Forest Structure and Community Composition of Cochin Mangroves,South-West Coast of India

This study presents the structural characteristics of Cochin mangroves in Kerala for proposing suitable management and rejuvenation measures of degrading mangrove habitats. The floristic diversity of mangroves revealed 14 species of true mangroves belonging to six families. Multivariate analysis of true mangroves belonging to selected mangrove forests of the study area based on density could be classified into four floristic groups, a water front or low–tide zonation, mid-tide preferring species, high tide and landward zonation. Shannon Weiner index of the three stations revealed that Site I was having higher value (H′ = 2.66) followed by Site II (H′ = 2.01) and Site III (H′ = 1.595). The density of the mangroves varied significantly with sites and species (Global R = 0.537, P < 0.001). The diameter at breast height (DBH) in the study area revealed that most of the species came under 1–10 cm DBH class. The overall structural data (including Importance Value Index, DBH and basal area) showed that Site III, the Mangalavanam forest was having more structural development and could be considered as matured forest whereas, Site I, Aroor is a maturing forest and Site II, Malippuram is the least matured forest from the study. The Importance Value Index and basal area of each species could be used for analysing the maturity of the forest and habitat preferences for restoration programmes of the degraded ecosystems.