EFFECTS OF FLOOD DURATION AND SEASON ON GERMINATION OF BLACK, CHERRYBARK, NORTHERN RED, AND WATER OAK ACORNS

Effects of hood duration (0, 10, 20, and 30 days) and season (winter a nd spring) on acorn germination were tested for two upland oaks [black and northern red oak (Quercus velutina Lam. and e. rubra L.)] and two bottomland oaks [cherrybark and water oak (e. pagoda Raf. and Q. nigr a L.)]. Acorns were stratified for 30 days before flooding at a depth of 15 cm along the edge of a small pond, After flooding, acorns were s owed in sand-filled plastic cups and germinated for 40 days. Flood dur ation and season strongly affected radicle and epicotyl emergence of t he upland oaks, but effects were generally limited to spring flooding. Embryo axes of the upland oak acorns were severely damaged with as li ttle as 10 days of spring flooding. Almost no epicotyls developed, but radicles developed from the connective tissues between embryo axes an d the cotyledons of many acorns. Spring flooding also significantly in creased the percentage of decayed acorns for the upland oaks. In contr ast, germination of the bottomland oaks was slightly improved by flood ing during both seasons. Results demonstrated that the effects of floo ding on the distribution of species within bottomlands can begin with seed storage and germination.