Light, rainfall and temperature have the strong influence on the establishment of mangrove ecosystem and also influence the growth and reproduction of mangroves.
Light
Mangrove plants are long day plants thus it requires high intensity with long duration of full sunlight. This makes tropical coastal zones an ideal habitat. The optimal range of light intensity for the growth of mangrove species is 3,000- 3,800 Kcal/m2/day.
Rainfall
The amount, duration and distribution of rainfall are important factors that determining the development and distribution of mangrove plants and animals.
ž Rainfall affects other environmental factors in the mangroves such as
¡ Air and water temperature
¡ Salinity of surface and groundwater
¡ Ultimately affects the survival of mangrove species.
ž Mangroves thrive in areas with a range of 1500-3000 mm of annual rainfall.
Temperature
ž Mangroves are restricted generally to areas where
o Mean air temperatures of the coldest months are higher than 20°C, and
o The seasonal range of temperature fluctuation does not exceed 10°C (Walsh, 1974; Chapman, 1975, 1977)
ž Global distributions of mangroves are limited chiefly by the physiological tolerance of each species to low temperature.
o For example: Viable propagules of Rhizophora mangle from Mexico routinely reach at the beaches and estuaries of southern Texas.
o Some propagules become established, but they usually killed during the freezing winter season (Sherrod, Hockday & McMillan, 1986).
