Maritime forests are a critical interface between ocean and terrestrial ecosystems, providing important ecosystem services and functions. Along the U.S. southern Atlantic coast, maritime forests are dominated by <i>Quercus virginiana</i>. Maritime forests and <i>Q. virginiana</i> have been heavily impacted by conversion to agriculture, residential development, and pine stands. Southern pine beetle outbreaks have led to salvage and thinning silvicultural treatments of pine stands which offer an opportunity to restore more complex maritime forests. This research project is comprised of two experiments which allowed me to study the performance of planted <i>Q. virginiana</i> seedlings in response to (1) animal browse, (2) competing vegetation, and (3) varying overstory pine canopies. For both experiments, one-year-old bareroot seedlings were planted as split-plot experimental designs. The first experiment evaluated control of deer browse (fenced and not fenced whole plots) and competing vegetation (0, 1, and 2-yr vegetation control subplots) as independent variables. Overall seedling survival was 60% after two years. There was a significant interaction between deer browse and competing vegetation for seedling height, diameter, crown width, and lateral branches. Seedlings were larger for all response parameters when fenced with vegetation control. Vegetation control significantly improved seedling performance only in fenced plots, indicating a shift in pressure from herbivory to competition when deer were excluded. Foliar nitrogen (N) was significantly greater in fenced plots than non-fenced plots and in 2-yr vegetation control subplots than non-weeded subplots. The second experiment evaluated varying pine overstories (clearcut, heavy thin, light thin, and no thin whole plots) and competing vegetation control (0 and 2-yr vegetation control subplots). Overall seedling survival was 78% after one growing season, with clearcut plots at the greatest survival (83%) and no thin at the lowest (72%). Seedling growth and foliar nitrogen were significantly greater in clearcut plots followed by the heavy thin, light thin, and no thin plots. Vegetation control consistently promoted seedling height, but was only beneficial to diameter and crown width in clearcut/heavy thin plots. <i>Q. virginiana</i> seedlings demonstrated plasticity in their ability to acclimate to the varying microclimates created by silvicultural treatments, as demonstrated by light response curves, stomatal density, and specific leaf area. These results highlight the importance of fencing to remove deer browse, introducing light in the understory, and further improving seedling performance by removing competing vegetation.

<p dir="ltr">Coastal ecosystems are critically important habitats for the services they provide on a global and local scale. Maritime forests are found within the southern Atlantic coast, and they serve as a boundary between the ocean and land. These forests stabilize coastlines, recharge groundwater, and provide a protective buffer against storm damage. Southern live oak (<i>Quercus virginiana</i>) was historically the dominant canopy species in maritime forests; however, previous land conversions to loblolly pine (<i>Pinus taeda</i>) plantations have shifted the abundance of loblolly pine to become the dominant canopy tree in maritime forests. Loblolly pines are fast growing, and they regenerate vigorously but they are not well adapted to coastal stressor. In recent decades, outbreaks of southern pine beetle (<i>Dendroctonus frontalis</i>) have provided restoration practitioners an opportunity to clear tracts of pine dominated maritime forest to restore live oak to the canopy. This research project is comprised of two experiments studying the performance of planted <i>Q. virginiana</i> seedlings on maritime forest restoration sites in coastal Georgia. The first experiment evaluated planting density (1-meter, 2-meters, 3-meters), mulch (with or without), and fertilizer (with or without). Overall seedling survival was 99% after four years. The application of fertilizer had an initial positive effect on seedling diameter after the first growing season. The application of mulch increased seedling height in the second to fourth growing seasons, diameter in third and fourth, and crown width in the fourth growing season. Planting density had no consistent effect over the first four years, and no biological significance was observed for foliar nutrient content. The second experiment examined eight different groupings of intra- and interspecific competition between <i>Q. virginiana</i> and <i>P. taeda</i> including: oak or pine alone; oak surrounded by oak, pine, or oak/pine; pine surrounded by pine, oak, or pine/oak at 0.5-m spacing between all seedlings. Two years after outplanting, survival did not vary by treatment. Oak centered competition plots were positively impacted by border tree height and diameter in year one and border height positively affected the center tree height in year two. Pine centered competition plots were positively impacted by border tree height in year one and year two. Oak centered competition plots with a mix of oak and pine on the border had significantly lower osmotic potential than other pine centric treatments after two years. Overall, oak centered treatments had lower osmotic potential than pine centered treatments. Ectomycorrhizal (EMF) species composition changed, and relative abundance increased from the initial planting to two years later but there was no variation between treatments and most EMF species were generalists. These results highlight the importance of mulch and fertilizer to reduce transplant shock and how competing seedlings can train seedlings to allocate photosynthate to shoot growth to help promote aboveground growth.</p>