Development of Mangrove Stands in Southeast Asia: With Special Reference to the West Coast of the Malay Peninsula

抄録

The authors analyzed the development of the size structure of some mangrove stands in Southeast Asia and how it changed with growth, productivity and growth performance, as a source of diverse benefits to sustain the livelihood of local residents. The similarity of the development pattern of natural Rhizophora- dominant stands to that of plantations suggested that the former were established as nearly evenly aged pure stands. Stand productivity varied according to dominant species, such that the pioneer Avicennia stand examined in Ranong was smaller than the late successional Rhizophora stand, reflecting low tree density with a smaller basal area. Regional or environmental differences were also apparent, e.g., the annual biomass growth rates in Kantang and some regions on the Thai Gulf side exceeded 15 Mg ha^-1 yr^-1 while those of Ranong and Merbok ranged between 10 and 15 Mg ha^-1 yr^-1, and stands in Bali showed smaller productivity, around 5 Mg ha^-1 yr^-1. The lack of a large river system supplying fertility from upper tributaries was the most likely factor affecting Bali’s low productivity. With biomass increase, forests release much plant mass as dead trees, and this loss sometimes reaches the same level of net gain in mangroves. The average tree weight of natural Rhizophora-dominant stands at certain stand densities showed lower productivity than those of plantations and this tendency was common over wide regions of Thailand, Malaysia and Indonesia.