PFGLiuData.xlsx

1. Global climate warming threatens biodiversity. The loss of plant functional groups (PFG) accompanying climate warming changes the composition and diversity of litter mixtures, affecting decomposition processes. No consensus has been reached regarding the effect of PFG loss on different microbial groups during the decomposition process. The decomposition effects of different microbial taxa are also unpredictable.
2. To explored the response of microbial communities to single-PFG loss during litter mixture decomposition in subalpine coniferous forests. We evaluated the compositions of bacterial and fungal communities by high-throughput sequencing, and the communities were further classified into abundant taxa and rare taxa to assess the subcommunity structure.
3. We found that bacteria were more sensitive to single-PFG loss, while the fungal community structure was stable between loss treatments and the total mixture (Tot.Mix.). The changes in rare taxa between single-PFG loss and Tot.Mix. were more significant than those in abundant taxa. K content increased the diversity of total bacterial and total and abundant fungal communities, and Ca content increased the diversity of rare bacterial community, while Mn decreased the diversity of total and abundant bacterial communities.. Additionally, the chemistry of the litter mixture was the most important direct driver determining mixture decomposition, and the microbial decomposition pathway was dominated by abundant fungal taxa. However, litter chemistry and fungal communities among different litter mixtures showed the same convergence in the late decomposition stage, resulting in no difference in litter mass loss among different treatments.
4. Overall, microbial community were influenced by the metallic elements that regulate litter degradability. And different microbial taxa showed unique responses to single-PFG loss, the decomposition of litter mixtures was regulated by these responses. Litter mixtures controlled by abundant fungi rather than bacteria and rare taxa, and abundant fungal subcommunity maintained stability after single PFG loss, which is conducive to maintaining the stability of carbon and nutrient cycling in alpine ecosystem after PFG loss.