Mangrove And Coastal Vegetation In Thailand
- Mangroves form another floral region with distinct animals and plant life. Mangroves grow where there is brackenish water from fresh water run off to the sea and in estuaries. They can be seen in lagoons, around protected bays or inlets. They are few in species numbers but provide shelter to house a wide variety of wildlife. Mangrove clusters trap silt and organic material to accumulate nutient rich areas for animal life and particularly breeding grounds for fish and invertebrates. Mangroves also provide shelter from the effects of harsh sea water movements to provide a breal water to prevent erosion of the coast lines. The principal varieties are Black Mangrove and Red Mangrove.
- The word ''mangroves'' has 3 meanings which need to be understood. In the first sense it means the habitat where the range of Mangrove species grows, the special biological issues that define where they grow and the total assembly of all species within that ecological area. Here terms such as mangrove forest and mangrove swamp are inter changeable. The technical term for the plant community where magroves habitat is a ''Mangal''.
- Secondly ''mangroves'' refers to the trees and schrubs in the mangal.
- Thirdly and more specifically it is the term for the specific species of Mangrove Family of plants called Rhizophoracae and also the genus ''Rhizophara''.
Different Mangrove Species in Thailand and Their Ecology
- Trees and shrubs in Mangals vary and each exploits differently the Mangal habitat by having different physiological adaptations to their enviroment. The major envirnmental issues they have to deal with are, (1) salinity and limiting salt, (2) tidal inundation, (3)limiting water loss, (4) nutrient uptake and (5) low oxygen.
- Red mangroves exclude salt by having significantly impermeable roots which are highly suberised, acting as an ultra-filtration mechanism to exclude sodium salts from the rest of the plant. Analysis of water inside mangrove plants has shown that anywhere from 90% to 97% of salt has been excluded at the roots. Any salt which does accumulate in the shoot is concentrated in old leaves which are then shed, as well as stored away safely in cell vacuoles. Some mangroves can secrete salts directly from two salt glands at each leaf base.
- Red mangroves, which can live in the most inundated areas, prop themselves up above the water level with stilt roots and can then take in air through pores in their bark. Black mangroves live on higher ground and make many pneumatophores which are specialised root-like structures which stick up out of the soil like straws for breathing and which are covered in lenticels. These "breathing tubes" typically reach heights of up to thirty centimeters, and in some species, over three meters. There are four types of pneumatophore—stilt or prop type, snorkel or peg type, knee type, and ribbon or plank type. Knee and ribbon types may be combined with buttress roots at the base of the tree. The roots also contain wide aerenchyma to facilitate oxygen transport within the plant.