Linkages Between Ecosystem Multifunctionality, Microbial Network and Carbon Metabolism During Mine Tailings Vegetation Succession

Tailings remediation alleviates ecosystem degradation and protects species. To conserve terrestrial biodiversity and address sustainability challenges while achieving economic growth, numerous researchers have devoted efforts to monitoring ecological functions and optimizing community structures. This study investigates the microbial characteristics and functional diversity across ecological succession stages of tailings. Selecting three typical restoration stages, including biological crust, moss, and grassland stages, we adopt 16S rRNA and ITS gene amplification, Illumina high-throughput sequencing, spectroscopy, and network correlation analysis to explore the responses of soil multifunctionality index, microbial communities, and carbon metabolism during tailings restoration. The experimental results indicate that the functional diversity index increases with ecological succession and is significantly correlated with the bacterial genera Rubrobacter and Arenimicrobium , whereas no significant correlation is observed with dominant fungi. The network interactions among bacterial communities are gradually strengthened along the succession process. In terms of carbon metabolic functions, the relative abundances of galactose, starch, and sucrose metabolism pathways increase obviously with restoration progression, while inositol phosphate metabolism, peroxisome metabolism, retinol metabolism, glyoxylate and dicarboxylate metabolism, and xenobiotics metabolism exhibit no significant variations. These findings provide novel empirical evidence for explaining microbe-mediated ecological succession in tailing ecosystems and highlight the necessity of multi-perspective analysis for ecological restoration. Policy and practical implications emphasize that the application of specific microorganisms and their interspecific interactions to promote iron tailings ecological restoration should fully consider the spatiotemporal heterogeneity of tailings areas. This study deepens the understanding of differential microbial responses at different tailings restoration stages and provides actionable insights for balancing mining economic development and terrestrial ecosystem conservation.