PHENOLOGICAL OBSERVATIONS ON POSIDONIA OCEANICA (L.) DELILE MEDOWS ALONG THE COAST OF AKKUM (SIGACIK BAY, AEGEAN SEA, TURKEY)

Phenological observations on Posidonia oceanica (L.) Delile medows along the coast of Akkum (Sıgacık Bay, Aegean Sea, Turkey)

Berrin Dural

Ege University, Faculty of Science, Department of Biology, Bornova, TURKEY

Abstract

Phenological observations were carried out on Posidonia oceanica meadows between December 1994 and April 1995 along the coast of Akkum (Sıgacık Bay, Aegean Sea, Turkey) from two shallow depths (1-3 m; 4-7 m). The highest flowering density of 136 inflorescence / m2 was observed in the 4-7 m depth during January 1995. Inflorescences more often occured on the orthotropic rhizomes in the dense beds. Inflorescence mostly bore 2 rarely 1 or 3 spikes, distichous with 2-3 flowers with a male flower and a sterile extension at the apex. Fruits started maturing in February and got mature during April. Plants at the 4-7 m depth produced 15 mature fruits from a total of 19 flowers in seven inflorescences. Shoot density was found to be maximum (880 shoots / m2) during December, with 7420 leaves / m2), at the 4-7 m depth. The leaf lengths of the plants at the 4-7 m depth gradually increased from December to April. Phenological differences between the two depths were mainly due to the fact that the plants in the sparse and isolated meadows in the shallower areas had short and even falciform leaves, compared to the ones in the deeper and central areas.

Keywords: Seagrass, Posidonia oceanica, phenology, the Aegean Sea, Turkey

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