Most mangrove species have buoyant,
water-borne propagules.
The dispersal of these propagules is
constrained by land masses blocking current flow, and by wide bodies of water.
Such limitations on dispersal usually confines
species to particular regions, depending on their dispersive range and their
ability to become established in new locations.
In order to establish new colonies and to
extend existing distributional ranges, species would need to across or around
either larger bodies of water or land.
The effective range of each species depends on
a number of factors including:
• The number of days propagules remain bouyant
and viable
• The rate of surface currents
• The water conditions and
• The availability of suitable habitats.
Flotation times of mangrove propagules, fruits
and seeds vary from a few days to many months (e.g. Steinke, 1975, 1986;
Rabinowitz, 1978).
Flotation time may also increase with
decreased water temperature (Steinke & Naidoo, 1991) and decreased water
salinity (e.g. Rabinowitz, 1978).
