Biocrusts from Iceland and Svalbard: does microbial community composition differ substantially?. undefined

A wide range of microorganisms inhabit biocrusts of arctic and sub-arctic regions. These taxa live and thrive under extreme conditions and, moreover, play important roles in biogeochemical cycling. Nevertheless, their diversity and abundance remain ambiguous. Here, we studied microbial community composition in biocrusts from Svalbard and Iceland using amplicon sequencing and epifluorescence microscopy. Sequencing of 16S rRNA gene revealed the dominance of Chloroflexi and Acidobacteria in the studied biocrusts, while Embryophyta, Trebouxiophyceae and Metazoa prevailed in the 18S rRNA sequencing dataset. Furthermore, cyanobacterial number of cells and biovolume exceeded the microalgal in the biocrusts. Community dissimilarities were explained by the measured chemical parameters such as conductivity, pH, soil organic matter and mineral nitrogen contents. In addition, co-occurrence analysis showed the dominance of positive potential interactions and, bacteria and eukaryotes co-occurred more frequently together.