Microbial community composition but not diversity changes along succession in arctic sand dunes

Abstract

Summary The generality of increasing diversity of fungi and bacteria across arctic sand dune succession was tested. Microbial communities were examined by high‐throughput sequencing of 16S rRNA genes (bacteria) and internal transcribed spacer (ITS) regions (fungi). We studied four microbial compartments (inside leaf, inside root, rhizosphere and bulk soil) and characterized microbes associated with a single plant species (Deschampsia flexuosa) across two sand dune successional stages (early and late). Bacterial richness increased across succession in bulk soil and leaf endosphere. In contrast, soil fungal richness remained constant while root endosphere fungal richness increased across succession. There was, however, no significant difference in Shannon diversity indices between early and late successional stage in any compartment. There was a significant difference in the composition of microbial communities between early and late successional stage in all compartments, although the major microbial OTUs were shared between early and late successional stage. Co‐occurrence network analysis revealed successional stage‐specific microbial groups. There were more co‐occurring modules in early successional stage than in late stage. Altogether, these results emphasize that succession strongly affects distribution of microbial species, but not microbial diversity in arctic sand dune ecosystem and that fungi and bacteria may not follow the same successional trajectories.

Soil Microbial Networks Shift Across a High-Elevation Successional Gradient

“…Some of the changes in relative abundance observed here agree with findings from other studies, such as an increase in Verrucomicrobia (Nemergut et al, 2007) and Acidobacteria (Nemergut et al, 2007;Yarwood and Högberg, 2017) over succession and an abundance of cyanobacteria (Schmidt et al, 2008;Zumsteg et al, 2012;Yarwood and Högberg, 2017) and algae (Kaštovská et al, 2005) in early successional stages. However, some of our results differ from prior studies that show decreases in Actinobacteria (Zumsteg et al, 2012;Poosakkannu et al, 2017) and shifts from Ascomycota to Basiodiomycota (Zumsteg et al, 2012) with succession in alpine and arctic areas, suggesting that succession may proceed differently at different sites even at a broad taxonomic level.…”

“…Recent work suggests that the composition of microbes changes considerably and predictably during primary succession (Nemergut et al, 2007;Tarlera et al, 2008;Roy-Bolduc et al, 2015;Poosakkannu et al, 2017), with certain groups like Actinobacteria and N fixers prevalent in early successional stages, and other groups such as Acidobacteria and mycorrhizal taxa dominating later stages (Rime et al, 2015;Poosakkannu et al, 2017;Yarwood and Högberg, 2017). Much work also suggests that the taxonomic diversity (Nemergut et al, 2007;Tarlera et al, 2008;Brown and Jumpponen, 2014;Rime et al, 2015;Poosakkannu et al, 2017) and functional diversity (Tscherko et al, 2003) of soil bacterial and fungal communities generally increase during succession. However, some studies find decreases, no change, or variable patterns for some or all taxa (Sigler and Zeyer, 2002;Brown and Jumpponen, 2014;Dini-Andreote et al, 2014;Poosakkannu et al, 2017).…”

“…Much work also suggests that the taxonomic diversity (Nemergut et al, 2007;Tarlera et al, 2008;Brown and Jumpponen, 2014;Rime et al, 2015;Poosakkannu et al, 2017) and functional diversity (Tscherko et al, 2003) of soil bacterial and fungal communities generally increase during succession. However, some studies find decreases, no change, or variable patterns for some or all taxa (Sigler and Zeyer, 2002;Brown and Jumpponen, 2014;Dini-Andreote et al, 2014;Poosakkannu et al, 2017).…”

Native arbuscular mycorrhizal symbiosis alters foliar bacterial community composition

“…DNA was extracted from the homogenized leaf (100 mg) and root (100 mg) material from each plant using Invisorb Spin Plant Mini Kit (Stratec molecular). We used the M13 system (Mäki et al 2016) for library preparation as described by Poosakkannu et al (2017). In brief, a nested approach was used to amplify the partial 16S rRNA genes; the first round of 16S rRNA amplification was performed with primers 799F (5´-AACMGGATTAGATACCCKG-3´) and 1492R (5´-GGYTACTTGTTACGACTT-3´) which excludes plant chloroplast amplification (Chelius and Triplett 2001).…”

“…Distinct factors such as plant part inhabited, host genotype and soil type affect the plantassociated microbial assemblage (Lundberg et al 2012;Edwards et al 2015;Coleman-Derr et al 2016;Robinson et al 2016;Poosakkannu et al 2015;Poosakkannu et al 2017).…”