Revista chilena de historia natural
versión impresa ISSN 0716-078X
SANGUINETTI, JAVIER y KITZBERGER, THOMAS. Araucaria araucana temporal and spatial seedling establishment patterns: masting, seed predation and understory vegetation effects. Rev. chil. hist. nat. [online]. 2009, vol.82, n.3, pp. 319-335. ISSN 0716-078X. doi: 10.4067/S0716-078X2009000300001.
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 intermedíate 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.
Palabras clave : Araucaria araucana; establishment; Janzen-Connell model; masting.