With the purpos e of demonstratin g hybridization betwee n Nothofagus dombey i (Mirb.) Oerst. and Nothofagus betuloide s (Mirb.) Oerst. and betwee n N. dombey i and Nothofagus nitida (Phil.) Krasser, material was collected from trees of the supposed parent trees and th e hybrid s in Antillanca and Anticur a sections of the Puyehu e Nationa l Park. In order to analyz e and prove hybridization between N. dombey i and N. betuloides the hybrid index, enhance d by a statistic test, was used togethe r with a pictorialized scatter diagram and chromatographi c analysis with the phenoli c compound s of the leaves. For analyzing hybridization between N. dombeyi and N. nitida only the chromatographi c metho d was used because only youn g hybrid trees withou t flowers and fruits were found.
Results clearly demonstrat e hybridization between N. dombey i and N. betuloides and suggest that the hybrid trees found, belong to the firts generation originated from a crossing between two species. The chromatographic analysis performed for N dombeyi x N. nitida also shows the hybri d conditions of the studied trees; the sites wher e these hybrids were found permit advancing the hypothesis tha t hybridization occurs unde r conditions wher e disturbanc e has determined a hybrid habitat.