Date of Graduation
Davis College of Agriculture, Natural Resources and Design
Forest Resource Management
Oak regeneration challenges are a widespread issue across the mixed oak and mixed mesophytic forests of the eastern United States. Following disturbance on many mesic and sub-mesic sites oaks are being replaced by faster growing or shade tolerant species. There are many contributing factors, but one thought to have the strongest influence is attributed to the effects of 20th century fire suppression. For millennia fire was an integral part of oak dominated ecosystems and is thought to have contributed to and perpetuated oak's importance in these forests. During the 20th century the frequency and spatial scale of fire was severely reduced in most eastern forests. In the absence of fire, oaks are unable to benefit from their unique developmental and physiological traits superiorly adapted to a periodic fire regime and maintain their dominance. The fire adapted traits important at different life stages of oaks include modest growing site requirements, hypogeal germination, early growth strategy of root development over of shoot development, ability to repeatedly sprout following dieback or topkill, development of thick fire resistant bark, and ability to compartmentalize wounds. As the ecological effects of fire suppression have materialized and compounded over time, prescribed fire has emerged as a silvicultural tool to modify competitive dynamics in an effort to maintain or restore oak communities. Although there are a rapidly increasing number of prescribed fire studies, replications are still necessary with different combinations of variables to determine the conditions that will produce successful results with greater certainty. This goal of this study was to examine the competitive relationship between oak seedlings and three of its competitors, develop first year survival probability models, and assess post-fire sprout growth dynamics. First year data show that oak survived at a higher rate than red maple, sweet birch, and yellow-poplar, and the differences were more apparent at smaller sizes. Probability of survival models as a function of height are superior to survival models as a function of diameter for red maple, sweet birch, and yellow-poplar. Oak survival was so high a meaningful survival probability model could not be developed.
Fenwick, Maria Adele, "First year sprouting and growth dynamics of northern red oak, yellow-poplar, red maple, and sweet birch on a mesic site following a release burn during a "shelterwood-burn" sequence" (2015). Graduate Theses, Dissertations, and Problem Reports. 5590.