An experimental study of seed ingestion and germination in a plant-animal assemblage in Ghana

Abstract

Fleshy fruits collected from abundant woody plants on the Accra Plains, Ghana, were fed to frugivorous species common in the area. Seeds of each plant species were retrieved from each frugivore species for germination trials, and ingested seeds compared to fresh seeds in germination percentage and rapidity. Altogether 85 plant X animal feeding combinations were attempted. In 73% of trials, ingestion did not affect germination percentage; the remain-ing trials were about equally divided between significant increases and decreases. Ingested seeds had significantly faster germination in 12%, and significantly slower germination in 8%, of the trials. Germination percentages in all samples of fresh seeds ( = 37%) did not differ signifi-cantly from those ingested seeds ( = 31%). There was a significant association between the effect of ingestion on both germination rapidity and percentage (significantly increased, decreased, or neither) and the plant species involved; there was no such association between the effect of ingestion and the animal species. Animals had inconsistent and frequently negligible effects on germination. Two-way analyses of variance (plants X animals) of germination percentage and of germination improvement showed that plant species were a significant source of variation and animal species were not. The fleshy-fruited plants of this assemblage are not generally dependent upon animals for successful germination of their seeds.