Macro-level environmental factors that determine the area, species diversity and biomass of the
mangrove wetlands of India are analysed. On the basis of the spatial and temporal variations in
these factors, major mangrove wetlands of India are classified. The Sunderbans and Mahanadi
mangroves can be classified as tide-dominated, whereas Godavari, Krishna, Pichavaram and
Muthupet mangrove wetlands can be grouped as river-dominated. The mangrove wetlands of
Gujarat fall under the category of drowned-river valley type. Changes in some of the environmental
factors, particularly changes in the periodicity and quantity of freshwater that flows into mangrove
wetlands are examined, which indicates that reduction in freshwater flow would lead to reduction
in the diversity of exclusive mangrove plant species. The current classification system can be utilized
to develop strategies for long-term conservation of mangrove wetlands.