08/26/2026
Tree bark covered with lichens may look like a simple textured surface, but at miniature scale it can form a surprisingly complex habitat. Cracks in bark, lichen branches, moss and trapped organic debris create humid refuges and feeding sites for numerous tiny invertebrates.
Springtails are frequent inhabitants of these microhabitats. Many feed on fungi, algae, microorganisms and decomposing material. Their characteristic furcula—a forked structure folded beneath the abdomen—allows many species to launch themselves rapidly away from danger.
Mites are another extremely diverse group found among lichens and bark crevices. Depending on the species, they may consume fungi and decaying material or prey upon other microscopic organisms.
Pseudoscorpions are miniature predators. Despite resembling tiny scorpions, they lack the long tail and sting. Instead, their enlarged pedipalps are used to seize small prey such as mites, springtails and other arthropods.
Barklice, or psocids, commonly graze on algae, fungi, lichens and microscopic organic films growing on bark. Small spiders may hunt among the same structures, turning a patch of lichen into a miniature predator-prey community.
Tiny snails, beetle larvae and moth larvae can also occur in bark-and-lichen habitats, although exactly which species are present depends strongly on climate, tree species, moisture and the type of lichen.
Lichens therefore contribute more than color to a tree trunk. Together with rough bark, mosses and accumulated debris, they increase structural complexity and provide shelter, food and hunting surfaces for an entire community that can easily go unnoticed without close inspection.