Bacterial Community Composition and Diversity Respond to Nutrient Amendment but Not Warming in a Maritime Antarctic Soil
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A resumption of climate warming in maritime Antarctica, arising from continued greenhouse gas emissions to the atmosphere, is predicted to lead to further expansions of plant populations across the region, with consequent increases in nutrient inputs to soils. Here, we test the main and interactive effects of warming, applied with open top chambers (OTCs), and nutrient amendment with tryptic soy broth (TSB), an artificial growth substrate, on bacterial community composition and diversity using Illumina sequencing of 16S rRNA genes in soil from a field experiment in the southern maritime Antarctic. Substantial effects of TSB application on bacterial communities were identified after 49 months, including reduced diversity, altered phylogenetic community assembly processes, increased Proteobacteria-to-Acidobacteria ratios and significant divergence in community composition, notably increases in the relative abundances of the gram-positive genera Arthrobacter, Paeniglutamicibacter and Planococcus. Contrary to previous observations from other maritime Antarctic field warming experiments, we recorded no effects of warming with OTCs, or interactive effects of OTCs and TSB application, on bacterial community composition or diversity. Based on these findings, we conclude that further warming of the maritime Antarctic is unlikely to influence soil bacterial community composition or diversity directly, but that increased nutrient inputs arising from enhanced plant growth across the region may affect the composition of soil bacterial communities, with possible effects on ecosystem productivity.
KeywordsAntarctica Bacterial community composition Climate warming Gram-positive and gram-negative bacteria Nutrient inputs Proteobacteria-to-Acidobacteria ratio
Logistical support was provided by the British Antarctic Survey’s Operations Unit, with Air Unit pilots Alan Meredith, Steve King, Doug Pearson and Ian Potten providing access to Mars Oasis. Adam Clark, Dickie Hall, Sharon Duggan and Paul Dennis provided valuable support. Two anonymous reviewers provided helpful comments. All are gratefully acknowledged.
This research was funded by the British Antarctic Survey’s Long-Term Monitoring and Survey programme, the NERC Antarctic Funding Initiative (grant number NE/D00893X/1) and a National Research Foundation of Korea Grant from the Korean Government (grant number 2018R1C1B6007755).
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
- 1.Adams B et al (2009) The instrumental period. In: Turner J, Bindschadler R, Convey P, di Prisco G, Fahrbach E, Gutt J, Hodgson D, Mayewski P, Summerhayes C (eds) Antarctic Climate Change and the Environment. Scientific Committee on Antarctic Research, Scott Polar Research Institute, Cambridge, pp 183–298Google Scholar
- 14.Haack SD, Garchow H, Odelsen DA, Forney LJ, Klug MJ (1994) Accuracy, reproducibility, and interpretation of fatty acid methyl ester profiles of model bacterial communities. Appl Environ Microbiol 60:2483–2493Google Scholar
- 25.Schloss PD, Westcott SL, Ryabin T, Hall JR, Hartmann M, Hollister EB, Lesniewski RI, Oakley BB, Parks DH, Robinson CJ, Sahl JW, Stres B, Thallinger GG, vam Horn DJ, Weber CF (2009) Introducing mothur: open-source, platform-independent, community-supported software for describing and comparing microbial communities. Appl Environ Microbiol 75:7537–7541CrossRefGoogle Scholar
- 37.Clarke KR, Gorley RN (2006) PRIMERv6: User Manual/Tutorial. PRIMER-E, PlymouthGoogle Scholar
- 47.Radujković D, Verbruggen E, Sigurdsson BD, Leblans NIW, Janssens IA, Vicca S, Weedon JT (2018) Prolonged exposure does not increase soil microbial community compositional response to warming along geothermal gradients. FEMS Microbiol Ecol 94. https://doi.org/10.1093/femsec/fix174
- 48.Bockheim JG, Schaefer CEGR (2015) Soils of Ellsworth Land, the Ellsworth Mountains. In: Bockheim JG (ed) The soils of Antarctica. World Soils Book Series. Springer, Switzerland, pp 169–181Google Scholar
- 58.Shaver G (2005) Daily summary of 10 cm soil temperatures in the Arctic LTER moist acidic experimental plots from 1998 to present, Toolik Lake Field Station, Alaska. Environ Data Initiative. https://doi.org/10.6073/pasta/89b6208bc6631129949eeca791063ed3 Accessed 12 September 2018