The Alerce forests were characterized and classified into subtypes, on the basis of the study and analysis of two areas (25.000 and 15.000 hectares) of the Alerce forest type located in the Andean and Coastal Mountain ranges respectively. The present national and international status of this forest type is clarified from the conservational point of view. The study defines and ecologically characterizes 5 almost undisturbed forest subtypes (Alerce-Coigue from Chiloe, Alerce-Coigue from Magallanes and Alerce-Cipres from Las Guaitecas in the Andes Mountains, and pure Alerce and mixed Alerce in the Coastal Mountains)*, and 1 marginal subtype, which represents an ecotone with evergreen forest type in both Mountains Ranges. Areas with different levels of disturbance, derived from exploitation, forest fires and a mixture of both disturbance agents, are also analyzed.