Lichens covering a cliff wall in the Sierra de la Demanda, La Rioja, Northern Spain

algae, areolate lichen, biodiverse, biodiversity, bush-like lichen, cliff wall, composite organism, crustose lichen, cyanobacteria, environmental conditions, environmental endurance, exposed rock surfaces, extreme environments, filamentous lichen, foliose lichen, fruticose lichen, fungal filaments, fungi, hyphae, la rioja, leafy lichen, leprose lichen, lichen, lichen morphology, lichenometry, long lifespan, long-lived, macrolichen, microecosystem, microhabitats, microlichen, microorganisms, moisture, mutualistic relationship, mutually beneficial symbiotic relationship, non-mutualistic symbiosis, northern spain, nutrients, photosynthesis, reindeer moss, rhizines, rimose lichen, sierra de la demanda, slow growth rate, squamulose lichen, substrate, symbiosis, symbiotic, symbiotic organism, thallus,