Ant sampling was carried out at the three sites along the pipeline transect from the north to
the south of TPP (Figure 1a). At each site, ants were collected in the disturbed area and in the adjacent forest, which was located at least one kilometer away from the pipeline collecting point to avoid any edge effect. Pitfall traps were placed along two sides of the transect (100 m length) with10 m between each trap. In the natural forest, placing of traps was conducted using the same method as in the disturbed forest (Figure 1b).Twenty traps were filled with 2/3 ethylene glycol(20%), and left in place for seven days. After seven days, trapped ants were transferred to glass bottles and preserved with 80% ethanol for later sorting and identification in the laboratory. Sampling was conducted during the period March 8-14, 2005.All ants collected were identified to the level of genera using the key of Bolton (1994) and Hashimoto (2003), and later on to the species and morphospecies level, using the reference collection of the Thailand National Science Museum. Voucher specimens were deposited in the Thailand National Science Museum and the Forest Insect Museum of the National Park, Wildlife and Plant Conservation Department, Thailand.