Electron donor‐driven bacterial and archaeal community patterns along forest ring edges in Ontario, Canada

Abstract

Forest rings are 50-1600 m diameter circular structures found in boreal forests around the globe. They are believed to be chemically reducing chimney features, having an accumulation of reduced species in the middle of the ring and oxidation processes occurring at the ring's edges. It has been suggested that microorganisms could be responsible for charge transfer from the inside to the outside of the ring. To explore this, we focused on the changes in bacterial and archaeal communities in the ring edges of two forest rings, the 'Bean' and the 'Thorn North' ring, in proximity to each other in Ontario, Canada. The drier samples from the methane-sourced Bean ring were characterized by the abundance of bacteria from the classes Deltaproteobacteria and Gemmatimonadetes. Geobacter spp. and methanotrophs, such as Candidatus Methylomirabilis and Methylobacter, were highly abundant in these samples. The Thorn North ring, centred on an H S accumulation in groundwater, had wetter samples and its communities were dominated by the classes Alphaproteobacteria and Anaerolineae. This ring's microbial communities showed an overall higher microbial diversity supported by higher available free energy. For both rings, the species diversity was highest near the borders of the 20-30 m broad ring edges.

Biogeochemical Behavior of Metals Along Two Permeable Reactive Barriers in a Mining‐Affected Wetland

“…To better understand the biogeochemical conditions in the investigated environment and the potential impact of the waste stream on microbes, DNA was extracted from peat (2017) and mineral soil (2018) samples from the field. DNA was isolated using the FastDNA SPIN Kit for soil (MP Biomedicals), and 16S rRNA was amplified by polymerase chain reaction following the 16S Metagenomic Sequencing Library Preparation Guide by Illumina () and using the universal bacterial and archaeal primers F515 (5′‐GTGCCAGCMGCCGCGGTAA‐3′) and R806 (5′‐GGACTACHVGGGTWTCTAAT‐3′; von Gunten et al, ). Sequencing was performed on an Illumina MiSeq platform for pair‐end reads using the Illumina NexteraXT library preparation kit.…”

Potential for natural hydrogen in Quebec (Canada): a first review

“…Dissolved methane sampled in the centre of forest rings is of biogenic origin (Hamilton et al, 2004), as is the CO 2 sampled in ring soils (Majeed, 2020). Some of the forest rings studied are further characterized by specific autotrophic microorganism communities (von Gunten et al, 2018).…”

Barren ground depressions, natural H2 and orogenic gold deposits: Spatial link and geochemical model

“…Karst development and human activity cannot explain all the observations made here, suggesting that other mechanisms related to the presence of orogenic gold deposits are involved in the development of ground depressions and self-organized spots of barren soil. S. Hamilton, who first proposed the reduced column model on which the model of Figure 6 is based (Hamilton, 1998), also studied geomorphological structures known as forest rings in boreal forests in Ontario (Canada; Hamilton and Hattori (2008); Brauneder et al (2016);von Gunten et al (2018)). Forest rings are depressed circular features commonly exceeding 500 m in diameter with a low tree density.…”