increase in rubber plantation (from 7 to 13.3% of the study area), while forest areas will decrease (60.3 to 54.1%). Built-up area, which is at 4.5% will expand to 6.5%. The paddy area will slightly decrease. Likewise cassava/ sugarcane and corn also would decrease while abandoned area and upland rice may slightly increase. In scenario 2 (Integrated land use), the forest area (deciduous, evergreen, forest plantation) increased to 64.5% of total area compared to the present situation of 60.3%, while agriculture area remained similar to that of the present situation. Only upland rice area was observed to slightly decrease as it causes high erosion and thus retaining less sediments. Abandoned area significantly decreased because this scenario does not allow the conversion of land in protected area. In case of scenario 3 (Biodiversity conservation), there will be substantial increase of forest cover from current 60.3% of study area to 78.3%. This is because besides the coverage of protected area at present it also includes the area to be established forest for protecting ecosystem services based on the findings of assessing impact of land uses on ecosystem services. D. Changes in the ecosystem services The results of the scenario 1 showed trend of all four services had negative change as it showed slight declines in sediment retention and carbon stock and small declines in habitat quality, while the trend of water yield showed slight decrease. In scenario 2, the trend showed improvement in all services. Water yield had slight decline, while rest of services had moderate increase. Scenario 3 showed dramatic increase in three services, although water yield had a small increase, the trend stillgoes in a positive way. V. CONCLUSIONS During 1989-2013, increase in rubber plantation mainly influenced by the government’s rubber promotion scheme was the major land use change, whereas the area under paddy, cassava, sugarcane, corn, and deciduous forest have slightly decreased while built-up area and upland rice have increased. No area in the watershed retain very high and intact ecosystem services. Only two- fifth of watershed is having high ecosystem services. Land use change has influenced overall ecosystem services during the study period, together with a variation in the spatial distribution and temporal change in those ecosystem services studied. Under ongoing trend of land demand, forest cover may decline in next 20 years due to demand for agriculture conversion or lack of policy enforcement. Built up areas and the encroachment for rubber plantation will substantially expand while the ecosystem services at the watershed level will decline. Simulation results show that encouraging certain land use can enhance ecosystem services from 6 to 20% of current situation. This implies proper land use assignments are necessary to balance production and ecosystem services and thus achieve sustainable development goals. REFERENCES 1 Srivastava P. and Kumar U. 2011. Growth in the greater Mekong subregion in 2000- 2010 and future prospects. Balancing Economic Growth and Environmental Sustainability. Asian Development Bank. 2 Minna H. 2009. Forest Conflict in Thailand: Northern Minorities in Focus. Environmental Management. 43: 381-395. 3 Trisurat Y., Alkemade R., Verburg P. H. 2010. Projecting Land-Use Change and Its Consequences for Biodiversity in 142 Proceedings of the International Conference on Climate Change, Biodiversity and Ecosystem Services for the Sustainable Development Goals (SDGs): Policy and Practice 27-29 June 2016, Cha-am, Phetchaburi, Thailand
Proceedings of International Conference on Climate Change, Biodiversity and Ecosystem Services for the Sustainable Development Goals : Policy and Practice 27-29 June 2016 at the Sirindhorn International Environmental Park, Cha-am, Phetchaburi, Thailand
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