Mangroves supports a diverse fauna and flora, approximately one million people of Bangladesh and India depend on it directly for their livelihood, and also it provides a critical natural habitat which helps protect the low lying country and its population from natural catastrophes such as cyclones. Despite this role, mangroves particularly Sundarbans has been facing tremendous problems, including that of dieback (top-dying), human destructions, deforestations, illicit fellings, miss-management of the main tree species (Heritiera fomes) which is affecting millions of trees. The cause of this dieback is still not well understood unknown. The present work has investigated one of the possible factors that might be causing this problems like top-dying, namely the concentrations of various chemical elements present in the sediments, particularly heavy metals, though other chemical parameters such as the pH, salinity, moisture content of the sediment and nutrient status were also assessed. Tree height and trunk diameter were determined as indications of tree growth, counts of seedlings and saplings were made to assess regeneration success, and the intensity of top-dying within the sampled plots was recorded on a rank scale. However, the present results have showed that Sn, Exchangeable K, soil pH, Pb , Zn and Ni could be directly linked with top-dying disease of Heritiera fomes (Sundri) in Sundarbans, probably particularly by weakening the vigor of the trees and people and allowing other factors such as pathological agents to attack the plants and surrounding people in Sundarbans, Bangladesh (Awal, 2014).
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