Consistent responses of soil microbial communities to elevated nutrient inputs in grasslands across the globe.


Journal Article

Soil microorganisms are critical to ecosystem functioning and the maintenance of soil fertility. However, despite global increases in the inputs of nitrogen (N) and phosphorus (P) to ecosystems due to human activities, we lack a predictive understanding of how microbial communities respond to elevated nutrient inputs across environmental gradients. Here we used high-throughput sequencing of marker genes to elucidate the responses of soil fungal, archaeal, and bacterial communities using an N and P addition experiment replicated at 25 globally distributed grassland sites. We also sequenced metagenomes from a subset of the sites to determine how the functional attributes of bacterial communities change in response to elevated nutrients. Despite strong compositional differences across sites, microbial communities shifted in a consistent manner with N or P additions, and the magnitude of these shifts was related to the magnitude of plant community responses to nutrient inputs. Mycorrhizal fungi and methanogenic archaea decreased in relative abundance with nutrient additions, as did the relative abundances of oligotrophic bacterial taxa. The metagenomic data provided additional evidence for this shift in bacterial life history strategies because nutrient additions decreased the average genome sizes of the bacterial community members and elicited changes in the relative abundances of representative functional genes. Our results suggest that elevated N and P inputs lead to predictable shifts in the taxonomic and functional traits of soil microbial communities, including increases in the relative abundances of faster-growing, copiotrophic bacterial taxa, with these shifts likely to impact belowground ecosystems worldwide.

Full Text

Cited Authors

  • Leff, JW; Jones, SE; Prober, SM; Barberán, A; Borer, ET; Firn, JL; Harpole, WS; Hobbie, SE; Hofmockel, KS; Knops, JMH; McCulley, RL; La Pierre, K; Risch, AC; Seabloom, EW; Schütz, M; Steenbock, C; Stevens, CJ; Fierer, N

Published Date

  • September 2015

Published In

Volume / Issue

  • 112 / 35

Start / End Page

  • 10967 - 10972

PubMed ID

  • 26283343

Pubmed Central ID

  • 26283343

Electronic International Standard Serial Number (EISSN)

  • 1091-6490

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.1508382112


  • eng