Disentangling factors affecting establishment and growth of white oak (Quercus alba) regeneration in Missouri, USA

Abstract

Due to lower site productivity and lack of aggressive competitors, oak regeneration in Missouri is often considered less problematic than in the rest of the Central Hardwoods Region. However, oak advance reproduction is scarce on more productive sites in the Missouri Outer Ozark Border Subsection where sugar maple has accumulated in the midstory. The purpose of our study was to identify barriers to accumulating competitive white oak advance reproduction in the Outer Ozark Border Subsection at different stages of the regeneration process, including seed germination, seedling establishment, and development as advance reproduction in a mature upland oak-hickory forest. We manipulated light availability through thinning of the overstory and removal of the midstory, and we controlled deer herbivory by installing fenced exclosures. We tracked the performance of sown acorns, naturally regenerated seedlings of known germination year, and underplanted bareroot seedlings. Our results demonstrate the importance of a mast year, as many sown acorns were removed by small mammals or infested with weevils. The underplanted seedlings had a low survival rate (<35%) after five years, during which time a new cohort of seedlings was established following a bumper acorn crop. Neither heavy shade nor deer herbivory limited germination of natural reproduction. Heavy shade limited the growth and persistence of white oak advance reproduction in the understory. Deer herbivory did not impact the survival of white oak but negatively impacted its size. Active management will be necessary to create adequate light for regeneration, which we achieved through either midstory removal or commercial thinning.

Citation

Huffman, Abby L.; Knapp, Benjamin O.; Dey, Daniel C. 2026. Disentangling factors affecting establishment and growth of white oak (Quercus alba) regeneration in Missouri, USA. Forest Ecology and Management. 619: 124059. 13 p. https://doi.org/10.1016/j.foreco.2026.124059.