DEMOGRAPHY OF A SHADE-TOLERANT TREE (FAGUS-GRANDIFOLIA) IN A HURRICANE-DISTURBED FOREST

We examined the demographic responses of Fagus grandifolia to Hurrican e Kate (1985) in an old-growth Southern mixed-hardwood forest in north ern Florida. ?Matrix population models were used to contrast pre-and p ost-hurricane population trends (1978-1992) with predictions of four h ypotheses of the persistence of this shade-tolerant species in hurrica ne-frequented forests (resistance, recovery, release, and complementat ion). Although growth and mortality schedules changed as a result of t he hurricane, the asymptotic population growth rate did not: change si gnificantly and did not depart significantly from lambda = 1 (stabilit y) in either the pre-or the posthurricane periods. Long-term trends si mulated for varying hurricane frequencies also projected stability in population size. These results supported the resistance hypothesis. El asticity analysis showed that, while recruitment had a minor influence , survival of medium-sized trees was the most critical character influ encing population growth, Similar patterns of life history sensitivity are common among other toes, suggesting that traits related to surviv al of large understory individuals would; often he under high selectio n pressure. Among these traits, those associated with hurricane resist ance could also be advantageous in forests subjected to light to moder ate disturbance. Thus, resistance to canopy disruption could have rema ined linked to shade tolerance during expansions and contractions of t he distribution of F. grandifolia.