs.est.4c06081. Epub 2024 Oct 10.
Resource demand by soil microorganisms critically influences microbial metabolism and then influences ecosystem resilience and multifunctionality. The ecological remediation of abandoned tailings is a topic of broad interest, yet our understanding of microbial metabolic status in restored soils, particularly at the aggregate scale, remains limited. This study investigated microbial resources within soil aggregates from revegetated tailings and applied a vector model of ecoenzymatic stoichiometry to examine how different vegetation patterns (grassland, forest, or bare land control) impact microbial resource limitation. Five-year vegetation restoration significantly elevated carbon (C) and nitrogen (N) concentrations and their stoichiometric ratios in soil aggregates (approximately 2-fold), although these increases were not translated to in the microbial biomass and its stoichiometry. The activities of C- and phosphorus (P)-acquiring extracellular enzymes in these aggregates increased substantially postvegetation, with the most pronounced escalation in macroaggregates (>0.25 mm). The vector model results indicated soil microbial metabolism was colimited by C and P, most acutely in microaggregates (<0.25 mm). This colimitation was exacerbated by monotypic vegetation cover but mitigated under diversified vegetation cover. Soil nutrient stoichiometric ratios in vegetation restoration controlled microbial resource limitation, overshadowing the impact of heavy metals. Our findings underscore that optimizing resource allocation within soil aggregates through strategic revegetation can enhance microbial metabolism in tailings, which advocates for the implementation of diverse vegetation covers as a viable strategy to improve the ecological development of degraded landscapes.
土壤微生物的资源需求对微生物代谢有重要影响，进而影响生态系统的弹性和多功能性。废弃尾矿的生态修复是一个备受关注的话题，但我们对恢复土壤中微生物代谢状况的理解仍然有限，尤其是在团聚体尺度上。本研究调查了植被恢复后的尾矿土壤团聚体中的微生物资源，并应用生态酶化学计量的向量模型来研究不同植被模式（草地、森林或裸地对照）如何影响微生物资源限制。五年的植被恢复显著提高了土壤团聚体中碳（C）和氮（N）的浓度及其化学计量比（约 2 倍），尽管这些增加并未转化为微生物生物量及其化学计量比。这些团聚体中 C 和磷（P）获取的胞外酶活性在植被恢复后大幅增加，其中大团聚体（>0.25 毫米）的增加最为显著。向量模型结果表明，土壤微生物代谢受到 C 和 P 的共同限制，在微团聚体（<0.25 毫米）中最为明显。单一种植物覆盖会加剧这种共同限制，但在多样化的植被覆盖下会得到缓解。土壤养分化学计量比在植被恢复中控制了微生物资源限制，超过了重金属的影响。我们的研究结果强调，通过战略性植被恢复优化土壤团聚体中的资源分配可以增强尾矿中的微生物代谢，这支持实施多样化的植被覆盖作为改善退化景观生态发展的可行策略。
