Seed source and greenhouse preconditioning effects on the survival and growth of two common Piedmont wetland restoration tree species

Flood tolerance and growth rate of seedlings are often deciding criteria for wetland and riparian restoration plantings; however, these efforts often result in inadequate survival and growth of planted tree species. In an attempt to determine if parental seed source ecotype and seedling greenhouse preconditioning could influence survival and growth of two common restoration tree species, seeds from American sycamore ( Platanus occidentalis L.) and willow oak ( Quercus phellos L.) were collected from upland and floodplain sites in the Piedmont and Ridge and Valley regions of Virginia and were subjected to greenhouse flooding and drought preconditioning prior to field planting. American sycamore seedlings grown under normal conditions were 15 % shorter than seedlings subjected to flood preconditioning but had 13 % greater height than drought preconditioned seedlings. Preconditioning did not have a significant effect on willow oak seedling height. American sycamore seedlings sourced from dry ecotypes were 14 % taller than seedlings sourced from wet ecotypes, while willow oak seedlings sourced from wet ecotypes were 11 % taller than dry ecotype acorns. Seedlings from dry ecotype parents for American sycamore and seedlings from wet ecotype parents for willow oak may increase survival and growth of these species on marginal Piedmont agricultural sites. Adaptations observed after greenhouse preconditioning did not increase survivability or growth. Selection of seed sources from trees that exhibit good growth and vigor in landscape settings similar to the restoration area may increase the likelihood of meeting restoration goals and objectives.