. Microsite-dependent changes in Methanogenic Populations in a Boreal Oligotrophic Fen.

Pierre E. Galand, Kim Olavi Yrjälä

Research output: Contribution to journalArticleScientificpeer-review


Wetlands, including peatlands, are the main source of natural methane emission. Well-defined fen microsites have different methane emissions rates, but it is
not known whether the methane-producing Archaea communities vary at these sites. Possible horizontal variations of communities, in a natural oligotrophic
fen, were analysed by characterizing the methanogens from two well-defined microsites: Eriophorum lawn and Hummock. Community structures were
studied at two different layers of the fen, showing, respectively, high and low methane production. The structure of methanogen populations was determined
using molecular techniques targeting the 16SrRNA gene and combined denaturing gradient gel electrophoresis (DGGE) and restriction fragment length
polymorphism (RFLP) analysis. Results subjected to non-metric multidimensional scaling (MDS), diversity indices calculation and phylogenetic analysis revealed that upper layer communities changed with site while deeper layer communities remained the same. Phylogenetic analyses revealed six different clusters of sequences grouping with only two known orders of methanogens. Upper layers of Hummock were dominated by sequences clustering with members of Methanomicrobiales and sequences dominating the upper part of the Eriophorum lawn were related to members of the order Methanosarcinales
. Novel methanogenic sequences were found at both sites at both depths. Vegetation characterizing the microsites probably influences the microbial communities in the layers of the fen where methane is produced.
Original languageEnglish
JournalEnvironmental Microbiology
Pages (from-to)1133 - 1143
Publication statusPublished - 2003
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 1183 Plant biology, microbiology, virology

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