Primary production and nutrient budgets of Sarcocornia perennis ssp. alpini (Lag.) Castroviejo in the salt marsh of the Palmones River estuary (Southern Spain)

Biomass, primary production and nutrient budgets associated to Sarcocornia perennis subspecies (ssp.) alpini were studied in the Palmones River estuary salt marsh (Southern Spain) to evaluate the nutrient sequestration capacity of the low marsh. Above- and belowground living and dead biomass, as well as carbon, nitrogen and phosphorus content were monitored during 1 year. Additionally, the fate of aboveground detritus was evaluated in an experiment on litter decomposition. The detritus production of S. perennis ssp. alpini was almost equivalent to its annual primary production indicating a rapid turnover of biomass. We calculated that only 12% of the aboveground detritus was exported out of the low marsh while the rest was decomposed in the sediment with a rate of 0.8 year−1. Changes in concentrations of total carbon, nitrogen and phosphorus in the sediment showed patterns related to S. perennis ssp. alpini belowground biomass. Our results suggested that the sediment functions as a net sink for nutrients accumulating 550 g C m−2 year−1, 55 g N m−2 year−1, and 13 g P m−2 year−1.