Semangok Forest Reserve is a typical hill dipterocarp forest in the Peninsula Malaysia. The average annual rainfall is 2414 mm, and the average annual minimum and maximum temperatures are 21.9℃ and 33.0℃, respectively. There are an 6ha permanent plot on a narrow ridge and steep slope in undisturbed forest and a 4ha permanent plot in selectively logged forest in this forest reserve. A emergent tree species, Shorea curtisi is common in undisturbed forest.