Study on the natural regenerations of the major mangrove tree species in the Sundarbans of Bangladesh

A study on the abundance of the natural regenerations of the major mangrove tree species such as sundri (Heritiera fomes), gewa (Excoecaria agallocha), goran (Ceriops decandra), kankra (Bruguiera gymnorrhiza), baen (Avicennia officinalis), passur (Xylocarpus mekongensis), khalshi (Aegiceras corniculatum), and amur (Amoora cuculata) was conducted in the three ecological (less saline, moderately saline and strongly saline) zones of the Sundarbans mangrove forests of Bangladesh. The newly recruited regenerations, old regenerations upto 1.3m height and saplings were observed and recorded in the temporary sample plot (TSP) areas. The study shows greater variations in the numbers of the regenerations in the three saline zones. It shows highest number of all types of regenerations of goran followed by gewa and sundri in the strong saline zone but highest number of new year regeneration of sundri followed by goran and kankra in the moderate saline zone, sundri followed by gewa and amur in the less saline zone. Regenerations of 1.3m ht. of sundri followed by goran and amur in the moderate saline zone, sundri followed by amur and gewa in the less saline zone and highest number of saplings of sundri followed by gewa and goran in the moderate saline zone and sundri followed by gewa and amur in the less saline zone were observed. Older regenerations of the mangrove species in the Sundarbans die at later ages due to deer browse, non availability of water and increase in salinity during the dry season.