Detection of the horizontal spatial structure of soil fungal communities in a natural forest
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Soil microbes are considered to be a key determinant of the aboveground plant community. They are not distributed uniformly in the environment, and their activity, abundance, and ecosystem functioning could vary across localities, characterized by high β-diversity. Investigating factors that contribute to high β-diversity can help infer the possible mechanisms of microbial community assembly, and predict the scale and extent of impacts that soil microbes have on the plant community. Because soil systems consist of multiple horizons (i.e., vertical stratification) associated with different soil properties, complete understanding of high β-diversity requires consideration of both horizontal and vertical spatial structures of soil microbial communities. We studied the community composition of soil fungi from the O- and A-horizons in a Castanopsis-dominated temperate forest, and compared horizontal spatial autocorrelation in species composition between the two soil horizons (O- versus A-horizons). Pyrosequencing analysis yielded 67,129 sequencing reads, summed across all the 48 forest soil samples. Clustering analysis resulted in 597 molecular operational taxonomic units (OTUs), 68 % of which were identified as fungi, represented by four phyla. The Mantel test revealed that the O-horizon communities are spatially clustered, and the observed high β-diversity was driven not only by changes in OTUs present, but also by high turnover in identities of OTUs in soil samples. Furthermore, Mantel correlogram analysis showed that the O-horizon communities resembled each other in composition within the range of 50 m, whereas the A-horizon communities lacked such horizontal autocorrelation. These differences in the scale patchiness could arise from two processes: (1) that environmental conditions could show higher heterogeneity in finer scale at the A-horizon than at the O-horizon; and/or (2) dispersal could be more frequent at the O-horizon than the A-horizon. The present study suggests that either environmental filtering (i.e., the niche-based process) or dispersal limitation (i.e., neutral process) could characterize the observed patterns of spatial clustering in the soil fungal community.
Keywords454 pyrosequencing Claident Dispersal Ectomycorrhiza ITS DNA sequence Spatial autocorrelation
We thank T Miki and two anonymous reviewers for comments that improved the manuscript. Financial support was provided through the Funding Program for Next Generation World-Leading Researchers of Cabinet Office, the Japanese Government (GS014) to HT.
Conflict of interest
The authors declare no conflict of interest.
- Abarenkov K, Nilsson RH, Larsson H-K, Alexander IJ, Eberhardt U, Erland S, Høiland K, Kjøller R, Larsson E, Pennanen T, Sen R, Taylor AFS, Tedersoo L, Ursing BM, Vrålstad T, Liimatainen K, Peintner U, Kõljalg U (2010) The UNITE database for molecular identification of fungi—recent updates and future perspectives. New Phytol 186:281–285PubMedCrossRefGoogle Scholar
- Legendre P, Legendre LFJ (1998) Numerical ecology. Elsevier Science, AmsterdamGoogle Scholar
- Martiny JBH, Eisen JA, Penn K, Allison SD, Clair Horner-Devine M (2011) Drivers of bacterial β-diversity depend on spatial scale. Proc Nat Acad Sci USA 108:7850–7854Google Scholar
- Nilsson RH, Tedersoo L, Lindahl BD, Kjøller R, Carlsen T, Quince C, Abarenkov K, Pennanen T, Stenlid J, Bruns T, Larsson K-H, Kõljalg U, Kauserud H (2011) Towards standardization of the description and publication of next-generation sequencing datasets of fungal communities. New Phytol 191:314–318CrossRefGoogle Scholar
- Oksanen J, Blanchet GF, Kindt R, Legendre P, Minchin PB, O’Hara RB, Simpson GL, Solymos P, Stevens MHH, Wagner H (2012) Vegan: community ecology package. R package version 2.0–9. http://CRAN.R-project.org/package=vegan
- R Development Core Team (2012) R: A language and environment for statistical computing. R Foundation for Statistical Computing, ViennaGoogle Scholar
- Ranjard L, Dequiedt S, Chemidlin Prevost-Boure N, Thioulouse J, Saby NPA, Lelievre M, Maron PA, Morin FER, Bispo A, Jolivet C, Arrouays D, Lemanceau P (2013) Turnover of soil bacterial diversity driven by wide-scale environmental heterogeneity. Nature Comm 4:1434Google Scholar
- Tanabe AS (2012) Assams v0.1.2012.05.24. http://www.fifthdimension.jp/