Effect of mineral fertilizers on microorganisms community characteristic during leaf litter decomposition under Pinus massoniana in a subtropical forest

Leaf litter decomposition is a crucial ecological process driven by bacteria and fungi, which release extracellular enzymes. However, the effects of mineral fertilizer application on microbial aspects in forest ecosystems are unclear. We hypothesized that mineral fertilizers significantly affect bacteria and fungi in terms of function, diversity, structure, and composition. We also proposed that microbial phyla respond more to fertilizers than untreated conditions and that there's a strong correlation between bacteria, fungi, and chemical factors under fertilizer treatments. Using next-generation sequencing, we investigated microbial responses in a Masson pine plantation across four sampling times (90, 180, 270, and 360 days) with control (CK), N fertilization (+N), N and P fertilization (+NP), and N, P, K fertilization (+NPK). Mineral fertilizer impacts were more pronounced on bacterial diversity than fungal diversity, especially in alpha diversity. Proteobacteria, Firmicutes, Bacteroidetes, Acidobacteria, and Cyanobacteria (11.76, 0.34, 0.08, 1.86, 7.17 %), respectively, responded positively to fertilizers, while only Ascomycota and Basidiomycota (14.77, 16.51 %), respectively, were influenced among fungal phyla. Beta diversity analysis revealed distinct groupings of bacterial and fungal communities over time. Redundancy analysis indicated shifts in community structure linked to soil chemical properties. Our findings concluded that NPK fertilizer might be a preferred management option, providing valuable insights for fertilization strategies in subtropical forest ecosystems, benefiting both surface and belowground components. However, the application of mineral fertilizer requires careful consideration of the implications and limitations on microbial communities.