Date of Award
Doctor of Philosophy
David S. Buckley, John M. Zobel
Donald G. Hodges, William L. Seaver
Our ability to successfully promote forest stand health and facilitate species under the threat of extinction will hinge on our ability to identify species regeneration requirements in an ever-changing environment. In the first chapter of this dissertation, I address what is known about the nature of threatened and imperiled hardwoods in the eastern United States, and in doing so, I identify several large knowledge gaps in current potentials and methodologies for regenerating them. In my second chapter, I use recent data from the United States Forest Service, Forest Inventory and Analysis program (FIA) to quantify ash regeneration counts across FIA forest type groups containing the emerald ash borer (EAB; Agrilus planipennis Fairmaire) threatened species white ash (Fraxinus americana L.), green ash (Fraxinus pensylvanica Marsh.), black ash (Fraxinus nigra Marsh.), blue ash (Fraxinus quadrangulata Michx.), Carolina ash (Fraxinus caroliniana Mill.), and pumpkin ash (Fraxinus profunda (Bush) Bush). In addition to this baseline calculation of ash regeneration potentials, all other species are quantified to determine overall species composition and levels of inter-specific competition. In the third chapter, Shannon-Wiener species diversity index values are calculated for forest communities containing each of the six ash species above. This facilitates identification of ash-dominated communities and states in need of greater conservation efforts. In the fourth chapter, I use field observations to quantify microsites supporting populations of mountain stewartia (Stewartia ovata (Cav.) Weatherby) across East Tennessee and examine the hypothesis that specific site requirements are limiting stewartia’s distribution and abundance across its natural range. In doing so, I am able to put forth a list of site requirements that may be necessary to guarantee the future regeneration and success of mountain stewartia. In the final chapter, a 25-year data set is used to investigate the success of a novel method for regenerating northern red oak (Quercus rubra L.) in Michigan oak and pine stands. Oak regeneration is more successful in pine stands than in oak stands due to several potential factors. Overall, my dissertation seeks to highlight regeneration requirements, potentials, and methods for regenerating an important group of threatened and imperiled hardwood species.
Granger, Joshua J., "Regeneration of Imperiled Hardwoods in the Eastern United States. " PhD diss., University of Tennessee, 2017.