Shifts in Soil Fungal Community and Trophic Modes During Mangrove Ecosystem Restoration

Mangrove ecosystems are valuable coastal ecosystems; however, studies on the diversity and functional features of their soil fungal communities during restoration are limited. In this study, we examined fungal diversity and trophic modes across mudflat, young mangrove, and mature mangrove stages. We found that Ascomycota and Basidiomycota were the dominant phyla, with saprotrophs as the most abundant trophic mode. The abundance of the major phyla and trophic modes significantly varied across restoration stages. Although fungal alpha (α)-diversity remained stable among the stages, beta (β)-diversity showed significant differentiation. Spearman's analysis and partial Mantel tests revealed that total nitrogen and inorganic phosphorus significantly influenced the fungal α-diversity, whereas temperature and pH primarily shaped the fungal β-diversity. Total nitrogen and carbon were key factors affecting the trophic mode α-diversity, whereas total phosphorus and inorganic phosphorus were the main drivers of the trophic mode β-diversity. Variation partitioning analysis confirmed that nutrients, rather than soil properties, were the primary factors shaping fungal communities and trophic modes. Random forest analysis identified key bioindicators, including species such as Paraphyton cookei, and trophic modes such as saprotrophs, both of which were strongly influenced by soil carbon. These findings advance our understanding of fungal ecology in mangrove restoration.