Functional composition of deep soil microbial communities changes with oak mortality (raw sequence reads)

Tree mortality in oak savannas is increasing under climate change, but its impact on microbial communities and soil carbon below the top 20 centimeters is relatively unknown. Deep tree roots, their ectomycorrhizal fungi, and associated bacteria may have a particularly important effect on landscape carbon storage, as they mediate the transfer of recently fixed plant carbon into deep soil and subsoil layers. To investigate how tree mortality impacts microbes and soil carbon, we sampled under living and recently dead Quercus douglasii trees in a California oak savanna, gathering depth-resolved soil cores to 45 cm below the surface. We captured finely-resolved biological detail on these soil samples, comparing living (RNA-based) to potential and historical (DNA-based) microbial communities and assessing microbial biomass with phospholipid fatty acid analysis.