Abstract
The team revealed the structure of habitat dynamics and evaluated the effects of the rapid sea-level rise due to greenhouse effects based on the biogeomorphological, interdisciplinary field research in Thailand and Malaysia.
During the gradual sea-level rise (2,000 to 1,000 yrs.B.P.), the mangrove habitat is able to keep its vertical situation in the tidal range by accumulatien of mangrove organic materials and fluvial sediment. In the phase of stable sea-level, during the past 1,000 years, the habitat raised its vertical situation from mid to higher portion in the tidal range. The stable condition of sea-level in the past 1,000 years is very important for evaluating the survivability of the habitat by rapid sea-level rise. In the macrotidal area, such as the Andaman sea coast mangroves, the vertical situation of the habitat is located O.5 to 2 meter higher than mean sea-level because of the large sedimentation and the ]large tide amplitude. The mangrove habitat where located in the macrotidal area which has been preserved in spite of great change in the inner structure of mangrove forest by 50 cm rise of sea-level in 100 yrs. because of the higher location of the habitat and the gradual accumulation of mangrove organic materials. The influence of rapid sea-level rise is relative]y severe.in the microtidal area. The reason suggested that is the thinner tidal area of the upper portion of the micretidal range has greater effects from the rapid sea-level rise. As a result, three factors which play a great role in the estimation of habitat change are as follows: {1) the velocity of sea-level rise, (2) the tidal amplitude and (3) the rate of sedimentation. The tidal amplitude is more or less 2 m in almost at the coastal area of the world]d. In case of less than 50 cm (5 mm/yr) rise of sea-level we can think that mangrove habitat can survive in almost all the area. In such case the mangrove forest can accumulate the organic material. It means that mangrove forest has a role]c of CO2 sink and that mitigates the global warming.
