Artificial regeneration of upland oaks (Quercus): new considerations of an old question


Stacy L. Clark, Scott E. Schlarbaum, Arnold M. Saxton, Barbara Crane, Allen Houston, and Ron Myers

Research Forester (SLC), Southern Research Station, USDA Forest Service; and Professor and Director (SES), UT Tree Improvement Program, Department of Forestry, Wildlife, and Fisheries, The University of Tennessee, 2431 Joe Johnson Dr., Rm 274 Ellington Plant Science, Knoxville, TN 37996-4563; Professor (AMS), Department of Animal Science, The University of Tennessee, 208C Brehm Animal Science Building, Knoxville, TN 37996-4574; Regional Geneticist (BC), Southern Region, USDA Forest Service, 1720 Peachtree Road, NW, Suite 816N North, Atlanta GA 30309; Forest Management Branch Head (RM), North Carolina Forest Service, 1616 Mail Service Center, Raleigh NC 27699-1616; Research Professor (AH), Department of Forestry, Wildlife, and Fisheries, The University of Tennessee and Director, Forest and Wildlife Management and Research, Ames Plantation, P.O. Box 389, Grand Junction, TN 38039

Abstract – Oaks (Quercus) are ecological keystone species and are the most important economic component of timber markets in much of eastern North America. These species have been difficult to naturally regenerate despite decades of research and management. Most recommendations for artificial oak regeneration (e.g., planting) were derived from research on relatively low quality sites where species composition are predictably more favorable for certain species of oak. However, artificial regeneration has been largely unsuccessful as site quality increases or where deer herbivory is significant. Unfortunately, in terms of sustaining high value stands, the most preferred species generally occur on better sites. We are currently developing and testing recommendations for artificial regeneration on post-harvest sites with moderate to high productivity. We will examine key factors expected to improve success of artificial regeneration, such as maintaining a genetically diverse seed source that is locally adapted, genetic improvement of seedlings, using advanced nursery technology, and implementing silvicultural treatments in the initial and intermediate stages of stand development. These considerations, individually, are not novel, but have been rarely integrated in a single approach, and as a composite, lack the rigorous testing and refinements required to ensure a satisfactory degree of predictability and success for artificial oak regeneration on higher quality sites. In addition, we are conducting research on methods to remove bias associated with seedling deployment in commonly used experimental designs. We are also testing new morphological seedling characteristics and operational methods to help identify and select high-quality seedlings that are practical to field managers.