Endozoochory by lowland tapirs improves seed germinability and accelerates germination time of native plant species in an Amazon-Cerrado transition restoration area

Abstract

Endozoochory by lowland tapirs (Tapirus terrestris) is regarded as a key seed dispersal mechanism in tropical forests and thus potentially useful for ecological restoration. Although previous studies attested the germination ability of seeds defecated by T. terrestris, no study has tested how tapir endozoochory affects the seed germination process in degraded lands. In an ecological restoration area in the Amazon-Cerrado transition, we ran germination trials to compare seed germination percentage and number of days until seed germination of six native plant species found in tapir feces with manually-scarified and manually-depulped (control) seeds. For all six plant species assessed, germination percentage was statistically higher and the number of days until seed germination was statistically lower for tapir-ingested seeds and manually-scarified (compared to control seeds). Results from the germination trials showed that tapir endozoochory was associated with higher seed germinability and accelerated germination time compared to manually-depulped seeds, likely because seed dormancy breaking is favored by the combined mechanical scarification and depulping during tapir gut passage. In summary, the seed germination advantages conferred by lowland tapir endozoochory can improve seedling recruitment and foster native vegetation restoration in South American tropical forests.