Mangrove community in an abandoned brick kiln: A structural and association analysis

Background: The presence of brick kiln along the Hoogly river sites of lower Bengal is very usual and this phenomenon is not only restricted to India alone but also to other south Asian countries. The abandoned brick kiln are important habitat for the formation of mangrove community due to tidal action, loose silty substratum and less anthropogenic interference. In this context, the aim of the present study is to visualize how the structural and association pattern regulate the community dynamics of a mangrove ecosystem. Materials and Methods: The entire study area was divided into 37 units (Quadrats of 27.31 sq m). Structural parameters like density, relative density, abundance, relative abundance, frequency, relative basal area were measured based on vegetation map, prepared through satellite image and ground truthing. Association indices (Ochiai, Dice and Jaccard) were measured based on 2X2 contingency/species association table. Results: Out of 10 species under 10 genera and 9 families found in the present habitat, Sonneratia caseolaris is the only mangrove tree species with 155 individuals along with other mangrove associates like Cryptocoryne ciliata, Crinum viviparum, Acanthus ilicifolius and Denis scandens. The high importance value index of Sonneratia caseolaris, Cryptocoryne ciliata, and Crinum viviparum indicated their significant role in community formation. The strong positive association of these 3 species also suggests helping in developing community in stressed environment. Conclusion: Identification of such potential mangrove habitat and study of their community dynamics would be helpful to find out the nature of mangrove establishment for future afforestation programme of threatened mangrove species.