SEED DORMANCY ENABLES A FORM OF TEMPORAL HABITAT SELECTION
D’Aguillo, M.D.1 and Donohue, K.2
1Graduate Program in Biology, Duke University, Durham, NC, USA
2Department of Biology, Duke University, Durham, NC, USA
Contact: Michelle D’Aguillo, firstname.lastname@example.org
Plants can engage in habitat selection through phenology, by undergoing development transitions in response to specific environmental cues that vary on an annual basis. By restricting germination, seed dormancy has the potential to enable a form of temporal habitat selection through germination phenology. Using dormant and non-dormant genotypes of Arabidopsis thaliana, we examined if seed dormancy alters or restricts the conditions to which seedlings and reproductive individuals are exposed. Seeds were matured under warm (25oC) and cool (14oC) environmental conditions and dispersed in a multi-year field experiment in central North Carolina. Soil temperature and moisture were recorded hourly, and germination and reproductive phenology were recorded weekly. We examined soil temperature and moisture experienced by seeds during the seven days preceding germination, the first two weeks of seedling establishment, the second two weeks of seedling establishment, and the reproductive period. Preliminary results indicate that dormant and non-dormant genotypes occupy different areas of environmental space early in the life cycle, and these differences tend to dissipate later in the life cycle. In general, dormant genotypes germinate in response to, and expose seedlings to, significantly higher soil moisture and temperature, and these differences are most pronounced when seeds were matured at cool rather than warm temperatures. These results indicate that seed dormancy can enable a form of temporal habitat selection and alter the environmental conditions experienced post-germination.