Identifying the microbial taxa which consistently respond to soil warming across time and space. soil metagenome

Soil microbial communities are the key drivers of many terrestrial biogeochemical processes. However, we currently lack a generalizable understanding of how these soil communities will change in response to predicted increases in global temperatures and which microbial lineages will be most impacted. Here, we identified a core group of abundant and nearly ubiquitous soil microbes that shift in relative abundance with elevated soil temperatures using high-throughput marker gene sequencing of soils collected from 18 sites throughout North America included in a 100-day lab temperature incubation experiment. We then validated and narrowed our list of temperature sensitive microbes by comparing the results from this laboratory experiment with data compiled from 49 soils representing multiple, independent global field studies sampled across spatial gradients with a wide range in mean annual temperatures. Our results reveal predictable and consistent responses to temperature for a core group of 189 ubiquitous soil bacterial and archaeal taxa, with these taxa exhibiting similar temperature responses across a broad range of soil types. These microbial ‘bioindicators’ are useful for understanding how and why soil microbial taxa respond to warming. Those taxa that were found to be sensitive to temperature represented a wide range of lineages and the direction of the temperature responses were not predictable from phylogeny alone, indicating that temperature responses are difficult to predict from simply describing soil microbial communities at broad taxonomic or phylogenetic levels of resolution. Together these results lay the foundation for a more predictive understanding of how soil microbial communities respond to soil warming and how warming may ultimately led to changes in soil biogeochemical processes.