Ecological studies in the Iture estuary mangrove forest in Ghana

Abstract

The study assessed the floristic composition as well as aspects of the structure of the mangrove vegetation of Iture estuary with the view to determining any possible changes in these attributes over the past few years. The density and basal area of the trees/shrubs were estimated using the Point-Centred Quarter Method. Seedling/sapling density was estimated in thirty 5 x 5 m contigu-ous plots. Land-use was assessed by observation, while the effects of pollution and over-cutting were assessed using the standardized site description and site rating criteria developed for the Global Environment Facility’s (GEF’s) Large Scale Ecosystem Project for the Gulf of Guinea. The flora consisted of five mangrove species in three genera, as well as eight mangrove associ-ates. The densities of Rhizophora, Avicennia and Laguncularia trees and seedlings/saplings were all considerably lower than density values recorded for the same area 15 years ago. The densities of dead seedlings/saplings were also significantly higher than those of living seedlings/saplings. The current most significant land-use was salt mining. The estuary had a poor site rat-ing, suggesting that it was under severe stress. The main stress factors were over-cutting of wood and garbage dumping. It is envisaged that the combined effects of wood extraction and salt min-ing will lead to further degradation of the mangrove forest.