SALINITY EFFECTS AND DIFFERENTIAL GERMINATION OF SEVERAL HALF-SIB FAMILIES OF BALDCYPRESS FROM DIFFERENT SEED SOURCES

Saltwater intrusion is responsible for the destruction of large expans es of baldcypress swamps along the Gulf of Mexico in the southern Unit ed States. Recent restoration efforts have focused on the identificati on, and subsequent planting, of moderately salt-tolerant plant materia l within these ''ghost forests.'' The long-term persistence of cypress swamps in these areas, however, will ultimately depend on the germina tion of seeds from the improved parent trees. This study investigates the germination capacity of seeds collected from baldcypress parent tr ees, located in both freshwater and brackish water environments. Seeds were tested at four different salinity levels under controlled condit ions for a period of 65 days. Mean germination under the 0, 2, 4, and 6 g l(-1) seawater treatments was 26.3, 22.9, 15.4, and 10.2%, respect ively. Although none of the eight families used in this study had a ge rmination greater than 50%, three families demonstrated superiority in their germination capacity under all four salinity treatments. In gen eral, brackish water seed sources had greater germination success than the two families from freshwater sources. Results indicate that famil ies previously identified as moderately salt-tolerant based on physiol ogical and morphological parameters may be equally successful in seed germination capacity under moderately saline conditions.