Linking soil bacterial diversity to satellite-derived vegetation productivity: a case study in arid and semi-arid desert areas

Increasing studies have begun to focus on biodiversity-productivity relationships for soil microorganisms through molecular ecology methods. However, most of these studies involve controlled experiments, and whether the relationship remains at large spatial scales is still largely unknown. To unravel this issue, archived desert soils from long-term experiments were analysed using high-throughput sequencing, and satellite-derived vegetation datasets were acquired to quantify productivity. Most of the abundant genera were significantly different between low- and high-productivity conditions, and soil bacterial communities were strongly impacted by productivity. Soil bacterial biodiversity, including observed operational taxonomic units and the Chao1, Shannon, and Faith's PD indexes, increased rapidly with productivity at low levels and then reached a relatively stable state, and similar phenomena were observed at multiple taxonomic ranks and for most of the dominant groups. Furthermore, we discovered that the mechanisms resulting in the observed relationship might be ecosystem resource availability in large-scale regions and species competition in local regions. Collectively, these results enhance our understanding of the linkage between belowground microorganisms and aboveground vegetation in arid and semi-arid areas and confirm the potential value of satellite-derived datasets in research on soil microbial diversity at large spatial scales.