THE EFFECT OF SALINITY AND WATERLOGGING ON GROWTH AND SURVIVAL OF BALDCYPRESS AND CHINESE TALLOW SEEDLINGS

Growth, biomass, and survival of four-month-old baldcypress (Taxodium distichum (L.) Rich.) and Chinese tallow (Sapium sebiferum (L.) Roxb.) seedlings were examined in an experiment varying water levels (watered, flooded) and salinity levels (0, 2, and 10 ppt, plus a simulated storm surge with 32 ppt water). Ah seedlings survived to the end of the experiment except for those flooded with 10 ppt water. Baldcypress survived two weeks whereas Chinese tallow survived for 6 weeks in 10 ppt water. Height growth of both species was unaffected by flooding with 0 and 2 ppt water, but heights of plants watered with 10 ppt water were significantly lower. Diameter growth was much more variable. Baldcypress final diameters were greater in flooded treatments than in drained treatments. Chinese tallow diameters were greater in drained treatments. Root and shoot biomasses were not significantly different among treatments for baldcypress, but were two to five times less in flooded treatments for Chinese tallow. Baldcypress is more tolerant of flooding. Chinese tallow can survive longer at higher salinities, thus increasing its chances of survival in coastal areas where salinity levels are rising.