Vegetatio

, Volume 98, Issue 1, pp 13–22

Age structure and dynamics of Patagonian beech forests in Torres del Paine National Park, Chile

Authors

  • J. J. Armesto
    • Laboratorio de Sistemática & Ecología Vegetal, Facultad de CienciasUniversidad de Chile
  • I. Casassa
    • Laboratorio de Sistemática & Ecología Vegetal, Facultad de CienciasUniversidad de Chile
  • O. Dollenz
    • Instituto de la PatagoniaUniversidad de Magallanes
Article

DOI: 10.1007/BF00031633

Cite this article as:
Armesto, J.J., Casassa, I. & Dollenz, O. Vegetatio (1992) 98: 13. doi:10.1007/BF00031633

Abstract

This study documents the stem size and age-structure in forests dominated by different species of Nothofagus in Torres del Paine National Park (51° S), in the Chilean Patagonian region. We also explored the relationship between the various types of Nothofagus forest and postglacial succession. Pioneer stands on moraine fields 1–2 km of the glacier front are dominated by Nothofagus betuloides and Nothofagus antarctica. Moraines appear to be first colonized by the evergreen N. betuloides, followed within 5–7 years by deciduous N. antarctica. Nothofagus antarctica may replace the former species and develop monospecific stands on glacial valleys. Most trees in the N. antarctica stand studied were older than 40 years and floods may cause a significant mortality of young trees. Recruitment from seed seems to be infrequent. Old-growth stands dominated by deciduous Nothofagus pumilio occupy more stable substrates, and probably represent the last stage of postglacial succession. This long-lived tree species had recorded ages over 200 years. The canopy of N. pumilio forests appears to be a mosaic of even-aged, old-growth patches. We propose that regeneration episodes follow the blowdown of a large portion of the canopy, with long intervals with little or no regeneration. Windstorms may be an important force influencing the regeneration of N. pumilio. Exogenous disturbances, such as floods and windstorms, are an integral part of the forest cycle in the Patagonian region.

Keywords

Forest successionDisturbanceNothofagusFloodingTree regenerationColonization of morainesPrimary succession
Download to read the full article text

Copyright information

© Kluwer Academic Publishers 1992