PARENT SESSION
Poster Session 17: Modelling
Wednesday, August 10, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Spatial variation in seed dispersal and recruitment: How patterns and patchiness influence demography and dispersal.
Herrick, Gabriel*,1, Fox, Gordon1, Teague, Kara1, 1 University of South Florida, Tampa, FL
ABSTRACT- Description of dispersal patterns in plants often involves curve-fitting the density of propagules to distance from a source. The common feature of these curves is that density decreases with distance from the source (adult tree) in and even and predictable manner, without explicitly considering spatial heterogeneity in dispersal and demography. For simplification, these curves are often fit to seedlings, with the demographic transitions from dispersed seeds to seedlings assumed to be non-limiting or spatially uniform. Using data from seed traps and maps of seedlings and adults in a population of slash pine (Pinus elliottii), we explore the effect of spatial heterogeneity on the assumption that seedlings follow a dispersal curve. We attempt to determine when it is acceptable to use the shortcut-assumption of curve-fit seedling dispersal, and when it is necessary to quanitfy patchiness in habitat suitability for recruitment. Data presented here indicate that such curve fitting to seedlings may not be appropriate beyond a putative threshold level of spatial heterogeneity in recruitment. Under such conditions of spatial dependence in recruitment, dispersal models should include spatially explicit considerations of habitat heterogeneity.
Key words: Dispersal, Demography, Pinus elliottii