Key Words: Foliicolous lichens, distribution ecology, species composition, Central America. The studies on distribution ecology of foliicolous lichens in Costa Rica are continued. An analysis of 36 different localities revealed that species composition is directly related to vegetation type or climate, and nine groups of localities with different and characteristic species composition may be distinguished: undisturbed lowland rain forests (0-800 m), disturbed lowland vegetation, undisturbed montane rain forests (800-1700 m), disturbed montane vegetation, undisturbed highland cloud forests (1700-2700 m), disturbed highland vegetation, moderately dry forest, dry forest, and highly disturbed vegetation used by man. Many species showed significant correlations to at least one of these groups.