Acorn viability following prescribed fire in upland hardwood forests

• Published in: Forest ecology and management 2012-07, Vol.275, p.79-86
• Main Authors: Greenberg, Cathryn H., Keyser, Tara L., Zarnoch, Stanley J., Connor, Kristina, Simon, Dean M., Warburton, Gordon S.
• Format: Article
• Language: English
• Subjects: Acorns; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Combustion; Fires; Forestry; Forests; Fundamental and applied biological sciences. Psychology; Germination; Hard mast; Litter; Mortality; Oak; Prescribed fire; Quercus; Restoration; Synecology; Terrestrial ecosystems; Viability
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/j.foreco.2012.03.012

► Burning reduced viability of acorns on the litter surface but not in duff or soil. ► Germination of acorns decreased with increasing fire temperature. ► Acorn mortality was virtually 100% at temperatures ⩾260°C. ► Fall burns could result in high acorn mortality and impact oak regeneration. Restoration of structure and function of mixed-oak (Quercus spp.) forests is a focal issue of forest land managers in the eastern United States due to widespread regeneration failure and poor overstory recruitment of oaks, particularly on productive sites. Prescribed fire is increasingly used as a tool in oak ecosystem restoration, with the goal of reducing competition, and creating light and seedbed conditions conducive to germination and growth of oak seedlings. Yet, oak seedling establishment is dependent on the presence of viable acorns, which may be vulnerable to prescribed fire. We assessed the effect of prescribed burning and fire temperature on the viability of white oak and northern red oak acorns placed on the leaf litter surface, in the duff, or in the mineral soil during five winter prescribed burns in southern Appalachian upland hardwood forests. Fire temperatures varied among acorn plots, ranging from