supported by the IVI index in table 3. Dipterocarpus
tuberculatus is the dominant species in the M area,
while Shorea obtusa and D. tuberculatus are the
dominant trees in the L area, as well as both S. obtusa
and Shorea siamensis as the dominant species in the
VL area. The impact of disturbance on species
diversity tends to follow the intermediate disturbance
hypothesis that stated ‘the highest diversity of tropical
rain forest trees should occur either at an intermediate
stage in succession after a large disturbance or with
smaller disturbances that are neither very frequent
or infrequent; either represents an open nonequilibrium.