PARENT SESSION
Poster Session 25: Mammalian Ecology
Thursday, August 11, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Effects of seed-caching mammals on hardwood seedling establishment in a patchy sandhill mosaic.
Ansley, Shannon*,1, Fox, Gordon1, 1 University of South Florida, Tampa, Florida, USA
ABSTRACT- Sandhill vegetation in the southeastern United States is subject to varying burn regimes. Under fire suppression, hardwood species such as turkey oak (Quercus laevis) encroach into patches of sandhill. Small mammals that cache acorns and seeds of other hardwood species may aid in the establishment of hardwoods in sandhill patches. However, little is known about the caching behavior of small mammals such as the grey squirrel (Sciurus carolinensis) and the cotton rat (Sigmodon hispidus) in Florida. If indeed these mammals do cache hardwood seeds, then there could be an increased chance of hardwoods being established. On the other hand, these mammals may have greater roles as seed predators, through either immediate ingestion of the seeds or cache recovery, which would slow the establishment of hardwood seedlings. Simulations of the effect of mammal seed-caching on seedling population size point to the interaction between caching in suitable germination sites and probability of cache recovery as being the critical quantity to estimate. We used mammal exclosures to monitor the establishment of hardwood seedlings in sandhill vegetation at the Ecological Research Area of the University of South Florida. Also, seeds were marked using fluorescent powder and tracked with an ultraviolet light to observe caching behavior. Initial results indicate that there is a trade-off between the advantage of a seed being buried by a mammal, and the disadvantage of that seed being recovered and eaten prior to germination. Thus, seed-caching mammals may be able to influence hardwood establishment, depending on how large the germination advantage is of mammal-buried seeds relative to the risk of being consumed by the mammals.
Key words: small mammals, caching, seedling establishment