In our study area, we observed differences in the swidden
farming practices, such as the number of crop-fallow cycles and
intensity of forest clearance, between the Kammu and Lao
people. The Lao people possess more swidden cultivation fields
than the Kammu people, and the former fallow the land for a
longer period than the latter. The Kammu people usually clearcut
all the vegetation without leaving some remnant trees on
their fields (Delang, 2007). Ethnic differences in swidden
cultivation and its effect on the fallow succession have also
been observed in Thailand (Kanjunt and Oberhauser, 1994;
Schmidt-Vogt, 1998; Fukushima et al., 2008). Distance from the
forest edge has no effect on diversity, perhaps due to the
dominance of few species, M. laccifera and P. dasyrachis, across all
distances, as evidenced also from the significant distance effect
on Simpson’s index.