Seed predation of Araucaria angustifolia Araucariaceae by small rodents in two areas with contrasting seed densities in the Brazilian Araucaria forest

Vieira, E. M.; Ribeiro, J. F.; Iob, G.

doi:10.1080/00222933.2010.536265

We investigated the effects of variation in seed density on small-rodent predation of Araucaria angustifolia seeds. Seed removal experiments were conducted simultaneously in two contrasting stands (seed-poor - planted with the slash pine Pinus elliottii and seed-rich - planted with A. angustifolia) outside the seed production period and also during the seed production period. Predator abundance (evaluated through live-trapping) did not vary significantly between stands. Tracking of thread-marked seeds indicated that rodents frequently move seeds away from the source point and that seed-carrying distance (range 3.91-8.30 m) is not significantly related to area or season. Seed removal rates were high in both areas outside the seed production period but during seed-producing months they were significantly lower in the seed-rich area, supporting the predator-satiation hypothesis. The A. angustifolia strategy of synchronous production of large seed crops but with high between-year variation is potentially successful at limiting the impacts of rodent predators.