Relationships Among Climate and Geochemical Drivers with Viral and Microbial Community Composition of Northern Poor Fen Peatlands
Abstract
Viruses are among the most abundant entities on Earth and play important roles in biogeochemical cycling, food web interactions, controlling of bacterial abundance and gene transfer. These viral mechanisms can influence and mediate greenhouse gas production in carbon rich environments such as northern peatlands, but further research is needed to understand their role.
To assess the relationship of climate on the peatland virome and its effect on methane production, we studied four poor fen peatlands with similar geochemistry but distributed along a contrasting climate gradient including: tundra (Daring Lake, NWT), boreal forest (Lutose, AB), temperate broadleaf (Bog Lake, MN) and mixed forest (Chicago Bog, NY). Soil samples were collected during the summer of 2018 and extraction of virus like particles (VLPs) was optimized. VLP samples were counted using SYBR gold and silica beads. Viral and microbial community composition was analyzed with canonical correspondence analysis (CCA) and regression of environmental variables to determine the major drivers of community composition. Results show that Saline Magnesium (SM) buffer was more effective at extracting VLPs from soil, SM buffer: 1.96 x 108 versus Amended Potassium Citrate buffer: 1.34 x 108 (p <0.05). SM buffer extracted VLPs were counted across all sites and ranged from 2.28 -4.69 x 108, with Daring lake: 4.24 x 108, Lutose Bog: 2.48 x 108, Bog Lake: 4.21 x 108 and Chicago Bog: 3.66 x 108 g-1 soil. CCA of the microbial community (based on 16S rRNA gene amplicon sequencing) with regression of environmental variables and VLP counts indicated that VLPs g-1 soil (r2=0.83), soil pH (r2=0.78), mean annual temperature (r2=0.75) mean annual precipitation (r2=0.75) and dissolved methane (r2=0.56) were significant (p <0.05). These findings imply that climate, pH, methane production and viral predation are tightly coupled with northern peatland microbial communities. Viral size-fraction metagenome (virome) preparation from these samples is ongoing. Regression analysis of viral community composition will allow for a more in depth understanding of how climate variables and host-virus dynamics can affect the carbon decomposition cascade and greenhouse gas production of northern peatlands.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.B51F2311S
- Keywords:
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- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0428 Carbon cycling;
- BIOGEOSCIENCES;
- 0448 Geomicrobiology;
- BIOGEOSCIENCES;
- 0465 Microbiology: ecology;
- physiology and genomics;
- BIOGEOSCIENCES