PNNL

Abstract

Increasing salinization in wetland systems is a major threat to ecosystem services carried out by microbial communities. Therefore, it is paramount to understand how salinity drives both microbial community structures and their diversity. Here we selected a range of highly saline soils (EC1:5 from 5.96 to 61.02 dS/m) from the Odiel Saltmarshes (SW Spain) and evaluated how the prokaryotic community structures and diversity were correlated to soil salinity and other soil physicochemical features. We found that these soils harbored unique communities mainly comprised of halophiles from the phyla Euryarchaeota, Proteobacteria and Bacteroidetes. Among the most abundant genera we found groups known for thriving in other hypersaline environments (Halorubrum, Natronomonas and Salinibacter) as well as others from which limited environmental information is available (Salinimicrobium, Fodinibius). In the studied soils, several site-specific properties, but not salinity, were correlated to the microbial community structure and individual abundances of individual genera. Therefore, the dominant halophiles residing in these soils are already well-adapted to a wide range of salinities.