In association with a devastating earthquake in 1960, thousands of debris avalanches, landslides, and mudflows occurred in
the Andes of south-central Chile. Catastrophic mass movements associated with seismic activity have affected the Andes of
south-central Chile several times in the past 400 years and have profoundly influenced the regional vegetation.
The most widespread forest types in the Andean Cordillera of the Province of Valdivia (latitude 39°25′ to 40°40′ S) are dominated
byNothofagus spp. andEucryphia cordifolia and characteristically have an intermediate layer of shade-tolerant trees. These forest types represent relatively early
successional phases following forest destruction by catastrophic phenomena. The supporting evidence for this interpretation
includes: (1) the nature of the colonization of the surfaces exposed by the 1960 mass movements, (2) the structure of the
existing forest vegetation, (3) the ecological characteristics of the dominant trees, and (4) the historical frequency of
similar catastrophic events in the Andes of south-central Chile.
Keywords Andes - Catastrophic events - Chile - Colonization - Fire - Forest structure - Nothofagus forest - Succession - Vulcanism
Nomenclatural authorities are given at the first mention of the species in Tables 6, 7, and 9, or at their first mention in
the text for those species not included in the tables.
Part of this work was supported by Celulosa Panguipulli Ltda. We are grateful to Dr. C. Ramírez of the Universidad Austral
for checking our initial plant identifications, to Dr. J. Díaz-Vaz of the Universidad Austral for identifying charcoal samples,
and to Dr. F. Schlegel and Dr. J. Schlatter of the Universidad Austral for discussing with us some aspects of vegetation and
soils in south-central Chile. We thank A. Veblen for assisting in the field and critically reading the manuscript. Dr. J.
Schlatter provided analyses of soil samples.
Sponsored by the Smithsonian-Peace Corps Environmental Program.