Total soil organic C, total N, labile C, recalcitrant C, microbial Penicillin G C and labile/recalcitrant C ratio were greater away from the glacier front, and decreased with increasing proximity to the glacier. This is consistent with pedogenesis (time factor), since these areas are longer exposed and have greater vegetation establishment (Thomazini et al., 2014). Hence, increases in the general soil organic matter parameters with distance from the glacier front are probably explained by a corresponding increase in soil development (La Scala et al., 2010, Mendon?a et al., 2010 and Cannone et al., 2012). With longer time of exposure, higher is the input of C in the soil by organisms such as lichens, grasses, birds, penguins and soil microbiota (Tatur et al., 1997, Simas et al., 2007, Mendon?a et al., 2010 and Cannone et al., 2012). This, in turn, favors the soil formation and organic C accumulation (Michel et al., 2006 and Cannone et al., 2012). Generally, sites with well developed vegetation communities tend to have greater total soil organic C and total N than sites without vegetation (Park et al., 2007). In sites near the glacier, erosion is intense and soils are less developed and have lower soil organic matter (Carvalho et al., 2012). Michel et al. (2006) reported soil organic C in Antarctic soils ranging from 10 to 140 g kg− 1. Simas et al. (2007) showed that at the surface, high organic matter accumulation forms dark brown umbric epipedons and in poorly drained areas, part of the organic matter is preserved within the permafrost. Since the organic C preservation is highly dependent on soil temperatures, long-term increases in air temperatures will decrease the background organic C reservoir of Antarctica soils (Mendon?a et al., 2010 and Michel et al., 2012). According to the PCA, the well formed groups in the bi-plot diagram (Fig. 5) are directly related to the variables related to soil organic matter status and vegetation appearance (labile C input) in the glacier retreat zone. There is a trend of higher labile/recalcitrant C ratio that is confronted with lower degree of humification in soil organic matter in soil samples away from the glacier. This is also demonstrated in the GC/MS pyrolysis analysis, where compounds identified in soil samples away from the glacier are more sensitive to mineralization.