Effects of oil palm expansion through direct and indirect land use change in Tapi river basin, Thailand

The Thai government has ambitious plan to further promote the use of biodiesel. However, there has been insufficient consideration on the environmental effects of oil palm expansion in Thailand. This paper focuses on the effects of oil palm expansion on land use. We analysed the direct land use change (dLUC) and indirect land use change (iLUC) caused by the oil palm expansion and its effects on ecosystem services supply. Our analysis shows that between 2000 and 2009 dLUC related to oil palm expansion was more prevalent than iLUC. dLUC involved new oil palm plantations replacing cropland rather than natural ecosystems. Rubber was most frequently replaced by oil palm but there was also conversion of natural ecosystems. Later, between 2009 and 2012, iLUC strongly increased. Forests were cleared for rubber production as an indirect effect of oil palm expansion. We also quantified the effects of land use change on selected ecosystem services. Oil palm expansion led to increased production of fresh fruit bunches; however, it reduced other crop production such as latex, rice and fruits. Biodiversity conservation was also negatively affected. Carbon storage was positively affected by conversion of unused land, rice and orchard area by oil palm, but negatively affected by the conversion of forests.