Ingestion by a Freshwater Turtle Alters Germination of Bottomland Hardwood Seeds

Seed dispersal by animals is well documented in many habitats; however, this knowledge is depauperate in bottomland hardwood forests. The alligator snapping turtle (Macrochelys temminckii) is a large freshwater turtle of the southeastern United States that consumes primarily fish but also eats vegetation, including seeds of trees. To evaluate the role this species may play as a seed disperser in bottomland hardwood systems, we investigated the effect of ingestion by M. temminckii on germination of seeds of the following trees: common persimmon (Diospyros virginiana), water tupelo (Nyssa aquatica), and willow oak (Quercus phellos). Captive turtles were presented seeds of these three species in a series of feeding trials. Ingestion reduced the proportion of seeds that germinated compared to uneaten controls for D. virginiana and N. aquatica but had the opposite effect on Q. phellos. Ingested D. virginiana and N. aquatica seeds also germinated more slowly than uneaten controls; however, ingested Q. phellos seeds germinated faster than uneaten controls. This study suggests M. temminckii may have a role as a disperser of Q. phellos, N. aquatica, and D. virginiana; however, information on post-dispersal seed fate is needed to completely assess this species and other freshwater turtles as dispersers of wetland vegetation.