Geochemical and microbial co-succession in a High-Arctic proglacial area

Recently deglaciated environments are ideal for studying the initial development of soils through the co-sucession of freshly exposed rock weathering and microbial ecosystems. Carbon (C), nitrogen (N) contents as well as pH and soil composition are thought to be dominant controls on soil microbial community structure development. However, the functional linkages between C and N contents, soil composition and microbial community structure remain poorly understood. Here, we examined the variations in geochemical properties and associated microbial structure along a transect in the proglacial area of a High-Arctic glacier (Longyearbreen, Svalbard). Our results reveal that C and N contents and isotopic compositions as well as weathering advancement and microbial abundance and community structure change in tandem along the transect. We found significant relationships between microbial and fungal community structures and total organic carbon (TOC), total nitrogen (TN) as well as Ca, Mg and Si. We suggest that the observed microbial and geochemical co-succession patterns of changes along our transect are primarily the result of the geomorphological heterogeneity of the progalcial terrain.