Forest soil carbon (C) accumulates predominantly from the decomposition of plant litter, with most plant-derived C being processed by soil microbes. However, the microbial mechanisms associated with C decomposition in...Forest soil carbon (C) accumulates predominantly from the decomposition of plant litter, with most plant-derived C being processed by soil microbes. However, the microbial mechanisms associated with C decomposition in forests across biomes remain elusive. Using metagenomic sequencing, we explored the topsoil microbial functional group of decomposer microbial carbohydrate-active enzymes (CAZyme) and studied the C decomposition of plant- and microbial-derived components in forests across biomesfrom tropical to temperate regions. The results showed that the composition of soil microbial CAZyme families, which degrade plant- and microbial-derived components, significantly varied from warmer to colder forest biomes. Soils with higher annual temperatures and lower organic matter (OM) recalcitrance (indicated by Alky-C/O-alkyl-C: A/O) in subtropical/tropical forests supported higher proportions of CAZyme genes fundamental for the decomposition of complex plant and fungal derived biomass. In contrast, soils with lower annual temperatures and higher OM recalcitrance (e.g., A/O, organic carbon, microbial biomass) in cold temperate forests exhibited higher proportions of CAZyme genes for the degradation of bacterial-derived peptidoglycan. Such trends of microbial CAZyme families were largely explained by the relative abundance of bacterial dominant phylum members (i.e., Proteobacteria, Actinobacteria, Acidobacteria, and Bacteroidetes). Collectively, our study demonstrated the importance of functional microbiome responsible for the decomposition of plant and microbial inputs, providing a solid mechanism to understand the often-reported responses of soil organic matter decomposition and C sequestration to warming. These results are integral to understanding the contribution of soil microbiome to C fluxes under on-going climate change.展开更多
基金financially supported by the Open Fund for Key Laboratory of Low carbon Green Agriculture in Northwestern China,Northwest A&F Universitythe National Natural Science Foundation of China+1 种基金Thanks for the support of the Restoration Project of Mountains,Rivers,Forests,Fields,Lakes,Grasslands and Deserts in the Northern Foothills of Qinling in Shaanxi ProvinceThe authors are also grateful to the anonymous reviewers whose comments and suggestions helped us to enhance the quality of this paper.
文摘Forest soil carbon (C) accumulates predominantly from the decomposition of plant litter, with most plant-derived C being processed by soil microbes. However, the microbial mechanisms associated with C decomposition in forests across biomes remain elusive. Using metagenomic sequencing, we explored the topsoil microbial functional group of decomposer microbial carbohydrate-active enzymes (CAZyme) and studied the C decomposition of plant- and microbial-derived components in forests across biomesfrom tropical to temperate regions. The results showed that the composition of soil microbial CAZyme families, which degrade plant- and microbial-derived components, significantly varied from warmer to colder forest biomes. Soils with higher annual temperatures and lower organic matter (OM) recalcitrance (indicated by Alky-C/O-alkyl-C: A/O) in subtropical/tropical forests supported higher proportions of CAZyme genes fundamental for the decomposition of complex plant and fungal derived biomass. In contrast, soils with lower annual temperatures and higher OM recalcitrance (e.g., A/O, organic carbon, microbial biomass) in cold temperate forests exhibited higher proportions of CAZyme genes for the degradation of bacterial-derived peptidoglycan. Such trends of microbial CAZyme families were largely explained by the relative abundance of bacterial dominant phylum members (i.e., Proteobacteria, Actinobacteria, Acidobacteria, and Bacteroidetes). Collectively, our study demonstrated the importance of functional microbiome responsible for the decomposition of plant and microbial inputs, providing a solid mechanism to understand the often-reported responses of soil organic matter decomposition and C sequestration to warming. These results are integral to understanding the contribution of soil microbiome to C fluxes under on-going climate change.
