Understanding relative flood tolerance of hardwood bottomland seedlings is fundamental to restoring floodplain ecosystems. Thus, we quantified the effects of three early growing season flood duration (0, 15, and 30 d) treatments on survival and growth of overcup Quercus lyrata, Nuttall Q. nuttallii, and willow Q. phellos oak seedlings. Seedlings (n = 5,003) were planted January-March 2004 in a randomized design among six impoundments in a western Tennessee bottomland. We flooded four impoundments (two 15-d and two 30-d treatments) after seedling bud break initiated in April 2005 and 2006 to simulate overbank flooding of a river. Overall seedling survival measured in July and October 2005 and July 2006 was 96, 89, and 84% overcup, Nuttall, and willow, respectively. Survival of Nuttall and willow was greatest in unflooded control impoundments. All species exhibited the least growth in the 30-d treatment. Growth of Nuttall and willow were generally greater in the 15-d treatment than in the control treatment. We ranked relative seedling flood tolerance as decreasing from overcup to Nuttall to willow, which corresponds with previous greenhouse studies. We recommend that natural resource practitioners plant overcup at low elevations in bottomlands that flood frequently, plant Nuttall at mid-range elevations, and plant willow exclusively at higher elevations that flood infrequently to increase the likelihood of restoration success.
