Cyanobacteria are also very common in hypolithic communities that are microbial communities growing under translucent rocks such as quartz rock. These communities can be a mixture of cyanobacteria, other bacteria, green algae, protists, mosses, lichen and fungi.
It is still very little known about these hypolithic communities. As environmental conditions in Antarctica are extreme scientists believe that hypolithic habitats can provide some protection from high UV radiation and rapid fluctuation of freeze-thaw processes. The Dry Valleys are cold deserts with very limited liquid water and hypolithic rock habitats provide an increased water availability through water condensation processes on the rock surfaces.
Below the same quartz rock
The green spots on the bottom of the rock are cyanobacterial communities
Green hypolithic community growing around the bottom of a small quartz rock