Microbial Communities of Mojave Desert Biological Soil Crusts are Shaped by Dominant Photoautotrophs and the Presence of Hypolithic Niches

Many of the critical functions performed by biocrusts are influenced by the composition of their bacterial communities, which may, in turn, depend on small-scale biocrust features like the presence of mosses or hypolithic spaces. Hypoliths occur when semi-translucent stones (usually quartz) are partially embedded in the soil surface. Since they receive sufficient light for photosynthesis, hypolithic spaces under quartz stones support their own biocrust communities. We know that the presence of mosses impacts the composition of bacterial taxa living in biocrusts on the soil surface, but we were curious as to how bacterial community composition might compare between these surface biocrusts and hypoliths. We used 16s rDNA sequencing to identify bacteria living in surface and hypolithic biocrusts, with and without moss cohabitants.