qiime_study_2036
Reconstructing the microbial diversity and function of pre-agricultural tallgrass prairie soils in the United States
Although soil microbes play critical roles in terrestrial ecosystems, factors controlling spatial variability in the diversity and functional capabilities of these communities remain poorly understood. Particular knowledge gaps exist for biomes severely impacted by human activities, including the native tallgrass prairie that once covered >65 million ha of the midwestern United States, but has been nearly eradicated by decades of agricultural practices. Here we have reconstructed the microbial biodiversity that once sustained this highly productive ecosystem by analyzing soils from prairie relicts via shotgun metagenomics and targeted sequencing of the 16S rRNA gene. The taxonomic and functional diversity of the microbial communities were well-correlated, demonstrating that these communities are not functionally equivalent as has often been assumed - even small changes in belowground diversity can have important impacts on soil processes. As for many plant and animal communities, we could predict the structure and functional traits of the microbial communities from climatic conditions, allowing us to build predictive maps of soil biodiversity across the historical range of the tallgrass prairie ecosystem. The biogeographical patterns were largely driven by changes in the abundance of Verrucomicrobia, a poorly-studied bacterial phylum that dominated the prairie soils. The shotgun metagenomic data suggest that these spatial patterns were associated with shifts in soil carbon and nitrogen dynamics across the tallgrass prairie ecosystem. We show that we can use metagenomic data to reconstruct the belowground biogeochemical and diversity gradients that once existed, information that could be essential to guiding ongoing efforts to restore the threatened tallgrass prairie ecosystem.