Magnesite driven the complementary effects of core fungi by optimizing the physicochemical parameters in pig manure composting

•Magnesite amendment could greatly influenced the fungi communities.•The superior fungi were Ascomycota (78.87%) and Neocallimastigomycota (41.40%).•Intense core fungi complementarity effects were driven by high additive amendment.•10% ratio amendment greatly improved the diversity of fungal structures.