Image: Life in Rocks

 This figure shows a layered community of organisms found in the tufa mounds (carbonate deposits) of Mono Lake, CA.  This environment is characterized by high pH (about 10) and high salinity, but in the rock environment, above the water level, and shielded from the sun by the carbonate rocks, is a healthy and ubiquitous population of photosynthetic cyanobacteria, living in harmony with many other prokaryotic species.