Ecological consequences of primary and secondary seed dispersal on seed and seedling fate of Dipteryx oleifera (Fabaceae)

The relative contributions of primary and secondary seed dispersal to plant demography have received little investigation. Evidence on these seed dispersal types, on seed fate and seedling recruitment of the tropical rain forest tree Dipteryx oleifera, is presented. The study was conducted in a 6.37ha permanent plot where seeds and seedlings were located and tagged for the 2007 cohort. A total of 2 814 seeds were threaded and their fate was followed one year after germination. Primary seed dispersal by bats protected seeds from insect larval predation below the adult tree. Bats congregated seeds in bat seed piles located at a mean distance of 40.94±1.48m from the nearest adult individual of D. oleifera. Terrestrial vertebrates congregated seeds in caches located 41.90±2.43m from the nearest adult individual of D. oleifera. The results of the fitted proportional hazard model suggested that primary seed dispersal decreased seed hazard probability by 1.12% for each meter from the adult conspecific (p<0.001) and that secondary seed dispersal decreased it by 23.97% (p<0.001). Besides, the odds ratio regression models results showed that the overall effect of unviable seeds was a reduction in viable seed predation rate. For each unviable seed deposited by bats into the seed piles, the rate of seed predation by terrestrial vertebrates decreased 6% (p<0.001). For each damaged seed by terrestrial vertebrates in the seed piles, the rate of germination decreased 4% (p