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

Leff, Jonathan W. and Jones, Stuart E. and Prober, Suzanne M. and Barberán, Albert and Borer, Elizabeth T. and Firn, Jennifer L. and Harpole, W. Stanley and Hobbie, Sarah E. and Hofmockel, Kirsten S. and Knops, Johannes M. H. and Mcculley, Rebecca L. and La Pierre, Kimberly and Risch, Anita C. and Seabloom, Eric W. and Schütz, Martin and Steenbock, Christopher and Stevens, Carly J. and Fierer, Noah (2015) Consistent responses of soil microbial communities to elevated nutrient inputs in grasslands across the globe. Proceedings of the National Academy of Sciences of the United States of America, 112 (35). pp. 10967-10972. ISSN 0027-8424

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Abstract

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.

Item Type:
Journal Article
Journal or Publication Title:
Proceedings of the National Academy of Sciences of the United States of America
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1000
Subjects:
ID Code:
76953
Deposited By:
Deposited On:
03 Dec 2015 11:14
Refereed?:
Yes
Published?:
Published
Last Modified:
23 Oct 2020 03:08