A Research Su1dy submitted in partial fulfilment of the requirements for the Degree of Master of Science, School of Environment, Resources & Development

Research Studies Project Report (M. Sc.) - Asian Institute of Technology, 1995

The nature, mechanism and the driving forces for global warming and greenhouse effect are briefly reviewed in the study. The practical con sequences for the rising rates of tropical deforestation and the potential gai ns obtained from conserving and increasing forest cover so as to expand a potential vegetal sink for ever-increasing carbon di oxide (co2) emissions through anthropogenic activities, are discussed and assessed in detail. Estimation of costs of carbon sequestration, as applicable to various available and appropriate forestry options for Thailand, are made with special focus on planting of the four major indigenous Tropical forest tree types viz . , Evergreen, Mixed Deciduous, Dry Dipterocarpous and Coniferous. The results obtained out of these estimations using Net Primary Productivity (NPP) of these f our tropical forest types, and Fractional Carbon Content (FCC) of Dry Matter, assumed to be 0.50 for t h is study, showed the transplanting and direct sowing of tropical dry Dipterocarpous trees to be mot economic forestry option (sequestration costs = U.S.$ 1.34 and U.S.$ 0.94, respectively), for transplanting and direct sowing of seeds, in Thailand. The carbon sequestration costs increase with a decrease in the NPP value of the forest tree types used for affore station. The policies, programmes, and projects presently in effect in Thai l and, for increasing the for est vegetal cover of the country, are critically analysed, reviewed and assessed for their contribution towards increasing potential forest sink for co2 sequestration. Though the policies and programmes currently in effect in Thailand show a keenness of the state towards ensuring the protection of the existing forests at the same time expanding the total forest vegetal cover through afforestation/reforestation, yet the success of these measures, as also found in this study, requires full consideration of factors like land availability and suitability, biotic potential for carbon fixation, proper selection of projects and accounting for implementation uncertainties.