Regeneration failure has been identified as a common phenomena associated with many oak species in the eastern United States, particularly on more mesic sites. We analyzed recruitment patterns within a disjunct population of overcup oak (Quercus lyrata Walt.) in a seasonally flooded karst depression located in southeastern Tennessee. Our study revealed a spatial segregation of life history states within this population and a pattern of life history state transitions which were temporally pulsed in association with different environmental variables. The density of seeds and seedlings were positively correlated with adult-canopy cover. In addition, seedling density was positively correlated with litter depth. Small sapling (<0.5m ht) density was positively correlated with seed rain, which differed from large saplings (0.5-1.5m ht) which showed a distinct positive correlation with patches of high light availability. Sub-canopy and canopy adults differed from juveniles in that they showed a strong positive relationship with maximum flood water depth. Sub-canopy adult density was negatively correlated with adult-canopy cover. An age profile of the population revealed an absence of individuals between the ages of 5-40 years . Furthermore, the data indicate that there has been a 37% decrease in adult density over the last 4 years. Regeneration failure in this population appears to be associated with the transition from large sapling to sub-canopy adults within light gaps. We hypothesize that a change in the karst hydrology within the past 40 years currently prevents adult recruitment into the canopy.

Key words: bottomland wetland hardwood forests, Quercus lyrata, recruitment patterns, regeneration failure