There are often quite clear zones among mangroves with bands of dominant species running parallel to the shoreline or to the banks of tidal creek systems, which species is dominant depends on factors such as soil salinity, the ratio of salt to fresh water, tide range and exposure to wind.The greatest concentration of mangrove species is usually at the mouth of tidal creeks and rivers where salt and fresh water mix in ideal proportions and floodwaters deposit material to build up the banks.
Again a number of factors will determine what happens on the landward side of this zone, some areas may be barren clay pans or under conditions of high rainfall regular flooding may lead to freshwater swamp areas dominated by the less salt-tolerant mangrove species such as freshwater mangroveand cottonwood.