PRIMARY PRODUCTION, STOCKS AND FLUXES IN THE MEDITERRANEAN SEAGRASS POSIDONIA-OCEANICA

Primary production in a Posidonia oceanica seagrass meadow (blades, sh eaths and rhizomes) was estimated at 3 sites in Lacco Ameno Bay (Ischi a, Italy). Foliar primary production ranged from 51 to 142 g dry Wt M2 yr-1 for sheaths and 167 to 530 g dry wt m2 yr-1 for blades. Rhizome production ranged from 20 to 42 g dry Wt M2 yr-1. The largest part of primary production was degraded in situ in the litter (42 %); the rema inder was either exported to other ecosystems (29 %) or buried in the matte (29 %). The loss of matter due to burial of sheaths and rhizomes in the matte, a phenomenon that is unique to Posidonia oceanica meado ws, is considerable.