What organisms grow on the sides of trees and on rocks and logs?

Organisms that grow on the sides of trees, rocks, and logs are often various types of lichens and mosses. Lichens are a symbiotic association between fungi and algae or cyanobacteria. They can be found on a variety of surfaces, including tree bark, rocks, and soil. Mosses are small, non-vascular plants that thrive in moist environments, and they are commonly found on the sides of trees, rocks, and logs. Both lichens and mosses play important roles in ecological processes and contribute to the biodiversity of their habitats.