Functional community composition has less environmental variability than taxonomic composition in straw-degrading bacteria.

To address environmental variations in metabolic composition of straw-decomposing bacterial community, we performed a 16-week field-based buried straw experiment at three experimental sites across subtropical China. We found that, although the taxonomic composition was highly variable, the functional composition was conserved across all experimental sites. This was likely because stochastic dispersal limitation governed the high taxonomic turnover of the community, leading to high environmental variability, whereas metabolic niche selection resulted in stable functional composition and lower redundancy. The integrated knowledge on the response of functional and taxonomic composition to environmental variability might help to understand microbial-driven straw decomposition at a large scale, considering the significance of microbial functional and taxonomic composition to biogeochemical cycling. [ABSTRACT FROM AUTHOR]