Rarefaction analysis of soil AMF samples from Järvselja forest reserve.

<p>Mean VT richness is estimated in relation to the number of reads analysed for subsets of the data representing soil samples collected in different months and from different plots.</p

Variation in the AMF communities present in soil at Järvselja forest reserve.

<p>The results of PERMANOVA analysis are shown. The seasonal model describes variation between sampling month (May, June, July and September) and sample location (SampleID) in Plot A; the spatial model describes variation between Plots A, B and C in September. In the seasonal model, the significance of explanatory variables was not sensitive to their order in the model.</p

Change in soil AMF community similarity as a function of spatial and temporal distance.

<p>A) spatial - soil samples from 10×10 m plots in September and; B) temporal - soil samples from plot A in May, June, July and September. The data points show pairwise similarity estimates between all samples; the bold red line shows the relationship between similarity and distance in the real data; the faint black lines show the same relationship in 1000 randomised data matrices. Note that the x axis does not represent direction in space or time; thus greater values denote the greatest distance between samples – e.g. between May and September – and not the timing or location of samples <i>per se</i>. The slope of the real model was steeper than the randomised set for the spatial model (P<0.01) but not the temporal model (P = 0.57).</p

Sampling design used to study soil AMF communities in Järvselja forest reserve.

<p>Nine soil samples (SampleID 1–9) were collected in each of three 10×10 m plots (A, B and C). See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0041938#pone-0041938-t001" target="_blank">Table 1</a> for further details of the sampling design.</p

Figure 3. Two-dimensional non-metric multi-dimensional scaling (NMDS) plots of variation in soil AMF community composition.

<p>A) in three spatially distinct 10×10 m plots (A–C) in September; and B) in plot A in May, June, July and September.</p

Site by OTU matrix

This file contains the relative abundance matrix of OTU detected in the study by each sample. Metadata is included

The abundance of soil microbes (A) and nutrients (B) in May (open bars) and July (closed bars).

<p>The abundance of arbuscular mycorrhizal (AM) fungi, other fungi and bacteria was estimated as the content of respective ester-linked fatty acid (y-axis on graph A, see Methods for details). Soil N concentration was measured in % (left y-axis of graph B) whereas P and K content were measured as mg/kg (right y-axis of graph B). Significant differences (Linear Mixed-Effect Models; p<0.05) in the measured parameters over time are marked with *.</p

The mean, standard deviation (SD) and the range of the soil nutrient content, ester-linked fatty acid (ELFA) biomarkers of AM fungi, other fungi, bacteria and vegetation characteristics measured at 1 m² scale.

<p>Due to destructive sampling, vegetation characteristics were only measured in plots B and C (see explanation in Methods). Different letters (when present) mark a significant difference among means according to Tukey HSD test (p<0.05).</p

Results of the generalized least square models performed to study the influence of environmental conditions on soil microbes.

<p>For each soil microbial group, the coefficient associated with the explanatory variable is presented. In addition, the AIC weight of the regression model (i.e. its importance as compared to other models containing a different subset of explanatory variables) and the R² are shown. * P<0.05; ** P<0.01.</p

Spatial pattern of soil phosphorus content and abundance of arbuscular mycorrhizal fungi (ester-linked fatty acid 16:1ω5c in soil) in plots A, B and C.

<p>Maps were created by kriging, using data from soil samples collected from 15×15 cm quadrats in each 105×105 cm plot.</p