Knowledge Gaps in Managing for Oak Regeneration

There are many unanswered questions relevant to how oaks regenerated in the past and how best to regenerate them in the future. The following comments will highlight some of the major gaps in current knowledge of oaks: (McGee and Loftis, 1993)

• How did current stands of oak regenerate?
• What was the role of fire in establishment of existing oak stands?
• Is there a role for prescribed fire in oak regeneration?
• What factors influence oak flowering and fruit maturation?
• Can flower and acorn production be predicted?
• Why do oak seedlings grow so slowly? the mechanisms controlling the flushing patterns and frequent dieback of shoots observed in the field are still unknown.
• Why are direct seeding and planting efforts succeeding better in the bottomlands than in the uplands?
• Can natural regeneration methods and artificial regeneration methods becombined?
• What are the economic realities related to artificial regeneration of oaks?(McGee and Loftis, 1993)

Even as the foregoing questions indicate gaps in the knowledge of oak regeneration, it is clear from the material in this hypertext document that much is known about the regeneration requirements of the oak genus. Continual efforts by forest scientists will provide answers to biological questions so that it is likely that oak regeneration in the future will be limited by economic and social constraints. (McGee and Loftis, 1993)

Shelterwood is the most flexible of all the methods of reproduction (Toliver and Jackson 1989); however, the timing of various cuts is critical for the continued development of oak reproduction. Treatment of the undesirable midstory and understory vegetation by herbicide or cutting is essential for the development of oak seedlings (Janzen and Hodges 1987, Loftis 1990). More research is needed before recommendations can be made on the shelterwood method of regenerating bottomland oaks, particularly in terms of the degree of competition control necessary, the number and intensity of cuts, and the interval between cuts. (Clatterbuck and Meadows, 1993)

Oak-dominated forests can be managed as even-aged or uneven-aged stands and regenerated by each of the conventional silvicultural methods. However, success in applying any one method will depend on understanding the oak regeneration processes intrinsic to the ecosystems in which it is applied. Our current inability to differentiate among the different kinds of oak-dominated ecosystems and the regeneration process inherent in each represents a mayor problem in managing and sustaining oak forests. Nevertheless, we have accumulated significant information and knowledge on how to manage many of these ecosystems for meeting a variety of traditional timber management objectives. We know much less about how to meet objectives associated with other values. (Johnson, 1993a)