Root-collar diameter and third-year survival of three bottomland hardwoods planted on former agricultural fields in the Lower Mississippi Alluvial ValleyThis article is part of a larger document. View the larger document here.
Athough the Lower Mississippi Alluvial Valley (LMAV) has experienced substantial afforestation of former agricultural fields during the past 2 decades, seedling standards that support satisfactory outplanting performance of bottomland hardwood tree species are not available. A series of experimental plantations, established on three afforestation sites in the LMAV, provided an opportunity to examine relationships between initial root-collar diameter and the probability of third-year survival for Nuttall oak (Quercus nuttallii), sweet pecan (Carya illinoensis), and green ash (Fraxinus pennsylvanica). Three years after planting, the probability of survival for Nuttall oak and sweet pecan seedlings improved with increasing initial root-collar diameter. The probability of survival for Nuttall oak and sweet pecan seedlings increased 26% and 33%, respectively, over the range of initial root-collar diameters (2 to 18 mm [0.08 to 0.71 in]). Intensive vegetation control during the first growing season also increased the probability of survival for both species. In contrast, green ash seedlings maintained a third-year survival of 95% across the three study sites, and the probability of survival was not influenced by initial root-collar diameter or first-year vegetation control. These results suggest that morphological variables, such as root-collar diameter, can provide practical, species-specific indices of potential survival for bottomland hardwood seedlings outplanted on former agricultural fields in the LMAV.