Some bacterial colonies derive energy from soil sulfur compounds. Fungal species may parasitize the algae and cyanobacteria or unite with them to form lichens. Moss species weave the whole community together. In the sub-stone microhabitats roam protozoa, nematodes, mites, and other arthropods, creating a microcosm where grazers and predators feed on bacteria, algae, fungi, detritus, or each other. Even exposed, porous desert rocks can support life.
Crustose lichens are the most conspicuous species found on hot desert surfaces.
These lichens can endure many months of dehydration, and can continue photosynthesizing at temperatures where other plants would shut down. But even these lichens have a limit, and when their threshold is exceeded, they are replaced by bacteria. The colonies obtain energy from inorganic and organic substances. They adsorb submicroscopic particles of wind-borne clay particles to their cellular surfaces to form a thin layer that protects them from direct sunlight. Interstitial Species Algal colonies may exist in places where neither lichen nor bacteria have been able to gain a foothold.