Decomposition processes of Spartina maritima in a salt marsh of the Basque Country

Decomposition dynamics of aerial parts and root-rhizomes of Spartina maritima in a Basque Country salt marsh was studied, using litter bags placed on the soil surface and buried 10 cm below ground. Aerial parts of the plant in aboveground position showed higher breakdown rates than samples placed belowground. There was no significant difference found between aerial parts and root-rhizomes buried. Nitrogen and phosphorus followed different dynamics (seasonal changes and progressive losses) that may be a consequence of distinctive mineralization pathways. The low faunal richness and densities belowground reflect the unfavourable life conditions in such a situation and, to a certain extent, the lower decomposition rates of buried litter. Four mathematical expressions that fit the data are presented and discussed.