Physical, chemical and microbial soil properties of frost boils at Browning Peninsula, Antarctica

Abstract

In a pilot study, we examined whether frost boils grossly mask the effect of site by comparing physical, chemical and microbial soil properties between the middle and edge of frost boils on remote and understudied Browning Peninsula, Antarctica. In addition, we determined the degree to which soil microbial community structure can be attributed to frost boil physical and chemical soil properties. Principle components (PCs) of physical and chemical soil properties and of microbial soil properties were compared between the middle and edge of frost boils and between frost boil replicates. Despite higher soil moisture, % C, % S and % N, pH, total DNA, 16S copy number, total phospholipid fatty acids, bacteria, fungi, proteobacteria, anaerobes, gram-positive bacteria and eukaryotes at frost boil edges, PCs were not significantly different between edge and middle positions. Physical and chemical soil properties between frost boil replicates differed significantly, but not microbial communities. In non-metric multidimensional scaling (NMS) ordinations, soil microbial community structure was affected by differences in frost boil replicates and some frost boil replicates were well separated. Therefore, site factors may play a critical role in determining the soil characteristics of frost boils. It remains to be seen whether stronger gradients in physical, chemical and microbial soil properties will develop across frost boils with continued warming of Antarctic soils. Frost boils may have subtle effects and require consideration in long-term sampling design for understanding the effects of climate change.