Fig. 1

Location of the study sites and sampling strategy. A. Geomorporhic distribution of the soil covered mantle of Lo Encañado Valley with drainage classes for each geomorphic unit. The floodplain is represented by 3 geomorphic units being a very poorly drained Fen, poorly drained Meadow and somewhat poorly drained Meadow. Hillslopes are represented by colluvial deposits facing south and north. Each position occupied in the landscape represents according to the USDA (2012) [16] a different drainage class which is referred to the frequency and duration of wet periods under conditions similar to those which the soil developed. Drainage class numbers go in a scale from number representing the less well drained (or most saturated soils) up to number 6 representing the excessively drained soils (LE01: poorly drained, LE02: somewhat poorly drained, LE03: somewhat excessively drained, LE04: well drained, LE05: very poorly drained). Arrows represent the position of the soil profiles at Lo Encañado. B. Vegetation present at each site with dominant species shown in each site as a colored box C. Soil profiles described and sampled at each site. Numbers (H1, H2...) represent a pedogenetic horizon, which are distinguishable among them as they express different morphological properties which are defined in the Field. As pedogenetic horizons are not fixed depth, a scale of 1m is shown for each profile. Violet dashed line with asterisk represents the limit between topsoil and subsoil according to soil bacterial community clustering