**3. Estimation of population viability**

To understand the population dynamics of mangrove forest in the face of anthropogenic action, the minimum viable population size (MVP) needs to be estimated. It is defined as the smallest isolated population size that has 99% survival probability for 100 years period [17]. It is a crucial tool of conservation for the prevention of extinction of species. For perennial plant such as mangroves, it should have a minimum population size of 500–5000 individuals in a given location from year to year. This means any isolated forest below 500 tree stands is not a viable population and has the risk of going into extinction within a short time would be high. Two methods can be employed in determining the MVP. They are:

