9411785 Bazzaz This dissertation research will evaluate the role of understory plants in shaping characteristics of the seedling bank in central New England forests. The understory has the potential to influence development and composition by acting as a filter through which all tree seeds and seedlings must pass. This project will explore whether the understory acts as a general filter that influences seedling abundance of all species similarly or whether selectivity of an understory filter predictably influences species composition and relative size structure of the seedling bank. Spatial correlations of tree seedlings and understory plants will be described in stands where overstory trees have been mapped so that seedlings-understory relationships can be established independently of seed rain patterns. Growth and survival of naturally recruiting tree seedlings will be monitored under different understory types for two years. Field experiments involving understory manipulation will test the effects of the presence and identity of two dominant ferns on dispersal, germination, growth, and survival of rd oak, red maple, and yellow birch seeds and seedlings. %%% Studies of forest regeneration have focused on the growth of tree seedlings with respect to the location and condition of canopy trees, yet little is known about how the understory herb and shrub strata influence stand succession. Results of this study will add to an understanding of forest regeneration following disturbance by focusing attention on processes which shape the starting array of advanced regenerants released by overstory removal.
