Primary production, stocks and fluxes in the Mediterranean seagrass Posidonia oceanica

Abstract

Primary production in a Posidonia oceanica seagrass meadow (blades, sheaths and rhizomes) was estimated at 3 sites in Lacco Ameno Bay (Ischia. Italy). Foliar primary production ranged from 51 to 142 g dry wt m2 yr-l for sheaths and 167 to 530 g dry wt m2 yr-' for blades. Rhizome production ranged from 20 to 42 g dry wt m2 yr-'. The largest part of primary production was degraded in sit11 In the litter (42 %l; the remainder was either exported to other ecosystems (29%) or buried in the rnatte (29%). The loss of matter due to burial of sheaths and rhizomes in the matte, a phenonlenon that is unique to Posidonja oceanica meadows, is considerable.