Abstract. Plant functional traits have increasingly been studied as determinants of ecosystem properties, especially for soil biogeochemical processes. While the relationships between biological community structures and ecological functions are a central issue in ecological theory, these relationships remain poorly understood at the large scale. We selected nine forests along the North–South Transect of Eastern China (NSTEC) to determine how plant functional traits influence the latitudinal pattern of soil microbial functions, and how soil microbial communities and functions are linked at the regional scale. We found that there was considerable variation in the profiles of different substrate use along the NSTEC. Soil microorganisms from temperate forests mainly metabolized high-energy substrates, while those from subtropical forests used all the substrates equally. The soil silt content and plant functional traits together shaped the biogeographical pattern of the soil microbial substrate use. Soil organic matter decomposition rates were significantly higher in temperate forests than in subtropical and tropical forests, which was consistent with the pattern of soil microbial biomass carbon concentrations. Soil organic matter decomposition rates were also significantly and negatively related to soil dissolved organic carbon concentrations, and carboxylic acid, polymer, and miscellaneous substrates. The soil microbial community structures and functions were significantly correlated along the NSTEC. Soil carbohydrate and polymer substrate use were mainly related to soil G+ bacterial and actinomycetes biomass, while the use of amine and miscellaneous substrates were related to soil G− bacteria, fungal biomass, and the F/B ratio. The contributions of different groups of microbial biomass to the production of soil enzyme activities differed. The relationship between soil microbial community structure and functions supported that there was functional dissimilarity.
Plant functional traits determined the latitudinal variations in soil microbial
functions: evidence from a forest transect in China
