Network analysis based on Pearson correlations considering the most abundant OTUs obtained by pyrosequencing.

The circles of the different colors indicate the taxonomic identification of each OTU (see Fig 2). The shaded shapes with dotted edges indicate the soil samples where the OTUs were more abundant: [Ct], Control; [Ag], Arctocephalus gazella; [Ml], Mirounga leonina; [Ld], Larus dominicanus; [Pa], Pygoscelis antarctica and [Pp], P. papua.