Bedrock and biotic influence on on community composition of soils from the Sør Rondane Mountains, East Antarctica

Antarctica is a continent of extremes. Low availability of liquid water and nutrients, extreme low temperatures and high levels of radiation exert high selective pressures on organisms. Consequently, most life forms are microbial. Estimations indicate that as little as 1-3 % of the continental surface represents ice-free regions. Relatively few biological studies focus on terrestrial samples which most often originate from the McMurdo dry valleys that make out the largest contiguous ice-free area. Mountain tops protruding through the ice sheets (nunataks) are less frequently studied although they might function as havens and reservoirs for terrestrial organisms. Geological data shows the presence of different kinds of bedrock in the Sør Rondane mountains (Queen Maud Land, East Antarctica). Patches of macroscopic organisms (lichens, mosses and arthropods) are scattered throughout these ice-free islands, indicating a high amount of variability in the presence of organic matter, and hence nutrients for microbial life. Here we present the results of a large scale sampling effort in the eastern Sør Rondane Mountains of such ice-free regions near the Belgian Princess Elisabeth station. Samples were subjected to both a genetic fingerprinting technique (ARISA) and second generation sequencing (Illumina MiSeq 300PE). We examined the composition and distribution of bacterial communities in these refugia, and investigated the possible impact of environmental parameters on these community compositions.

Jaar van publicatie:2015