| This study presents the results of several investigations of the patterns and mechanisms of revegetation of an old-growth Beech-Hemlock forest that was destroyed by a large tornado on 31 May, 1985. I documented general patterns of vegetation recovery and seedling demography over six growing seasons in the windthrow and the surrounding intact forest edges. I also experimentally demonstrated the significance of different patch types, such as treefall pits, debris piles, and areas of dense advance regeneration, to the germination, establishment and growth of tree seedlings.;I found rapid vegetation response to the disturbance: by August of 1986, species richness, tree seedling density, and total percent cover were significantly greater in the windthrow than in the surrounding forest. Shade-intolerant forbs (e.g. Erechtites hieraciifolia and Dennsteadtia punctilobula) and shrubs (e.g. Rubus allegheniensis) established and became dominant during the first three years of the study, but by year six had begun to decline in abundance. Tree seedlings established in decreasing amounts through the six years of the study, and there was very strong dominance in August 1991 by survivors or early colonists. Woody vegetation was dominated by species of intermediate (e.g. Betula alleghaniensis) and shade-tolerant (Fagus grandifolia) physiologies, in contrast to the expected dominance by shade-intolerant species. Regeneration strategies that contributed significant numbers of woody seedlings included germination of newly-dispersed seeds, root sprouting, and release of pre-disturbance advance regeneration (the 'seedling bank').;Patch types differed significantly in their effects on seed germination, seedling growth, and the incidence of mammalian herbivory. Treefall pits and mounds, and areas covered in thick litter were slow to be colonized, while other effects of patches may be due to differences in available solar radiation. Patch dynamics offers a means of simplifying the complexity of disturbed areas, and when combined with knowledge of the history of disturbance and community development, may be a route to more predictive understanding of plant community dynamics. |
