Aboveground–belowground interactions exert critical controls over many parameters of terrestrial ecosystems, i.e., community composition, primary production, and nutrient cycling. They are expected to continuously change regarding vegetation and basic soil properties, that is, C: N ratio, soil pH, and microbial community.

This project aimed to evaluate microbial community composition and the land use effect on the soil respiration rate of three different land types in a selected Fichtel Mountains temperate zone (Germany) region. Further, it aimed to identify the alpha and beta diversity variations in each land type and the genus-level microbial communities.

The project selected one hundred and twenty sample sites from forests, grasslands, and arable lands in the Fichtel mountains for soil DNA extraction, followed by 16S rRNA gene amplicon sequencing. In parallel, soil basal respiration was measured by a respirometer (respicond VI), and microbial biomass carbon was determined by substrate-induced respiration.

Using these methods and statistical models, the representative results demonstrated significant differences in bacterial community composition among the different land types. Bacterial communities in forest soils were clearly differentiated from those in grassland and arable land. Further, a general linear model analysis showed a strong correlation between forest land type and microbial biomass carbon. Candidatus Udaeobacter was found to be the most abundant genus in sample sites, which showed the highest soil respiration.

Results from this project will contribute to a better understanding of how alpha and beta diversity of microbial communities vary with land types and how microbial biomass affects the soil respiration amounts in temperate regions.