Mangrove floristic and zonation patterns of Coringa, Kakinada Bay, East Coast of India

Studies (1996-'99) on the community structure of a mangrove forest in Coringa Wildlife Sanctuary in the Godavari estuarine system on the East Coast of India revealed altogether 15 species of mangroves represented by 8 families and 10 genera besides, 6 associate plant species and 6 of marshgrass. Description of forest structure (PCQM method) included measures of species composition, tree density, basal area and spatial distribution patterns of component vegetation at 75 GPS fixed locations. Avicennia marina, A. officinalis, Excoecaria agallocha, Aegiceras corniculatum, Sonneratia apetala, Ceriops decandra, Rhizophora apiculata and R. mucronata were the important mangrove species. Tree density varied between 47 and 1731 stems/0.1 ha and basal area 0.1 and 10.9 m2/0.01 ha. With the help of multivariate analysis (PRIMER) and based on species composition and tree density, it was possible to subdivide the sites into five groups that showed characteristic zonation patterns. For example, E. agallocha was typical of landward locations. A. marina (along with A. officinalis and A. alba) represented sites at the bed level and neap high tide level. There was a large group of sites inhabited by diverse species (14) indicative of spring high tide level conditions. Tidal elevation and ambient salinity appeared important in determining the observed zonation.