Functional implications of the pH-trait distribution of the microbial community in a re-inoculation experiment across a pH gradient

Research output: Contribution to journalArticle

Abstract

We compared the influence of the microbial community composition and the environmental conditions for the functioning - microbial growth and respiration - and trait distribution - bacterial pH tolerance - of soil microorganisms across a pH gradient. Sterilised soil microcosms, including pH 4.1, 5.2, 6.7 and 8.3, with added plant litter were inoculated with unsterilized soil in a factorial design and monitored during two months. The trait distribution - pH-tolerance - of bacterial communities converged with the pH of the soil environment. Still, the different inoculum communities could result in suboptimal pH-tolerance in all soil pH environments; inoculum communities derived from low pHs had lower than optimal pH-tolerance in high soil pH environments, and vice versa. The functioning of bacterial communities with trait distributions mismatched to the soil pH environment was impaired. The legacy of the initial bacterial trait distribution on bacterial pH tolerance and functioning was detected within one week and remained for two months in all soil pH environments. Fungal inoculum communities derived from low compared to high pHs resulted in higher fungal functioning. Thus, in contrast with bacteria there was no evidence that variation in pH-tolerance influenced fungal performance. Instead the fungal inoculum size appeared to explain these results. Bacteria dominated respiration in high pH while fungi dominated at low pH environments. Consequently, respiration was affected by how well-matched the bacterial trait distribution was to the pH of the soil environment at higher pHs. At low pH, the inoculum size of fungi appeared to determine the respiration.

Details

Authors
Organisations
External organisations
  • University of Seville
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Biological Sciences

Keywords

  • Community assembly, Founder control, Fungal to bacterial dominance, Microbial ecology, Microbial growth, Trait distribution
Original languageEnglish
Pages (from-to)69-78
Number of pages10
JournalSoil Biology & Biochemistry
Volume93
Publication statusPublished - 2016 Feb 1
Publication categoryResearch
Peer-reviewedYes