Shadows from the past: The importance of seed dispersal to spatial patterns of tree composition in Indiana old field forests

There are considerable theoretical expectations that plant community development relies upon a template established by the process of seed dispersal. Empirical studies in old field successional habitats suggest that spatial patterns of tree seedlings reflect patterns of seed dispersal at initial establishment. Less is known about how spatial patterns that are created during tree establishment change as forests develop. Intervening factors such as competition and herbivory obscure the relationship tree seedlings and saplings have with seed dispersal patterns. The purpose of this study was to examine how spatial patterns of seedling and sapling diversity in old field succession reflect the process of seed dispersal in forests aged 25-30 years.  On my study areas, wind-dispersed seedling densities tended to higher than species with other dispersal modes close to the parent forest. Bird-dispersed sapling densities tended to be higher than species with other dispersal modes farther distances away from the parent forest. Considerable variation of seedling and sapling patterns among transects suggested the importance of other factors that shape spatial patterns of tree diversity in young forests. Individual species characteristics, edge effects, and disturbance from past land use also contributed to spatial patterns of tree density and composition in these systems. However, shadows from the process of seed dispersal existed in spatial patterns of trees at this stage of forest development despite intervening factors.