Abstract: An enduring trend in eastern deciduous forests is the observed failure of oak and hickory to recruit in the forest understory. Forest canopies dominated by long-lived oak and hickory contain understories often dominated by non-conspecific species (i.e., maples, beech). To address this issue, prescribed burning and mechanical thinning have often been used to revert understory conditions to those thought to favor oak and hickory regeneration. It remains uncertain how these groups respond to these treatments, as oak and hickory are often treated as a single unit in determining efficacy, obscuring species specific patterns. The true effect of silvicultural management on each species may be obscured by their grouping. Therefore, this research aimed to answer two questions. First, do oak and hickory exhibit species-specific responses to prescribed burning and mechanical thinning? Second, are prescribed burning and mechanical thinning treatments effective in increasing understory oak and hickory regeneration after 22 years of management? In southeast Ohio, two study areas were designated in 2000, with each location split into four treatment areas; i) control, ii) mechanical thinning only, iii) prescribed burning only, and iv) both mechanical thinning and prescribed burning. Multiple field surveys of seedling and sapling regeneration were conducted beginning the year before management started (2000) to the prior growing season (2022). These data were used to model and compare species-specific responses of four oak and three hickory species common to the region. Oak and hickory saplings and large seedlings did not exhibit a significantly different species-specific response to the individual treatments as of the 2022 growing season. Oak and hickory differed only in the magnitude of their response to the treatments with hickory stem densities generally being less than oak. Oak stem densities were significantly increased by the burn only treatment, while oak and hickory stem densities were significantly increased by the prescribed burning and thinning treatment. However, stem densities only exceeded pre-treatment levels after 15-20 years. The results of this study support the efficacy of prescribed burning and mechanical thinning treatments used to increase oak and hickory regeneration levels. However, the timeline to observe an increase in regeneration levels may take many years or decades, and should be accounted for when developing management strategies.
