The study was carried out to determine the natural regeneration of four species of mangroves along with estimation of physico-chemical characteristics of sediment and water from seven sites of mangroves in the southern Gulf of Kachchh. Spatial variation of different parameters of water and sediment investigated were: water-pH (7.87–8.04); Salinity (37.07–39.42 ppt); Nitrate (1.21–2.71 ppm); Nitrite (0.03–0.08 ppm); Phosphate (0.39–0.95 ppm) and sediment-pH (7.39–7.61); Bulk density (0.36–0.54 g/cc); Particle density (1.19–1.68 g/cc); Organic carbon (0.77–1.05%); and Organic matter (1.06–1.71%). The density (recruit/sq. m) of natural recruitment of four mangrove species was in order of Avicennia marina > Ceriops tagal > Aegiceras corniculatum > Rhizophora mucronata. Cluster analysis grouped seven sites in three major clusters i.e. Group A (Poshitra & Khijadiya - 91% similarity); Group B (Dedeka-Mundeka, Kalubhar & Pirotan- 94% similarity) and Group C (Sikka & Jodiya- 93% similarity) whereas Non-metric multidimensional scaling showed formation of two groups (Coastal and Islands) depending on the environmental conditions and mangrove natural regeneration. Principal component analysis showed the number of parameters such as salinity, texture and organic carbon which affects the natural regeneration of mangrove species in the study area.

ABSTRACT-Floristic inventory and diversity assessment are necessary to understand the present diversity status of the conservation of biodiversity. Shorelines are one of the most rapidly changing places on the Earth. The Gulf of Kachchh (GoK) is a semi-enclosed coastal indentation with predominance of mangrove ecosystems, coral reefs, associated rich marine diversity and coastal terrestrial vegetation. Halophytes are flowering plants, which are naturally found in saline habitats such as coastal swamps, coastal dunes, inland salt flats etc. Present works reveals the diversity of halophytes in GoK. Total 27 halophytes were encountered from 13 coastal talukas and islands of GoK. Islands of GoK, and Bhachau taluka are the area with highest diversity in GoK. In the present study α diversity (Shannon diversity index, Simpson's Index, species richness, evenness index) of the halophyte community was studied. From the study of biodiversity it was observed that highest species diversity (Shannon-Wiener diversity H') was observed in Jamnagar district and its islands whereas species richness index (d) was highest in Devbhumi Dwarka district and its islands. Evenness index (e) was highest (0.528) in Morbi district.

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