Shifts in adaptive strategies of soil microbial communities during coral island revegetation

Vegetation and soil microbes establish dynamic synergies that regulate biogeochemical cycles and facilitate ecological restoration. However, how microbial communities respond and adapt to vegetation restoration during primary succession in nutrient‐constrained ecosystems of coral islands remain poorly understood. We conducted a field‐based vegetation restoration experiment on tropical coral islands using multiple pioneer plant species and a barren control. Based on soil physicochemical changes, sites were classified into different restoration levels, and both rhizosphere and bulk soils were sampled to investigate microbial community composition, functional potential and life‐history strategies using amplicon and metagenomic sequencing. The results indicated that nitrogen‐fixing plants (e.g. Leucaena leucocephala , Casuarina equisetifolia ) increased soil organic carbon and total nitrogen while reducing soil pH. Concurrently, microbial communities underwent a pronounced taxonomic and functional reorganization. Specifically, vegetation restoration enhanced microbial carbon and nitrogen cycling and drove a fundamental metabolic shift from autotrophy‐dominated to heterotrophy‐driven processes, while nitrogen cycling transitioned from an input‐dominated to a turnover‐dominated regime. Trait‐based analyses further revealed a shift in microbial life‐history strategies from stress‐tolerant, high‐redundancy survival strategies to more specialized and resource‐efficient strategies, with stronger responses observed in the rhizosphere than in bulk soil. Synthesis and applications : These strategy shifts mechanistically link plant‐driven changes in soil properties to microbial‐mediated biogeochemical processes, thereby underpinning ecosystem functional restoration. Integrating plant functional traits and rhizosphere microbial responses into restoration planning can help optimize plant selection and management strategies for coral islands and other nutrient‐constrained ecosystems.