PARENT SESSION
Poster Session #14: Dispersal.
Monday, August 5. Presentation from 5:00 PM to 6:30 PM. Exhibit Hall B & C, TCC
140
Distance-dependent effects on patterns of secondary seed movement, infestation, and predation of two neotropical palms.
PATRICK, LISA*,1, NOTMAN, EVAN2, VILLEGAS, ANA2, 1 Barnard College, New York, NY2 Organization for Tropical Studies, Costa Rica
ABSTRACT- Although studies of seed predators have frequently found evidence for distance and/or density dependent seed predation, little is known about how these factors might influence secondary dispersal. This study investigated patterns of secondary seed dispersal and its subsequent influence on insect infestation and mammal predation for two species of palms (Welfia regia &Iriatea deltoidea) in lowland primary forest at La Selva Biological Station in Costa Rica. The relative importance of different mortality sources (vertebrate vs. invertebrate) and the interaction of mortality source with distance from the parent tree were quantified. Ten fruiting individuals of each species were chosen as focal trees and 20 seeds were placed around each tree, 10 in wire cages (vertebrate exclosures) and 10 unprotected, but attached to nylon thread in order to follow seed movement. Seeds were also placed 10 m from each focal tree in the same treatments. Seeds were checked weekly for movement, predation (mammal or insect) and germination. After seven weeks, significantly more seed movement was found within 10 m of the focal tree for both species. Moved seeds from below the parent tree were also found to experience greater mammal predation than seeds moved from the 10 m distance treatment. Neither the number of seeds infested, nor the number of beetle holes were related to distance. Beetle activity appears to be related to the presence of a fungal pathogen.
KEY WORDS: seeds, palms, predation, dispersal