BIOMASS AND ABOVEGROUND PRODUCTIVITY OF SALT-MARSH PLANTS IN SOUTH-EASTERN AUSTRALIA

The above-ground biomass of three dominant salt-marsh vascular plants (Juncus kraussii, Sarcocornia quinqueflora and Sporobolus virginicus) was measured to assess both spatial and temporal Variation and to prov ide baseline data. Additionally, the culm dynamics of the rush J. krau ssii were measured so that aboveground productivity could be estimated . No distinct seasonal patterns were detected in above-ground biomass in J. kraussii. Averaged over all sites and times, the above-ground bi omass of J. kraussii was 1116 g dry weight m(-2). Culms are replaced a nnually, hence standing crop approximated annual above-ground producti vity. Much of the dead aboveground biomass appears to accumulate in th e upper marsh, as evidenced by the elevated nutrient and organic carbo n content of the soil there relative to the sediment in the mangrove z one. Above-ground biomass of the decumbent perennial grass Sporobolus virginicus and the procumbent perennial chenopod Sarcocornia quinquefl ora showed no consistent spatial or temporal trends. The above-ground standing crops of these species were about one-third that of J. krauss ii.