Exploring the Critical Role of Mycorrhizal Fungi in Forest Carbon Sequestration: Evidence from Taiwan Spruce

Soil microorganisms play a crucial role in long-term carbon storage, with mycorrhizal fungi being one of the most studied groups due to their ecological importance. These fungi form symbiotic associations with plants, significantly enhancing biomass accumulation and promoting the uptake of atmospheric CO₂, thereby increasing plant carbon assimilation. This study was conducted at the Xitou nursery (elevation 1180–1200 m) of the Experimental Forest, National Taiwan University. Taiwan spruce (Picea morrisonicola), one of key native afforestation species in Taiwan, was selected to evaluate the effects of mycorrhizal inoculation on nutrient cycling and carbon dynamics in forest soils. Measurements of soil physicochemical properties, nutrient availability, microbial composition, spruce growth performance, and biochemical traits were carried out to identify potential correlations. Microbial community analysis revealed specific taxa closely linked to improved seedling growth and increased carbon sequestration potential. Observations of phenotypic and biochemical traits across developmental stages indicated that mycorrhizal fungi regulate seedling metabolic activity. Comparative analysis between inoculated and control treatments confirmed that mycorrhizal fungi significantly influence plant physiological responses and enhance soil carbon retention. The findings support the application of native mycorrhizal inoculants in sustainable soil management and reforestation strategies to strengthen the carbon sink function of forest ecosystems.