Seed rain, seed predation and germination of native species in Pinus radiata plantations in south-central Chile: effects of distance to native forest and presence of understory

Abstract

Native vegetation development in forestry plantations may depend on seed dispersal, seed predation and seed germination. These processes may depend on distance to native forest fragments and presence of understory. In this study we evaluated the effect of distance to native forests on seed rain and seed predation and the effect of presence of understory on seed rain, post-dispersal predation and germination in Pinus radiata plantations of Chile. We installed seed traps, Petri dishes with Quillaja saponaria seeds and sowed seeds of this species at different distances to native forest fragments, in plantations with and without understory. The total number of seeds and species richness in the seed rain was negatively correlated to distance to native forests, although only in plantations with understory. The total number of seeds did not vary between plantations with and without understory, but the species richness in the seed rain was higher in the one with understory. Seed predation was not related to distance to native forests, neither was the presence of understory and germination higher in plantations with understory. These results suggest that regeneration of native woody species in plantations is negatively affected by distance to native forest and positively affected by the presence of understory. Thus, forestry management should consider dispersal distances and preservation of understory in plantations in order to improve the biodiversity conservation in forest landscapes.