STRUCTURAL AND FUNCTIONAL CHARACTERISTICS OF AVICENNIA GERMINANS MANGROVE FORMATION OF CHENGUE BAY (COLOMBIAN CARIBBEAN)

Abstract

Within the framework of the CARICOMP(Caribbean Coastal Marine Productivity) monitoring program, a study of the Avicennia germinans mangrove formation of Chengue bay (Tayrona Natural Park, Colombia) was performed between June 1995 and July 1996, based on the evaluation of structural and functional characteristics at three monitoring plots (10 x 10 m). The structure of the studied formation is coincident with that of fringing forests of the Caribbean region in having small trees (dbh=11.3 cm, total height=6.3 m) and high densities (16.3 trunks/0.01 ha). During the monitored period there was a low mortality rate (0.7 trees/year) and there were significant increases of the circumferences at breast height (as well as of the variables derived from this measure). Average tree growth rates expressed in height, dbh and basal area were 26.7 cm/year, 0.17 cm/year and 2.9 cm2/year respectively. Litterfall was composed principally by leaves (66.1%) and represented a mean production rate of 43.1 g/m2/month (5.2 t/ha/year). There was a temporal pattern of litterfall production associated with the climatic seasons in the area: during rainy months the production of total litterfall, leaves and fruits was higher, while during the dry season there was a reduction of these components and an increase of flowers and wood/twigs. Therefore, flowering and fruit production periods are fitted to an annual reproductive cycle. In general, the information gathered during this study is a new contribution to the knowledge of mangrove ecology in Chengue, and showed that the monitored trees had the conditions to grow and develop during the evaluated period.