Genetic improvement and root pruning effects on cherrybark oak (Quercus pagoda L.) seedling growth and survival in southern Arkansas
Cherrybark oak is a highly desirable hardwood species across the southeastern United States. Silvicultural techniques for establishment have been carefully studied, but advances in tree improvement have yet to be realized. Cherrybark oak seedlings of genetically improved and unimproved stock were tested in field plantings in southern Arkansas and in a controlled pot study for root pruning effects. After 2 years, initial growth advantages of improved stock were no longer present; however, improved stock averaged 19 percent higher survival compared with unimproved seedlings. The improved stock also had greater resprouting after top dieback, indicating more resiliency. In the root pruning study, seedlings with pruned roots were easier to plant, had better survival, and exhibited less transpiration and stomatal conductance. Also, larger roots of the improved stock were more apt to be uncovered by erosion, potentially killing the tree. Larger roots systems are considered more desirable, but caution must be taken when planting. The larger root systems of genetically improved cherrybark oak seedlings make proper planting more challenging. However, pruning may offer a remedy making the seedlings easier to plant and more drought hardy initially.