Revista Chilena de Historia Natural 82 (3): 319-335, 2009
RESEARCH ARTICLE
Efectos de la producción de semillas y la heterogeneidad vegetal sobre la supervivencia de
semillas y el patrón espacio-temporal de establecimiento de plántulas en Araucaria araucana
Seedling establishment may be limited by a poor seed production and/or granivory, or the
availability of microsites for germination and plant growth. Seed dispersal and survival from mother tree could determine the spatial
pattern of seedling establishment and the literature proposes several distance mother-recruit models. We studied the effects of
masting, seed predation and understory vegetation on seedling establishment in A. araucana. Using tree cone production
and seed survival data and through seedling surveys in different microsites we evaluated the temporal and spatial establishment
pattern. In the study site A. araucana showed a pulsed pattern for seedling establishment, synchronized
among trees, and associated with masting due to an increase of seed survivorship. At dense microsites, mainly Chusquea
bamboo, seedling regeneration was strongly inhibited by an excessive seed predation and not due to competition with the
bamboo. The observed distance mother-recruit pattern mainly fits the Janzen-Connell model that considers the increase of seed
survivorship with distance and the establishment peak occurrence at intermediate distances from the seeding tree. However, we
detected a significantly difference on the distance mother-recruit between seedlings and saplings, presumably due to differential age-
and distance- dependent mortality patterns. These results suggest that the occurrence of A. araucana regeneration is
mainly controlled by seed production and granivory, and its interaction with vegetation, modulate the seedling establishment
intensity.
Key words:
Araucaria
araucana, establishment, Janzen-Connell model, masting
