Seasonal changes in weight of above- and below-ground vegetation and dead plant material in a salt marsh at Colne Point, Essex.

Randomly selected quadrats in a 1-ha study area of a marsh dominated by Puccinellia maritima and Halimione portulacoides were harvested by cutting above-ground material and extracting below-ground material from soil cores. Dry-weight of live material per unit area, averaged over a year, was 660 + or - 36 g m^-2 with a summer maximum of 831 + or - 75 g m^-2. Some 55% of this biomass was below-ground. Large amounts of dead vegetation were found throughout the year, an average of 4800 + or - 168 g m^{- 2} and a maximum of 5820 + or - 281 g m^-2. Some 85% of this material was below-ground. Amounts of live vegetation are similar to those reported for N. American marshes at similar latitudes, but amounts of dead vegetation are much higher. Live vegetation and litter on the marsh constituted a large potential source of energy and reduced carbon for other trophic levels, both in the salt marsh and adjacent coastal ecosystems.-from Authors