Climate change is an important threat for biodiversity, and in particular, for lichens. Lichens are photosynthetic symbiotic organisms that are sensitive to climate variations and to atmospheric contamination. Lichens are bioindicators, and since they help us better understand environmental conditions, they are a natural meter for atmospheric conditions and radioactive contamination, certain phenomena like acid rain, small changes in temperature, or humidity in the environment. This project's objective is to analyze the distribution and diversity of lichens in general, and the use of some representative species and indicators, already used in California and other parts of the world. Researchers and students of CICESE and UABC will participate.