Seed Dispersal and Regeneration in a Tanzanian Rain Forest

Many plants have complicated relationships with rodents- just think of squirrels and acorns. They collect acorns and bury them all over the place, intending to come back and eat them later. As far as the plant is concerned, it's a mixed bag to deal with a squirrel. On the one hand, it eats and kills most of the seeds. But on the bright side, the unwitting foresters inevitably forget a few seeds, which have the opportunity to sprout.

Part of my dissertation, "Seed dispersal and regeneration in a Tanzanian rain forest," focuses on a valuable canopy tree (Allanblackia stuhlmannii) and the role of giant pouched rats (Cricetomys gambianus) in dispersing its seeds. The seeds of Allanblackia can be pressed for vegetable oil and provide a source of income to people living in the East Usambara Mountains of Tanzania. It is important to understand what affects Allanblackia regeneration to ensure that seed harvest is sustainable. I tracked the fate over 1000 Allanblackia seeds to determine which animals dispersed the seeds, how far they were moved, and whether or not the seeds germinated. Giant pouched rats were overwhelmingly the most common dispersers and the furthest seed movement we recorded was 95 meters. Although few tagged seeds germinated, each tree needs only one adult offspring from the thousands of seeds produced over the course of its lifetime to keep the population stable.

I expect to finish my Ph.D. in Biological Sciences at the University of Illinois at Chicago (USA) in 2013. In addition to funding for this project from the Rufford Small Grants for Nature Conservation, National Science Foundation Graduate Research Fellowship (NSF GRF) & Integrative Graduate Education and Research Traineeship (NSF IGERT), and the University of Illinois at Chicago, other doctoral research has been supported by the Field Museum's Council on Africa, Bat Conservation International, and the American Society of Mammalogists.

It has been a delight to think about my science through dance and work with so many enthusiastic and talented people. The seed dancers and the videographers were all undergraduates at Earlham College (Richmond, Indiana, USA). Thank you to everyone who helped this project come to fruition!