It is not well understood how disturbances such as frequent, low- intensity (e.g. sublethal) fire have influenced life history evolution in plants. Pityopsis graminifolia is a fire-adapted, clonal perennial herb that inhabits frequently burned sandhills in Southeastern longleaf pine savannas. The reproductive biology of this species differs in two sandhill communities in which it has been studied despite the fact that fire results in little adult mortality or seedling establishment in either community. The proposed study has two major objectives. It will first examine how low intensity fires change the favorability of environmental conditions in these two sandhill populations of P. graminifolia. Specifically, if and to what extent fire reduces the cost of flowering and vegetative reproduction (e.g. clonal growth) in this stress-tolerant species by increasing the availability of nutrients in each of these communities will be examined. The impact of floral herbivory and seed predation following fire in each of these sites will also be examined. The significance of their impact in light of the phenotypic variation in reproductive behavior exhibited by this species following fires in each of these sandhill communities will be assessed. Results may indicate how fluctuating environmental conditions during the life of a plant influence life history evolution. The second goal of the study is to address how the dynamics of flowering and clonal growth respond to fires that differ in their historical, evolutionary importance (e.g. growing season vs. dormant season fires). In particular, whether the more profuse flowering and fruiting of shorter duration following historically important growing season fires reduces the impact of floral herbivory and/or seed predation in this species will be assessed. Evidence of this kind could provide insight regarding the adaptive significance of growing season vs. dormant season sublethal fires in longleaf pine savannas.
