Aboveground Production of Seven Marsh Plant Species in Coastal Louisiana

Results of a 2—yr evaluation of aboveground production of 7 plant species commonly found in Louisiana's coastal marshes show a generally higher level of production compared to other studies. In 5 of the 7 species significant growth occurred throughout the year. Calculated annual production in grams per square metre for each species was; Distichlis spicata–3237; Juncus roemerianus–3416; Phragmites communis–2318; Sagittaria falcata–1501; Spartina alterniflora–2658; Spartina cynosuroids—1355; and Spartina patens–6043. Sampling variability, expressed as the ratio of the standard error to the mean x 100, averaged between 8 and 18 different species. Instantaneous loss rates (mg x g(—1) x day(—1)) of dead vegetation from the marsh, averaged over the year, ranged from 4.7 for P. communis to 25.2 for S. falcata.