Artificial regeneration of northern red oak and white oak on high-quality sites: effect of root morphology and relevant biological characteristics
Northern red oak (Quercus rubra) and white oak (Quercus alba) are important components of high-quality mesic sites and are essential as lumber species and hard mast producers. Regeneration of these species has been difficult, and their absence in newly regenerated stands is a major concern of foresters and wildlife biologists. Several important biological traits of oak species may contribute to regeneration difficulties. These primary determinable biological traits may be shade intolerance and aging, which affects their reproductive potential. These factors, coupled with incompatibility of closely related individuals, greatly hamper natural regeneration efforts by decreasing adequate advance oak regeneration for future stands. Artificial regeneration can significantly increase the oak component because large oak seedlings that exceed the suggested size of advance oak regeneration can readily be produced in forest tree nurseries with specific nursery prescriptions. Seedlings produced in this fashion can readily be evaluated. Those from the top 50 percent, based upon first-order-lateral root numbers, have proven to be very effective in artificial regeneration of stands, in establishing plantings for seed orchards, and in establishing mast-producing areas within larger forested stands.