Primary production of edaphic algal communities in a Delaware salt marsh1

Gross primary production of edaphic algae was estimated for five areas in a high salinity tidal marsh near Lewes, Delaware. Salt pan and bare bank (free of angiosperms) algal production did not vary significantly from one part of the year to another. Algal productivity in the tall Spartina alterniflora and Distichlis spicata areas was greatest from mid‐January to mid‐May. In the short S. alterniflora area algal productivity did not decrease in the warmest part of the year as it did in the two other grass areas. Annual cycles of light, temperature, and salinity were measured. Gross algal production was about a third of the angiosperm net production. Since much of the algal production occurs when angiosperms are dormant, it complements the pattern of angiosperm energy fixation.